posted on 2023-12-08, 14:20authored byDennis Juarez, Roberta Buono, Shannon M. Matulis, Vikas A. Gupta, Madeleine Duong, Jacob Yudiono, Madhuri Paul, Sharmila Mallya, Grace Diep, Peter Hsin, Alexander Lu, Sang Mi Suh, Vy M. Dong, Andrew W. Roberts, Joel D. Leverson, Muhammad Jalaluddin, Zhuangzhuang Liu, Orlando F. Bueno, Lawrence H. Boise, David A. Fruman
<p>Pitavastatin-mediated activation of the ISR induces NOXA to sensitize to venetoclax separately from PUMA. Heat map summary of BCL2 family Western blot screen across all statin-sensitive cells (NCI-H929, MM.1S, L363, OPM2, MOLP8, and KMS12PE) for 16 (<b>A</b>) and 40 hours (<b>B</b>) treatments with 1 µmol/L pitavastatin. log<sub>2</sub> transformed mean fold change of three replicates of each MMCL are plotted on a double gradient scale. <b>C,</b> Western blot analysis of the t(4;14) OPM2 and non-t(4;14) MM1S treated with 1 µmol/L pitavastatin or pitavastatin/ISRIB. NOXA upregulation is partially blocked by ISRIB, but PUMA is mostly ISR independent. Representative of <i>n</i> = 2 for tested cell lines. <b>D,</b> The apoptosis sensitizing effects of pitavastatin are blocked in <i>BBC3</i> (PUMA) knockout L363 cell line treated with ISRIB in a 40-hour Annexin V-PI viability assay, <i>n</i> = 4.</p>
The BCL2 inhibitor venetoclax promotes apoptosis in blood cancer cells and is approved for treatment of chronic lymphocytic leukemia and acute myeloid leukemia. However, multiple myeloma cells are frequently more dependent on MCL-1 for survival, conferring resistance to venetoclax. Here we report that mevalonate pathway inhibition with statins can overcome resistance to venetoclax in multiple myeloma cell lines and primary cells. In addition, statins sensitize to apoptosis induced by MCL-1 inhibitor, S63845. In retrospective analysis of venetoclax clinical studies in multiple myeloma, background statin use was associated with a significantly enhanced rate of stringent complete response and absence of progressive disease. Statins sensitize multiple myeloma cells to venetoclax by upregulating two proapoptotic proteins: PUMA via a p53-independent mechanism and NOXA via the integrated stress response. These findings provide rationale for prospective testing of statins with venetoclax regimens in multiple myeloma.
BH3 mimetics including venetoclax hold promise for treatment of multiple myeloma but rational combinations are needed to broaden efficacy. This study presents mechanistic and clinical data to support addition of pitavastatin to venetoclax regimens in myeloma. The results open a new avenue for repurposing statins in blood cancer.