Role of ghrelin axis in colorectal cancer: a novel association

Recently discovered orexigenic peptide, ghrelin, which is primarily produced by gastrointestinal tract, has been implicated in the malignant cell proliferation and invasion, presumably through an autocrine/paracrine mechanism. This study was aimed to identify the role of endogenously produced ghrelin in colorectal cancer progression. Malignant intestinal epithelial cells differentially over-express ghrelin receptors and produce more ghrelin as compared to normal human colonocytes, leading to their enhanced proliferative and invasive behavior. Though, systemically available endocrine ghrelin levels in patients with colorectal cancer do not exhibit significant correlation with any tumor stage or grade, however, locally produced autocrine tissue ghrelin strongly correlates both with advancing colorectal malignancy in a stage-dependent manner and BMI of the colorectal patients. We conclude that ghrelin might play an important role in promoting colorectal malignancy.