Christopher Counter, Pharmacology and Cancer Biology

The goal of my lab is to understand the molecular mechanisms underlying the evolution of normal cells into human cancers. In particular, we have focused on how cancer cells acquire the ability to divide indefinitely, or become immortal, a process believed to be critical for tumor development. Telomerase, the enzyme that elongates the ends of chromosomes, is central to this immortalization process. In most cancer cells telomerase is illegitimately activated, which in turn endows these cells with an immortal phenotype.

To elucidate how telomerase is activated during tumorigenesis we cloned the gene encoding the catalytic subunit of telomerase and showed that this gene is activated in cancer cells and able to immortalize human cells. Moreover, simply expressing this gene in conjunction with the oncogenes T-Ag and H-ras is sufficient to convert normal human cells into cancer producing cells in vivo. Given that telomerase is clearly required for tumorgenesis, we are now focusing our efforts on understanding the regulation of this enzyme, particularly in regard to its activation in cancer cells.