Expression Undercurrents of Sonic Hedgehog in Colorectal and Pancreatic Cancers

Purpose: Sonic hedgehog (SHH) protein is a morphogen which functions as a ligand for the SHH pathway, has significant roles during embryonic development. Aberrant activation of the SHH pathway via ligand overexpression has been implicated in many cancers including those of gastrointestinal tract. In this study, we investigated mRNA and protein expression of SHH in colorectal and pancreatic cancers in our population and correlated results with various clinicopathological parameters. Methods: We determined mRNA and protein expression of SHH in sixty-one and thirty-three (n=61) and (n=33) colorectal and pancreatic cancer cases respectively and their histopathologically confirmed adjacent normal tissues using quantitative real-time PCR and western blotting. Results: At the protein level, we found SHH was overexpressed in 29.5% (18/61) and 72.7% (24/33) of colorectal and pancreatic tumour tissues respectively. SHH overexpression was significantly associated with lymph node metastasis and late-stage disease in colorectal cancer and with lymph node metastasis in pancreatic cancer. Conclusion: Our results strongly suggest SHH overexpression may be involved in tumour progression towards a more malignant phenotype. Since SHH protein is significantly upregulated (P > 0.05) in pancreatic cancers than in colorectal cancers it can be an attractive target in cancer therapeutics for treating pancreatic cancer.