[Expression and clinical significance of Tspan 1 and Integrin α6 in human pancreatic ductal adenocarcinoma].

OBJECTIVE: To explore the clinicopathological significance and relationship of Tspan 1 and Integrin α6 expression in pancreatic ductal adenocarcinoma (PDAC) tissue and pancreatic cancer cell lines.

METHODS: Immunohistochemistry was used to detect the expression of Tspan 1 and Integrin α6 in 95 paraffin-embedded PDAC specimens and 55 adjacent non-cancerous pancreatic tissues which were collected from May 2004 to January 2013.Western blot and quantitative real-time polymerase chain reaction (qRT-PCR) were used to detected the protein and mRNA expression in 16 paired fresh PDAC specimens of the pancreas and adjacent non-cancerous pancreatic tissues and 6 different pancreatic cancer cell lines.χ(2) test, Spearman-rank correlation analysis, Kaplan-Meier method and multivariate Cox regression analysis were used to analyze the data.

RESULTS: Tspan 1 and Integrin α6 were significantly over-expressed in PDAC than in adjacent non-cancerous pancreatic tissues (χ(2) = 7.429, P < 0.05; χ(2) = 15.1, P < 0.01). Lymph node metastasis, TNM stage and post-operation recurrence were positively correlated with the expression of Tspan 1 (χ(2) = 6.688, P < 0.01; χ(2) = 13.055, P < 0.01; χ(2) = 6.116, P < 0.05) . TNM stage was positively correlated with the expression of Integrin α6 (χ(2) = 8.896, P < 0.05) . Tspan 1 was correlated with Integrin α6 (r = 0.223, P < 0.05) . The expressions of Tspan 1 and Integrin α6 were negatively correlated with survival time (χ(2) = 5.263, P < 0.05;χ(2) = 10.124, P < 0.01) . Multivariate analysis revealed that Tspan 1 and Integrin α6 expressions were independent prognostic factors in PDAC patients (χ(2) = 6.152, P < 0.05; χ(2) = 9.479, P < 0.01). Western blot (t = 2.278, P < 0.05; t = 3.153, P < 0.05) and qRT-PCR (t = 2.439, P < 0.05; t = 3.258, P < 0.05) showed that Tspan 1 and Integrin α6 expressions were higher in PDAC tissues than in adjacent non-cancerous pancreatic. Tspan 1 and Integrin α6 were expressed in all six pancreatic cancer cell lines.In SW1990 which derived from metastasis PDAC, Tspan 1 and Integrin α6 expressions were higher than the cell lines from primary tumor.

CONCLUSION: Tspan 1 and Integrin α6 expression can up-regulate the invasion and metastasis of PDAC and may be used to predict the prognosis of PDAC.