Mal, T-cell differentiation protein (MAL) is a candidate tumor suppressor gene that functions in membrane trafficking processes in polarized epithelial cells. The aim of the present study was to determine its clinical significance in colorectal cancer (CRC). The RNA and protein expression levels of MAL in 30 colorectal specimens were detected by semi-quantitative polymerase chain reaction and immunohistochemistry analysis. Statistical analysis was performed using SPSS software. The RNA level of MAL was significantly downregulated in the CRC tissues compared with the adjacent healthy tissue (P<0.05). MAL was only positively expressed in 20% of the CRC tissues, but in 66.7% of the adjacent tissues, as determined by immunohistochemistry analysis. The expression of the MAL RNA transcript exhibited a positive correlation with protein expression. The expression levels of MAL were significantly associated with different tumor-node-metastasis stages and lymph node metastasis (P<0.05), but not with age, gender, tumor site, differentiation status and pathological type (P>0.05). Suppression of MAL expression was significantly correlated with metastasis in CRC. The present study indicated that MAL may function as an anti-metastasis factor and represent a potential biomarker for malignant colorectal tumors.
Keywords: MAL; colorectal cancer; metastasis.