Expression of transketolase-like 1 protein (TKTL1) in human endometrial cancer

Abstract

Background: Malignant tumors metabolize glucose to lactate even in the presence of oxygen (aerobic glycolysis). The metabolic switch from oxidative glycolysis to non-oxidative fermentation of glucose and proteins performed by the tumor cells seems to be associated with TKTL1 and pAkt overexpression. Therefore the aim of the present study was to investigate the expression of TKTL1 and pAkt in human specimens of endometrial cancer as compared to benign endometrium. Additionally, expression of the glucose transporter GLUT1 was also investigated as aerobic glycolysis is associated with an increased need for glucose.

Materials and methods: Levels of TKTL1, pAkt, and GLUT1 expression were immunhistochemically evaluated on paraffin embedded biopsy material from 10 benign and 41 malignant endometrial tissue samples. TKTL1 mRNA levels in the endometrial cancer cell lines Ishikawa and HEC-1A were evaluated by RT-PCR.

Results: Expression of TKTL1, GLUT1 and pAKT was significantly increased in endometrial carcinomas as compared to benign endometrial tissue. There was a significantly weaker TKTL1 expression in highly differentiated G1 tumors. In the human endometrial cancer cell lines Ishikawa and HEC-1A, TKTL1 mRNA was clearly detectable.

Conclusion: The levels of TKTL1, GLUT1 and pAKT expression point to the glycolytic phenotype of malignant endometrial tissue. Given the pronounced TKTL1 expression across all different subtypes of endometrial cancer, this protein could serve as a target for future cancer treatments.