Growth Hormone Receptor Expression is Up-Regulated During Tumorigenesis of Human Colorectal Cancer

BackgroundThe aim of the present study was to analyze the expression of growth hormone receptor (GHR) in the colorectal adenoma-carcinoma sequence to determine whether its expression correlates with the various stages of cancer transformation.MethodsGHR distribution was assessed by immunohistochemistry and semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR) in normal, premalignant, and malignant colorectal lesions.ResultsMost of the normal mucous tissues and hyperplastic polyps showed no or weak immunoreactivity for GHR. In contrast, most of the adenoma and adenocarcinoma samples reacted strongly or moderately with monoclonal GHR antibodies. In RT-PCR, amplified fragments of the expected sizes (247bp) were detected in 90 of 90 samples examined, and the semiquantitative RT-PCR result showed an up-regulation of GHR mRNA expression during the polyp-adenoma-carcinoma sequence, which was consistent with the immunohistochemical results.ConclusionsOur results suggest that growth hormone/GHR plays a role in the development of colorectal carcinoma.