Shawn Ahmed

Telomeres, the ends of linear chromosomes, are usually composed of simple repetitive sequences. Telomeres are maintained by an enzyme called telomerase, which adds repeats to the end of a chromosome. Telomerase is absent from most normal human somatic cells, but is active in the vast majority of cancers, making it an attractive target for directed cancer therapy. We study telomerase using the nematode Caenorhabditis elegans. We also study genome rearrangements that occur at critically shortened telomeres, which may drive genome instability during tumor development.

Somatic cells may be deficient for processes that allow germ cells to proliferate from one generation to the next, indefinitely. Our research group also studies pathways that enable germ cells to combat proliferative aging; pathways that ensure germ cell immortality. Dysfunction of such pathways may lead to stem cell dysfunction in somatic cells or to transmission of epigenetic damage via germ cells, either of which may be relevant to oncogenesis.

We have demonstrated that the majority of end-to-end chromosome fusions may occur as a consequence of complex genome rearrangements.