Quantitative analysis and significance of CXCL12 and CXCR4 expression with lymphangiogenesis of pancreatic adenocarcinoma

Abstract

To investigate the expression of CXCL12, its receptor CXCR4 and its correlations with clinical pathology and lymphangiogenesis in pancreatic adenocarcinoma (PAC). The tissue samples were obtained from 30 patients with PAC by surgery between January 2005 and December 2007, which including PAC, the cancerous peripheral tissues, the normal pancreatic tissues and peripheral lymph nodes. The patients age ranged from 35 to 78 years old (median 57.2 years old). The expressions of CXCL12 and CXCR4 in these tissues were assayed by immunohistochemical staining, RT-PCR and fluorescence quantitative real-time PCR. In the immunohistochemical staining, the CXCL12 protein mainly located in the normal pancreatic cell envelopes and/or cytolymphs. In the immunohistochemical staining, the CXCR4 protein mainly located in the cell envelopes and/or cytolymphs of PAC. The results of RT-PCR and fluorescence quantitative real-time PCR indicated that the expression levels of CXCR4 mRNA in PAC tissues, the cancerous peripheral tissues and peripheral lympho nodes were higher than that in the normal pancreatic tissues (P < 0.01). The MLVD in PAC were detected by morphometric analysis respectively. The level of MLVD in III-IV stages was higher than I-II stages of PAC (P < 0.01), and in these cases which had lymphatic metastasis, the level of MLVD significantly increased (P < 0.01). And there was no correlation between the differentiation and histology types of PAC (P > 0.05). There was 22 samples that the CXCR4 protein was positive, and among these samples the MLVD was higher than that in negative group of CXCR4 protein (P = 0.003). The expression of CXCR4 was significantly associated with lymphatic metastasis of PAC, and the higher expression of CXCR4 in PAC tissues was significantly associated with lymphangiogenesis of PAC.