Drug-induced aneuploidy and polyploidy is a mechanism of disease relapse in MYC/BCL2-addicted diffuse large B-cell lymphoma

Abstract

Double-hit (DH) or double-expresser (DE) lymphomas are high-grade diffuse large B-cell lymphomas (DLBCL) that are mostly incurable with standard chemo-immunotherapy due to treatment resistance. The generation of drug-induced aneuploid/polyploid (DIAP) cells is a common effect of anti-DLBCL therapies (e.g. vincristine, doxorubicin). DIAP cells are thought to be responsible for treatment resistance, as they are capable of re-entering the cell cycle during off-therapy periods. Previously we have shown that combination of alisertib plus ibrutinib plus rituximab can partially abrogate DIAP cells and induce cell death. Here, we provide evidence that DIAP cells can re-enter the cell cycle and escape cell death during anti-DLBCL treatment. We also discuss MYC/BCL2 mediated molecular mechanism that underlie treatment resistance. We isolated aneuploid/polyploid populations of DH/DE-DLBCL cells after treatment with the aurora kinase (AK) inhibitor alisertib. Time-lapse microscopy of single polyploid cells revealed that following drug removal, a subset of these DIAP cells divide and proliferate by reductive cell divisions, including multipolar mitosis, meiosis-like nuclear fission and budding. Genomic, proteomic, and kinomic profiling demonstrated that alisertib-induced aneuploid/polyploid cells up-regulate DNA damage, DNA replication and immune evasion pathways. In addition, we identified amplified receptor tyrosine kinase and T-cell receptor signaling, as well as MYC-mediated dysregulation of the spindle assembly checkpoints RanGAP1, TPX2 and KPNA2. We infer that these factors contribute to treatment resistance of DIAP cells. These findings provide opportunities to develop novel DH/DE-DLBCL therapies, specifically targeting DIAP cells.Key Points● MYC mediated upregulation of TPX2, KPNA2 and RanGAP1 dysregulate the spindle assembly checkpoint in drug-induced polyploid cells.● Drug-induced polyploid cells re-enter the cell cycle via multipolar mitosis, fission or budding, a mechanism of disease relapse.

Resistance to histone deacetylase inhibitors confers hypersensitivity to oncolytic reovirus therapy

“…Finally, significantly expressed genes between parental and drug-resistant cells were searched in the DAVID database system to identify the most affected pathways as previously described. 29 Quantitative real-time PCR…”

Drug-induced resistance: nipping it in the ‘budding’

“…Islam et al report on pages 35875-35890 new data in support of this latter concept, i.e. the role of drug-induced resistance via polyploidization in response to widely used anticancer therapies [ 4 ]. To study this phenomenon, they employed a model of high-grade Diffuse Large B-cell Lymphoma (DLBCL), time-lapse imaging, genomic, proteomic and kinomic profiling using patient-derived cells.…”

“…Firstly, they made use of time-lapse imaging to determine that a widely-applied combination of drugs including AK inhibitors with other cytotoxic agents result in a diversity of cell phenotypes. These include the induction of surviving 4n and >4n tumor cells, which undergo mitotic slippage, endoreduplication, and/or reductive cell division that could be described as ‘budding’ along with meiosis-type cell divisions leading to a cadre of variable aneuploid daughter cells capable of re-entering the cell cycle [ 4 ]. This makes sense because others, including our own lab, have pin-pointed rapid DNA amplification and cell state-switching as an escape mechanism in response to conventionally-used anticancer drugs [ 7 ].…”

“…Secondly, the researchers provide a molecular ‘view’ of these distinct phenotypic behavior using a multidimensional proteomic and transcriptomic screen integrated with a bioinformatic-based approach. They implicate a dynamic collaboration between Myc and Bcl2 with KPNA2, Ran-GAP1, TPX2 and AK-A as the molecular drivers of drug-induced phenotypic diversification and reductive cell division after relieving therapeutic pressure [ 4 ]. They further implicate gene ontologies associated with immune response, which could have major implications on combinations of drugs that target immune cells, such as checkpoint inhibitors.…”

“…Finally, Islam et al suggest novel therapeutic options to thwart drug-induced polyploidization and cell death-escape that can be integrated in combinatorial fashion. One argument they make is to target the enzyme Ran-GAP1, which functions as a lynchpin in their molecular cascade, while other drivers such as BCL-2 may only target a subset of the phenotypically-distinct drug resistant cells [ 4 ]. Thus, a rational combination and likely sequence or schedule of therapies is implicated in potential combination therapies.…”