for all you dog-lovers--from the journal of Medical Hypotheses

[Lani]

Med Hypotheses. 2006;67(1):21-6. Epub 2006 Mar 3. Links
Do dogs harbour risk factors for human breast cancer?

Laumbacher B, Fellerhoff B, Herzberger B, Wank R.
Institute of Immunology, Klinikum Innenstadt, University of Munich, Goethestrasse 31, 80336 Muenchen, Germany.
We ask consulting patients regularly whether they keep pets in order to identify zoonotic factors. It became apparent that patients with breast carcinoma (N=69) owned significantly more often dogs but not cats compared to age matched female controls. We compared the frequencies of dog and pet ownership with data from public available statistics on women (N=1320) of the same age group in Bavaria. The most striking result was that more than twice the number of patients kept dogs permanently in the last 10 years and at the time of interrogation as compared to control individuals at the time of interrogation (p=0.0000003, relative risk 3.5). Further internet search on the morbidity of breast carcinoma showed in dogs a protracted course of disease and metastases into lung, liver and bones, resembling the course of disease in human breast cancer. In contrast with this, breast cancer presented in cats a dramatically short course and the main but unusual location of metastasis presents in the hind legs. A recent publication in Norway reported on a high frequency (53.3%) of breast carcinomas in 14,401 investigated dogs. Which transmissible factor or factors come into question? Variants of the mouse mammary tumor virus (MMTV) can productively replicate in human cells and in different animals, including dogs. Many investigators, but not all, could identify MMTV-like sequences in sporadic human breast cancer. MMTV or MMTV-like sequences have not been investigated in canine breast carcinomas until now. It is also conceivable that other microbes from the dog, for example bacteria, could participate in the first steps of carcinogenesis in human. It was recently shown that bartonella species promote vascularization and prevent apoptosis of infected cells with the same methods as helicobacter pylori. Our considerations require further research. Epidemiologic cohort studies and identification of potential carcinogenic microbial factors will prove or disprove our hypothesis that risk factors from dogs could contribute to the carcinogenesis of human breast cancer.
PMID: 16516398 [PubMed - indexed for MEDLINE]

I am sure Gina will like the bit about H. Pylori

[Lani]

Cancer Res. 2005 Aug 1;65(15):6651-9.



Mouse mammary tumor virus infects human cells.

Indik S, Günzburg WH, Salmons B, Rouault F.
Research Institute for Virology and Biomedicine, University of Veterinary Medicine, Vienna, Austria.
Mouse mammary tumor virus (MMTV) has long been speculated to be involved in human breast cancer and more recently in human primary biliary cirrhosis. Despite complete proviral sequences markedly homologous to MMTV being identified in human breast cancer tissue, no convincing evidence has been presented to date that MMTV can infect human cells. Using both wild-type and a genetically marked virus (MMTV-EGFP), we show here the successful infection of a number of different human cells by MMTV. Furthermore, infection of human cells is shown to be almost as efficient as the infection of murine mammary epithelial cells. Sequencing of PCR products from integrated proviruses reveals that reverse transcription and integration of the viral genome has occurred as expected. Furthermore, sequencing of two independent MMTV proviral integration sites reveal them to be present only in the human and not in the mouse genome. Infection requires an intact MMTV envelope protein and is blocked either by heat inactivation of the virus or by specific neutralizing anti-MMTV serum, ruling out a nonspecific mechanism of viral transfer. Thus, MMTV can infect human cells and this finding provides a possible explanation for the detection by others of MMTV sequences in human breast cancer patients.
PMID: 16061645 [PubMed - indexed for MEDLINE]
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Cancer Res. 2005 Feb 1;65(3):907-12.



Spontaneous feline mammary carcinoma is a model of HER2 overexpressing poor prognosis human breast cancer.

De Maria R, Olivero M, Iussich S, Nakaichi M, Murata T, Biolatti B, Di Renzo MF.
Department of Animal Pathology, School of Veterinary Medicine, University of Turin, Grugliasco, Turin, Italy.
Companion animal spontaneous tumors are suitable models for human cancer, primarily because both animal population and the tumors are genetically heterogeneous. Feline mammary carcinoma (FMC) is a highly aggressive, mainly hormone receptor-negative cancer, which has been proposed as a model for poor prognosis human breast cancer. We have identified and studied the feline orthologue of the HER2 gene, which is both an important prognostic marker and therapeutic target in human cancer. Feline HER2 (f-HER2) gene kinase domain is 92% similar to the human HER2 kinase. F-HER2-specific mRNA was found 3- to 18-fold increased in 3 of 3 FMC cell lines, in 1 of 4 mammary adenomas and 6 of 11 FMC samples using quantitative reverse transcription-PCR. Western blot showed that an anti-human HER2 antibody recognized a protein comigrating with the human p185HER2 in FMC cell lines. The same antibodies strongly stained 13 of 36 FMC archival samples. These data show that feline HER2 overexpression qualifies FMC as homologous to the subset of HER2 overexpressing, poor prognosis human breast carcinomas and as a suitable model to test innovative approaches to therapy of aggressive tumors.
PMID: 15705889 [PubMed - indexed for MEDLINE]
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Microsc Res Tech. 2005 Nov;68(3-4):209-21.



Human, rhesus macaque, and feline sequences highly similar to mouse mammary tumor virus sequences.

Szabo S, Haislip AM, Traina-Dorge V, Costin JM, Crawford BE 2nd, Wilson RB, Garry RF.
Department of Pathology, Children's Hospital, New Orleans, Louisiana 70118, USA. sszabo@lsuhsc.edu
Sequences highly similar (>95%) to the mouse mammary tumor virus (MMTV) env gene have been amplified from human DNA samples, including DNA samples from patients with breast cancer (BC) and persons who did not have BC. The sequences from human DNA were distinct from the MMTV sequences used as controls in these PCR reactions, indicating that these results are not simply due to contamination. In addition to both, mouse and human-related sequences were also amplified from some monkey and cat genomic DNA samples. These products were shown to be distinct from, but highly related to, the MMTV env gene, whereas, testing of other sources (lambda phage, snake, cockroach, sea urchin, chicken, or dog) demonstrated no specific amplification. A sequence 90% similar to the MMTV group antigen gene (gag) was amplified from cat DNA. These results indicate that DNA from vertebrate species other than rodents, including some but not all humans, monkeys, and cats, can contain sequences closely related to MMTV. 2005 Wiley-Liss, Inc.
PMID: 16276510 [PubMed - indexed for MEDLINE]
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Microsc Res Tech. 2005 Nov;68(3-4):197-208.


Of mice, cats, and men: is human breast cancer a zoonosis?

Szabo S, Haislip AM, Garry RF.
Department of Pathology, Children's Hospital, New Orleans, Louisiana 70118, USA. sszabo@lsuhsc.edu
Mouse mammary tumor virus (MMTV), a member of the betaretroviridae, is the most common cause of breast cancer (BC) in mice. MMTV is transmitted in mice both in the germline as endogenous proviruses and exogenously as infectious virions. Here, we review a variety of evidence accumulated for six decades that has suggested that a human homologue of MMTV may exist. The findings include recent studies from several independent laboratories that have detected sequences very closely related to MMTV in DNA isolated from human BC tumors. Other laboratories, however, have failed to detect the MMTV-related sequences in human DNA samples, and conclusive evidence for a human mammary tumor virus has been elusive. We also reviewed additional studies, suggesting that betaretroviruses are present in a much wider range of species than previously known, including rodents, felines, and primates. The observation that a subset of cats may be infected with a close homologue of MMTV may be of epidemiological significance for human BC. Cats may become infected by MMTV from mice, and in turn may transmit the virus to humans, possibly after selection for variants with an expanded host range. 2005 Wiley-Liss, Inc.
PMID: 16276516 [PubMed - indexed for MEDLINE]

MMTV and feline bc in particular are caused by a her2 gene which is very simililar to the human her2 gene--in fact 92% of the DNA making up the feline her2 gene is IDENTICAL to the DNA making up the human her2 gene

[hutchibk]

Well, I've always thought I was a cat, and after reading these, it just might be true...

[SoCalGal]

Just doing a quick check in and of course, wanted to read what Lani posted before I see my onc today for the big meeting.

Wanted to say, I adopted my dog a year before my initial diagnosis and realized that she has survived all these years without ANY chemo. The only treatment she has had is LOVE. She has no real stressors in life - doesn't work, doesn't pay bills, parties with my kids and plays with her friends. Occassionally she barks to keep random people from our front gate. She sleeps most of the day, goes to bed early and seems to smile a lot.

Forget the gluten free diet - omega's schmo-mega's- I am eating dog food from now on...hopefully it's not too late for RB to add a chapter in his book. My dog Gracie and I will be eating Science Diet (for seniors - small bites).

Will post a more serious follow up after my onc appt. Here's wishes for a good Monday to all. xo Flori

[PinkGirl]

Flori

I have heard that Purina One (lamb and rice formula) is also quite
good, as is Iams for seniors.

[hutchibk]

I have been on Science Diet Feline CD for a few years now. However, I often sit at Mark's feet and cry for the savory flavor of human food when I hear him using the can opener, but he usually only lets me lick the bottom of his cereal bowl from time to time. LOL

[Donna]

...because none of my cats or dogs will let me near their food!

:-) Donna