Abstract 18273: Cardiomyocytes Inhibit the Growth of Lung and Breast Cancer Cells but Fail to Abrogate the Proliferation of Melanoma Cells

The adult heart is an organ resistant to primary cancer formation and secondary metastatic invasion. Rhabdomyosarcomas are rare and the majority of primary tumors are benign and restricted to the atria. Similarly, secondary invasion of cancer cells is not a common event. Despite the widespread diffusion of breast and lung cancer, intracardiac metastases are uncommon. However, skin melanoma cells have a particularly high propensity for cardiac seeding. In this study, we tested whether the interaction of cardiomyocytes and their miRs with lung (A549), breast (MCF7) and melanoma cancer cells (B16) differed, providing a molecular basis for the distinct invasive properties of these tumors in the heart. The in vitro growth rate of the three cancer cell lines was determined and found to be greater in A549 and B16 cells than in MCF7 cells. The expression of the muscle specific miR-1 and miR-133a was high in myocytes and barely detectable in A549, B16 and MCF7 cells. To determine whether miRs transfer from myocyte...