Bovine HDL and Dual Domain HDL-Mimetic Peptides Inhibit Tumor Develop- ment in Mice

A growing body of literature supports the role of apolipoproteins present in HDL in the treatment of pro-inflamma- tory diseases including cancer. We examined whether bovine HDL (bHDL) and three dual-domain peptides, namely AEM- 28 and its analog AEM-28-2, and HM-10/10, affect tumor growth and development in mouse models of ovarian and colon cancer. We demonstrate that bHDL inhibits mouse colorectal cancer cell line CT26-mediated lung tumor development, and mouse ovarian cancer cell line ID8-mediated tumor burden. We also demonstrate that, although to different degrees, du- al-domain peptides inhibit cell viability of mouse and human ovarian and colon cancer cell lines, but not that of normal hu- man colonic epithelial cells or NIH3T3 mouse fibroblasts. Dual-domain peptides administered subcutaneously or in a chow diet decrease CT26 cell-mediated tumor burden, tumor growth, and tumor dissemination in BALB/c mice. Plasma levels of lysophosphatidic acid (LPA) are significantly reduced in mice that received bHDL and the dual-domain peptides, suggesting that reduction by effecting accumulation and/or synthesis of pro-inflammatory lipids may be one of the mechanisms for the inhibition of tumor development by bHDL and the dual-domain peptides. Our studies suggest that therapeutics based on apolipoproteins present in HDL may be novel agents for the treatment of epithelial adenocarcinomas of the ovary and colon.