Sulforaphane (from broccoli)

[Rich66]

(apoptotic, anti breast cancer stem cell, HDAC inhib, Anti ER/PR, P38, Cox2, w/selenium, Akt/mTOR, w/lycopene)

Available as:
Jarrow Broccomax @ GNC, Amazon, Vitamin Shoppe, Vitamin Deal
or
Oncoplex (Johns Hopkins patent)




Cancer Lett. 2008 Oct 8;269(2):291-304. Epub 2008 May 27.
Multi-targeted prevention of cancer by sulforaphane.



Clarke JD, Dashwood RH, Ho E.
Department of Nutrition and Exercise Sciences, 117 Milam Hall, Oregon State University, Corvallis, OR 97331, USA.
Abstract

Isothiocyanates are found in cruciferous vegetables such as broccoli, Brussels sprouts, cauliflower, and cabbage. Epidemiologic studies suggest that cruciferous vegetable intake may lower overall cancer risk, including colon and prostate cancer. Sulforaphane (SFN) is an isothiocyanate found in cruciferous vegetables and is especially high in broccoli and broccoli sprouts. SFN has proved to be an effective chemoprotective agent in cell culture, carcinogen-induced and genetic animal cancer models, as well as in xenograft models of cancer. Early research focused on the "blocking activity" of SFN via Phase 2 enzyme induction, as well as inhibition of enzymes involved in carcinogen activation, but there has been growing interest in other mechanisms of chemoprotection by SFN. Recent studies suggest that SFN offers protection against tumor development during the "post-initiation" phase and mechanisms for suppression effects of SFN, including cell cycle arrest and apoptosis induction are of particular interest. In humans, a key factor in determining the efficacy of SFN as a chemoprevention agent is gaining an understanding of the metabolism, distribution and bioavailability of SFN and the factors that alter these parameters. This review discusses the established anti-cancer properties of SFN, with an emphasis on the possible chemoprevention mechanisms. The current status of SFN in human clinical trials also is included, with consideration of the chemistry, metabolism, absorption and factors influencing SFN bioavailability.

PMID: 18504070 [PubMed - indexed for MEDLINE]PMCID: PMC2579766Free PMC Article



Clin Cancer Res. 2010 Apr 13. [Epub ahead of print]
Sulforaphane, a Dietary Component of Broccoli/Broccoli Sprouts, Inhibits Breast Cancer Stem Cells.

PURCHASE TEXT

Li Y, Zhang T, Korkaya H, Liu S, Lee HF, Newman B, Yu Y, Clouthier SG, Schwartz SJ, Wicha MS, Sun D.
Authors' Affiliations: Department of Pharmaceutical Sciences, College of Pharmacy, University of Michigan and Comprehensive Cancer Center, Department of Internal Medicine, University of Michigan; and Department of Food Science and Technology, The Ohio State University, Columbus, Ohio.
Abstract

PURPOSE: The existence of cancer stem cells (CSCs) in breast cancer has profound implications for cancer prevention. In this study, we evaluated sulforaphane, a natural compound derived from broccoli/broccoli sprouts, for its efficacy to inhibit breast CSCs and its potential mechanism. EXPERIMENTAL DESIGN: Aldefluor assay and mammosphere formation assay were used to evaluate the effect of sulforaphane on breast CSCs in vitro. A nonobese diabetic/severe combined immunodeficient xenograft model was used to determine whether sulforaphane could target breast CSCs in vivo, as assessed by Aldefluor assay, and tumor growth upon cell reimplantation in secondary mice. The potential mechanism was investigated using Western blotting analysis and beta-catenin reporter assay. RESULTS: Sulforaphane (1-5 mumol/L) decreased aldehyde dehydrogenase-positive cell population by 65% to 80% in human breast cancer cells (P < 0.01) and reduced the size and number of primary mammospheres by 8- to 125-fold and 45% to 75% (P < 0.01), respectively. Daily injection with 50 mg/kg sulforaphane for 2 weeks reduced aldehyde dehydrogenase-positive cells by >50% in nonobese diabetic/severe combined immunodeficient xenograft tumors (P = 0.003). Sulforaphane eliminated breast CSCs in vivo, thereby abrogating tumor growth after the reimplantation of primary tumor cells into the secondary mice (P < 0.01). Western blotting analysis and beta-catenin reporter assay showed that sulforaphane downregulated the Wnt/beta-catenin self-renewal pathway. CONCLUSIONS: Sulforaphane inhibits breast CSCs and downregulates the Wnt/beta-catenin self-renewal pathway. These findings support the use of sulforaphane for the chemoprevention of breast cancer stem cells and warrant further clinical evaluation. Clin Cancer Res; 16(9); OF1-11. (c)2010 AACR.

PMID: 20388854 [PubMed - as supplied by publisher]




Mol Cancer Ther. 2007 Mar;6(3):1013-21. Epub 2007 Mar 5.
Sulforaphane induces cell type-specific apoptosis in human breast cancer cell lines.

Pledgie-Tracy A, Sobolewski MD, Davidson NE.
The Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University, 1550 Orleans Street, Baltimore, MD 21231, USA.


FREE ARTICLE
Abstract


Sulforaphane, an isothiocyanate found in cruciferous vegetables, has been shown to induce phase 2 detoxication enzymes and inhibit the growth of chemically induced mammary tumors in rats, although the exact mechanisms of action of sulforaphane are not understood. In this study, we evaluated the effects of sulforaphane on cell growth and death in several human breast cancer cell lines and examined the hypothesis that sulforaphane acts as a histone deacetylase (HDAC) inhibitor in these cell lines. Sulforaphane treatment inhibited cell growth, induced a G(2)-M cell cycle block, increased expression of cyclin B1, and induced oligonucleosomal DNA fragmentation in the four human breast cancer cell lines examined, MDA-MB-231, MDA-MB-468, MCF-7, and T47D cells. Activation of apoptosis by sulforaphane in MDA-MB-231 cells seemed to be initiated through induction of Fas ligand, which resulted in activation of caspase-8, caspase-3, and poly(ADP-ribose) polymerase, whereas apoptosis in the other breast cancer cell lines was initiated by decreased Bcl-2 expression, release of cytochrome c into the cytosol, activation of caspase-9 and caspase-3, but not caspase-8, and poly(ADP-ribose) polymerase cleavage. Sulforaphane inhibited HDAC activity and decreased the expression of estrogen receptor-alpha, epidermal growth factor receptor, and human epidermal growth factor receptor-2 in each cell line, although no change in the acetylation of H3 or H4 was seen. These data suggest that sulforaphane inhibits cell growth, activates apoptosis, inhibits HDAC activity, and decreases the expression of key proteins involved in breast cancer proliferation in human breast cancer cells. These results support testing sulforaphane in vivo and warrant future studies examining the clinical potential of sulforaphane in human breast cancer.
PMID: 17339367 [PubMed - indexed for MEDLINE]Free Article





Environ Mol Mutagen. 2009 Apr;50(3):213-21.
Modulation of histone deacetylase activity by dietary isothiocyanates and allyl sulfides: studies with sulforaphane and garlic organosulfur compounds.

Nian H, Delage B, Ho E, Dashwood RH.
Linus Pauling Institute, Oregon State University, Corvallis, Oregon 97331-6512, USA.

FREE TEXT

Abstract

Histone deacetylase (HDAC) inhibitors reactivate epigenetically-silenced genes in cancer cells, triggering cell cycle arrest and apoptosis. Recent evidence suggests that dietary constituents can act as HDAC inhibitors, such as the isothiocyanates found in cruciferous vegetables and the allyl compounds present in garlic. Broccoli sprouts are a rich source of sulforaphane (SFN), an isothiocyanate that is metabolized via the mercapturic acid pathway and inhibits HDAC activity in human colon, prostate, and breast cancer cells. In mouse preclinical models, SFN inhibited HDAC activity and induced histone hyperacetylation coincident with tumor suppression. Inhibition of HDAC activity also was observed in circulating peripheral blood mononuclear cells obtained from people who consumed a single serving of broccoli sprouts. Garlic organosulfur compounds can be metabolized to allyl mercaptan (AM), a competitive HDAC inhibitor that induced rapid and sustained histone hyperacetylation in human colon cancer cells. Inhibition of HDAC activity by AM was associated with increased histone acetylation and Sp3 transcription factor binding to the promoter region of the P21WAF1 gene, resulting in elevated p21 protein expression and cell cycle arrest. Collectively, the results from these studies, and others reviewed herein, provide new insights into the relationships between reversible histone modifications, diet, and cancer chemoprevention.

PMID: 19197985 [PubMed - indexed for MEDLINE]PMCID: PMC2701665Free PMC Article




J Nutr Biochem. 2009 Mar;20(3):195-201. Epub 2008 Jul 7.
Regulation of estrogen receptor alpha expression in human breast cancer cells by sulforaphane.

Ramirez MC, Singletary K.
Department of Food Science and Human Nutrition, University of Illinois, Urbana, 61801, USA.
Abstract

Sulforaphane [SUL, 1-isothiocyanato-4-(methylsulfinyl)butane] is an isothiocyanate derived from glucoraphanin present in cruciferous vegetables, and it has a variety of potential chemopreventive actions. We analyzed the effects of SUL on the proliferation of human breast cancer cells and on the expression of estrogen receptor alpha (ERalpha) protein and mRNA in MCF-7 cells. Sulforaphane inhibited cell proliferation with IC(50) values at 24 and 48 h of 12.5 and 7.5 muM doses, respectively, and decreased ERalpha protein expression at concentrations between 2.5 and 30 muM. Inhibition of ERalpha protein expression was also accompanied by decreased progesterone receptor expression. MCF-7 ERalpha mRNA expression was inhibited by SUL at a dose of 30 muM, but not at lower SUL concentrations. At SUL doses <30 muM, the SUL-induced suppression of ERalpha protein was reversed by preincubation with the proteasome inhibitor MG132 and was accompanied by an increase in protein levels of the 20S catalytic core subunit PSMB5. Therefore, SUL can inhibit the expression of ERalpha protein in MCF-7 cells in part by inhibition of ERalpha mRNA transcription as well as by a mechanism that may involve increased proteasome-mediated degradation. These data provide new insights into mechanisms by which SUL inhibits proliferation of and down-regulates hormone receptor expression in MCF-7 cells.

PMID: 18602823 [PubMed - indexed for MEDLINE]




Eur J Cancer Prev. 2007 Dec;16(6):505-10.
Efficacy of sulforaphane is mediated by p38 MAP kinase and caspase-7 activations in ER-positive and COX-2-expressed human breast cancer cells.

Jo EH, Kim SH, Ahn NS, Park JS, Hwang JW, Lee YS, Kang KS.
Laboratory of Stem Cell and Tumor Biology, Department of Veterinary Public Health, College of Veterinary Medicine Kwanak-gu, Korea.
Abstract

Sulforaphane is an antioxidant and a potent stimulator of natural detoxifying enzyme and associated with lowered risk of cancer that is associated with the consumption of cruciferous vegetables. The chemopreventive effects of SFN was investigated using the MCF-7 human breast cancer cells and the M13SV1-immortalized human breast luminal epithelial cells. Sulforaphane reduced proliferation in MCF-7 cells and inhibited cyclooxygenase-2 expression in M13SV1 cells treated with 12-O-tetradecanoylphorbol-13-acetate (TPA). The chemopreventive effects of sulforaphane were associated with p38 mitogen-activated protein kinase suggest its important role in cell survival/apoptosis regulation and stabilization of cyclooxygenase-2. Sulforaphane upregulates p38 in MCF-7 cells and prevented TPA-reduced phosphorylation of p38 in M13SV1 cells, but activated caspase-7 associated with apoptosis in MCF-7 cells. These results suggest that sulforaphane may be an alternative candidate for targeted prevention of ER-positive and cyclooxygenase-2-induced phenotypes and breast cancer.

PMID: 18090122 [PubMed - indexed for MEDLINE]



J Nutr. 2004 Sep;134(9):2229-36.
Sulforaphane inhibits human MCF-7 mammary cancer cell mitotic progression and tubulin polymerization.

Jackson SJ, Singletary KW.
Department of Food Science and Human Nutrition, University of Illinois, Urbana, IL 61801, USA.



Abstract

Sulforaphane (SUL), an isothiocyanate derived from hydrolysis of glucoraphanin in broccoli and other cruciferous vegetables, was shown to induce phase II detoxification enzymes, inhibit chemically induced mammary tumors in rodents, and more recently, to induce cell cycle arrest and apoptosis in colon cancer cells. In the present study, we demonstrate that SUL also acts to inhibit proliferation of MCF-7 adenocarcinoma cells from the human breast. Treatment of synchronized MCF-7 cells with 15 micromol/L SUL resulted in significant (P < 0.05) G(2)/M cell cycle arrest (167% of control) and elevated cyclin B1 protein (175% of control) within 24 h. Moreover, 15 micromol/L SUL significantly (P < 0.05) induced phosphorylation of histone H1 (167% of control), blocked cells in early mitosis ( approximately 10-fold increase over control), and disrupted polymerization of mitotic microtubules in vivo. Subsequent exposure of purified bovine brain tubulin to relatively high doses of SUL significantly (P < 0.05) inhibited both tubulin polymerization rate (51% of control) and total tubulin polymerization (78% of control) in vitro. Additionally, polymerization of purified tubulin exposed to isothiocyanate-containing analogs of SUL was similarly inhibited. Taken together, these findings indicate that SUL has mammary cancer suppressive actions involving mitotic cell cycle arrest and suggest a mechanism linked to the disruption of normal tubulin polymerization and/or more subtle effects on microtubule dynamics.

PMID: 15333709 [PubMed - indexed for MEDLINE]Free Article



Exp Biol Med (Maywood). 2009 Mar;234(3):287-95. Epub 2009 Jan 14.
Comparison of the effects of phenethyl isothiocyanate and sulforaphane on gene expression in breast cancer and normal mammary epithelial cells.

FREE TEXT

Telang U, Brazeau DA, Morris ME.
Department of Pharmaceutical Sciences, 517 Hochstetter Hall, University at Buffalo, State University of New York, Amherst, NY 14260-1200, USA.

Abstract
(PEITC in watercress, sulforaphane in broccoli sprout/seed)

Phenethyl isothiocyanate (PEITC) and sulforaphane (SF) exhibit tumor preventive activity in lung, prostate, breast and colon cancers. Our objective was to examine the effect of these two isothiocyanates on estrogen receptor-related genes, and genes related to apoptosis and cell cycle in the estrogen-dependent breast cancer cell line MCF7 and in normal human epithelial breast (HME) cells. We treated cells with 0.3 microM or 3.0 microM concentrations of PEITC or SF. In HME cells, gene expression was significantly altered for 23 genes by PEITC at a concentration of 0.3 microM and 4 genes at 3.0 microM. SF altered the expression of 16 genes at a concentration of 0.3 microM and 2 genes at 3.0 microM. In HME cells, genes altered by both PEITC and SF exhibited changes in gene expression that were similar in extent as well as direction of change. In MCF-7 cells, PEITC did not produce any significant changes in the gene expression at both treatment levels. SF produced significant changes in 7 genes, but only at the higher treatment level of 3.0 microM. Normal mammary cells exhibited more changes in the expression of estrogen receptor related genes than did breast cancer cells, and significantly these changes occurred predominantly at the low concentration of 0.3 microM, a concentration achievable by dietary input of isothiocyanates. Novel findings were the upregulation of the pro-apoptotic gene BAD and estrogen receptor beta gene in normal human mammary cells. These gene alterations observed, along with upregulation of tumor suppressors p21 and p27, may provide a protective effect to mammary cells against breast cancer.

PMID: 19144873 [PubMed - indexed for MEDLINE]

Conclusion.
Overall, isothiocyanates have numerous effects on gene expression in human mammary cells. A very significant finding was the greater number of changes in gene expression observed at dietary concentrations of isothiocyanates (0.3 µM) compared with that observed following a 10-fold higher concentration. Several effects observed in HME cells are consistent with reports of ITCs effects in other cancer cell lines. Novel findings were the upregulation of the pro-apoptotic gene BAD and estrogen receptor beta gene in normal human mammary epithelial cells. These gene alterations observed, along with upregulation of tumor suppressors p21 and p27, may provide a protective effect to mammary cells against breast cancer. However, we need to be cautious about the net effects of isothiocyanates as several other alterations, such as upregulation of her2 and EGFR, may present unfavorable effects of isothiocyanates. These need to be investigated in order to further understand the effects of isothiocyanates on breast cancer. Additional studies such as determining contribution of metabolites and parent compounds to apoptosis and cellular adhesion in normal versus cancer cell lines up on treatment of cells at these concentrations will be helpful in determining the final effects of these treatments on the cells.

Vascul Pharmacol. 2007 Feb;46(2):77-84. Epub 2006 Jul 14.
Sulforaphane suppresses angiogenesis and disrupts endothelial mitotic progression and microtubule polymerization.

Jackson SJ, Singletary KW, Venema RC.
Medical College of Georgia, Vascular Biology Center, CB 3330, 1459 Laney Walker Boulevard Augusta, GA 30912, USA.
Abstract

Sulforaphane (SUL), an isothiocyanate derived from broccoli and other cruciferous vegetables, is known to induce phase II detoxification enzymes, disrupt cancer cell microtubule polymerization, and trigger cell cycle arrest in breast and colon cancer cells. Here, we provide the first evidence that SUL also acts to inhibit angiogenesis via suppression of endothelial cell proliferation. Bovine aortic endothelial (BAE) cells were exposed to concentrations of up to 15 microM SUL prior to cell cycle analysis and mitotic index quantification. Within 24 h, 15 microM SUL clearly induced G(2)/M accumulation and pre-metaphase arrest in BAE cells. Moreover, immunofluorescence tubulin staining indicated that this same SUL concentration was efficacious in not only disrupting mitotic progression, but also in perturbing normal polymerization of mitotic (and cytoplasmic) microtubules. Furthermore, daily administration of SUL (100 nmol/day, i.v. for 7 days) to female Balb/c mice bearing VEGF-impregnated Matrigel plugs strongly and significantly (P<0.05) suppressed angiogenesis progression as measured by hemoglobin concentration. Taken together, these findings suggest that the endothelial cell population is a novel target of SUL action both in vitro and in vivo. This mechanism of SUL-induced endothelial microtubule disruption and early mitotic arrest may further discern a potential role of SUL as a chemopreventive agent.

PMID: 16938492 [PubMed - indexed for MEDLINE]



Carcinogenesis. 2004 Feb;25(2):219-27. Epub 2003 Oct 24.
Sulforaphane: a naturally occurring mammary carcinoma mitotic inhibitor, which disrupts tubulin polymerization.

Jackson SJ, Singletary KW.
Department of Food Science and Human Nutrition, University of Illinois, 467 Bevier Hall-M/C 182, 905 S Goodwin Ave, Urbana, IL 61801, USA.



Abstract

Sulforaphane (SUL), an isothiocyanate found in broccoli and other cruciferous vegetables, has been shown to induce phase II detoxification enzymes, inhibit chemically induced mammary tumors in rats, and more recently to induce cell cycle arrest and apoptosis in cancer cells of the colon. Here, we provide evidence that SUL also acts as a breast cancer anti-proliferative agent. The BALB/c mouse mammary carcinoma cell line F3II was treated with SUL at concentrations up to 15 microM and examined for markers of cell cycle arrest and apoptosis. Treatment of asynchronous F3II cells with 15 microM SUL resulted in G2/M cell cycle arrest, elevated p34cdc2 (cdc2) kinase activity, Bcl-2 down-regulation, evidence of caspase activation, and aggregation of condensed nuclear chromatin. Subsequent exposure of synchronized cells to 15 microM SUL resulted in elevated numbers of prophase/prometaphase mitotic figures, indicating cell cycle progression beyond G2 and arrest early within mitosis. Moreover, cells treated with 15 microM SUL displayed aberrant mitotic spindles, and higher doses of SUL inhibited tubulin polymerization in vitro. In addition, BALB/c mice injected s.c. with F3II cells and subsequently injected daily i.v. with SUL (15 nmol/day for 13 days) developed significantly smaller tumors (approximately 60% less in mass) than vehicle-treated controls. Western blot analysis of tumor proteins demonstrated significantly (P<0.05) reduced PCNA and elevated PARP fragmentation in samples from animals dosed with SUL. Taken together, these results indicate that SUL has mammary cancer suppressive actions both in cell culture and in the whole animal. Inhibition of mammary carcinogenesis appears in part to involve perturbation of mitotic microtubules and early M-phase block associated with cdc2 kinase activation, indicating that cells arrest prior to metaphase exit.

PMID: 14578157 [PubMed - indexed for MEDLINE]Free Article




Curr Cancer Drug Targets. 2006 Mar;6(2):135-45.
Signaling pathways and intracellular targets of sulforaphane mediating cell cycle arrest and apoptosis.

Gamet-Payrastre L.
Department of Human Food, UMR 1089 Xénobiotiques National Institute of Agricultural Research (INRA), Toulouse, France. lpayrast@toulouse.inra.fr

Abstract
Epidemiological studies have revealed an inverse correlation between the intake of cruciferous vegetables and the risk of certain types of cancer. In animal studies, results suggest that the anti-cancerous effect of cruciferous vegetables is due to isothiocyanates that exist as thioglucoside conjugates in a variety of edible plants, including broccoli cabbage for example. Among isothiocyanates (ITC), Sulforaphane (SF) has received a great deal of interest due to its potent anti-tumoral properties in carcinogen-treated animals. The molecular pathways mediating the effects of SF have not been fully elucidated. However, many studies have shown that SF (as well as other ITCs) can induce phase II drug metabolizing enzymes in vitro as well as in animals. This commonly occurs via the activation of a basic leucine zipper transcription factor, Nrf2. In addition, accumulating evidence now indicates that SF can inhibit the proliferation of cancer cells in culture through the induction of cell cycle arrest via the regulation of cell cycle protein levels and/or cyclin-dependent kinase activity, tubulin polymerization and histone acetylation. Furthermore, ITCs have been shown to induce apoptotic cell death via a P53 dependent or independent pathway. Here, it is proposed to review the different intracellular targets involved in the in vitro effects of SF in various cancer cell lines. The relationship will then be discussed that exists between the various cell signaling pathways involved in this effect, and finally, the important aspects will be identified that must be addressed to fully understand the exact mechanism of action of SF.

PMID: 16529543 [PubMed - indexed for MEDLINE]




AAPS J. 2010 Mar;12(1):87-97. Epub 2009 Dec 15.
Molecular targets of dietary phenethyl isothiocyanate and sulforaphane for cancer chemoprevention.

Cheung KL, Kong AN.
Graduate Program in Pharmaceutical Science, Department of Pharmaceutics, Ernest Mario School of Pharmacy, Rutgers, The State University of New Jersey, Piscataway, New Jersey, USA.

Abstract
Development of cancer is a long-term and multistep process which comprises initiation, progression, and promotion stages of carcinogenesis. Conceivably, it can be targeted and interrupted along these different stages. In this context, many naturally occurring dietary compounds from our daily consumption of fruits and vegetables have been shown to possess cancer preventive effects. Phenethyl isothiocyanate (PEITC) and sulforaphane (SFN) are two of the most widely investigated isothiocyanates from the crucifers. Both have been found to be very potent chemopreventive agents in numerous animal carcinogenesis models as well as cell culture models. They exert their chemopreventive effects through regulation of diverse molecular mechanisms. In this review, we will discuss the molecular targets of PEITC and SFN potentially involved in cancer chemoprevention. These include the regulation of drug-metabolizing enzymes phase I cytochrome P450s and phase II metabolizing enzymes. In addition, the signaling pathways including Nrf2-Keap 1, anti-inflammatory NFkappaB, apoptosis, and cell cycle arrest as well as some receptors will also be discussed. Furthermore, we will also discuss the similarities and their potential differences in the regulation of these molecular targets by PEITC and SFN.

PMID: 20013083 [PubMed - indexed for MEDLINE]PMCID: PMC2811646 [Available on 2010/12/15]




BMC Cancer. 2009 Nov 30;9:414.
Selenium enrichment of broccoli sprout extract increases chemosensitivity and apoptosis of LNCaP prostate cancer cells.

Abdulah R, Faried A, Kobayashi K, Yamazaki C, Suradji EW, Ito K, Suzuki K, Murakami M, Kuwano H, Koyama H.
Department of Public Health, Gunma University Graduate School of Medicine, Japan. abdulahrizky@gmail.com



Abstract

BACKGROUND: Broccoli is a Brassica vegetable that is believed to possess chemopreventive properties. Selenium also shows promise as an anticancer agent. Thus, selenium enrichment of broccoli has the potential to enhance the anticancer properties of broccoli sprouts. METHOD: Selenium-enriched broccoli sprouts were prepared using a sodium selenite solution. Their anticancer properties were evaluated in human prostate cancer cell lines and compared with those of a control broccoli sprout extract. RESULTS: Selenium-enriched broccoli sprouts were superior to normal broccoli sprouts in inhibiting cell proliferation, decreasing prostate-specific antigen secretion, and inducing apoptosis of prostate cancer cells. Furthermore, selenium-enriched broccoli sprouts but, not normal broccoli sprouts, induced a downregulation of the survival Akt/mTOR pathway. CONCLUSION: Our results suggest that selenium-enriched broccoli sprouts could potentially be used as an alternative selenium source for prostate cancer prevention and therapy.

PMID: 19943972 [PubMed - indexed for MEDLINE]PMCID: PMC2794877Free PMC Article


Cancer Res. 2007 Jan 15;67(2):836-43. Epub 2007 Jan 9.
Combinations of tomato and broccoli enhance antitumor activity in dunning r3327-h prostate adenocarcinomas.

Canene-Adams K, Lindshield BL, Wang S, Jeffery EH, Clinton SK, Erdman JW Jr.
Division of Nutritional Sciences and Department of Food Science and Human Nutrition, University of Illinois, Urbana, Illinois 61801, and Department of Internal Medicine, James Cancer Hospital and Solove Research Institute, Columbus, Ohio, USA.



Abstract

The consumption of diets containing 5 to 10 servings of fruits and vegetables daily is the foundation of public health recommendations for cancer prevention, yet this concept has not been tested in experimental models of prostate cancer. We evaluated combinations of tomato and broccoli in the Dunning R3327-H prostate adenocarcinoma model. Male Copenhagen rats (n=206) were fed diets containing 10% tomato, 10% broccoli, 5% tomato plus 5% broccoli (5:5 combination), 10% tomato plus 10% broccoli (10:10 combination) powders, or lycopene (23 or 224 nmol/g diet) for approximately 22 weeks starting 1 month prior to receiving s.c. tumor implants. We compared the effects of diet to surgical castration (2 weeks before termination) or finasteride (5 mg/kg body weight orally, 6 d/wk). Castration reduced prostate weights, tumor areas, and tumor weight (62%, P<0.001), whereas finasteride reduced prostate weights (P<0.0001), but had no effect on tumor area or weight. Lycopene at 23 or 224 nmol/g of the diet insignificantly reduced tumor weights by 7% or 18%, respectively, whereas tomato reduced tumor weight by 34% (P<0.05). Broccoli decreased tumor weights by 42% (P<0.01) whereas the 10:10 combination caused a 52% decrease (P<0.001). Tumor growth reductions were associated with reduced proliferation and increased apoptosis, as quantified by proliferating cell nuclear antigen immunohistochemistry and the ApopTag assay. The combination of tomato and broccoli was more effective at slowing tumor growth than either tomato or broccoli alone and supports the public health recommendations to increase the intake of a variety of plant components.

PMID: 17213256 [PubMed - indexed for MEDLINE]Free Article

[Ellie F]

Thanks Rich
Almost missed this post!!

Ellie

[Rich66]

(Il-6, Stat 3, Bcl-2, cyclin D1, survivin, w/resveratrol, Hif1 alpha, w/Sorafenib)




PLoS One. 2010 Jul 6;5(7):e11457.
Sulforaphane causes epigenetic repression of hTERT expression in human breast cancer cell lines.

Meeran SM, Patel SN, Tollefsbol TO.
Department of Biology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America.



Abstract

BACKGROUND: Sulforaphane (SFN), an isothiocyanate found in cruciferous vegetables, is a common dietary component that has histone deacetylase inhibition activity and exciting potential in cancer prevention. The mechanisms by which SFN imparts its chemopreventive properties are of considerable interest and little is known of its preventive potential for breast cancer. PRINCIPAL FINDINGS: We found that SFN significantly inhibits the viability and proliferation of breast cancer cells in vitro while it has negligible effects on normal breast cells. Inhibition of telomerase has received considerable attention because of its high expression in cancer cells and extremely low level of expression in normal cells. SFN treatment dose- and time-dependently inhibited human telomerase reverse transcriptase (hTERT), the catalytic regulatory subunit of telomerase, in both MCF-7 and MDA-MB-231 human breast cancer cells. DNA methyltransferases (DNMTs), especially DNMT1 and DNMT3a, were also decreased in SFN-treated breast cancer cells suggesting that SFN may repress hTERT by impacting epigenetic pathways. Down-regulation of DNMTs in response to SFN induced site-specific CpG demethylation occurring primarily in the first exon of the hTERT gene thereby facilitating CTCF binding associated with hTERT repression. Chromatin immunoprecipitation (ChIP) analysis of the hTERT promoter revealed that SFN increased the level of active chromatin markers acetyl-H3, acetyl-H3K9 and acetyl-H4, whereas the trimethyl-H3K9 and trimethyl-H3K27 inactive chromatin markers were decreased in a dose-dependent manner. SFN-induced hyperacetylation facilitated the binding of many hTERT repressor proteins such as MAD1 and CTCF to the hTERT regulatory region. Depletion of CTCF using siRNA reduced the SFN-induced down-regulation of hTERT mRNA transcription in these breast cancer cells. In addition, down-regulation of hTERT expression facilitated the induction of cellular apoptosis in human breast cancer cells. SIGNIFICANCE: Collectively, our results provide novel insights into SFN-mediated epigenetic down-regulation of telomerase in breast cancer prevention and may open new avenues for approaches to SFN-mediated cancer prevention.

PMID: 20625516 [PubMed - in process]PMCID: PMC2897894Free PMC Article





Cancer Prev Res (Phila Pa). 2010 Apr;3(4):484-94. Epub 2010 Mar 16.
Sulforaphane inhibits constitutive and interleukin-6-induced activation of signal transducer and activator of transcription 3 in prostate cancer cells.

Hahm ER, Singh SV.
2.32A Hillman Cancer Center Research Pavilion, University of Pittsburgh Cancer Institute, 5117 Centre Avenue, Pittsburgh, PA 15213, USA.



Abstract

D,L-sulforaphane (SFN), a synthetic analogue of broccoli-derived L-isomer, inhibits viability of human prostate cancer cells and prevents development of prostate cancer and distant site metastasis in a transgenic mouse model. However, the mechanism underlying the anticancer effect of SFN is not fully understood. We now show that SFN inhibits constitutive and interleukin-6 (IL-6)-inducible activation of signal transducer and activator of transcription 3 (STAT3), which is an oncogenic transcription factor activated in many human malignancies, including prostate cancer. Growth-suppressive concentrations of SFN (20 and 40 micromol/L) decreased constitutive (DU145 cells) and IL-6-induced (DU145 and LNCaP cells) phosphorylation of STAT3 (Tyr(705)) as well as its upstream regulator Janus-activated kinase 2 (Tyr(1007/1008)). Exposure of DU145 and LNCaP cells to SFN resulted in suppression of (a) IL-6-induced transcriptional activity of STAT3 as judged by luciferase reporter assay and (b) nuclear translocation of phospho-STAT3 as revealed by immunofluorescence microscopy. Levels of many STAT3-regulated gene products, including Bcl-2, cyclin D1, and survivin, were also reduced in SFN-treated cells. The IL-6-mediated activation of STAT3 conferred partial but marked protection against SFN-induced apoptosis as evidenced by cytoplasmic histone-associated DNA fragmentation and cleavage of poly(ADP-ribose) polymerase and procaspase-3. Furthermore, knockdown of STAT3 protein using small interfering RNA resulted in a modest yet statistically significant increase in SFN-induced apoptotic DNA fragmentation in DU145 cells. Suppression of STAT3 activation was also observed in cells treated with naturally occurring analogues of SFN. In conclusion, the present study indicates that inhibition of STAT3 partially contributes to the proapoptotic effect of SFN. (c) 2010 AACR.

PMID: 20233902 [PubMed - in process]PMCID: PMC2853726 [Available on 2011/4/1]






Neurochem Res. 2010 Jan;35(1):152-61. Epub 2009 Aug 15.
Combination treatment with resveratrol and sulforaphane induces apoptosis in human U251 glioma cells.

Jiang H, Shang X, Wu H, Huang G, Wang Y, Al-Holou S, Gautam SC, Chopp M.
Department of Neurology, Henry Ford Hospital, Detroit, MI 48202, USA. hjiang1@hfhs.org



Abstract

Resveratrol is a naturally occurring polyphenolic compound highly enriched in grapes, peanuts, red wine, and a variety of food sources. Sulforaphane belongs to the family of isothiocyanates and is highly enriched in cruciferous vegetables. Our previous study showed that resveratrol, when used at high concentrations, inhibited cell proliferation, caused the cell cycle arrest and induced apoptotic cell death in glioma cells. In the current study, we tested the effect of combination treatment with resveratrol and sulforaphane, when both were used at low concentrations, on cell proliferation, migration and death in human U251 glioma cells. Our study shows that combination treatment with resveratrol and sulforaphane inhibits cell proliferation and migration, reduces cell viability, induces lactate dehydrogenase release, decreases pro-survival Akt phosphorylation and increases caspase-3 activation. The use of combination of bioactive food components, such as resveratrol and sulforaphane, may be a viable approach for the treatment of glioma.

PMID: 19685289 [PubMed - indexed for MEDLINE]PMCID: PMC2821708Free PMC Article


Mutat Res. 2007 May-Jun;635(2-3):90-104. Epub 2006 Nov 28.
Sulforaphane as a promising molecule for fighting cancer.

Fimognari C, Hrelia P.
Department of Pharmacology, University of Bologna, Bologna, Italy. carmela.fimognari@unibo.it
Abstract

A number of natural compounds with inhibitory effects on tumorigenesis have been identified from our diet. Several studies have documented the cancer-preventive activity of a significant number of isothiocyanates (ITCs), the majority of which occur in plants, especially in Cruciferous vegetables. The most characterized ITC is sulforaphane (SFN). SFN has received a great deal of attention because of its ability to simultaneously modulate multiple cellular targets involved in cancer development, including: (i) DNA protection by modulating carcinogen-metabolizing enzymes and blocking the action of mutagens; (ii) inhibition of cell proliferation and induction of apoptosis, thereby retarding or eliminating clonal expansion of initiated, transformed, and/or neoplastic cells; (iii) inhibition of neoangiogenesis, progression of benign tumors to malignant tumors, and metastasis formation. SFN is therefore able to prevent, delay, or reverse preneoplastic lesions, as well as to act on cancer cells as a therapeutic agent. Taking into account this evidence and its favorable toxicological profile, SFN can be viewed as a conceptually promising agent in cancer prevention and/or therapy.

PMID: 17134937 [PubMed - indexed for MEDLINE]



Int J Cancer. 2008 Sep 15;123(6):1255-61.
Sulforaphane inhibited expression of hypoxia-inducible factor-1alpha in human tongue squamous cancer cells and prostate cancer cells.

Yao H, Wang H, Zhang Z, Jiang BH, Luo J, Shi X.
Graduate Center for Toxicology, College of Medicine, The University of Kentucky, Lexington, KY 40503, USA.
Abstract

Previous studies show that a number of natural compounds from our diet have anticancer effects. Sulforaphane is the most characterized isothiocyanates (ITCs), which are identified in cruciferous vegetables. Sulforaphane is viewed as a conceptually promising agent in cancer prevention. Because of its ability to induce cancer cell apoptosis, it inhibits progression of benign tumors to malignant tumors and interrupts metastasis. However, the effect of sulforaphane on tongue cancer cell proliferation has not yet been reported, and the mechanisms that sulforaphane inhibits cancer development are still unclear. Hypoxia-inducible factor 1 (HIF-1) expression is associated with tumorigenesis and angiogenesis. It regulates the expression of many genes including vascular endothelial growth factor (VEGF), inducible nitric oxide synthase, and lactate dehydrogenase A. In our study, we investigated the effects of sulforaphane on expression of hypoxia-inducible factor-1alpha (HIF-1alpha), which was overexpressed in many human malignant tumors, human tongue squamous cell carcinoma and prostate cancer DU145 cells. Sulforaphane inhibited hypoxia induced expression of HIF-1alpha via inhibiting synthesis of HIF-1alpha. Sulforaphane was also found to inhibit hypoxia induced HIF-1alpha expression through activating JNK and ERK signaling pathways, but not AKT pathway. Inhibition of HIF-1alpha by sulforaphane resulted in decreasing expression of VEGF. Taken together, these results suggest that sulforaphane is an effective chemopreventive compound against tongue cancers and prostate cell angiogenesis in vitro, and that the HIF-1alpha target provides a new sight into the mechanisms of sulforaphane's inhibition against tumor cell proliferation. Copyright 2008 Wiley-Liss, Inc.

PMID: 18561315 [PubMed - indexed for MEDLINE]


Cancer Res. 2010 Jun 8. [Epub ahead of print]
Synergistic Activity of Sorafenib and Sulforaphane Abolishes Pancreatic Cancer Stem Cell Characteristics.

Rausch V, Liu L, Kallifatidis G, Baumann B, Mattern J, Gladkich J, Wirth T, Schemmer P, Büchler MW, Zöller M, Salnikov AV, Herr I.
Authors' Affiliations: Molecular OncoSurgery and Tumor Cell Biology, University of Heidelberg and German Cancer Research Center; Department of General Surgery, University of Heidelberg; Translational Immunology Unit, German Cancer Research Center, Heidelberg, Germany; and Institute of Physiological Chemistry, University of Ulm, Ulm, Germany.
Abstract

Recent evidence suggests that pancreatic cancer and other solid tumors contain a subset of tumorigenic cells capable of extensive self-renewal that contribute to metastasis and treatment resistance. Sorafenib (SO) is a promising new multikinase inhibitor for treatment of advanced kidney and liver cancers. We report here targeting of pancreatic cancer stem cells (CSC) by SO and the development of a strategy to enhance this effect. Although SO administration diminished clonogenicity, spheroid formation, aldehyde dehydrogenase 1 (ALDH1) activity, growth on immunodeficient mice, proliferation, and angiogenesis and induced apoptosis, we observed SO-induced activation of NF-kappaB associated with survival and regrowth of spheroids. For enhanced elimination of CSC characteristics by SO, we cotreated cells with sulforaphane (SF). This broccoli isothiocyanate was recently described to eliminate pancreatic CSCs by downregulation of NF-kappaB activity without inducing toxic side effects. On combination treatment, SF completely eradicated SO-induced NF-kappaB binding, which was associated with abrogated clonogenicity, spheroid formation, ALDH1 activity, migratory capacity, and induction of apoptosis. In vivo, combination therapy reduced the tumor size in a synergistic manner. This was due to induction of apoptosis, inhibition of proliferation and angiogenesis, and downregulation of SO-induced expression of proteins involved in epithelial-mesenchymal transition. Our data suggest that SF may be suited to increase targeting of CSCs by SO. Cancer Res; 70(12); 5004-13. (c)2010 AACR.

PMID: 20530687 [PubMed - as supplied by publisher]





Raw broccoli doubles survival in bladder cancer patients
Jacob Schor, ND, FABNO
July 1, 2010


An interesting paper came out a few weeks ago of particular interest to people with bladder cancer but that is worth all of us noticing. The paper is the latest in a sequence of papers authored by Li Tang and colleagues at the Roswell Cancer Research Center in New York.

Tang has been studying the effect of cruciferous vegetables on bladder cancer for years. In 2004, Tang reported that cruciferous vegetables inhibit the growth of human bladder cancer cells in 2004. [1]

In 2008, Tang, using data from a hospital based case-controlled study, reported that consumption of raw cruciferous vegetables lowered the risk of getting bladder cancer. They found a strong and statistically significant inverse association between bladder cancer risk and raw cruciferous vegetable intake (adjusted OR for highest versus lowest category = 0.64). In the early study, as in the current study, no significant benefit was found for fruit, total vegetables, or cooked cruciferous vegetable consumption. Only eating raw cruciferous vegetables provided protection. [2]

In a February 2010 paper, Tang reported that the isothiocyanates found in cruciferous vegetables inhibited the growth of bladder tumor cells in a rat model of human bladder cancer. [3]

The results of Tang’s current paper are fully congruent with the earlier findings.

Tang’s most recent paper was published June 15. In this paper, data from the Roswell Park Cancer Institute’s Tumor Registry, patient medical records, and routinely collected questionnaire data, were analyzed for potential associations between intake of cruciferous vegetables and survival among bladder cancer patients.

A total of 239 bladder cancer patients were included in the study. After an average of 8 years of follow-up, 179 deaths occurred, with 101 deaths attributable to bladder cancer.

Analysis of the data revealed a strong and statistically significant inverse association between raw broccoli intake and bladder cancer mortality. Those eating one or more servings of raw broccoli a month compared to those eating less than one serving a month reduced their chance of dying from bladder cancer by 57% and reduced the risk of dying from all causes by 45%. No significant associations were found in the data for total vegetables, total fruits or for other individual cruciferous vegetables. [4]

These effects, though striking, are entirely plausible. Consumption of cruciferous vegetables is associated with reduced risk of bladder cancer. These plants contain a number of chemopreventive agents, including isothiocyanates. Isothiocyanate metabolites that reach the bladder still retain their anti-cancer action. They concentrate in the urine, reaching levels two to three times higher in the bladder than in the blood serum. Cooking lowers isothiocyanate levels: urinary levels are 3-4 times higher after eating raw broccoli than cooked broccoli. Broccoli contains higher levels of isothiocyanates than any other cruciferous vegetable, 40% more than cabbage and more than double the amount found in cauliflower. The type of isothiocyanate found varies with type of vegetable. In broccoli, the major isothiocyanate is sulforaphane; cabbage and cauliflower contain allyl isothiocyanate.

It is not just in bladder cancer where raw is better. Li Tang had another important study published in April 2010 that reported cruciferous vegetable consumption lowers the risk of lung cancer in smokers. Only consumption of raw cruciferous vegetables had a statistically significantly effect on lung cancer risk, those smokers in the middle tertile of consumption had half the risk of those in the lower tertile. [5]

These studies give us good reason to be more specific in what we tell our patients. Not only should we encourage patient to eat cruciferous vegetables, but we should tell them to eat broccoli and make a point to eat it raw.



Bottom Line:
1. Raw broccoli significantly halves the risk of dying for people who have had bladder cancer from any cause but particularly from bladder cancer.
2. Raw broccoli is more effective than cooked broccoli.
3. Broccoli is more effective than other cruciferous vegetables.
4. Raw broccoli protects against other cancers such as lung cancer in smokers.




Cancer Prev Res (Phila Pa). 2010 Apr;3(4):484-94. Epub 2010 Mar 16.
Sulforaphane inhibits constitutive and interleukin-6-induced activation of signal transducer and activator of transcription 3 in prostate cancer cells.

Hahm ER, Singh SV.
2.32A Hillman Cancer Center Research Pavilion, University of Pittsburgh Cancer Institute, 5117 Centre Avenue, Pittsburgh, PA 15213, USA.


purchase TEXT

Abstract

D,L-sulforaphane (SFN), a synthetic analogue of broccoli-derived L-isomer, inhibits viability of human prostate cancer cells and prevents development of prostate cancer and distant site metastasis in a transgenic mouse model. However, the mechanism underlying the anticancer effect of SFN is not fully understood. We now show that SFN inhibits constitutive and interleukin-6 (IL-6)-inducible activation of signal transducer and activator of transcription 3 (STAT3), which is an oncogenic transcription factor activated in many human malignancies, including prostate cancer. Growth-suppressive concentrations of SFN (20 and 40 micromol/L) decreased constitutive (DU145 cells) and IL-6-induced (DU145 and LNCaP cells) phosphorylation of STAT3 (Tyr(705)) as well as its upstream regulator Janus-activated kinase 2 (Tyr(1007/1008)). Exposure of DU145 and LNCaP cells to SFN resulted in suppression of (a) IL-6-induced transcriptional activity of STAT3 as judged by luciferase reporter assay and (b) nuclear translocation of phospho-STAT3 as revealed by immunofluorescence microscopy. Levels of many STAT3-regulated gene products, including Bcl-2, cyclin D1, and survivin, were also reduced in SFN-treated cells. The IL-6-mediated activation of STAT3 conferred partial but marked protection against SFN-induced apoptosis as evidenced by cytoplasmic histone-associated DNA fragmentation and cleavage of poly(ADP-ribose) polymerase and procaspase-3. Furthermore, knockdown of STAT3 protein using small interfering RNA resulted in a modest yet statistically significant increase in SFN-induced apoptotic DNA fragmentation in DU145 cells. Suppression of STAT3 activation was also observed in cells treated with naturally occurring analogues of SFN. In conclusion, the present study indicates that inhibition of STAT3 partially contributes to the proapoptotic effect of SFN.

PMID: 20233902 [PubMed - indexed for MEDLINE]PMCID: PMC2853726 [Available on 2011/4/1]


J Biol Chem. 2010 Sep 10. [Epub ahead of print]
Sulforaphane activates heat shock response and enhances proteasome activity through upregulation of HSP27.
Gan N, Wu YC, Brunet M, Garrido C, Chung FL, Dai C, Mi L.
Georegtown University Medical Center, United States;


FREE TEXT

Abstract
It is conceivable that stimulating proteasome activity for rapid removal of misfolded and oxidized proteins is a promising strategy to prevent and alleviate aging-related diseases. Sulforaphane (SFN), an effective cancer preventive agent derived from cruciferous vegetables, has been shown to enhance proteasome activities in mammalian cells and to reduce the level of oxidized proteins and amyloid beta-induced cytotoxicity. Here we report that SFN activates heat shock transcription factor 1 (Hsf1)-mediated heat shock response. Specifically, SFN-induced expression of heat shock protein 27 (Hsp27) underlies SFN-stimulated proteasome activity. SFN-induced proteasome activity was significantly enhanced in Hsp27-overexpressing cells while absent in Hsp27-silenced cells. The role of Hsp27 in regulating proteasome activity was further confirmed in isogenic REG cells in which SFN-induced proteasome activation was only observed in cells stably overexpressing Hsp27, but not in the Hsp27-free parental cells. Finally, we demonstrated that phosphorylation of Hsp27 is irrelevant to SFN-induced proteasome activation. This study provides a novel mechanism underlying SFN-induced proteasome activity. This is the first report that heat shock response by SFN, in addition to the antioxidant response mediated by the Keap1-Nrf2 pathway, may contribute to cytoprotection.

PMID: 20833711 [PubMed - as supplied by publisher]Free Article

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Ann Surg Oncol. 2010 Feb;17(2):592-602. Epub 2009 Oct 15.
Inhibition of autophagy potentiates sulforaphane-induced apoptosis in human colon cancer cells.

Nishikawa T, Tsuno NH, Okaji Y, Shuno Y, Sasaki K, Hongo K, Sunami E, Kitayama J, Takahashi K, Nagawa H.
Department of Surgical Oncology, Faculty of Medical Science, The University of Tokyo, Tokyo, Japan. takn-tky@umin.ac.jp
Abstract

BACKGROUND: Sulforaphane (SUL), an isothiocyanate naturally present in widely consumed vegetables, particularly broccoli, has recently attracted attention due to its inhibitory effects on tumor cell growth by inducing apoptosis. We investigated the ability of SUL to induce autophagy in human colon cancer cells and whether inhibition of autophagy could potentiate the proapoptotic effect of SUL.
METHODS: The proliferation of cells treated with SUL was assessed by MTS assay and colony-forming assay. Apoptosis and caspases activity were investigated by flow cytometry. The formation of acidic vesicular organelles (AVOs) was detected in acridine-orange-stained cells by flow cytometry. Western blotting was used for the detection of light chain 3 (LC3). Localizations of LC3 and cytochrome c were analyzed by immunocytochemistry.
RESULTS: The proapoptotic effect was observed by treatment of cells with relatively high concentrations of SUL for long periods of time. After 16 h of treatment, evident formation of AVOs and recruitment of LC3 to autophagosomes, features of autophagy, were observed. Treatment of cells with a specific autophagy inhibitor (3-methyladenine) potentiated the proapoptotic effect of SUL, which was dependent on the activation of caspases and the release of cytochrome c to the cytosol.
CONCLUSION: The present results demonstrate induction of autophagy in colon cancer cells as a protective reaction against the proapoptotic effect of SUL, and consequently, the potentiation of the proapoptotic effect by autophagy inhibition. These findings provide a premise for use of autophagy inhibitors in combination with chemotherapeutic agents for treatment of colorectal cancer.

PMID: 19830499 [PubMed - indexed for MEDLINE]



Angiogenesis. 2010 Aug 8. [Epub ahead of print]
The inhibition of autophagy potentiates anti-angiogenic effects of sulforaphane by inducing apoptosis.

Nishikawa T, Tsuno NH, Okaji Y, Sunami E, Shuno Y, Sasaki K, Hongo K, Kaneko M, Hiyoshi M, Kawai K, Kitayama J, Takahashi K, Nagawa H.
Department of Surgical Oncology, Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan, takn-tky@umin.ac.jp.
Abstract

BACKGROUND: Sulforaphane (SUL), a kind of isothiocyanate, has recently been focused due to its strong pro-apoptotic effect on cancer cells as well as tumor vascular endothelial cells (ECs). And recently, we demonstrated the induction of autophagy by colon cancer cells as a protective mechanism against SUL. In the present study, we aimed to investigate the possible role of autophagy induction by ECs as a defense mechanism against SUL.
METHODS: Human umbilical vein endothelial cells (HUVECs) were used as the in vitro model of angiogenic ECs. The induction of autophagy was evaluated by the detection of acidic vesicular organelles (AVOs) by flow-cytometry, after the staining with acridine orange, as well as the detection of light chain 3(LC3) by Western blot. Finally, the functional implication of autophagy inhibition and SUL treatment in ECs was investigated by their ability to form vascular-like structures on Matrigel.
RESULTS: Treatment of HUVECs with relatively low concentrations of SUL for 16 h resulted in the evident formation of AVOs and the recruitment of LC3 to autophagosomes, the pathognomonic features of autophagy. Co-treatment of cells with the specific autophagy inhibitor (3-methyladenine) potentiated the proapoptotic effect of SUL. And inhibition of autophagy potentiated the inhibitory effect of SUL on the ability of ECs to form capillary-like structures.
CONCLUSION: Similar to cancer cells, ECs induced autophagy in response to the pro-apoptotic agent, SUL, and the inhibition of autophagy potentiated the pro-apoptotic effect. These findings open premises for the use of autophagy inhibitors in combination with anti-angiogenic agents.

PMID: 20694744 [PubMed - as supplied by publisher]

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