Project description:Resistance to the first approved BCL-2 inhibitor venetoclax is emerging in lymphoid malignancies. The study aimed to identify the genetic determinants of such resistance. From genome-scale screens we determined the genes influencing the sensitivity to BCL-2 inhibition. The present set of data is related to expression changes (assessed by RNA sequencing) observed in the resistant OCI-Ly1 lymphoma cell line as well as those resulting from genetic perturbation (using CRISPR-Cas9) targeting the genes highlighted in our genome-scale screen.
Project description:Venetoclax is the first example of personalized medicine for multiple myeloma (MM), with meaningful clinical activity as a monotherapy and in combination in myeloma patients harboring the t(11:14) translocation. However, despite the high response rates and prolonged PFS, a significant proportion of patients eventually relapse. Here, we aimed to study adaptive molecular responses after the acquisition of venetoclax resistance in sensitive t(11:14) MM cell models. We therefore generated single-cell venetoclax-resistant t(11:14) MM cell lines and investigated the mechanisms contributing to resistance as well as the cells’ sensitivity to other treatments. Our data suggests that acquired resistance to venetoclax is characterized by reduced mitochondrial priming and changes in BCL-2 family proteins’ expression in MM cells, conferring broad resistance to standard-of-care anti-myeloma drugs. However, our results show that the resistant cells are still sensitive to immunotherapeutic treatments, highlighting the need to consider appropriate sequencing of these treatments following venetoclax-based regimens.
Project description:The goal of this study was to profile the changes in gene expression in an AML cell line with acquired resistance to venetoclax in response to treatment with venetoclax, tedizolid, or combination of the 2 drugs.
Project description:The BCL-2 family plays important roles in acute myeloid leukemia (AML) and Venetoclax, a selective BCL-2 inhibitor, has received FDA approval for treatment of AML. However, drug resistance ensues after prolonged treatment, highlighting the need for a greater understanding of the underlying mechanisms. Using a genome-wide CRISPR/Cas9 screen in human AML, we identified genes whose inactivation sensitizes AML blasts to Venetoclax. Genes involved in mitochondrial organization and function were significantly depleted throughout our screen, including the mitochondrial chaperonin CLPB. We demonstrated that CLPB is upregulated in human AML, it is further induced upon acquisition of Venetoclax resistance and its ablation sensitizes AML cells to Venetoclax. Mechanistically, CLPB maintains the mitochondrial cristae structure via its interaction with the cristae-shaping protein OPA1, whereas its loss promotes apoptosis by inducing cristae remodeling and mitochondrial stress responses. Overall, our data suggest that targeting mitochondrial architecture may provide a promising approach to circumvent Venetoclax resistance.
Project description:FOXM1 and AKT are crucial pro-oncogenic regulators of cancer therapy resistance. Due to reciprocal regulatory links they establish a positive feedback autoregulation loop in AML cells. Disruption of this loop via inhibition of either FOXM1 or AKT results in similar gene expression changes, drastic upregulation of HOXA genes and sensitization of AML cells to cytarabine and venetoclax treatment.
Project description:30 million OCI-AML2 cells were infected with CRISPR/Cas9 library, selected for puromycin resistance for integration events and exposed DMSO, venetoclax (0.5 uM) or venetoclax (0.1 uM) plus ruxolitinib (1 uM). Cells were collected at day 14 and 21 , DNA was extracted and sgRNA barcodes were amplified. PCR library was deep sequenced using Novaseq 6000 high throughput Illumina platform.