Prognostic value of regulator of G-protein signaling 6 in colorectal cancer.

Reprogrammed metabolism is a hallmark of cancer cells. Regulator of G-protein signaling 6 (RGS6), which is frequently down-regulated in multiple human malignancies, has been demonstrated to play a critical function in energy metabolism, cell apoptosis and tumorigenesis. However, limited knowledge is known about the expression pattern and prognostic value of RGS6 in colorectal cancer (CRC). In this study, we first observed that RGS6 mRNA and protein is commonly downregulated in 32 paired CRC tissues compared with their normal counterparts. Furthermore, by a large scale of immunohistochemical analysis in a tissue microarray containing 310 cases of CRC specimens, we demonstrated that the protein expression of RGS6 expression is downregulated in 40.97% (127/310) samples and detected that decreasing RGS6 expression is closely correlated with enhanced tumor size, CEA level, T classification, TNM stage, and easier lymphatic and distant metastasis. Meanwhile, Kaplan-Meier survival analysis showed that CRC patients with a lower RGS6 expression have a poorer clinical outcome than those with a higher RGS6 expression. Multivariate Cox regression analysis revealed that RGS6, lymphatic metastasis and distant metastasis are the independent prognostic factors for overall survival rate of CRC patients. Taken together, our studies reveal the prognostic value of RGS6 in CRC and support that RGS6 may act as a molecular target for CRC treatment.