Enhanced expression of resistin-like molecule beta in human colon cancer and its clinical significance

Previous studies have indicated that resistin-like molecule beta (RELM beta), an intestinal goblet cell-specific protein, is markedly increased in the intestinal tumors of min mice and over-expressed in a human colon cancer cell line. We hypothesized that RELM beta might be enhanced in human colon cancer. The aim of this study was to examine the clinical importance of RELM beta expression in colon cancer patients and to correlate its expression with various clinicopathological parameters, upstream regulatory molecule expression, tumor proliferative capacity, and patients' survival. Of the 80 colon cancer patients studied, 65 (81.25%) tested positive for RELM beta, mainly in the cytoplasm of colon mucosa. Contrasting sharply with the strongly RELM beta-positive tumors, normal colon mucous membrane was negative or weakly positive. RELM beta positivity in colon cancer was correlated with histological grade of differentiation and lymph node metastasis, but not with age, gender, tumor location and size, tumor infiltration, Dukes' stage, liver metastasis, and venous invasion. RELM beta expression was significantly correlated with the expression of transcription factor CDX-2 (P < 0.01) but not with that of proliferative index Ki-67 (P > 0.05). The mean postoperative survival time (2.76 years) of RELM beta-positive patients was significantly longer than that (1.26 years) of RELM beta-negative patients (P = 0.032). These findings support evidence of the enhanced RELM beta expression in colon cancer patients and suggest that further investigation is warranted to explore the role of RELM beta in colon cancer.