The elastic fiber protein MAGP‐2 is ectopically expressed in ovarian carcinoma cells

Abstract

Microfibril‐associated Glycoprotein‐2 (MAGP‐2) is a secreted protein component of elastic fiber microfibril sheaths. Gene expression profiling studies have linked elevated MAGP‐2 expression to advanced stage papillary serous ovarian tumors. These tumors primarily consist of epithelial‐derived tumor cells, but stromal cells are also present, and include endothelial cells from the tumor neovasculature. Since whole tissue assays do not indicate which cells in the tumor expressed increased levels of MAGP‐2, we assayed MAGP‐2 expression by quantitative Reverse Transcriptase PCR (qRT‐PCR) in three ovarian epithelial carcinoma cell lines and normal human ovarian surface epithelial cells. Interestingly, the data revealed that two of the three carcinoma cell lines did express significantly higher levels of MAGP‐2 than the normal cells, suggesting that ectopic expression of MAGP‐2 in the tumor cells themselves may have a role in cancer progression. Our data agree with recently published work on a non‐overlapping set of ovarian epithelial carcinoma cell lines by Mok et al. (Cancer Cell 16:521 2009) showing elevated MAGP‐2 protein levels in approximately 30% of carcinoma cell lines. Studies from our lab and others indicate that ectopic MAGP‐2 can modulate signaling by Notch or integrins, and can induce angiogenesis, suggesting that MAGP‐2 may play multiple roles in ovarian cancer progression. (CSUPERB, MARC)