The regulatory effects of quercetin combined with DDP on Bcl-2 and Bax expressions in transplanted lung adeno-carcinoma in mice and their significance / 肿瘤

ABSTRACT

Objective: To observe the inhibitory effects of quercetin combined with DDP on the growth of transplanted lung adenocarcinoma LA795 cells in T739 mice and detect the expression levels of Bel-2 and Bax and apoptotic index to explore the action mechanism for the combination therapy. Methods: Thirty-two T739 mice inoculated with LA795 lung adenocarcinoma cells were randomly divided into four groups with 8 mice in each group: control group (A), DDP treatment group (B), quercetin treatment group (C), DDP plus quercetin treatment group (D). The tumor growth was observed on day 16 after drug administration. All mice were sacrificed on day 24 after inoculation. The weight and volume of transplanted tumors were recorded. The expression levels of Bcl-2 and Bax were quantified using immunohistochemical method and image analyzing system. The apoptotic index of transplanted tumors was measured by TdT-mediated dUTP-biotin nick end labeling(TUNEL) method. Results: The growth of transplanted tumors in groups B, C, and D were significantly inhibited. The weight of tumor body in the three groups were markedly lower than that of group A. The tumor inhibitory rates were 38.57%, 26.03%, and 51.58% in groups B, C, and D, respectively. The inhibitory effect of quercetin combined with DDP on tumor growth was enhanced compared with quercetin or DDP alone treatment. The expression of Bcl-2 was significantly higher but Bax was significantly lower in group A compared with group B, C, and D. The difference between the drug therapy groups and control group was significant (P< 0.05 or P<0.01). The apoptotic index was significantly increased in the three drug therapy groups compared with control group and the difference was significant (P<0.01). Conclusion: The combination therapy for quercetin plus DDP significantly suppresses the growth of lung adenocarcinoma cells in mice. The action mechanism may be due to regulation of Bcl-2 and Bax expressions, thereby, inhibiting cell proliferation and inducing apoptosis.