EGFR-overexpression induces telomerase reactivation in immortalized oral epithelial cells by phosphorylation of the PI3K/AKT pathway

Introduction: Immortalization is closely linked to the maintenance of telomeres either through telomerase activation or alternative lengthening of telomeres (ALT). Oral-esophageal carcinomas frequently involve cyclin D1 overexpression, inactivation of p53 as well as EGFR-overexpression. Following these genetic events, we defined the role of cyclin D1 overexpression, p53 inactivation and EGFR overexpression in immortalization and malignant transformation of human oral epithelial cells. We demonstrated, that the combination of cyclin D1 overexpression and p53 inactivation led to immortalization, without activation…