PCBs (as in plastics) may play role in Breast cancer development

[Lani]

: Chem Biol Interact. 2006 Jul 1; [Epub ahead of print] Links
Induction of ROS formation, poly(ADP-ribose) polymerase-1 activation, and cell death by PCB126 and PCB153 in human T47D and MDA-MB-231 breast cancer cells.

Lin CH,
Lin PH.
Department of Environmental Engineering, National Chung Hsing University, Taichung, Taiwan, ROC.
The primary purpose of this research is to investigate whether exposure to polychlorinated biphenyls (PCBs), i.e. PCB153 and PCB126, is associated with induction of reactive oxygen species (ROS), poly(ADP-ribose) polymerase-1 (PARP-1) activation, and cell death in human T47D and MDA-MB-231 breast cancer cells. Results indicated that PCB153 and PCB126 induced concentration- and time-dependent increases in cytotoxic response and ROS formation in both T47D and MDA-MB-231 cells. At non-cytotoxic concentrations both PCB153 and PCB126 induced decreases in intracellular NAD(P)H and NAD(+) in T47D and MDA-MB-231 cells where T47D cells were more resistant to PCB-induced reduction in intracellular NAD(P)H than MDA-MB-231 cells. Further investigation indicated that three specific PARP inhibitors completely blocked PCB-induced decreases in intracellular NAD(P)H in both T47D and MDA-MB-231 cells. These results imply that decreases in intracellular NAD(P)H in PCB-treated cells may be, in part, due to depletion of intracellular NAD(+) pool mediated by PARP-1 activation through formation of DNA strand breaks. Overall, the extent of cytotoxic response, ROS formation, and PARP-1 activation generated in T47D and MDA-MB-231 cells was greater for PCB153 than for PCB126. In addition, the cytotoxicity induced by PCB153 and PCB126 in both T47D and MDA-MB-231 cells was completely blocked by co-treatment of catalase, dimethylsulfoxide, cupper (I)-/iron (II)-specific chelators, and CYP1A/2B inhibitors. This evidence suggests the involvement of ROS, Cu(I), Fe(II), and CYP1A/2B enzymes in mediating the induction of cell death by PCB153 and PCB126. Further, antagonism was observed between PCB126 and PCB153 for effects on cytotoxic response and ROS formation in T47D and MDA-MB-231 cells. Antagonism was also observed between PCB153 and PCB126 in the induction of NAD(P)H depletion at lower concentration (<10muM) in T47D cells, but not in MDA-MB-231 cells. In conclusions, results from our investigation suggest that ROS formation induced by PCBs is a significant determinant factor in mediating the DNA damage and cell death in human breast cancer cells. The data also suggests that the status of estrogen receptor alpha may play a role in modulating the PCB-induced oxidative DNA damage and cell death in human breast cancer cells.
PMID: 16884709 [PubMed - as supplied by publisher]

[Susan2]

Interesting. 6 years ago when I was interviewing oncologists, I walked into his office carrying a bottle of water. One of the first things he said was that my cancer was probably caused by drinking from plastic bottles. I've read other articles that say that more acidic drinks cause more problems because they leach toxins from the plastics.

[R.B.]

Another reason for taking acidic drinks out of diet

More food for thought

RB


http://www.ajcn.org/cgi/content/full/81/2/341

"Acid-base balance
After digestion, absorption, and metabolism, nearly all foods release either acid or bicarbonate (base) into the systemic circulation (146, 147). As shown in Table 5Go, fish, meat, poultry, eggs, shellfish, cheese, milk, and cereal grains are net acid producing, whereas fresh fruit, vegetables, tubers, roots, and nuts are net base producing. Legumes yield near-zero mean acid values, which reflects an overlapping distribution from slightly net acid producing to slightly net base producing. Not shown in Table 5Go are energy-dense, nutrient-poor foods such as separated fats and refined sugars that contribute neither to the acid nor the base load. Additionally, salt is net acid producing because of the chloride ion (146).


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TABLE 5 Potential net acid (or base) loads of 17 food groups1


The typical Western diet yields a net acid load estimated to be 50 mEq/d (148). As a result, healthy adults consuming the standard US diet sustain a chronic, low-grade pathogenic metabolic acidosis that worsens with age as kidney function declines (146, 149). Virtually all preagricultural diets were net base yielding because of the absence of cereals and energy-dense, nutrient-poor foods—foods that were introduced during the Neolithic and Industrial Eras and that displaced base-yielding fruit and vegetables (147). Consequently, a net base-producing diet was the norm throughout most of hominin evolution (147). The known health benefits of a net base-yielding diet include preventing and treating osteoporosis (150, 151), age-related muscle wasting (152), calcium kidney stones (153, 154), hypertension (155, 156), and exercise-induced asthma (157) and slow the progression of age- and disease-related chronic renal insufficiency (158)."