Abstract
German Non-planar di-ortho-substituted PCB 153 (2,2',4,4',5,5'-hexachlorobiphenyl), one of the most abundant PCB congeners in the environment and in biological and human tissues, has been identified as potential endocrine disruptor affecting the reproductive and endocrine systems in rodents, wildlife, and humans. The aim of this study was to gain a deeper insight into its mode/mechanism of action in Chinese hamster ovary K1 cells (CHO-K1). PCB 153 (10-100 μmol/L) inhibited CHO-K1 cell proliferation, which was confirmed with four bioassays (Trypan Blue, Neutral Red, Kenacid Blue, and MTT), of which the MTT assay proved the most sensitive. PCB 153 also induced ROS formation in a dose-dependent manner. Apoptosis was seen after 6 h of exposure to PCB 153 doses ≥50 μmol/L, while prolonged exposure resulted in the activation of the necrotic pathway. PCB 153-induced disturbances in normal cell cycle progression were time-dependent, with the most significant effects occurring after 72 h. Neplanarni di-ortho-supstituirani PCB 153 (2,2’,4,4’,5,5’-heksaklorobifenil) jedan je od najčešćih PCB kongenera detektiranih u biološkim i u uzorcima iz okoliša. Identificiran je kao potencijalni endokrini modulator koji uzrokuje štetne učinke na reproduktivnom i endokrinom sustavu glodavaca, divljih životinja i ljudi. Ovo istraživanje pruža uvid u mehanizme djelovanja PCB 153 na stanicama ovarija. Primjenom četiriju metoda (Trypan Blue, Neutral Red, Kenacid Blue i MTT) utvrđeno je da PCB 153 (10–100 μmol/L) reducira proliferaciju CHO-K1 stanica, a od primijenjenih se metoda MTT test pokazao kao najosjetljiviji. PCB 153 inducirao je stvaranje ROS-a u stanicama ovarija, ovisno o primijenjenoj dozi. Citofluorimetrijska analiza upozorava na indukciju apoptoze nakon šest sati izloženosti stanica PCB-u 153 u dozama ≥50 μmol/L, a produljena izloženost rezultirala je aktivacijom nekroze. PCB 153 uzrokovao je poremećaje u progresiji staničnog ciklusa, s najznačajnijim promjenama uočenima nakon 72 sata izloženosti.