Expression of Glucose Transporter Gene in Colorectal Cancer

Lee, Suk Hwan; Park, Jae Hoon; Kim, Yoon Wha; Oh, Soo Myung; Yoon, Choong; Joo, Hoong Zae; Lee, Kee Hyung

Abstract

PURPOSE
The primary metabolic characteristic of malignant cells is an increased uptake of glucose and its anaerobic glycolysis. Recent studies have demonstrated that facilitative glucose transport across the plasma membrane is mediated by a family of proteins, i.e., glucose transporters. PURPOSE: In order to evaluate the clinicopathologic correlations of glucose transporter genes expressed in colorectal cancer, the author studied the expression of glucose transporter genes in human colorectal cancer and analyzed their expression in normal and malignant colorectal tissues.
METHODS
A reverse transcriptase-polymerase chain reaction (RT-PCR) was applied to quantitatively determine the levels of the glucose transporter genes, GLUT1 and GLUT3, from Crohnes diseases (N=2), adenomatous polyps (N=4), and colorectal cancers (N=40) and their normal counterparts.
RESULTS
The expresssion of the GLUT1 gene was detected in 50% of the inflammatory colonic mucosae and adenomatous polyp tissues, but the levels of expression were not significantly different from their normal counterparts. Among the 40 colorectal cancer patients, 23 patients (57.5%) showed GLUT1 gene expression and the levels of expression were increaed by 1.8 as compared to their normal counterparts (p<0.05). The expression of the GLUT3 gene was detected in almost all tissues examined, and the levels of expression were not significantly different from their normal counterparts. In colorectal cancers, there was correlation between GLUT1 expression, the extent of lymph node involvement and the stage of colorectal cancers (p<0.05). But, the correlation between the expressions of the GLUT3 gene and the clinicopathologic prognostic factors of colorectal cancers could not be determined because almost all tissues showed a GLUT3 gene expression.
CONCLUSIONS
In conclusion, the GLUT1 glucose transporter expression in colorectal cancer was associated with high possibilities of lymph node metastases and poorer prognosis, and the assessment of GLUT1 expression in colorectal cancer would be useful in identifying high risk patients.