ABSTRACT
ABSTRACT:Objective To investigate the effect of SDF-1/CXCR7 on inflammatory cytokine synthesis and secretion in gastric cancer SGC-7901 cells.Methods CXCR7 gene in SGC-7901 cells was silenced by shRNA lentiviral vector and the expression of CXCR7 was detected using Western blot and Real-time PCR.There were four groups as follows:LV-shRNA-NC,LV-shRNA-NC+SDF-1,LV-shRNA-CXCR7,and LV-shRNA-CXCR7+SDF-1 groups.Real-time PCR was used to detect the mRNA expressions of TNF-α,IL-1β,IL-6 and IL-8.ELISA was used to detect the protein levels of TNF-α,IL-1β,IL-6 and IL-8 in the culture supernatant.Western blot was used to detect the protein expressions of NF-κB pathway.Results ① Transfection of SGC-7901 cells with CXCR7-shRNA lentiviral vector resulted in a significantly decreased expression of CXCR7 at both mRNA and protein levels (all P<0.01).② Compared with those in LV-shRNA-NC group,IL-6 and IL-8 mRNA expressions and protein levels in the culture supernatant were increased in LV-shRNA-NC+SDF-1 group (P<0.01 )and decreased in LV-shRNA-CXCR7 group (P<0.05).Compared with those in LV-shRNA-NC+SDF-1 group,the expressions of IL-6 and IL-8 at mRNA and protein levels in the culture supernatant were significantly cut down in LV-shRNA-CXCR7+SDF-1 group (P<0.01 ).However,the expressions of TNF-αand IL-1βat mRNA and protein levels in the culture supernatant were not significantly changed by SDF-1 and CXCR7 shRNA.③ The protein expressions of nuclear NF-κB p65,t-IκBαand p-IκBαexhibited no significant differences among the four groups.Conclusion SDF-1/CXCR7 can promote the synthesis and secretion of inflammatory cytokines IL-6 and IL-8 in gastric cancer SGC-7 9 0 1 cells through an NF-κB-independent pathway.
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the expression status of CXCR7 in gastric cancer tissues and cell lines.</p><p><b>METHODS</b>The expression status of CXCR7 was detected in 35 primary gastric cancer tissues and matched adjacent tissues by immunohistochemistry and RT-PCR. The correlation of CXCR7 expression with the clinicopathological parameters and risk factors of gastric cancer was analyzed. The expression of CXCR7 in gastric cell lines (HGC-27, MGC-803, BGC-823, SGC-7901 and MKN-28) was also detected by immunofluorescence assay.</p><p><b>RESULTS</b>The expression of CXCR7 was significantly higher in gastric cancer tissues than in adjacent tissues (P<0.01). CXCR7 expression was not correlated with age, gender, smoking history, Helicobacter pylori infection, tumor location or the pathological type, but showed a higher expression level in patients with a alcohol-drinking history than in those without (P<0.05). CXCR7 was expressed with variable intensities in the 5 gastric cancer cell lines without correlation with the degrees of cell differentiation; its expression was the highest in SGC-7901 cells, a moderately differentiated human gastric adenocarcinoma cell line.</p><p><b>CONCLUSIONS</b>CXCR7 is highly expressed in gastric cancer tissues with variable intensities in 5 gastric cancer cell lines, suggesting its important role in gastric cancer progression.</p>