Expression of stromal cell-derived factor 1 and CXCR7 ligand receptor system in pancreatic adenocarcinoma

BACKGROUND Stromal cell-derived factor 1 (SDF-1) is a chemokine that is expressed in some cancer cells and is involved in tumor cell migration and metastasis. CXCR7, a novel receptor for SDF-1, has been identified recently. Research has demonstrated that SDF-1/CXCR7 interaction could play an important role in cancer progression. In this study, we aimed to investigate the expression of the SDF-1/CXCR7 ligand receptor system and the relationship between this expressions and clinicopathological characteristics in pancreatic adenocarcinoma. METHODS Expressions of SDF-1 and CXCR7 in 64 cases of pancreatic adenocarcinoma tissue and 24 cases of normal pancreatic tissue were detected immunohistochemically. RESULTS Expressions of SDF-1 and CXCR7 were negative in normal pancreatic tissues. Respectively, positive expression rates of SDF-1 and CXCR7 in pancreatic adenocarcinoma were 45.3% and 51.6%. The expression of SDF-1 correlated with histological grades; the expression rate in moderate to low differentiation was higher than in high differentiation (P<0.05). The expression of CXCR7 positively correlated with lymph node metastasis (P<0.05). A log-rank test showed that the expression of SDF-1+/CXCR7+ correlated with poor prognosis (P<0.05). CONCLUSIONS The SDF-1/CXCR7 receptor ligand system may take part in invasive progression and metastasis of pancreatic adenocarcinoma, and might be useful as an index for evaluating invasiveness and prognosis.