In the bone marrow microenvironment, adipocytes and multiple myeloma cells have an intricate bidirectional relationship. Adipokines have been linked to shifting typical behavior in many cancers such as proliferation. Our previous research found that adipocyte secreted Fatty Acid Binding Proteins (FABPs) contribute to tumor growth, invasion, and survival. To test if external FABPs are important to myeloma cells, recombinant FABP4 or FABP5 was spiked into myeloma cell lines (MM1.S and OPM2) in serum and serum-free conditions. This data was cell counted using bioluminescence imaging (BLI). Analysis showed that there was no impact on cell growth with the spike in. Thus, external FABPs are not important to myeloma cells. It was hypothesized that intracellular inhibition of FABP4 or FABP5 in myeloma cells would decrease proliferation and tumor burden, providing a novel mechanism to treat the cancer. To test the effect that FABPs may have on myeloma cell growth, a cell line was treated with inhibitors of FABP4, FABP5, and a co-treatment in cell culture. BLI was used to cell count the myeloma cells at time 0, 24, 48, and 72 hours. Analysis of the inhibitor spike in showed that myeloma cell growth was decreased over time with the inhibitor treatment. In a mouse model it was concluded that inhibition of FABP4, FABP5, or a co-treatment did decrease myeloma cell growth and tumor burden over time. Furthermore, the inhibitors increased mouse survival. This supports the idea that FABP inhibitors could prove as a future cancer therapeutic
