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Maura, F.

Publications and source records attributed to Maura, F..

At least 19 recordsLinked to original sources

Lymphoma response to chimeric antigen receptor T cell therapy is driven by endogenous tumor-reactive CD8⁺ T cells

CD19-directed chimeric antigen receptor T-cell (CAR-T) therapy induces durable remissions in a subset of patients with relapsed or refractory large B-cell lymphoma; however, most patients fail to respond or eventually relapse. By integrating whole-genome and transcriptome profiling of 54 patients with functional assays, syngeneic models, and mathematical modeling, we demonstrate that durable CAR-T efficacy requires cooperation between CAR-T cells and endogenous CD8 (eCD8) T cells recruited to join the attack on malignant cells. Tumors with biallelic loss of MHC class I or CD58 exhibited high genomic complexity, increased neoantigen burden, and resistance to CAR-T therapy. MHC-I-deficient lymphomas showed suboptimal response in immunocompetent hosts compared to wild type. Importantly, sustained responses in mice occurred only in the presence of eCD8 cells, whereas all CD8-depleted mice relapsed after initial CAR-T-mediated tumor regression. Patients and murine ELISPOT assays confirmed enhanced endogenous T-cell activation post-CAR-T. These findings reveal that CAR-T therapy functions not only as a cytotoxic modality but also as a catalyst for endogenous anti-tumor immunity.

cancer biology↗

Plasma cell identity escape drives resistance to anti-BCMA T-cell-redirecting therapy in multiple myeloma

Chimeric antigen receptor T-cell (CART) and T-cell engager (TCE) therapies targeting B-cell maturation antigen (BCMA) are transforming the treatment landscape for relapsed multiple myeloma (MM). However, despite impressive initial response rates, most patients eventually relapse. To investigate this unmet medical need, we applied whole-genome sequencing (WGS) to MM cells from cohorts of 102 relapsed patients treated with anti-BCMA CART and TCE therapies. Several genomic alterations were associated with clinical outcomes, particularly primary refractoriness, including high genomic complexity and mutations in genes regulating plasma cell identity, which predicted resistance to therapy. Single-cell RNA sequencing further revealed that MM cells from refractory patients exhibited high proliferation signatures and reduced expression of TNFRSF17 (encoding BCMA), while were less enriched for plasma cell-associated transcriptional programs, a phenomenon we term "plasma cell identity escape." This profile was strongly associated with immune dysregulation of CD8 T cells including increased activation and exhaustion. This evolution of MM toward a more proliferative and lineage-divergent state, refractory to the anti-BCMA T-cell redirecting therapies, was functionally validated in preclinical MM mouse models. Collectively, our results comprehensively define the cellular and molecular mechanisms underlying primary resistance to anti-BCMA therapies.

cancer biology↗

RHOA Loss of Function Impairs the IFNγ Response and Promotes CD19 Antigen Escape to Drive CAR-T Resistance in Diffuse Large B-cell Lymphoma

CD19-directed chimeric antigen receptor (CAR)-T cells are breakthrough therapies for aggressive B-cell lymphomas, but less than half of patients achieve durable responses. We previously showed through whole-genome sequencing of tumors from CAR-T-treated patients that deletions of RHOA (3p21.31) are enriched in cases progressing after treatment. RHOAs roles in resistance and pathogenesis are poorly defined, despite loss-of-function alterations that occur in [~]20% of newly diagnosed large B-cell lymphoma (LBCL) cases. We created RHOA-deficient LBCL systems and confirmed cell-intrinsic loss of response to CAR-19 in vitro and in vivo driven by CD19 downregulation. Impact on CD19, however, was variable and would not explain selection for RHOA deletion in newly diagnosed cases. We therefore created RHOA-deficient tumors in immunocompetent mice and found remarkable correlation with dysfunctional lymphoma microenvironment (LME) signatures in CAR-19 resistant patients. These LMEs are marked by a type 1-like immune infiltrate with terminally exhausted CD8 T cells, Th1-like CD4 cytotoxic lymphocytes (CTLs), and increased production of interferon gamma (IFN{gamma}). RHOA-deficient tumor cells themselves have significantly impaired IFN{gamma} responses, providing resistance to CD8 T cell clearance by way of diminished induction of major histocompatibility complex class I (MHC-I). These findings support a model that depletion of healthy effector populations by RHOA-deficient lymphoma is a key driver of immune dysfunction thwarting CAR-19 clinical responses. Overall, we describe for the first time how a single-gene alteration found recurrently in CAR-19-resistant LBCL contributes to treatment failures.

cancer biology↗

Mutagenic impact and evolutionary influence of radiotherapy in hematologic malignancies

Ionizing radiotherapy (RT) is a widely used palliative and curative treatment strategy for malignancies. In solid tumors, RT-induced double strand breaks lead to the accumulation of indels, and their repair by non-homologous end-joining has been linked to the ID8 mutational signature in resistant cells. However, the extent of RT-induced DNA damage in hematologic malignancies and its impact on their evolution and interplay with commonly used chemotherapies has not yet been explored. Here, we interrogated 580 whole genome sequencing (WGS) from patients with large B-cell lymphoma, multiple myeloma, and myeloid neoplasms and identified ID8 only in relapsed disease. Yet, it was detected after exposure to both RT and mutagenic chemotherapy (i.e., platinum). Using WGS of single-cell colonies derived from treated lymphoma cells, we revealed a dose-response relationship between RT and platinum and ID8. Finally, using ID8 as a genomic barcode we demonstrate that a single RT-resistant cell may seed systemic relapse.

genomics↗

The cyclin-G associated kinase (GAK) is a novel mitotic kinase and therapeutic target in diffuse large B-cell lymphoma

New drug targets are needed for diffuse large B-cell lymphoma (DLBCL), the most common lymphoma subtype, to enable enable development better treatments for patients not cured by standard care. We conducted a phenotypic screen of kinase inhibitors and identified the cyclin G-associated kinase (GAK) as a tumor-selective target. Though GAK is previously described primarily as a participant in membrane trafficking, we found its kinase activity is a key mitotic regulator in DLBCL. Inhibition caused G2/M-phase arrest, chromosome misalignment, and spindle distortion, effects absent in non-malignant controls. Transcriptomics data from clinical samples showed increased GAK expression associates with RB1 deficiency in DLBCL cases, suggesting dependency on GAK linked to retinoblastoma associated protein (RB) loss of function, a common DLBCL driver. RB-deficient DLBCL cells treated with a selective GAK tool compound showed complete arrest at G2/M, pronounced distortion of mitotic spindles, and widespread chromosomal damage. High-content live-cell imaging revealed onset of mitotic catastrophe in response to GAK inhibition, which was more rapid and severe in isogenic cells with RB1 deletion. No GAK-selective inhibitors suitable for clinical development are currently available, but several drugs approved or under development inhibit GAK activity even more potently than thier intended clinical targets. For instance, OTS167, developed against MELK for use in solid tumors, has particularly potent anti-GAK potency and has achieved single-agent tumor-burden reduction in vivo against a DLBCL patient-derived xenograft. GAK is therefore a novel mitotic kinase in DLBCL, linked to the common, undruggable RB loss of function biomarker, and suitable for rapid clinical translation through drug repurposing. SignificanceWe identify cyclin-G associated kinase (GAK) as a novel therapeutic vulnerability in diffuse large B-cell lymphoma. Clinical kinase inhibitors with GAK activity create an opportunity for rapid therapeutic translation through drug repurposing.

cancer biology↗

NRF2 translation block by inhibition of cap-dependent initiation sensitizes lymphoma cells to ferroptosis and CAR-T immunotherapy

Cancers coopt stress-response pathways to drive oncogenesis, dodge immune surveillance, and resist cytotoxic therapies. Several of these provide protection from ferroptosis, iron-mediated oxidative cell death. Here, we found dramatic sensitization to ferroptosis upon disruption of cap-dependent translation in diffuse large B-cell lymphoma (DLBCL). Specifically, rocaglate inhibitors of the eIF4A1 RNA helicase synergized with pharmacologic ferroptosis inducers, driven by a collapse of glutathione production that protects polyunsaturated fatty acids from ferroptotic oxidation. These effects occur despite initial up-regulation of specific protective factors. We find lost translation of NRF2, oncogenic master regulator of antioxidant gene-expression, is a key consequence of eIF4A1 inhibition. In vivo, combination of the clinical rocaglate zotatifin with a pharmacologically optimized ferroptosis inducer eradicated DLBCL patient derived xenografts. Moreover, we found zotatifin pre-exposure sensitized DLBCL to CD19-directed chimeric antigen receptor (CAR-19) T cells. Translational disruption therefore provides new opportunities to leverage therapeutic impacts of ferroptosis inducers including cytotoxic immunotherapies. SignificanceWe find translational disruption sensitizes lymphomas to ferroptosis, enhancing efficacy of CAR-T cells and multiple drugs. NRF2 loss mediates these effects, informing promising new therapeutic combinations. Multiple cancers exploit NRF2 to resist a wide variety treatments. These results expand therapeutic implications from its loss downstream of eIF4A1 inhibition.

cancer biology↗

Timing antigenic escape in multiple myeloma treated with T-cell redirecting immunotherapies

Recent data highlight genomic events driving antigen escape as a recurring cause of chimeric antigen receptor T-cell (CAR-T) and bispecific T-cell engager (TCE) resistance in multiple myeloma (MM). Yet, it remains unclear if these events, leading to clonal dominance at progression, result from acquisition under treatment selection or selection of pre-existing undetectable clones. This differentiation gains importance as these immunotherapies progress to earlier lines of treatment, prompting the need for innovative diagnostic testing to detect these events early on. By reconstructing phylogenetic trees and exploring chemotherapy mutational signatures as temporal barcodes in 11 relapsed refractory MM patients with available whole genome sequencing data before and after CART/TCE treatment, we demonstrated that somatic antigen escape mechanisms for BCMA- and GPRC5D-targeting therapies are acquired post-diagnosis, likely during CART/TCE treatment. Longitudinal tracking of these mutations using digital PCR in 4 patients consistently showed that genomic events promoting antigen escape were not detectable during the initial months of therapy but began to emerge nearly 1 year post therapy initiation. This finding reduces the necessity for a diagnostic panel to identify these events before CART/TCE. Instead, it underscores the importance of surveillance and identifying patients at higher risk of acquiring these events. KEY POINTSO_LIGenomic events driving antigen escape are recurrent mechanisms of resistance to CART and T-cell engagers in multiple myeloma. C_LIO_LIUsing chemotherapy mutational signatures, we demonstrated that these events are most likely acquired during treatment. C_LI

genomics↗

Impact of rare structural variant events in newly diagnosed multiple myeloma

Whole genome sequencing (WGS) of newly diagnosed multiple myeloma patients (NDMM) has shown recurrent structural variant (SV) involvement in distinct regions of the genome (i.e. hotspots) and causing recurrent copy number alterations. Together with canonical immunoglobulin translocations, these SVs are recognized as "recurrent SVs". More than half SVs were not involved in recurrent events. The significance of these "rare SVs" has not been previously examined. In this study, we utilize 752 WGS and 591 RNA-seq data from NDMM patients to determine the role of rare SVs in myeloma pathogenesis. 94% of patients harbored at least one rare SV event. Rare SVs showed an SV-class specific enrichment within genes and superenhancers associated with outlier gene expression. Furthermore, known myeloma driver genes recurrently impacted by point mutations were dysregulated by rare SVs. Overall, we demonstrate the association of rare SVs with aberrant gene expression supporting a driver role in myeloma pathogenesis. SIGNIFICANCECharacterization of multiple myeloma genome revealed that more than half structural variants are not involved in recurrent events. Here, we demonstrate that these rare SVs hold potential for myeloma pathogenesis through their gene expression impact. Rare SVs contribute to MM heterogeneity and have implications for development of individualized treatment.

cancer biology↗

Childhood cancer mutagenesis caused by a domesticated DNA transposase

Genomic rearrangements are a hallmark of most solid tumors, including medulloblastoma, one of the most common brain tumors in children. Childhood cancers involve dysregulated cell development, but their mutational causes remain largely unknown. One of the most common forms of medulloblastoma is caused by ectopic activation of Sonic Hedgehog (SHH) signaling in cerebellar granule cell progenitors, associated with genetic deletions, amplifications, and other oncogenic chromosomal rearrangements. Here, we show that PiggyBac Transposable Element Derived 5 (Pgbd5) promotes tumor development in multiple developmentally-accurate mouse models of SHH medulloblastoma. Most mice with Pgbd5 deficiency do not develop tumors, while Pgbd5-deficient mice maintain largely normal cerebellar development. Mouse medulloblastomas expressing Pgbd5 exhibit significantly increased numbers of somatic structural DNA rearrangements, with PGBD5-specific transposon sequences at their breakpoints. Similar sequence breakpoints recurrently affect somatic DNA rearrangements of known tumor suppressors and oncogenes in medulloblastomas in 329 children. Therefore, this study identifies PGBD5 as a primary medulloblastoma mutator and provides a genetic mechanism responsible for the generation of somatic oncogenic DNA rearrangements in childhood cancer. One-Sentence SummaryInduction of somatic oncogenic mutations by the DNA transposase PGBD5 in cerebellar progenitor cells promotes medulloblastoma development.

cancer biology↗

Chemotherapy Signatures Map Evolution of Therapy-Related Myeloid Neoplasms

Patients treated with cytotoxic therapies, including autologous stem cell transplantation, are at risk for developing therapy-related myeloid neoplasms1, 2. Pre-leukemic clones (i.e., clonal hematopoiesis) are detectable years before the development of these aggressive malignancies3-5, though the genomic events leading to transformation and expansion are not well-defined. Here, leveraging distinctive chemotherapy-associated mutational signatures6-12 from whole-genome sequencing data and targeted sequencing of pre-chemotherapy samples, we reconstruct the evolutionary life-history of 39 therapy-related myeloid malignancies. A dichotomy is revealed, in which neoplasms with evidence of chemotherapy-induced mutagenesis from platinum and melphalan are relatively hypermutated and enriched for complex structural variants (i.e., chromothripsis), while neoplasms with alternative exposures bear a similar profile to de novo acute myeloid leukemia. Using chemotherapy-associated mutational signatures as a temporal barcode in each patients life, we estimate that several complex events and genomic drivers are acquired after chemotherapy exposure. In the case of treatment with high-dose melphalan and autologous stem cell transplantation, we demonstrate that the procedure allows clonal hematopoiesis to escape chemotherapy exposure entirely, and to be reinfused to expand to malignancy. This information reveals a novel mode of malignant progression for therapy-related malignancies that is not reliant on direct mutagenesis or even exposure to chemotherapy, itself, and prompts further investigation into leukemia-permissive effects of cytotoxic drugs.

cancer biology↗

Genomic drivers of large B-cell lymphoma resistance to CD19 CAR-T therapy

Chimeric antigen receptor-reprogrammed autologous T cells directed to CD19 are breakthrough immunotherapies for heavily pretreated patients with aggressive B-cell lymphomas but still fail to cure most patients. Host inflammatory and tumor microenvironmental factors associate with CAR-19 resistance, but the tumor-intrinsic factors underlying these phenomena remain undefined. To characterize genomic drivers of resistance, we interrogated whole genome sequencing of 30 tumor samples from 28 uniformly CAR-19-treated large-cell lymphoma patients. We reveal that patterns of genomic complexity (i.e., chromothripsis and APOBEC mutational activity), and distinct genomic alterations (deletions of RB1 or RHOA) associate with more exhausted immune microenvironments and poor outcome after CAR-19 therapy. Strikingly, pretreatment reduced expression or sub-clonal mutation of CD19 did not affect responses, suggesting CAR-19 therapy successes are due not only to direct antigen-dependent cytotoxicity but require surmounting immune exhaustion in tumor microenvironments to permit broader host responses that eliminate tumors.

cancer biology↗

Genome-wide mutational signatures of immunological diversification in normal lymphocytes

A lymphocyte suffers many threats to its genome, including programmed mutation during differentiation, antigen-driven proliferation and residency in diverse microenvironments. After developing protocols for single-cell lymphocyte expansions, we sequenced whole genomes from 717 normal naive and memory B and T lymphocytes and hematopoietic stem cells. Lymphocytes carried more point mutations and structural variation than stem cells, accruing at higher rates in T than B cells, attributable to both exogenous and endogenous mutational processes. Ultraviolet light exposure and other sporadic mutational processes generated hundreds to thousands of mutations in some memory lymphocytes. Memory B cells acquired, on average, 18 off-target mutations genome-wide for every one on-target IGV mutation during the germinal center reaction. Structural variation was 16-fold higher in lymphocytes than stem cells, with ~15% of deletions being attributable to off-target RAG activity. One Sentence SummaryThe mutational landscape of normal lymphocytes chronicles the off-target effects of programmed genome engineering during immunological diversification and the consequences of differentiation, proliferation and residency in diverse microenvironments.

genomics↗

Copy number signatures predict chromothripsis and associate with poor clinical outcomes in patients with newly diagnosed multiple myeloma

Chromothripsis is detectable in 20-30% of newly diagnosed multiple myeloma (NDMM) patients and is emerging as a new independent adverse prognostic factor. In this study, we interrogate 752 NDMM patients using whole genome sequencing (WGS) to study the relationship of copy number (CN) signatures to chromothripsis and show they are highly associated. CN signatures are highly predictive of the presence of chromothripsis (AUC=0.90) and can be used to identify its adverse prognostic impact. The ability of CN signatures to predict the presence of chromothripsis was confirmed in a validation series of WGS comprised of 235 hematological cancers (AUC=0.97) and an independent series of 34 NDMM (AUC=0.87). We show that CN signatures can also be derived from whole exome data (WES) and using 677 cases from the same series of NDMM, we were able to predict both the presence of chromothripsis (AUC=0.82) and its adverse prognostic impact. CN signatures constitute a flexible tool to identify the presence of chromothripsis and is applicable to WES and WGS data.

genomics↗

Whole genome sequencing provides evidence of two biologically and clinically distinct entities of asymptomatic monoclonal gammopathies: progressive versus stable myeloma precursor condition

Multiple myeloma (MM) is consistently preceded by precursor conditions recognized clinically as monoclonal gammopathy of undetermined significance (MGUS) or smoldering myeloma (SMM). We interrogate, for the first time, the whole genome sequence (WGS) profile of 18 MGUS and compare them with those from 14 SMMs and 80 MMs. We show that cases with a non-progressing, clinically stable myeloma precursor condition (n=15) are characterized by later initiation in the patients life and by the absence of myeloma defining genomic events including: chromothripsis, templated insertions, mutations in driver genes, aneuploidy, and canonical APOBEC mutational activity. This data provides evidence that WGS can be used to recognize two biologically and clinically distinct myeloma precursor entities that are either progressive or stable.

cancer biology↗

Accelerated single cell seeding in relapsed multiple myeloma

The malignant progression of multiple myeloma is characterized by the seeding of cancer cells in different anatomic sites followed by their clonal expansion. It has been demonstrated that this spatial evolution at varying anatomic sites is characterized by genomic heterogeneity. However, it is unclear whether each anatomic site at relapse reflects the expansion of pre-existing but previously undetected disease or secondary seeding from other sites. Furthermore, genomic evolution over time at spatially distinct sites of disease has not been investigated in a systematic manner. To address this, we interrogated 25 samples, by whole genome sequencing, collected at autopsy from 4 patients with relapsed multiple myeloma and demonstrated that each site had a unique evolutionary trajectory characterized by distinct single and complex structural variants and copy number changes. By analyzing the landscape of mutational signatures at these sites and for an additional set of 125 published whole exomes collected from 51 patients, we demonstrate the profound mutagenic effect of melphalan and platinum in relapsed multiple myeloma. Chemotherapy-related mutagenic processes are known to introduce hundreds of unique mutations in each surviving cancer cell. These mutations can be detectable by bulk sequencing only in cases of clonal expansion of a single cancer cell bearing the mutational signature linked to chemotherapy exposure thus representing a unique single-cell genomic barcode linked to a discrete time window in each patients life. We leveraged this concept to show that multiple myeloma systemic seeding is accelerated at clinical relapse and appears to be driven by the survival and subsequent expansion of a single myeloma cell following treatment with high dose melphalan therapy and autologous stem cell transplant.

cancer biology↗

Revealing the impact of recurrent and rare structural variants in multiple myeloma

The landscape of structural variants (SVs) in multiple myeloma remains poorly understood. Here, we performed comprehensive classification and analysis of SVs in multiple myeloma, interrogating a large cohort of 762 patients with whole genome and RNA sequencing. We identified 100 SV hotspots involving 31 new candidate driver genes, including drug targets BCMA (TNFRSF17) and SLAMF7. Complex SVs, including chromothripsis and templated insertions, were present in 61 % of patients and frequently resulted in the simultaneous acquisition of multiple drivers. After accounting for all recurrent events, 63 % of SVs remained unexplained. Intriguingly, these rare SVs were associated with up to 7-fold enrichment for outlier gene expression, indicating that many rare driver SVs remain unrecognized and are likely important in the biology of individual tumors.

genomics↗

The mutational landscape of normal human endometrial epithelium

All normal somatic cells are thought to acquire mutations. However, characterisation of the patterns and consequences of somatic mutation in normal tissues is limited. Uterine endometrium is a dynamic tissue that undergoes cyclical shedding and reconstitution and is lined by a gland-forming epithelium. Whole genome sequencing of normal endometrial glands showed that most are clonal cell populations derived from a recent common ancestor with mutation burdens differing from other normal cell types and manyfold lower than endometrial cancers. Mutational signatures found ubiquitously account for most mutations. Many, in some women potentially all, endometrial glands are colonised by cell clones carrying driver mutations in cancer genes, often with multiple drivers. Total and driver mutation burdens increase with age but are also influenced by other factors including body mass index and parity. Clones with drivers often originate during early decades of life. The somatic mutational landscapes of normal cells differ between cell types and are revealing the procession of neoplastic change leading to cancer.

cancer biology↗

Genomic landscape and chronological reconstruction of driver events in multiple myeloma

Multiple myeloma (MM) has a heterogeneous genome, evolving through both pre-clinical and post-diagnosis phases. Here, using sequences from 67 MM genomes serially collected from 30 patients together with public datasets, we establish a hierarchy of driver lesions. Point mutations, structural variants and copy number aberrations define at least 7 genomic subgroups of MM, each with distinct sets of co-operating driver mutations. Complex structural events are major drivers of MM, including chromothripsis, chromoplexy and a replication-based mechanism of templated insertions: these typically occur early. Hyperdiploidy also occurs early, with individual chromosomes often gained in more than one chronological epoch of MM evolution, showing a preferred order of acquisition. Positively selected point mutations frequently occur in later phases of disease development, as do structural variants involving MYC. Thus, initiating driver events of MM, drawn from a limited repertoire of structural and numerical chromosomal changes, shape preferred trajectories of subsequent evolution.

cancer biology↗