Regulation of telomerase activity in normal and malignant human cells

In recent years, a particular type of reverse transcriptase termed telomerase has attracted much attention because of its potential utility as both a diagnostic marker and a therapeutic target in cancer. This enzyme is present in almost all cancer, but not in normal cells. Understanding telomerase structure, expression, and activity regulation is pivotal for the prospects of using it as a target in cancer therapy, with respect to both therapeutic and undesirable side effects. This review presents the current state of studies on the regulatory pathways of telomerase activity in human cells.