Analysis of the Expression of Genes Related to Lipidic and Glycogenic Metabolism in Pleomorphic Adenomas and Carcinomas Ex Pleomorphic Adenomas

Introduction The carcinoma ex pleomorphic adenoma (CXPA) arises from a pleomorphic adenoma (PA) and is supposed to gain lipogenesis and glycogenesis during its malignant transformation. Increased lipogenesis is a characteristic of cancer cells, consisting of increased fatty acid synthesis by the enzyme fatty acid synthase (FASN) and by the accumulation of cytoplasmic lipid droplets, which express adipophilin. The increase in glycolytic metabolism has been associated with the activity of glycolytic enzymes and glucose transporters (GLUTs), whose expression is induced by HIF-1 (inducing factor of hypoxia 1). Objectives To analyze the gene expression of FASN, adipophilin, HIF-1α, and GLUT-1 in PA and CXPA samples. Methodology Gene expression analysis of the FASN, adipophilin, HIF1-α, and GLUT-1 genes was performed by the real-time PCR (qPCR) method. Fourteen cases of PA and 14 cases of CXAP were evaluated. Results FASN, adipophilin, HIF-1α, and GLUT-1 were more expressed in CXAP than in AP, although there was no significant difference between levels of adipophilin expression in CXPA and PA. Conclusion Increased expression of FASN, HIF1-α, and GLUT-1 in CXAP may be associated with malignant transformation of PA, while additional studies are needed to understand the role of adipophilin in PA carcinogenesis. Moreover, this is the first study to investigate the role of these genes in the malignant transformation of PA.