[Anti-tumor mechanism of norcantharidin for the implanted tumors of human gallbladder carcinoma in nude mice in vivo].

OBJECTIVE: To explore the anti-tumor mechanism of norcantharidin (NCTD) for the implanted tumors of human gallbladder carcinoma in nude mice in vivo.

METHODS: Animal model of implanted tumors of human gallbladder carcinoma in nude mice was established. Mice were randomly divided into control, 5-FU, NCTD and NCTD + 5-FU groups and were taken different treatment. The expressions of PCNA, Ki-67, cyclin D1, p27, Bcl-2, Bax, Survivin, nm23/nm23-H1, MMP2 and TIMP2 proteins or genes in each tissue section of every group were determined by immunohistochemistry and RT-PCR.

RESULTS: (1) On proliferation-related gene proteins, the expression of PCNA, Ki-67, cyclin D1 was significantly decreased, with significantly increased expression of p27 protein, in paraffin sections of NCTD group when compared with control group (P < 0.05); The expression of PCNA mRNA, cyclin D1 mRNA was decreased, with significantly increased expression of p27 mRNA in NCTD group. (2) On apoptosis-related gene proteins, the expression of Bcl-2 was significantly decreased in paraffin sections of NCTD group when compared with control group (P < 0.05); The expression of Bcl-2 mRNA, Survivin mRNA was significantly decreased, with significantly increased expression of Bax mRNA in NCTD group. (3) There was significant difference on invasion around tumor and lung metastasis in NCTD group when compared with control group (P < 0.01). On metastasis-related gene proteins, the expression of nm23 and TIMP2 was significantly increased, with significantly decreased expression of MMP2 in paraffin sections of NCTD group when compared with control group (P < 0.05); The expression of nm23-H1 mRNA, TIMP2 mRNA was significantly increased, with significantly decreased expression of MMP2 mRNA in NCTD group.

CONCLUSIONS: The anti-tumor mechanism of NCTD for human gallbladder carcinoma in nude mice might correlated with inhibition of cell proliferation, blockage of cell cycle, induction of cell apoptosis, reducing of cell motility and invasive capability, alteration of the expression of proliferation-, apoptosis- and metastasis-related gene proteins such as PCNA, Ki-67, cyclin D1, p27, Bcl-2, Bax, Survivin, nm23, MMP2 and TIMP2.