Silencing of CXCR4 and CXCR7 expression by RNA interference suppresses human endometrial carcinoma growth in vivo

In this paper, the effect of silencing the expression of CXCR4 and CXCR7 by RNAi on the growth of endometrial carcinoma (EC), in vivo, was evaluated. To establish endometrial carcinoma model, thirty nude mice were subcutaneously inoculated with 1 × 10⁷ Ishikawa cells. All tumor-bearing mice were randomly assigned to five groups (six mice in each group) when the tumor xenografts reached 5-7 mm in diameter, and treated with CXCR4-siRNA (5 nmol), CXCR7-siRNA (5 nmol), CXCR4-siRNA (5 nmol) plus CXCR7-siRNA (5 nmol), negative-siRNA (5 nmol) and normal saline, respectively. Following intra-tumor injection, the growth rate of tumor xenografts in the three treatment groups was significantly delayed compared with those in Ne-si and NS group (P<0.05). The results of QRT-PCR and immunohistochemical assessment showed that the expression levels of CXCR4 and CXCR7 could be down regulated by RNA interference. We also observed that treatment with CXCR4-siRNA and CXCR7-siRNA reduced cell proliferation, but there was no significant difference in apoptosis among the five groups. CXCR4 and CXCR7 silencing by RNAi inhibit the growth of human endometrial carcinoma xenografts by inhibiting cancer cell proliferation, in vivo. These results indicate that CXCR4 and CXCR7 could serve as potential alternative targets for gene therapy in endometrial carcinoma.