Effect on proliferation of SW480 cell line with p33~(ING1b) genetransfection / 中国癌症杂志

ABSTRACT

Background and purpose:As a new candidate tumor suppressor gene, p33ING1b has many biological functions. This study was done to investigate its role in the regulation of the proliferation of human colon cancer cell line SW480. Methods:The pcDNA3.1(+)/p33ING1b/SW480 cells were identified by Western blot and S-P immunohistochemical method. In order to elucidate the effect of expression of exogenous p33ING1b gene on the colorectal cancer cell SW480, the proliferation rates were analyzed by growth curves and colony formation assay in soft agar for cells including SW480, pcDNA3.1(+)/p33ING1b/SW480 and pcDNA3.1(+)/SW480. At same time, the apoptotic rate of cells and the cell cycle analysis were also tested by flow cytometry.Furthermore,using western blot analysis,we detected the expression level of the protein p53, p21WAF1,Bax and Bcl-2 in those three group cells, which initially indicate the molecule mechanism of inducing apoptosis by gene p33ING1b. Results:The cell growth rates of SW480 cells transfected with pcDNA3.1 (+)/p33ING1b were slower than those transfected with pcDNA3.1(+) or untransfected.The colony formation efficiency of pcDNA3.1(+)/p33ING1b/SW480 were decreased and the apoptotic rates were increased compared with pcDNA3.1(+)/SW480 and SW480(P0.05). Conclusion:After overexpression of exogenous p33ING1b protein in SW480 cell, there were inhibition of the proliferation rate and induction of apoptosis, the molecular mechanism might be associated with up- regulated expression of Bax and down-regulated expression of Bcl-2 by p33ING1b gene.