SGO 2018: PARP-7 Protein May Be Piece of Survival Puzzle in Ovarian Cancer
Posted: Wednesday, April 4, 2018
While investigating ovarian cancer cases, Lavanya Palavalli Parsons, MD, and Jayanthi Lea, MD, of The University of Texas Southwestern Medical Center in Dallas, noticed the The Cancer Genome Atlas database offered clues to the potential role the PARP-7 protein (and its future inhibitors) may play in fighting this malignancy. Patients with PARP-7 genetic alterations had a median overall survival of 44.8 months versus 15.7 months for those with no genetic alterations. Dr. Palavalli Parsons presented these findings at the 2018 Society of Gynecologic Oncology (SGO) Annual Meeting on Women’s Cancer in New Orleans (Abstract 18).
“If you took the specific patients who had alterations, they all had gene amplifications that correlated with higher levels of expression of PARP-7,” Dr. Palavalli Parsons said in an SGO press release. “These patients with ovarian cancer lived longer.” Furthermore, those who had platinum-sensitive disease and no alterations versus those who had PARP-7 expression had shorter overall survival (14.7 vs. 36 months).
Inspired by those statistics, the duo’s complex proteomic work began with creating 10 different mutants of PARP-7 and infecting insect cells with them to express PARP-7 proteins. It concluded with identifying the most “promising” mutant and having it react with OVCAR 4 (immortalized ovarian cancer cell line) lysate. “Identifying that PARP-7 modifies extracellular matrix protein helps understand the potential biology of PARP-7 significance to ovarian cancer,” according to the abstract.
PARP-7 and many other PARP inhibitors await more research. “I feel like we are only seeing the tip of a huge iceberg which is on the verge of being uncovered with the influx of new knowledge about the PARP family,” said Dr. Palavalli Parsons in an SGO news release.
