Immunohistochemistry was used to correlate calponin and insulin-like growth factor binding protein-5 (IGFBP-5) RNA levels with protein expression in PDACs and revealed peritumoral calponin staining in the reactive stroma and intense focal staining of islets cells expressing IGFBP-5 at the edge of tumors; thus implicating the interplay of various cell types to promote neoplastic cell growth within pancreatic carcinomas.
Only 5 genes were overexpressed in all carcinomas including fibronectin 1 (FN1), tissue metalloproteinase inhibitor 1 (TIMP1), biglycan (BGN), tenascin-C (HXB), and insulin-like growth factor binding protein 5 (IGFBP5), whereas 16 genes were underexpressed.