Objective: The study is to explore the effects of genistein on proliferation and apoptosis in human colon cancer HT-29 cells and the likely underlying molecular mechanisms.
Methods: HT-29 cultures were maintained in DMEM containing 10% fetal bovine serum. Cell proliferation was determined by MTT assay and cell cycle distribution by cytometry. Apoptosis was detected by the Cell Death Detection ELISA and cytometry. The expressions of bax, bcl-2, and PCNA were examined using reverse transcriptase-polymerase chain reaction (RT-PCR) and Western-blot both at mRNA and protein levels, respectively.
Results: Genistein inhibited proliferation and induced G2/M phase arrest and apoptotic death in colon cancer HT-29 cells. We investigated the effects of genistein on molecules that regulate apoptosis and cell cycle progress. Genistein increased expression of bax and significantly reduced PCNA with a slightly decrease in bcl-2 expression both at mRNA and protein level.
Conclusion: Our results demonstrated that genistein inhibited the viability of human colon cancer HT-29 cell via induction of apoptosis mainly through regulation of PCNA and Bax/Bcl-2 expression. These data suggested a role of genistein in prevention of colon tumor and might reduce colon tumor growth.