Validating the relevance of FOXO1 in BMP induced apoptosis of multiple myeloma cells

Sammanfattning

Background Multiple myeloma is an incurable cancer disease that emerges from the bone marrow. Bone morphogenetic proteins (BMPs) are ligands that activates intracellular signaling pathways causing activation of transcription factors. Previous studies show that BMP treatment of myeloma cells induce apoptosis, a mechanism dependent on downregulation of c-MYC. BMPs uses different receptors on myeloma cells, but it is still unclear how the intracellular signaling pathway leading to apoptosis works. A recent whole genome CRISPR/Cas9 knockout screening suggested FOXO1 as a gene involved in the mechanism of apoptosis during BMP treatment. We therefore aimed to investigate further on how FOXO1 has an impact on BMP induced apoptosis. Methods Our hypothesis was that knockout of FOXO1 would protect the cells from apoptosis. To begin to address this issue we tested INA-6 FOXO1 knock-out cell clones that was generated before the start of the project and treated them with BMP-9 to look for effects on cell viability and protein expression. We measured cell viability using CellTiter-Glo® 2.0 Cell viability assay and expression of c-MYC and FOXO1 protein using Western blot. Results and conclusions Treatment with BMP-9 for 72 hours showed a decrease in viability of the cells, up to 98%. Protein expression of c-MYC was inhibited by BMP-9 treatment while a constant expression of FOXO1 was seen in all cells clones regardless of BMP treatment. Expression of FOXO1 in the FOXO1 knock-out cells indicates that the knock-out has not worked. More experiments are needed to clarify the role of FOXO1 in BMP-induced apoptosis.