mRNA Expression of IGF-1 and IGF-1R in Patients with Colorectal Adenocarcinoma and Type 2 Diabetes.

Background and Aims: Increasing studies show that messenger RNA (mRNA) levels of local IGF-system are overexpressed in cancer tissue of patients with colorectal cancer (CRC). However, the influence of type 2 diabetes (T2DM) on the expression of insulin-like growth factor-1 (IGF-1) and IGF-1 receptor (IGF-1R) mRNA in colorectal cancer tissue and adjacent non-cancerous tissue (ANCT) is unknown. The aim of this study was to assess mRNA expression of IGF-1 and IGF-1R in paired samples of cancer tissue and ANCT between colorectal adenocarcinoma (CA) patients with and without T2DM. Methods: To quantify the levels of IGF-1 and IGF-1R mRNA in CA, we analyzed the expression of IGF-1 and IGF-1R mRNA levels in paired samples of cancer tissue and ANCT in CA patients with and without T2DM using real-time reverse transcription-polymerase chain reaction (RT-PCR). Results: mRNA levels of IGF-1 and IGF-1R were significantly higher in cancer tissue compared with its ANCT in CA patients with and without T2DM. Compared with the CA group, significantly higher levels of IGF-1 and IGF-1R mRNA were observed in cancer tissue in CA with T2DM group. No significant differences were observed in the role of cancer locations, Dukes stages and diabetes duration on mRNA expression of IGF-1. After adjusting for age, gender and Dukes stages, multivariate analysis indicated IGF-1 mRNA level was a risk factor for prognosis (p <0.05). Conclusions: Our results support the hypothesis that IGF system plays an important role in CRC. Further larger studies are needed. [Copyright &y& Elsevier]