Marker of drug response could signal cancer progression

The gene MGMT has been studied as a marker for response to the cancer chemotherapy temozolomide, but according to Australian researchers, it may also serve as a sign of tumor progression. In previous research, in patients with pituitary cancer, the tumors with lower levels of gene expression tended to be more aggressive and less likely to respond to treatment.

In the current research, the team found that the tumors expressing high levels of MGMT also showed activation of genes implicated in chemotherapy resistance. Conversely, those with low MGMT expression showed activation of genes involved in DNA damage and repair, as well as genes involved in gene transcription.

Based on their findings looking at the role of MGMT in pituitary tumor progression, the researchers believe that the results may apply to many other cancer types.

"Pituitary tumors display a strong tendency towards 'senescence,' akin to hibernation, and most do not become aggressive or malignant," said Ann McCormack, one of the researchers. "In a small number of cases, however, the tumors emerge from their senescent state and become aggressive. It is likely that prolonged DNA damage signaling contributes to this progression."

McCormack believes that MGMT may also act as a prognostic indicator. However, this will need more research.

- read the press release