The anticancer activity of genistein on implanted tumor of human primary gastric carcinoma cells in nude mice / 中国病理生理杂志

ABSTRACT

AIM: To investigate the apoptosis of implanted tumor of primary human gastric cancer cells in nude mice induced by genistein and the relation between this apoptosis and expression of bcl - 2 and bax. METHODS: Establishing a transplanted tumor model by injecting human primary gastric cancer cells into subcutaneous tissue of nude mice. The different doses of genistein (0.5mg/kg, 1mg/kg and 1.5 mg/kg ) were directly injected beside tumor body respectively,for six times at an interval of two days. Then changes of tumor volume were measured continuously and tumor inhibition rate of each group was calculated. We observed the morphologic alteration by electron microscope, measured the apoptotic rate by TUNEL staining method, detected the expression of apoptosis - regulated gene bcl - 2 and bax by immunohistochemical staining and RT- PCR. RESULTS: Genistein could significantly inhibit carcinoma growth when it was injected near the carcinoma. Genistein induced implanted tumors cells to undergo apoptosis with apoptotic characteristics by transmission electron microscope. The apoptosis index of above three groups was increased progressively. Positive rate of Bcl - 2 protein of above three groups was decreased progressively and positive rate of Bax protein of above three groups was increased progressively by immunohistochemical staining. The density of bcl -2 mRNA decreased progressively and the density of bax mRNA increased progressively with elongation of time by RT - PCR. CONCLUSION: Genistein is able to induce the apoptosis of transplanted tumor cells. This apoptosis may be mediated by down - regulating bcl - 2 and up - regulating bax mRNA and its protein.