The Expression Of P-gp, VEGFR2and Ki-67in Shrna CXCR4Transfected Xenografts In Nude Mice

Objective:To study the the expression of P-gp, VEGFR2and Ki-67in CXCR4inhibited chemo-resistant adenoid cystic carcinoma (ACC) xenograft in vivo,and investigate the biological effects of CXCR4in chemo-resistant ACC.Method:1. The CXCR4-targeting eukaryotic expression vectors were transfectedinto the chemo-resistant daughter cell line NACC-DDP by liposome in vitro.The transfected cells were injected into the parotid gland to establish xenograftmodels.2. The nude mice was randomly divided into4groups as: non-transfectedgroup, null vector group, negative vector control group and CXCR4inhibited(shCXCR4) group. The mice were executed on the35thday after cancer cellimplantation, and pathological sections were prepared3. We deparaffinized tissue sections by dewaxing, hydrating, place thedeparaffinized slides in the antigen retrieval solution and put in the microwave,peroxidase blocking, after that we used1-2drops of primary antibody such asP-gp (1:200), VEGFR2(1:50), and Ki-67, add drops of biotin-labeled secondary antibody working solution, add drops of streptavidin labeled with horseradishperoxidase working solution, add drops of DAB substrate solution,add drops ofhematoxylin,and lastly add drops of gum to fixate the glass slide.Immunohistochemistry was used to detect P-gp, VEGFR2, and Ki-67expression.Results:1. P-gp and VEGFR2mainly expressed in cancer cell plasma. The resultshows that, the expression of P-gp and VEGFR2protein were significantlydecreased in shCXCR4group, compared by non-transfected group, null vectorgroup and negative vector control group (P<0.05).2. Ki-67mainly expressed in nucleus. The result shows that, the expressionof Ki-67protein were significantly decreased in shCXCR4group, compared bynon-transfected group, null vector group and negative vector control group(P<0.05).Conclusion:NACC-DDP cells with interference CXCR4gene significantly slowedtumor growth, reduced the expression of P-gp, VEGFR2, Ki-67significantly,suggesting that interference of the CXCR4gene expression can suppress theproliferation of chemo-resistant adenoid cystic carcinoma; lowered resistanceprotein expresion; has anti-angiogenic effect. Targeted inhibition of CXCR4gene is expected to become a potential therapy for chemo-resistant adenoidcystic carcinoma.