Self-cannibalization facilitates survival.
A single tumor-suppressing gene is a key to understanding--and perhaps killing--dormant ovarian cancer cells that hide out after initial treatment, only to reawaken years later, report researchers at the University of Texas M.D. Anderson Cancer Center, Houston.
The team found that expression of a gene called ARHI acts as a switch for autophagy, or self-cannibalization, in ovarian cancer cells. Often a mechanism for cancer cell death, "self-eating," in this case, acts as a survival mechanism for dormant cancer cells. "Prolonged autophagy is lethal to cancer cells, but a little autophagy can help dormant cancer cells survive, possibly by avoiding starvation," indicates senior author Robert Bast, vice president for translational research.
"Dormant cells are a major problems in ovarian cancer, breast cancer, and other malignancies. We often see ovarian cancer removed, leaving no sign of disease. After two or three years, the cancer grows back. If any remaining cancer cells had continued to grow normally, the disease should have returned in weeks or months. So, the assumption is that some cells remain dormant without dividing and without developing a blood supply, but the mechanism for this has not been well understood."
Autophagy is a cellular survival mechanism that protects cells in a variety of ways. In the case of stress caused by lack of nutrients, autophagy roughly is comparable to a person burning body fat to survive the absence of food. Several protein survival factors were detected within the microenvironment of the ovarian cancer grafts that could prevent autophagy-induced death of ovarian cancer cells in the laboratory. Blocking these survival factors could provide a novel strategy for eliminating dormant ovarian cancer cells and curing more patients.
|Printer friendly Cite/link Email Feedback|
|Title Annotation:||CANCER CELLS|
|Publication:||USA Today (Magazine)|
|Date:||Oct 1, 2009|
|Previous Article:||Very postmortem: mummies and medicine.|
|Next Article:||Skyrocketing rates for minorities and elderly.|