The polychlorinated biphenyls (PCBs, Aroclor1254) is widely dispersed environmental pollutants and
shows its toxic effects including neurotoxicity, hepatotoxicity, carcinogenicity, immunotoxicity and
cardiotoxicity. These toxicities depend on the chemical structure of congeners, each of which is
chlorinated to various degrees. The PCBs causes abnormalities in the developing central nervous system.
Due to the structural similarities of PCBs and TH (thyroid hormone), the PCBs might affect systems
involving this hormones. Previous studies in our laboratory, we found that the PCBs treatment decreased
cell proliferation in diverse organ cells like kidney, liver, and heart etc. And we investigated DNA
fragmentation which is a hall mark of apoptosis by exposure of the PCBs in 293T cell in previous
research. In this study, we identified cellular factors which possibly induce apoptosis by PCBs treatment.
As a result, we found the changes of protein expression in the 293T cells with PCBs treatment by two
dimensional electrophoresis and matrix assisted laser desorption ionisation time-of-flight mass spectrometry
(MALDI-TOF-MS) analysis. The proteins were DNA-binding protein, polycystin-2 homolog
(PKD2L), cytosolic inorganic pyrophosphatase, glutathione transferase / fatty-acyl-ethel-ester synthase.

Keywords: PCBs, Aroclor1254, Apoptosis, Viability, Gene expression