In multiple myeloma, as in B-cell malignancies, mono- and especially bi-allelic gene inactivation is a high-risk factor for treatment resistance, and there are currently no therapies specifically targeting p53 deficiency. In this study, we evaluated if the loss of cell cycle control in p53-deficient myeloma cells would confer a metabolically actionable vulnerability. We show that CTP synthase 1 (), which encodes a CTP synthesis rate-limiting enzyme essential for DNA and RNA synthesis in lymphoid cells, is overexpressed in samples from myeloma patients displaying a high proliferation rate (high expression) or a low p53 score (synonymous with deletion and/or mutation).
View Article and Find Full Text PDFBispecific antibodies targeting GPRC5D demonstrated promising efficacy in multiple myeloma, but acquired resistance usually occurs within a few months. Using a single-nucleus multi-omic strategy in three patients from the MYRACLE cohort (ClinicalTrials.gov registration: NCT03807128 ), we identified two resistance mechanisms, by bi-allelic genetic inactivation of GPRC5D or by long-range epigenetic silencing of its promoter and enhancer regions.
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