Effects of PCB70 and PCB75 on HeLa cell proliferation, membrane integrity and cell signaling pathway.

Polychlorinated biphenyls (PCBs) are persistent pollutants and pose toxic effects to humans and environment. In the current study, we focused to assess the effects of PCBs congeners (PCB70 and PCB75) upon HeLa cells using different concentrations (10^-3, 10^-2, 1, 10 and 15 µg/mL) and time (12, 24 and 48 h). The 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay revealed that PCB70 and PCB75 induces cell proliferation at low doses (10^-3, 10-² and 1 µg/g) and inhibit the proliferation at high doses (10 and 15 µg/g) with different time suggesting cytotoxicity. The HeLa cells were analyzed for quantification of membrane integrity and it is found that PCB70 did not cause deformity in membrane integrity. However, PCB75 showed to cause deformity in membrane integrity in dose and time dependent manners. The results from western blot assay demonstrated that PCB70 and PCB75 exposure induced the expression of extracellular signal regulated-kinases (ERK1/2) and Jun N-terminal kinases (JNK) in dose- and time-dependent manners in the HeLa cells. The findings might provide mechanistic insight of PCB congeners induced cytotoxicity to HeLa cells. [ABSTRACT FROM AUTHOR]