Apoptosis Inhibitors Are Biomarkers for Ovarian Cancer Prognosis

Cancer researchers have found that contrary to expectations, expression of proteins linked to tumor cell survival were actually biomarkers for improved patient survival in ovarian cancer.

Investigators at the [U.S.] National Cancer Institute (Bethesda, MD, USA) employed immunohistochemical analysis to study the expression patterns of BAG-1, BAG-3, BAG-4, and Bcl-xL proteins in tissue samples obtained at diagnosis from 28 women with stage III or stage IV ovarian cancer undergoing chemotherapy with platinum-based drugs. These proteins are all known for inhibiting apoptosis and promoting tumor growth. Association of these proteins, as well as BAG-6, heat shock protein 70 (Hsp70), Hsp27, and Bcl-2 was then tested in ovarian cancer tissue arrays.

Results published in the November 15, 2007, issue of Clinical Cancer Research revealed that elevated cytoplasmic expression of BAG-4 was strongly and positively associated with long-term patient survival (both overall and progression-free survival). Bcl-2 staining was significantly more frequent on the tissue array in lower stage and grade tumors, whereas Hsp70 was prominent in higher-grade cases. Furthermore, Bcl-xL was more closely associated with serous compared with endometrioid ovarian cancers.

"We selected these proteins for study assuming that, because of their known abilities to promote the survival of cancer cells, they would likely correlate with worse clinical outcomes and high tumor aggressiveness,” said senior author Dr. Elise Kohn, head of the molecular signaling section at the [U.S.] National Cancer Institute. "We did not expect to find that increased expression of these proteins would actually be linked with better survival.”


Related Links:
[U.S.] National Cancer Institute