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BACKGROUND AND OBJECTIVES: Information about the role of the stromal cell-derived factor-1α (SDF-1α)/chemokine receptor type 4 (CXCR4) axis in ischemic postconditioning (IPOC) is currently limited. We hypothesized that the SDF-1α/CXCR4 signaling pathway is directly involved in the cardioprotective effect of IPOC. METHODS: Isolated rat hearts were divided into four groups. The control group was subjected to 30-min of regional ischemia and 2-hour of reperfusion (n=12). The IPOC group was induced with 6 cycles of 10-second reperfusion and 10-second global ischemia (n=8) in each cycle. The CXCR4 antagonist, AMD3100, was applied before reperfusion in the IPOC group (AMD+IPOC group, n=11) and control group (AMD group, n=9). Hemodynamic changes with electrocardiography were monitored and infarct size was measured. The SDF-1α, lactate dehydrogenase (LDH) and creatine kinase (CK) concentrations in perfusate were measured. We also analyzed extracellular signal-regulated kinase 1/2 (ERK1/2) and Akt phosphorylation state expression. RESULTS: IPOC significantly reduced infarct size, but AMD3100 attenuated the infarct reducing effect of IPOC. IPOC significantly decreased LDH and CK, but these effects were reversed by AMD3100. ERK1/2 and Akt phosphorylation increased with IPOC and these effects were blocked by AMD3100. CONCLUSION: Based on the results of this study, SDF-1α/CXCR4 signaling may be involved in IPOC cardioprotection and this signaling pathway couples to the ERK1/2 and Akt pathways.
Subject(s)
Animals , Rats , Creatine Kinase , Electrocardiography , Family Characteristics , Heart , Hemodynamics , Ischemia , Ischemic Postconditioning , L-Lactate Dehydrogenase , Phosphorylation , Phosphotransferases , Receptors, CXCR4 , Reperfusion , Reperfusion InjuryABSTRACT
Objective To investigate the nuclear expression of CXC chemokine receptor 4 (CXCR4) in renal cancer, and analyze its relation with renal cancer metastasis and prognosis. Methods A total of 413 patients with renal cancer who were treated in our urologic center from Mar. 2011 to Nov. 2012 were included in the present study. The subcellular expression of CXCR4 was examined by immunofluorescence staining; the correlation between CXCR4 nuclear location and clinical features, prognosis was analyzed. Results We found that 170 of the 413 renal cancer patients were CXCR4 nuclear staining-positive (group A), and the rest 243 cases were CXCR4 nuclear staining-negative (group B); the two groups had matchable baseline data. Compared with group B, group A had significantly higher Robson stage (P <0.01), more frequent cancer embolus (P <0.01), more frequent lymphatic metastasis (P <0.01), and more frequent distant metastasis (P <0.01). The overall survival rate of group A (86.5%, 147/170) was significantly lower than that of group B (97.1%, 236/243; P <0.001). Conclusion Nuclear expression of CXCR4 in renal cancer tissues is associated with higher Robson stage, more frequent cancer embolus, more frequent lymphatic metastasis, more frequent distant metastasis and poor prognosis.
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Objective To transfect CXCR4 and enhanced green fluorescent protein (EGFP)-CXCR4 plasmids into renal carcinoma cell line A498 cells to preparecell lines stably expressing CXCR4. Methods Two specific plasmids containing CXCR4 or EGFP-CXCR4 were transfected into renal cell carcinoma cell line A498. Then the cells stably expressing CXCR4 were screened by using G418. Confocal microscopy was used to observe the changes of EGFP-CXCR4 fusion protein in A498 cells before and after stimulation with SDF-1. Western blotting analysis was used to determine CXCR4 expression after transfection. Proliferation of A498 cells was detected by MTT and the invasion ability of cells was detected by transwell assay. Results The sequencing result of two plasmids was consistent with CXCR4 DNA sequence, and two cell lines were screened out by G418 screening after the plasmids were transfected into A498 cells. EGFP-CXCR4 fusion protein was found in the cell membrane and cytoplasm of EGFP-CXCR4 transfection group under confocal microscopy. EGFP-CXCR4 migrated into cells after SDF-1 stimulation. Western blotting analysis revealed higher CXCR4 expression in A498 cells stably transfected with CXCR4 plasmids compared with normal A498 cells. The proliferation of cells in pCNDA-CXCR4 and pEGFP-CXCR4 groups were significantly higher than that in normal A498 cell group (P<0. 01). Transwell assay showed that the cell invasion ability of cells with stable CXCR4 expression was significantly increased compared with that in the normal A498 cell group (P<0. 01). Conclusion We have successfully established A498 cell lines stably expressing CXCR4, which have enhanced proliferation levels and higher invasive ability.
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Objective To investigate the anti-tumor effect of doxycycline against ovarian cancer cells and the underlying mechanism. Methods MTT assay was used to test the tumor cell viability after treated with doxycycline alone or in combination with cisplatin. RT-RCR was used to examine CXCR4 mRNA expression in H08910 cells. Western blotting analysis was used to determine CXCR4 protein expression after doxycycline treatment. Results Treatment with low dose of doxycycline (10 ¡j.g/mL) for 48 hours notably inhibited the proliferation of ovarian cancer cell H08910 (P<0. 01), with the inhibition rate being (70±2) % when doxycycline concentration was at 50 jg/mL. Doxycycline combined with cisplatin had greater inhibitory effect against H08910 cells compared with cisplatin alone at the same concentration. Doxycycline treatment down-regulated CXCR4 expression in H08910 cells. Conclusion Doxycycline has a definite inhibitory effect against proliferation of ovarian cancer H08910 cells, and it can increase the sensitivity of tumor cells to cisplatin, which may involve SDF-1/CXCR4 signaling pathway.
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Objective To discuss the relationship of CXCR4 expression with clinical pathology, post-operative metastasis, recurrence and prognosis of gastric cancer patients. Methods A total of 141 gastric cancer tissues and the corresponding adjacent tissues were taken from patients who were treated in the Department of General Surgery, The Affiliated Provincial Hospital of Anhui Medical University between November 2007 to November 2008. Immunohistochemistry was performed to detect the CXCR4 expression in the gastric cancer tissues and adjacent tissues, the relationship of CXCR4 expression with clinical pathology of the patients was analyzed. The relationship of CXCR4 expression with recurrence and prognosis was analyzed based on a 3 year-follow-up. Results The positive rate of CXCR4 was 60 3% (85/141) in gastric cancer tissues, which was significantly higher than that in the corresponding adjacent tissues 26. 2% (37/141, P<0. 05). CXCR4 expression in the gastric cancer tissues was positively correlated with the TNM stage, depth of invasion, invasion of the pancreas capsule, and lymphatic metastasis (P<0 05). Logistic multivariate regression analysis showed that lymphatic metastasis and recurrence after surgery were correlated with the expression of CXCR4 in gastric cancer tissues(P<0. 05). The 3-year survival rate of patients with CXCR4 expression was significantly lower than patients without CXCR4 expression(43. 1% vs 56. 6%,P<0 05). Conclusion CXCR4 is over-expressed in gastric cancer tissues, and the expression is positively correlated with the lymphatic metastasis and recurrence after surgery. CXCR4 positive patients have a lower survival rate than patients without CXCR4 expression, all these makes CXCR4 a possible molecular marker for lymphatic metastasis, postoperative recurrence and prognosis in gastric cancer.
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Objective: To investigate the expression of chemokine receptor CXCR4 in hepatocellular carcinoma tissues, hepatocellular carcinoma cell line-MHCC97,human umbilical vein endothelial cells (HUVECs) and the ascites level of CXCL12, ligand of CXCR4, so as to lay a foundation for studying the role of CXCR4 in the metastasis of hepatocellular carcinoma. Methods: The expression of CXCR4 mRNA and protein was examined by RT-PCR and Western blotting in 21 specimens of hepatocellular carcinoma tissues,MHCC97 cells,HUVECs,and 17 specimens of normal hepatic tissues. Meanwhile,the levels of CXCL12 in ascitic fluids were assayed by ELISA in 18 hepatic cancer patients. Results: The relative expression values of CXCR4 mRNA in hepatocellular carcinoma tissues, MHCC97 cells, and HVECs were 2.21 ± 1.09, 2.14 ± 1.15 and 1.72 ± 1.20, respectively; and those of CXCR4 protein were 1.51 ± 0.12, 1.76 ± 0.25, and 1.89 ± 0.24, respectively; and those of CXCR4 protein were 1.51 ± 0.12, 1.76 ± 0.25, and 1.89 ± 0.24, respectively. CXCR4 mRNA and protein were not detected in normal hepatic tissues. ELISA results showed that the 18 hepatocellular carcinoma samples had a CXCL12 concentration range of 783-8 364 pg/ml (median value 6 871 pg/ml) in ascitic fluids. Conclusion: CXCR4 is highly expressed in the hepatocellular carcinoma tissues and cells, which is not associated with the clinical staging of the cancer. The elevated CXCL12 level in the ascitic fluid of cancer patients indicate that CXCR4 may play an important role in the metastasis of hepatocellular carcinoma.
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BACKGROUND: Expression of CXCR4 chemokine receptor, initially described to be involved in the homing of lymphocytes in inflammatory tissue, on breast cancer cell lines is associated with the development of lung metastases. In the present study, we evaluated CXCR4 expression in patients with non-small cell lung cancer (NSCLC). METHODS: Tissue microarray blocks were constructed from 408 formalin-fixed, paraffin-embedded NSCLC samples and analyzed via immunohistochemical staining. RESULTS: We observed CXCR4 expression in 214 (66.3%) of the 323 tumors with cytoplasmic or nuclear staining patterns. These tumors were then divided into 109 negative, 166 weak-positive and 48 strong-positive expression groups. Strong expression of CXCR4 correlated with NSCLC recurrence (p=0.047) and distant metastasis (p=0.035). However, lymph node metastasis (p=0.683) and locoregional recurrence (p=0.856) were not associated with CXCR4 expression. Interestingly, the median overall survival times relative to CXCR4 expression were 71 months in the CXCR4-negative group, 43 months in the weakly positive CXCR4 group and 23 months in the strongly positive CXCR4 group. Strongly positive CXCR4 staining was associated with significantly worse outcomes (p=0.005, log-rank test). CONCLUSIONS: Expression of CXCR4 was associated with distant NSCLC metastases and shorter survival times.
Subject(s)
Neoplasm Metastasis , Breast Neoplasms , Lung NeoplasmsABSTRACT
Objective:To investigate the expression of chemokine receptor CXCR4 in hepatocellular carcinoma tissues,hepatocellular carcinoma cell line-MHCC97,human umbilical vein endothelial cells(HUVECs)and the ascites level of CXCL12,ligand of CXCR4,so as to lay a foundation for studying the role of CXCR4 in the metastasis of hepatocellular carcinoma.Methods:The expression of CXCR4 mRNA and protein was examined by RT-PCR and Western blotting in 21 specimens of hepatocellular carcinoma tissues,MHCC97 cells,HUVECs,and 17 specimens of normal hepatic tissues.Meanwhile,the levels of CXCL12 in ascitic fluids were assayed by ELISA in 18 hepatic cancer patients.Results:The relative expression values of CXCR4 mRNA in hepatocellular carcinoma tissues,MHCC97 cells,and HVECs were 2.21?1.09,2.14?1.15 and 1.72?1.20,respectively;and those of CXCR4 protein were 1.51?0.12,1.76?0.25,and 1.89?0.24,respectively;and those of CXCR4 protein were 1.51?0.12,1.76?0.25,and 1.89?0.24,respectively.CXCR4 mRNA and protein were not detected in normal hepatic tissues.ELISA results showed that the 18 hepatocellular carcinoma samples had a CXCL12 concentration range of 783-8 364 pg/ml(median value 6 871 pg/ml)in ascitic fluids.Conclusion:CXCR4 is highly expressed in the hepatocellular carcinoma tissues and cells,which is not associated with the clinical staging of the cancer.The elevated CXCL12 level in the ascitic fluid of cancer patients indicate that CXCR4 may play an important role in the metastasis of hepatocellular carcinoma.