ABSTRACT
<p><b>OBJECTIVE</b>To investigate the role of B7-H1 expression in IL-10 production, the B7-H1 and IL-10 expression levels in pancreatic carcinoma tissues and to analyze the correlation between B7-H1 expression and IL-10 level.</p><p><b>METHODS</b>The mRNA and protein levels expressions of B7-H1 and IL-10 in 35 cases of pancreatic cancer and corresponding paracarcinoma tissues and 5 cases of normal pancreas tissues were detected by RT-PCR, Western blot and immunohistochemistry respectively.</p><p><b>RESULTS</b>The findings for the first time provided the evidences that there was a clear trend for B7-H1 and IL-10 expressions to be most highly expressed in carcinoma tissue, intermediately expressed in paracarcinoma tissue, and expressed at the lowest level in normal pancreatic tissue at mRNA and protein levels. Moreover, there were statistically significant differences in B7-H1 and IL-10 expression between pancreatic carcinoma tissues, corresponding paracarcinoma tissues and normal pancreatic tissues at mRNA and protein levels (P < 0.05). Furthermore, the immunohistochemistry indicated that there were high expression levels of B7-H1 (60.5% +/- 12.7%) and IL-10 (65.3% +/- 16.2%) in pancreatic carcinoma tissues while there were no significant expressions in normal pancreatic tissues. Meanwhile, correlation analysis revealed that B7-H1 expression was significant associated with IL-10 level in tumor tissues at mRNA (P = 0.008, r = 0.841) and protein levels (P = 0.007, r = 0.838).</p><p><b>CONCLUSIONS</b>Over-expression of B7-H1 may be responsible for the increasing IL-10 production in pancreatic cancer, which caused reduced immune response to tumor cells and contributed to pancreatic carcinoma escape from immune attack.</p>