Role of chemokine receptor CXCR4 in sorafenib resistance of renal cell carcinoma / 中华泌尿外科杂志

Objective To investigate the role and possible mechanism of Chemokine receptor CXCR4 in the drug resistance of sorafenib in renal cell carcinoma.Methods 786-O cells were inoculated into the anterior sciatic region of nude mice subcutaneously,5 × 106 cells per point.The mice were given normal saline and sorafenib intragastric (80 mg/kg,1 time/day) when the transplanted tumor volume reached about 100 mm3.The tumor volume in the saline group was more than 1 500 mm3 at the 5th week,and the tumor was taken as the control tissue.Sorafenib group tumors started to grow accelerately at week 8,and the tumor volume was more than 1 500 mm3 at week 13.The 13th week tumors were used as resistant tissue.The expression of CXCR4 in control tissues and drug resistant tissues was detected by real-time quantitative PCR,western blotting and immunohistochemistry.The pcDNA3.1-CXCR4 plasmid was constructed and transfected into 786-O cells.The expression of CXCR4 was detected by real-time quantitative PCR and western blotting.The drug reactivity of the cells was measured by CCK-8 and monoclonal assay to compare the drug resistance of the control group,CXCR4 overexpression group and CXCR4 overexpression + CXCR4 inhibitor AMD3100 group.The phosphorylation of PKB,ERK and STAT3 in the control group,the sorafenib alone group,the overexpressing CXCR4 + sorafenib group and the overexpressing CXCR4 + sorafenib + AMD3100 group were deternined by Western blotting.Results Compared with the control tissues,the mRNA levels of CXCR4 in the drug-resistant tissues increased (3.22 ± 0.23) times,and the levels of protein expression increased (2.33 ± 0.47) according to western blotting,the differences were statistically significant (P ＜ 0.01).After overexpression of CXCR4,the nRNA expression of CXCR4 increased (78.3 ± 5.3) times,and the protein expression level increased (2.80 ± 0.95) times,and the differences were statistically significant (P ＜ 0.01),indicating that the expression model was established successfully.The drug response curves of the control group,CXCR4 overexpression group and CXCR4 overexpression + AMD3100 group on sorafenib were measured by cck8 method,and the ICS0 was (7.5 ±0.8) μmo]/L,(10.3 ±0.7) μmol/L,(5.7 ±0.6) μmol/L,the differences were statistically significant (P ＜ 0.05);The numbers of clones formed in the above three groups were 26 ± 5,56 ± 12 and 42 ± 9,respectively.The differences were statistically significant (P ＜ 0.05).Sorafenib could reduce the phosphorylation of PKB,ERK and STAT3,and overexpression of CXCR4 could reverse the inhibition of phosphatidylation of PKB,ERK and STAT3 by sorafenib.After inhibition of chemokine receptor CXCR4 activity by AMD3100,PKB,ERK,STAT3 phosphorylation was re-suppressed.Conclusions CXCR4 can promote renal cell carcinoma sorafenib resistance.The expression of CXCR4 increased in secondary resistant tumor tissue increased;CXCR4 may promote drug resistance by activating the cell viable pathway.The inhibition of CXCR4 signaling pathway is expected to improve the therapeutic effect of sorafenib in renal cell carcinoma.

Effects of CXCR4 gene transfection on biologicalbehavior of bone marrow mesenchymal stem cells (in vitro) / 中国药理学通报

Aim To observate the effect of chemokine receptor(CXCR4) gene transfection on biological behavior of bone marrow mesenchymal stem cells in vitro.Methods Firstly, bone marrow mesenchymal stem cells were divided into three groups:GFP(transfected GFP into MSCs), CXCR4+(transfected CXCR4+ into MSCs) and CXCR4-(transfected CXCR4-into MSCs) group.Then, their capacity of proliferation, differentiation and migration ability (in vitro) was assessed with immunofluorescence cytochemistry method, flow cytometry assay and Transwell cell chemotaxis test.Results The high or low expression of CXCR4 had no effect on their ability of proliferation and differentiation into lung tissue.Compared with GFP group, however, CXCR4+-MSCs group significantly increased the number of migrating cells, while CXCR4——MSCs group showed no change in the number of migrating cells.Conclusions The proliferation and differentiation capacities are not affected by the high or low expression of CXCR4.The high expression of CXCR4 can significantly enhance the migration ability of MSCs to inflammatory lesions, and the low one has no effect on the migration of the cells.After the transplantation of MSCs, CXCR4′s high expression will access to the lesion area to participate in tissue repairing rapidly and largely, significantly enhancing the therapeutic efficacy.

Inhibiting effects on invasion and metastasis of melanoma by CXCR4 gene silence in nude mice / 中华医学美学美容杂志

ObjectiveTo study the inhibiting effects on the invasion and metastasis of melanoma by CXCR4 gene silence in nude mice.MethodsThe CXCR4 specific recombinant plasmid vector was constructed and transfected into the cultured MV3 cell line with lipofectamine.The models of subcutaneous melanoma in nude mice were established with MV3 cells.The nude mouse model of lung metastasis was established by injection of MV3 cells into the tail vein.The animals were sacrificed at 8weeks after the melanoma cells injection.CXCR4-shRNA plasmid vectors were discontinuously injected directly into the established tumor and vein.The changes of weight and size of the tumors and the mice body weight during the therapy were calculated respectively.Histological observation was performed to evaluate the presence and number of metastatic tumors.ResultsThe subcutaneous melanoma tumors in nude mice were established successfully.The growth of tumors in the CXCR4-shRNA injected nude mice was inhibitted obviously through tumor growth curve. There were significant differences between negative shRNA control nude mice and blank control nude mice (P＜0.01).Melanoma cells with CXCR4 shRNA permanent transfection had a much lower lung and brain and liver metastatic potential in nude mice than control cells and mock control cells in vivo.ConclusionsCXCR4 gene silencing mediated by shRNA significantly suppresses the growth of MV3 cell in vitro.Silencing of CXCR4 mediated by shRNA can also effectively decrease the metastatic potential of lung and liver and brain.

LPS-Induced Migration of Peritoneal B-1 Cells is Associated with Upregulation of CXCR4 and Increased Migratory Sensitivity to CXCL12

B-1 cells, which constitute a predominant lymphocyte subset in serosal cavities and produce most of natural antibodies, are subdivided into the CD5+ B-1a and CD5- B-1b cell subpopulations, but the differential roles of B-1a and B-1b cells are not well understood. We report that B-1a cells preferentially migrate out of the peritoneal cavity and upregulate the expression of CXCR4 with heightened sensitivity to CXCL12 and CXCL13 upon LPS treatment compared to B-1b and B-2 cells. Whereas B-1a cells were slightly more abundant than B-1b and B-2 cells in the homeostatic condition, the number of B-1a cells preferentially decreased 48 hr after LPS treatment. The decrease in the peritoneal B-1a cell number was accompanied with increased migration of B-1a cells toward CXCL-12 and CXCL-13 in in vitro transmigration assay using peritoneal B cells from LPS treated mice. The expression level of CXCR4, but not of CXCR5, was also more prominently increased in B-1a cells upon LPS stimulation. LPS-stimulated B-1a cells did not accumulate in omental milky spots in contrast to B-2 cells. These results suggest that B-1a cells actively migrate out of the peritoneal cavity through the regulation of the migratory responsiveness to chemokines and actively participate in systemic immune responses.

Relationshinp between the expression of CXCR4 and VEGF-C with lymph node metastasis in human rectal cancer / 中国现代普通外科进展

Objective: To explore the relationship between the expressions of chemokine receptor CXCR4 and vascular endothelial growth factor C (VEGF-C ) with lymph node metastasis in human rectal cancer. Methods: Immuohistochemical staining was used to detect the expressions of CXCR4 and VEGF-C in 73 samples of human rectal cancer. The relationship between CXCR4 and VEGF-C in 73 samples of human rectal cancer. The relationship between CXCR4 and VEGF-C expressions was analyzed. Results: The positive rate of CXCR4 expression with lymph node metastasis was higher than that without lymph node metastasis (60.1% vs 23.3%,P