The Expression Of Chemokine Receptor CXCR4and CXCR7in Esophageal Cancer

Effect of CXCR4and CXCR7on biological behavior of human esophageal cancer cell linesObjective:To investigate the expression levels of chemokine receptor CXCR4and CXCR7in human esophageal cancer cell lines Eca109and CaEs-17; To explore their potential role and mechanisms in cell proliferation, invasiveness and apoptosis.Methods:The expression levels of CXCR4and CXCR7in esophageal cancer cell lines Eca109, CaEs-17were showed by real-time PCR, Western blot and flow cytometeric analysis. To specifically silence CXCR4and CXCR7expression through trasfectin recombinant plasmid of CXCR4shRNA and CXCR7shRNA into Eca109cells. The protein level of CXCR4and CXCR7in Eca109cells transfected with shCXCR4and, shCXCR7were detected by Western blot and flow cytometeric analysis. Effect of CXCR4and CXCR7on the cell proliferation, invasiveness, cell cycle distribution and-apoptosis in Eca109cell line were investigated by CCK-8, transwell assay and flow cytometric analysis. The potential signaling pathways were detected by Western blot.Results:CXCR4and CXCR7were differentially expressed in human esophageal cancer cell lines. In vitro test showed that reduction of CXCR4and CXCR7in Eca109cells reduces the ability of cell proliferation and invasion by CCK-8test and Transwell assay while cell cycle distribution and apoptosis were not changed; Western blot showed that down-regulated CXCR4and CXCR7in Eca109cell line can obviously restain the expression level of RhoA, Rac-1and Cdc42, meanwhile the phosphorylation of Akt and ERK proteins were suppressed, too; Using CXCL12to stimulate Eca109cell line, Western blot showed that downregulation of CXCR4and CXCR7can obviously inhibit the upregulation level of those proteins; Using Akt and MEK inhibitor to block Akt and ERK signaling pathways, Western blot showed that the expression level of RhoA, Rac-1and Cdc42were upregulated with the phosphorylation of Akt.Conclusion:CXCR4and CXCR7were different expressed in human esophageal cancer cell lines. Reduction of CXCR4and CXCR7in Eca109can reduce cells’ ability of proliferation and invasion while has no effect on cell cycle distribution and apotosis. Down-regulated CXCR4and CXCR7in Eca109cell line can obviously restain the chemotactic response to CXCL12, which is through PI3K/Akt pathway to reduce the expression levels of RhoA, Rac-1and Cdc42. Effect of CXCR4and CXCR7silencing on tumor growth of Eca109cells xenograft in nude miceObjective:To explore the impact on CXCR4and CXCR7silencing on tumor growth of Eca109cells xenograft in nude mice.Methods:To specifically silence CXCR4and CXCR7expression through trasfectin recombinant plasmid of CXCR4shRNA and CXCR7shRNA into Eca109cells. The Eca109cells, Eca109/shCtl cells, Eca109/shCXCR4cells and Eca109/shCXCR7cells were subcutaneously injected in the left flank of each mouse respectively. Tumor sizes were measured weekly as soon as tumors were measurable. On day35, mice were sacrificed, and tumors were measured right after being dissected. Tumor tissue sections were prepared and immunostainging was analyzed using CD34antibody for calculation of MVD. The CXCL12expression levels of xenografts were tested by Western blot.Results:Tumor growth was significantly inhibited in CXCR4and CXCR7down-regulation groups compared to control and wild-type groups. Furthermore, the cells stably transfected with CXCR4shRNA and CXCR7shRNA showed significantly reduced expression of CD34and decreased MVD compared with control and wild-type groups. The expression levels of CXCL12of xneografts were down-regulation in Eca109/shCXCR4and Eca109/shCXCR7groups compared with the other two groups.Conclusions:Down-regulation of CXCR4and CXCR7can significantly inhibit tumor growth of Eca109cells xenograft in nude mice. Silencing of CXCR4and CXCR7substantially suppressed angiogenesis and the secretion of CXCL12to inhibit tumor growth. CXCR4and CXCR7may be a potential target for treatment of esophageal cancer. The clinical significance of CXCR7expression in esophageal squamous cell carcinomaObjective:To evaluate the clinical feature and prognostic impact of the expression of the chemokine receptor7(CXCR7) in patient with esophageal squamous cell carcinoma (ESCC).Methods:Expression of CXCR7in specimens from154patients with ESCC and49specimens of normal esophageal squamous epithelium tissue were evaluated by immunochemistry staining and matched with clinicopathological parameters and survival.Results:Expression of CXCR7was higher in ESCC than in the normal tissues (p<0.001). High expression of CXCR7was associated with tumor depth (P=0.009), lymph nodes metastasis (P<0.001) and pTNM stage (P=0.001). Univariate analysis indicated that patient’s sex (p=0.030), age (p=0.049), tumor depth (p<0.001), lymph node metastasis (p<0.001), pTNM stage (p<0.001) and the expression of CXCR7are prognosis factors for ESCC patients. Multivariate analysis indicated that pTNM stage (p=0.017) and the expression of CXCR7(p=0.006) are independent prognosis factors.Conclusions:There was significant correlation among the expression of CXCR7and the prognostic impact in patients with ESCC. It revealed that CXCR7expression status might be potential prognostic indicators for patitents with ESCC.