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Age =50 years has been reported to be an adverse risk factor for allogeneic BMT, and consequently many of these patients are either not transplanted or treated on nonmyeloablative protocols. To study if older patients perform poorly relative to younger adults following myeloablative allogeneic transplants, we compared the outcomes of consecutive adults aged =50 years (n=51) to those <50 years (n=262) who received BU, CY±etoposide and allogeneic transplantation for AML, CML, MDS and NHL from 1984 to 2000. Median ages were 53 (range 50-66) and 35 (range 18-49) years for older and younger patients, respectively. Patients were low-risk if they had AML in CR1, CML in first chronic phase, refractory anemia, or NHL in remission or sensitive relapse at the time of transplantation. All others were high-risk. In patients with low-risk disease, there was no significant difference in overall survival (OS) between older and younger adults (P=0.64), while older patients tended to have a shorter OS among high-risk patients (P=0.06). The 3-year OS was 53% (95% CI, 29-77%) compared to 60% (95% CI, 50-69%) for older and younger patients with low-risk disease, respectively. The corresponding 3-year OS were 27% (95% CI, 11-43%) and 37% (95% CI, 25-45%) for high-risk patients. In low-risk patients, the incidence of acute and chronic graft-versus-host disease, and treatment-related mortality were similar in older and younger patients, while older patients experienced more treatment-related deaths by day 100. On multivariable analysis, age =50 years was a significant adverse factor only when high-risk patients were considered. We conclude that when radiation-free conditioning is used, age =50 years is not a significant adverse risk factor for allogeneic BMT in patients with low-risk disease, and that such patients should not be excluded from conventional myeloablative approaches until the efficacy of nonmyeloablative transplantation is better established.Bone Marrow... [ABSTRACT FROM AUTHOR]

Long-term outcome was analyzed in 28 patients transplanted between 1989 and 1992 following busulfan and cyclophosphamide and who had busulfan levels studied. While there was no significant correlation of busulfan levels with diagnosis, patients who had received extensive prior chemotherapy had a significantly higher area under the curve (AUC; P = 0.02) and maximum busulfan levels (Cmax; P = 0.03). High AUC was associated with the development of hepatic veno-occlusive disease (P = 0.03) and with early transplant-related mortality (P = 0.06). No significant correlation of busulfan levels with relapse, late non-relapse death, late complications, nor event-free survival was detected. Bone Marrow Transplantation (2001) 27, 1121–1124. [ABSTRACT FROM AUTHOR]

Results in 164 patients who underwent allogeneic marrow transplantation following busulfan and cyclophosphamide over a 15 year period were analyzed. Age (median 37, range 14–66 years) did not significantly affect the incidence of graft-versus-host disease (GVHD), but patients who received methotrexate with cyclosporine had a significantly lower incidence (P = 0.002) of chronic GVHD compared to those who received methylprednisolone with cyclosporine. Hepatic veno-occlusive disease (VOD) occurred less frequently in chronic phase patients (P = 0.002) and in those transplanted shortly after diagnosis (P = 0.001). Five year leukemia-free survival (LFS) for the entire group was 49% (95% CI 41–57%). For 102 patients who underwent transplantation in chronic phase, results were significantly improved by transplantation at a short interval following diagnosis, particularly within 3 months (P = 0.01), by the use of methotrexate and not corticosteroids for GVHD prevention (P = 0.03), and by use of HLA-identical sibling donors (P = 0.01). Age was not a significant adverse prognostic factor and transplantation was successfully performed in individuals up to age 66. Allogeneic transplantation in CML, including older patients and those with unrelated donors, can be most safely and effectively performed shortly after diagnosis. Bone Marrow Transplantation (2000) 26, 1037–1043. [ABSTRACT FROM AUTHOR]

Prognostic factors in 42 patients aged 11 to 62 (median 46) years, with myelodysplastic syndrome (MDS) or after leukemic transformation, who underwent allogeneic marrow transplantation between 1984 and 1999 were analyzed. Thirty-six had advanced disease morphology; 19 had leukemic transformation. Twenty-nine received a preparative regimen of BuCy2 and 13 busulfan 14 mg/kg, etoposide 50 mg/kg and cyclophosphamide 120 mg/kg. Severe hepatic veno-occlusive disease (VOD) occurred in three patients all of whom received anti-leukemic chemotherapy prior to transplantation. Fifteen patients (36%) died from early transplant-related complications; nine patients relapsed. The estimated 4 year disease-free survival (DFS) was 35% (95% CI 26–44%). Older age was the most significant adverse prognostic factor. Patients with leukemic transformation who underwent early transplantation had significantly better DFS than those treated first with chemotherapy (P = 0.002). Delayed toxicity was rare in these patients; no late relapses occurred. Bone Marrow Transplantation (2000) 25, 1219–1222. [ABSTRACT FROM AUTHOR]

The purpose of the study was to determine the toxicities and effectiveness of a novel preparative regimen of busulfan (Bu) 14 mg/kg, etoposide 50 or 60 mg/kg, and cyclophosphamide (Cy) 120 mg/kg in non-Hodgkin’s lymphoma (NHL) and to analyze results using doses based on different body weight parameters and the two different etoposide doses. Three hundred and eighty-two patients aged 16 to 72 underwent first autologous transplantation with mobilized peripheral blood progenitor cells between August 1992 and December 1998 at either of two transplant centers. Mucositis was the most common toxicity. Hepatic toxicity was the most common life-threatening toxicity; severe hepatic VOD occurred in 11 patients (2.9%). Ten patients (2.6%) died from treatment-related toxicity. The 3-year progression-free survival (PFS) for the entire group was 46.9% (95% CI, 40.5–53.3%). Elevated LDH, resistance to chemotherapy, and intermediate/aggressive histology were significant adverse prognostic factors. For patients in sensitive first relapse PFS was 47.0% (95% CI, 37–57%). Neither etoposide dose nor body weight parameter utilized significantly affected outcome. In conclusion, the novel preparative regimen of Bu, etoposide and Cy results in a low incidence of treatment-related mortality and is effective in the treatment of patients with NHL. Bone Marrow Transplantation (2000) 25, 1243–1248. [ABSTRACT FROM AUTHOR]

Abstract Background The granulocyte colony-stimulating factor receptor (G-CSFR) plays a critical role in maintaining homeostatic levels of circulating neutrophils (PMN). The mechanisms modulating G-CSFR surface expression to prevent chronic neutrophilia are poorly understood. Here, we report that neutrophil elastase (NE) proteolytically cleaves the G-CSFR on human PMN and blocks G-CSFR-mediated granulopoiesis in vitro. Methods Human peripheral blood PMN isolated from healthy donors were incubated with NE. Expression of the G-CSFR was analyzed by flow cytometry and western blot analyses. Detection of G-CSFR cleavage products from the culture supernatants was also performed. Human bone marrow mononuclear cells were also cultured in the presence or absence of NE to determine its effects on the proliferation of granulocyte-macrophage colony forming units (CFU-GM). Results Treatment of PMN with NE induced a time-dependent decrease in G-CSFR expression that correlated with its degradation and the appearance of proteolytic cleavage fragments in conditioned media. Immunoblot analysis confirmed the G-CSFR was cleaved at its amino-terminus. Treatment of progenitor cells with NE prior to culture inhibited the growth of granulocyte-macrophage colony forming units. Conclusions These findings indicate that in addition to transcriptional controls and ligand-induced internalization, direct proteolytic cleavage of the G-CSFR by NE also downregulates G-CSFR expression and inhibits G-CSFR-mediated granulopoiesis in vitro. Our results suggest that NE negatively regulates granulopoiesis through a novel negative feedback loop.

Background/Objectives : HIV-associated neurocognitive impairment (NCI) remains a prevalent issue among people with HIV (PWH) despite advancements in antiretroviral therapy (ART). The pathogenesis of HIV-associated NCI is linked to chronic neuroinflammation caused by HIV, even in those with successful viral suppression. Growth Differentiation Factor 15 (GDF15), a protein involved in inflammatory and metabolic stress responses, has emerged as a key player and potential biomarker for various neurological conditions. This study investigates the relationship between GDF15 expression and HIV-associated NCI. Methods : PWH from the California NeuroAIDS Tissue Network (CNTN) underwent comprehensive neuropsychological exams within 12 months before death and were categorized based on cognitive performance. We examined GDF15 levels in their CSF (Cerebrospinal Fluid) and brain tissues using immunoblotting, immunohistochemistry, double immunolabeling, and ELISA. Results : The cohort was of a similar age across HIV-associated NCI statuses (mean = 40.5), with a predominance of males (77%). The mean plasma viral load was 3.56 log 10 copies/mL for Neurocognitively Unimpaired (NUI) PWH and 5.38 log10 copies/mL for people with HIV-associated NCI. GDF15 protein levels were significantly elevated in the frontal cortices of PWH with NCI compared to NUI PWH. Conclusions : The findings indicate that GDF15 may play a role in the pathogenesis of HIV-associated NCI, possibly through neuroinflammatory mechanisms. The strong association between GDF15 levels and cognitive impairment severity suggests its potential as a biomarker for the early detection and monitoring of NCI in PWH.

APOBEC3B (A3B) is implicated in DNA mutations that facilitate tumor evolution. Although structures of its individual N- and C-terminal domains (NTD and CTD) have been resolved through X-ray crystallography, the full-length A3B (fl-A3B) structure remains elusive, limiting understanding of its dynamics and mechanisms. In particular, the APOBEC3B C-terminal domain (A3Bctd) active site is frequently closed in models and structures. In this study, we built several new models of fl-A3B using integrative structural biology methods and selected a top model for further dynamical investigation. We compared dynamics of the truncated (A3Bctd) to the fl-A3B via conventional and Gaussian accelerated molecular dynamics (MD) simulations. Subsequently, we employed weighted ensemble methods to explore the fl-A3B active site opening mechanism, finding that interactions at the NTD-CTD interface enhance the opening frequency of the fl-A3B active site. Our findings shed light on the structural dynamics of fl-A3B, which may offer new avenues for therapeutic intervention in cancer., Competing Interests: Conflict of Interest The authors declare no conflict of interest.

Using haploidentical donors for allogeneic hematopoietic cell transplantation (HCT) broadens transplant accessibility to a growing number of patients with hematologic disorders. Moreover, haploidentical HCT with post-transplant cyclophosphamide (PTCy) has become widespread practice due to accumulating evidence demonstrating favorable rates of survival and graft-versus-host disease (GvHD). Most studies comparing outcomes by donor sources have been confounded by variability in conditioning regimens, graft type (peripheral blood [PB] or bone marrow), and post-transplant GvHD prophylaxis (PTCy or non-PTCy), making it difficult to define the effect of donor source on outcomes. Levine Cancer Institute started a transplant and cellular therapy program in 2014, with both haploidentical and matched related donor (MRD) transplants initially performed using a uniform reduced-intensity conditioning (RIC) regimen, PB grafts, and PTCy-based GvHD prophylaxis. This retrospective observational study was conducted to compare the clinical outcomes associated with RIC haploidentical HCT and MRD HCT in patients receiving identical conditioning regimens, graft types, and supportive care. Our transplant database was queried to evaluate demographic characteristics, clinical features, and outcomes of RIC HCT for consecutive patients with hematologic malignancies who received haploidentical or MRD grafts between March 2014 and December 2017. An MRD was the preferred donor source; when unavailable, a haploidentical donor was used. Sixty-seven patients underwent haploidentical HCT and 25 MRD HCT. Overall, characteristics of transplant recipients were similar for the haploidentical and MRD groups; however, haploidentical donors were younger than MRDs (median 36 yr versus 57 yr, P < .0001). Results of univariable analysis showed similar overall survival (OS) for haploidentical and MRD HCT (hazard ratio [HR], 1.15; 95% CI, 0.61 to 2.15; P = .669). One-year, 1-yr, and 5-yr OS were 80.2%, 54.7%, and 41.2% for haploidentical HCT and 76.0%, 55.7%, and 51.1% for MRD HCT, respectively. With a median follow-up of 81.90 months, results of multivariable analysis revealed that donor source (haploidentical versus MRD) was not significantly associated with OS (HR, 0.97; 95% CI, 0.51 to 1.87; P = .933), relapse-free survival (HR, 0.75; 95% CI, 0.42 to 1.35; P = .337), cumulative incidence of relapse (HR, 0.81; 95% CI, 0.39 to 1.70; P = .579), or non-relapse mortality (HR, 1.12; 95% CI, 0.40 to 3.14; P = .827). Cumulative incidences of acute GvHD (aGvHD) and chronic GvHD (cGvHD) were not significantly different for haploidentical and MRD HCT (grades II to IV aGvHD: HR, 1.78; 95% CI, 0.72 to 4.37; P = .210; grades III to IV aGvHD: HR, 2.84; 95% CI, 0.34 to 23.63; P = .335; cGvHD: HR, 1.00; 95% CI 0.36 to 2.76; P = .995). With care that was homogenous in terms of conditioning regimens, graft type, GvHD prophylaxis, and supportive care, 92 patients who were biologically randomized to either haploidentical HCT or MRD HCT after RIC with PTCy had comparable outcomes., (Copyright © 2024 The American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc. All rights reserved.)

Purpose: Venetoclax has made a significant impact in the treatment of chronic lymphocytic leukemia (CLL) due to its ability to induce deep and durable remissions with a finite duration of oral therapy. However, it can lead to tumor lysis syndrome (TLS) which is mitigated with dose escalation strategies. Patients who initiate venetoclax need to follow rigorous, and potentially burdensome, TLS monitoring during dose ramp-up. The frequency with which this rigorous monitoring leads to therapeutic interventions in clinical practice has not been well described. We conducted a study to assess the incidence of TLS and interventions needed after initiation of venetoclax in patients with CLL., Methods: Adult patients with CLL who started treatment with venetoclax between July 2017 and March 2021 at Levine Cancer Institute were included in this study. Adherence to the venetoclax package insert (PI) for tumor lysis monitoring, incidence of laboratory as well as clinical TLS, and interventions resulting from the monitoring of TLS were collected., Results: We report outcomes on 73 consecutive patients with CLL who initiated venetoclax. The majority of patients had low (49%) or medium (44%) tumor burden. During venetoclax ramp-up, 66% of patients adhered strictly to TLS monitoring as per the venetoclax PI. One patient developed laboratory TLS, and no patients developed clinical TLS. Six patients received unplanned interventions to treat TLS; all had medium or high tumor burden. There were no unplanned interventions in patients with low tumor burden., Conclusion: In patients with low and medium tumor burden CLL who start venetoclax, the incidence of TLS is very low, and interventions are uncommonly needed.

Malignancy is a well-known risk factor for venous thromboembolism (VTE), and the Khorana risk score is effective for screening patients with solid tumors. However, there is a lack of validated screening tools and established risk factors for patients undergoing hematopoietic stem cell transplantation (HCT). Current literature reports a 2.5% to 8.5% incidence of VTE in HCT recipients. Anticoagulation is difficult to manage post-transplantation, given prolonged thrombocytopenia and the likelihood of bleeding. By identifying risk factors, a predictive model may be developed to prospectively test prophylaxis strategies in patients at the highest risk of a thromboembolic event (TE). This retrospective single-center study evaluated the cumulative incidence of TE at 6 months following allogeneic or autologous HCT in adult subjects undergoing transplantation between March 2014 and December 2019. The study also aimed to identify risk factors for developing a TE, evaluate the time from HCT to TE, and compare 1-year survival following HCT between patients with a TE and those without a TE. In evaluating the incidence of TE, ICD-9 and ICD-10 codes were used to determine cancer diagnosis, TE events occurring up 180 days after HCT, and comorbidities of interest. Each subject was reviewed for data accuracy by a manual retrospective chart review. Statistical tests including the cumulative incidence method with competing risks, Gray's test, and univariate and multivariate Cox proportional hazards models were used to analyze the time to first TE, evaluate risk factors, and assess 1-year survival post-HCT in relation to TEs occurring within 180 days of HCT. Variables examined included age, sex, body mass index, transplant type, hospital length of stay (LOS), history of TE prior to transplantation, active infections, graft-versus-host disease (GVHD), veno-occlusive disorder, cytomegalovirus serostatus, and other factors. The study included 636 evaluable patients; the majority were male (57.9%) and white (68.7%) and had undergone autologous HCT (68.4%). Twenty-nine patients (4.6%) experienced a TE within 180 days post-transplantation. TEs were more common in the allogeneic HCT recipients (n = 13/201; 6.5%) compared to the autologous HCT recipients (n = 16/435; 3.7%; P = .122). The cumulative incidence of TE was higher in patients who developed an active infection compared to those who did not (7.6% versus 3.1%; P = .011). Hospital LOS (hazard ratio [HR], 1.03; 95% confidence interval [CI], 1.0 to 1.06; P = .036) and active infection (HR, 2.34; 95% CI, 1.1 to 4.95; P = .027) were significantly associated with TE in univariate analysis but were not retained in the final multivariate model. There was no difference in 1-year survival between all patients who experienced a TE and those who did not; however, in the autologous HCT group, 1-year survival rate was significantly lower in patients with a TE compared to those without TE (80.4% versus 95.3%; P = .01) (Figure 3C). None of the examined variables, including a history of TE and GVHD, were associated with TE risk. Although the overall incidence of TE in our study was low, many patients received pharmacologic or mechanical prophylaxis, suggesting that such strategies may be effective in mitigating TE risk. Such factors as infection and hospital LOS may further increase TE risk. Providers should continuously monitor for risk factors and signs and symptoms of TE post-transplantation. It is also imperative to consider chemical prophylaxis if counts are recovered during hospitalization., (Copyright © 2024 The American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc. All rights reserved.)

The implementation of chimeric antigen receptor T (CAR T) therapy in the real-world setting is hindered by logistical and financial barriers, impacting timely access to this life-saving treatment. Clinical trials have reported the time from leukapheresis to CAR T cell infusion (vein-to-vein time) but not the time from CAR T referral to infusion (decision-to-vein time). Herein, we report the barriers to CAR T therapy in a real-world setting. We evaluated the factors influencing the decision-to-vein time and explored the association with clinical outcomes in patients with relapsed or refractory diffuse large B cell lymphoma (DLBCL) who received CAR T therapy. We conducted a retrospective study of adult patients with relapsed/refractory DLBCL who underwent consultation for CAR T cell therapy at Levine Cancer Institute and Wake Forest Comprehensive Cancer Center and collected information regarding demographic data, referral type, insurance type, CAR T product, and survival outcomes. The effects of variables on decision-to-vein time were analyzed by Fisher's exact test for categorial variables and Wilcoxon rank-sum test for continuous variables. Survival analyses were performed using Kaplan-Meier and Cox Proportional Hazard models. The study included 142 patients who were referred for CAR T of which 99 patients received CAR T. Median decision-to-vein time was 62 days compared to median vein-to-vein time of 32 days. Patients with private insurance took longer to obtain financial clearance compared to patients with government insurance (median 25 versus 9 days, P < .001). Of those with private insurance (n = 63), 35% needed a single-case agreement (SCA) which led to significant delay in receiving financial clearance (median 50.5 versus 19 days, P < .001) and increased decision-to-vein time (median 75 versus 55 days, P < .001) compared to those who did not need SCA. Decision-to-vein time was significantly different among various products, clinical trial being the shortest (median 47 days, n = 9) and non-conforming products being the longest (median 94.5 days, n = 6) (P< .001). Axi-cel had the shortest median decision-to-vein time at 61 days compared to 81 days with tisa-cel and 85 days with liso-cel. Although delays in receiving CAR T therapy did not impact survival, the median overall survival for patients who were referred for CAR T therapy but did not receive it, was significantly lower than those who received CAR T cell therapy (9.0 versus 21.0 months, P < .001). Decision-to-vein time is a major cause of delay in receiving CAR T therapy. SCAs lead to significant increase in decision-to-vein time leading to delays in CAR T therapy in a real-world setting. Patients who were referred for CAR T but are not able to receive it, have inferior survival compared to CAR T recipients. Our findings underscore the significance of addressing administrative hurdles, such as SCAs and insurance approvals, for timely access to CAR T therapy for patients with DLBCL., Competing Interests: Conflict of Interest Statement The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this article., (Copyright © 2024 The American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc. All rights reserved.)

Background: Aside from the canonical role of PDL1 as a tumour surface-expressed immune checkpoint molecule, tumour-intrinsic PDL1 signals regulate non-canonical immunopathological pathways mediating treatment resistance whose significance, mechanisms, and therapeutic targeting remain incompletely understood. Recent reports implicate tumour-intrinsic PDL1 signals in the DNA damage response (DDR), including promoting homologous recombination DNA damage repair and mRNA stability of DDR proteins, but many mechanistic details remain undefined., Methods: We genetically depleted PDL1 from transplantable mouse and human cancer cell lines to understand consequences of tumour-intrinsic PDL1 signals in the DNA damage response. We complemented this work with studies of primary human tumours and inducible mouse tumours. We developed novel approaches to show tumour-intrinsic PDL1 signals in specific subcellular locations. We pharmacologically depleted tumour PDL1 in vivo in mouse models with repurposed FDA-approved drugs for proof-of-concept clinical translation studies., Results: We show that tumour-intrinsic PDL1 promotes the checkpoint kinase-2 (Chk2)-mediated DNA damage response. Intracellular but not surface-expressed PDL1 controlled Chk2 protein content post-translationally and independently of PD1 by antagonising PIRH2 E3 ligase-mediated Chk2 polyubiquitination and protein degradation. Genetic tumour PDL1 depletion specifically reduced tumour Chk2 content but not ATM, ATR, or Chk1 DDR proteins, enhanced Chk1 inhibitor (Chk1i) synthetic lethality in vitro in diverse human and murine tumour models, and improved Chk1i efficacy in vivo. Pharmacologic tumour PDL1 depletion with cefepime or ceftazidime replicated genetic tumour PDL1 depletion by reducing tumour Chk2, inducing Chk1i synthetic lethality in a tumour PDL1-dependent manner, and reducing in vivo tumour growth when combined with Chk1i., Conclusions: Our data challenge the prevailing surface PDL1 paradigm, elucidate important and previously unappreciated roles for tumour-intrinsic PDL1 in regulating the ATM/Chk2 DNA damage response axis and E3 ligase-mediated protein degradation, suggest tumour PDL1 as a biomarker for Chk1i efficacy, and support the rapid clinical potential of pharmacologic tumour PDL1 depletion to treat selected cancers., (© 2024. The Author(s).)

Triggering receptor expressed on myeloid cells 2 (TREM2) is involved in neuroinflammation and HIV-associated neurocognitive impairment (NCI). People with HIV (PWH) using cannabis exhibit lower inflammation and neurological disorders. We hypothesized that TREM2 dysfunction mediates HIV neuropathogenesis and can be reversed by cannabinoids. EcoHIV-infected wildtype (WT) and TREM2 R47H mutant mice were used to study HIV's impact on TREM2 and behavior. TREM2 and related gene expressions were examined in monocyte-derived macrophages (MDMs) from PWH ( n = 42) and people without HIV (PWoH; n = 19) with varying cannabis use via RNA sequencing and qPCR. Differences in membrane-bound and soluble TREM2 (sTREM2) were evaluated using immunocytochemistry (ICC) and ELISA. EcoHIV increased immature and C-terminal fragment forms of TREM2 in WT mice but not in TREM2 R47H mice, with increased IBA1 protein in TREM2 R47H hippocampi, correlating with worse memory test performance. TREM2 mRNA levels increased with age in PWoH but not in PWH. Cannabidiol (CBD) treatment increased TREM2 mRNA alone and with IL1β. RNA-seq showed the upregulation of TREM2-related transcripts in cannabis-using PWH compared to naïve controls. IL1β increased sTREM2 and reduced membrane-bound TREM2, effects partially reversed by CBD. These findings suggest HIV affects TREM2 expression modulated by cannabis and CBD, offering insights for therapeutic strategies.

Chemotherapy induced polyploidy is a mechanism of inherited drug resistance resulting in an aggressive disease course in cancer patients. Alisertib, an Aurora Kinase A (AK-A) ATP site inhibitor, induces cell cycle disruption resulting in polyaneuploidy in Diffuse Large B Cell Lymphoma (DLBCL). Propidium iodide flow cytometry was utilized to quantify alisertib induced polyploidy in U2932 and VAL cell lines. In U2932 cells, 1µM alisertib generated 8n+ polyploidy in 48% of the total cell population after 5 days of treatment. Combination of Aurkin A an AK-A/TPX2 site inhibitor, plus alisertib disrupted alisertib induced polyploidy in a dose-dependent manner with associated increased apoptosis. We generated a stable FUCCI U2932 cell line expressing Geminin-clover (S/G 2 /M) and cdt1-mKO (G 1 ), to monitor cell cycle progression. Using this system, we identified alisertib induces polyploidy through endomitosis, which was eliminated with Aurkin A treatment. In a VAL mouse xenograft model, we show polyploidy generation in alisertib treated mice versus vehicle control or Aurkin A. Aurkin A plus alisertib significantly reduced polyploidy to vehicle control levels. Our in vitro and in vivo studies show that Aurkin A synergizes with alisertib and significantly decreases the alisertib dose needed to disrupt polyploidy while increasing apoptosis in DLBCL cells., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Inc.)

Transcription and splicing of pre-messenger RNA are closely coordinated, but how this functional coupling is disrupted in human diseases remains unexplored. Using isogenic cell lines, patient samples, and a mutant mouse model, we investigated how cancer-associated mutations in SF3B1 alter transcription. We found that these mutations reduce the elongation rate of RNA polymerase II (RNAPII) along gene bodies and its density at promoters. The elongation defect results from disrupted pre-spliceosome assembly due to impaired protein-protein interactions of mutant SF3B1. The decreased promoter-proximal RNAPII density reduces both chromatin accessibility and H3K4me3 marks at promoters. Through an unbiased screen, we identified epigenetic factors in the Sin3/HDAC/H3K4me pathway, which, when modulated, reverse both transcription and chromatin changes. Our findings reveal how splicing factor mutant states behave functionally as epigenetic disorders through impaired transcription-related changes to the chromatin landscape. We also present a rationale for targeting the Sin3/HDAC complex as a therapeutic strategy., Competing Interests: Declaration of interests Amit Verma has received research funding from Prelude, B.M.S., G.S.K., Incyte, Medpacto, Curis, and Eli Lilly; is a scientific advisor for Stelexis, Bakx, Novartis, Acceleron, and Celgene; receives honoraria from Stelexis and Janssen; and holds equity in Stelexis and Bakx., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Efficient DNA repair and limitation of genome rearrangements rely on crosstalk between different DNA double-strand break (DSB) repair pathways, and their synchronization with the cell cycle. The selection, timing and efficacy of DSB repair pathways are influenced by post-translational modifications of histones and DNA damage repair (DDR) proteins, such as phosphorylation. While the importance of kinases and serine/threonine phosphatases in DDR have been extensively studied, the role of tyrosine phosphatases in DNA repair remains poorly understood. In this study, we have identified EYA4 as the protein phosphatase that dephosphorylates RAD51 on residue Tyr315. Through its Tyr phosphatase activity, EYA4 regulates RAD51 localization, presynaptic filament formation, foci formation, and activity. Thus, it is essential for homologous recombination (HR) at DSBs. DNA binding stimulates EYA4 phosphatase activity. Depletion of EYA4 decreases single-stranded DNA accumulation following DNA damage and impairs HR, while overexpression of EYA4 in cells promotes dephosphorylation and stabilization of RAD51, and thereby nucleoprotein filament formation. Our data have implications for a pathological version of RAD51 in EYA4-overexpressing cancers., (© The Author(s) 2023. Published by Oxford University Press on behalf of Nucleic Acids Research.)

Purpose: Patients with chronic lymphocytic leukemia (CLL) treated with ibrutinib are at risk of developing cardiovascular side effects (CVSE). The molecular determinants of CVSEs have not been fully elucidated. We interrogated genetic polymorphisms in the Bruton tyrosine kinase (BTK) signaling pathway for their association with ibrutinib-related CVSEs., Experimental Design: We conducted a retrospective/prospective observational pharmacogenetic study of 50 patients with newly diagnosed or relapsed CLL who received ibrutinib at a starting daily dose of 420 mg for at least 6 months. CVSEs, primarily atrial fibrillation and hypertension, occurred in 10 patients (20%), of whom 4 discontinued therapy. DNA was isolated from buccal swabs of all 50 patients and genotyped for 40 SNPs in GATA4, SGK1, KCNQ1, KCNA4, NPPA, and SCN5A using a customized next-generation sequencing panel. Univariate and multivariate logistic regression analysis were performed to determine genetic and clinical factors associated with the incidence of ibrutinib-related CVSEs., Results: GATA4 rs804280 AA (P = 0.043), KCNQ1 rs163182 GG (P = 0.036), and KCNQ1 rs2237895 AA (P = 0.023) genotypes were univariately associated with ibrutinib-related CVSEs. On the basis of multivariate analysis, a high genetic risk score, defined as the presence of at least two of these genotypes, was associated with 11.5-fold increased odds of CVSEs (P = 0.019; 95% confidence interval, 1.79-119.73)., Conclusions: Our findings suggest possible genetic determinants of ibrutinib-related CVSEs in CLL. If replicated in a larger study, pretreatment pharmacogenetic testing for GATA4 and KCNQ1 polymorphisms may be a useful clinical tool for personalizing treatment selection for CLL and/or instituting early risk mitigation strategies., (©2023 American Association for Cancer Research.)

Background: Increasing evidence suggests that the endocannabinoid system (ECS) in the brain controls anxiety and may be a therapeutic target for the treatment of anxiety disorders. For example, both pharmacological and genetic disruption of cannabinoid receptor subtype-1 (CB 1 R) signaling in the central nervous system is associated with increased anxiety-like behaviors in rodents, while activating the system is anxiolytic. Sex is also a critical factor that controls the behavioral expression of anxiety; however, roles for the ECS in the gut in these processes and possible differences between sexes are largely unknown. Objective: In this study, we aimed to determine if CB 1 Rs in the intestinal epithelium exert control over anxiety-like behaviors in a sex-dependent manner. Methods: We subjected male and female mice with conditional deletion of CB 1 Rs in the intestinal epithelium (intCB 1 -/- ) and controls (intCB 1 +/+ ) to the elevated plus maze (EPM), light/dark box, and open field test. Corticosterone (CORT) levels in plasma were measured at baseline and immediately after EPM exposure. Results: When compared with intCB 1 +/+ male mice, intCB 1 -/- male mice exhibited reduced levels of anxiety-like behaviors in the EPM and light/dark box. In contrast to male mice, no differences were found between female intCB 1 +/+ and intCB 1 -/- mice. Circulating CORT was higher in female versus male mice for both genotype groups at baseline and after EPM exposure; however, there was no effect of genotype on CORT levels. Conclusions: Collectively, these results indicate that genetic deletion of CB 1 Rs in the intestinal epithelium is associated with an anxiolytic phenotype in a sex-dependent manner.

CYP2C19-guided voriconazole dosing reduces pharmacokinetic variability, but many patients remain subtherapeutic. The aim of this study was to evaluate the effect of candidate genes and a novel CYP2C haplotype on voriconazole trough concentrations in patients receiving CYP2C19-guided dosing. This is a retrospective candidate gene study in allogeneic hematopoietic cell transplant (HCT) patients receiving CYP2C19-guided voriconazole dosing. Patients were genotyped for ABCB1, ABCG2, CYP2C9, CYP3A4, CYP3A5, and the CYP2C haplotype. Of 185 patients, 36% were subtherapeutic (of which 79% were normal or intermediate metabolizers). In all patients, CYP2C19 (p < 0.001), age (p = 0.018), and letermovir use (p = 0.001) were associated with voriconazole concentrations. In the subset receiving 200 mg daily (non-RM/UMs), CYP2C19 (p = 0.004) and ABCG2 (p = 0.015) were associated with voriconazole concentrations; CYP2C19 (p = 0.028) and letermovir use (p = 0.001) were associated with subtherapeutic status. CYP2C19 phenotype and letermovir use were significantly associated with subtherapeutic voriconazole concentrations and may be used to improve voriconazole precision dosing, while further research is needed to clarify the role of ABCG2 in voriconazole dosing., (© 2023. The Author(s), under exclusive licence to Springer Nature Limited.)

The Eyes Absent (EYA) family of proteins is an atypical group of four dual-functioning protein phosphatases (PP), which have been linked to many vital cellular processes and organogenesis pathways. The four family members of this PP family possess transcriptional activation and phosphatase functions, with serine/threonine and tyrosine phosphatase domains. EYA4 has been associated with several human cancers, with tumor-suppressing and tumor-promoting roles. However, EYA4 is the least well-characterized member of this unique family of PP, with its biological functions and molecular mechanisms in cancer progression, particularly in breast cancer, still largely unknown. In the present study, we found that the over-expression of EYA4 in breast tissue leads to an aggressive and invasive breast cancer phenotype, while the inhibition of EYA4 reduced tumorigenic properties of breast cancer cells in vitro and in vivo. Cellular changes downstream of EYA4, including cell proliferation and migration, may explain the increased metastatic power of breast cancer cells over-expressing EYA4. Mechanistically, EYA4 prevents genome instability by inhibiting the accumulation of replication-associated DNA damage. Its depletion results in polyploidy as a consequence of endoreplication, a phenomenon that can occur in response to stress. The absence of EYA4 leads to spontaneous replication stress characterized by the activation of the ATR pathway, sensitivity to hydroxyurea, and accumulation of endogenous DNA damage as indicated by increased γH2AX levels. In addition, we show that EYA4, specifically its serine/threonine phosphatase domain, plays an important and so far, unexpected role in replication fork progression. This phosphatase activity is essential for breast cancer progression and metastasis. Taken together, our data indicate that EYA4 is a novel potential breast cancer oncogene that supports primary tumor growth and metastasis. Developing therapeutics aimed at the serine/threonine phosphatase activity of EYA4 represents a robust strategy for killing breast cancer cells, to limit metastasis and overcome chemotherapy resistance caused by endoreplication and genomic rearrangements., (© 2023. BioMed Central Ltd., part of Springer Nature.)

Mutations in the Fragile X Messenger Ribonucleoprotein 1 (FMR1) gene are linked to Fragile X Syndrome, the most common monogenic cause of intellectual disability and autism. People affected with mutations in FMR1 have higher incidence of obesity, but the mechanisms are largely unknown. In the current study, we determined that male Fmr1 knockout mice (KO, Fmr1 -/y ), but not female Fmr1 -/- , exhibit increased weight when compared to wild-type controls, similarly to humans with FMR1 mutations. No differences in food or water intake were found between groups; however, male Fmr1 -/y display lower locomotor activity, especially during their active phase. Moreover, Fmr1 -/y have olfactory dysfunction determined by buried food test, although they exhibit increased compulsive behavior, determined by marble burying test. Since olfactory brain regions communicate with hypothalamic regions that regulate food intake, including POMC neurons that also regulate locomotion, we examined POMC neuron innervation and numbers in Fmr1 -/y mice. POMC neurons express Fmrp, and POMC neurons in Fmr1 -/y have higher inhibitory GABAergic synaptic inputs. Consistent with increased inhibitory innervation, POMC neurons in the Fmr1 -/y mice exhibit lower activity, based on cFOS expression. Notably, Fmr1 -/y mice have fewer POMC neurons than controls, specifically in the rostral arcuate nucleus, which could contribute to decreased locomotion and increased body weight. These results suggest a role for Fmr1 in the regulation of POMC neuron function and the etiology of Fmr1-linked obesity., (© 2023. Springer Nature Limited.)

The Eyes Absent (EYA) family of proteins is an atypical group of four dual-functioning protein phosphatases, which have been linked to many vital cellular processes and organogenesis pathways. Like the other isoforms, EYA4 possesses transcriptional activation and phosphatase functions, with serine/threonine and tyrosine phosphatase domains. EYA4 has been associated with several human cancers, with tumor-suppressing and tumor-promoting roles. However, EYA4 is the least well-characterized member of this unique family of phosphatases, with its biological functions and molecular mechanisms in cancer progression, particularly in breast cancer, still largely unknown. In the present study, we found that the over-expression of EYA4 in breast tissue leads to an aggressive and invasive breast cancer phenotype, while the inhibition of EYA4 reduced tumorigenic properties of breast cancer cells in vitro and in vivo . Cellular changes downstream of EYA4, including cell proliferation and migration, may explain the increased metastatic power of breast cancer cells over-expressing EYA4. Mechanistically, EYA4 prevents genome instability by inhibiting the accumulation of replication-associated DNA damage. Its depletion results in polyploidy as a consequence of endoreplication, a phenomenon that can occur in response to stress. The absence of EYA4 leads to spontaneous replication stress characterized by the activation of the ATR pathway, sensitivity to hydroxyurea, and accumulation of endogenous DNA damage as indicated by increased γH2AX levels. In addition, we show that EYA4, specifically its serine/threonine phosphatase domain, plays an important and so far, unexpected role in replication fork progression. This phosphatase activity is essential for breast cancer progression and metastasis. Taken together, our data indicate that EYA4 is a novel breast cancer oncogene that supports primary tumor growth and metastasis. Developing therapeutics aimed at the serine/threonine phosphatase activity of EYA4 represents a robust strategy for killing breast cancer cells, to limit metastasis and overcome chemotherapy resistance caused by endoreplication and genomic rearrangements.

Transcription and splicing of pre-messenger RNA are closely coordinated, but how this functional coupling is disrupted in human disease remains unexplored. Here, we investigated the impact of non-synonymous mutations in SF3B1 and U2AF1, two commonly mutated splicing factors in cancer, on transcription. We find that the mutations impair RNA Polymerase II (RNAPII) transcription elongation along gene bodies leading to transcription-replication conflicts, replication stress and altered chromatin organization. This elongation defect is linked to disrupted pre-spliceosome assembly due to impaired association of HTATSF1 with mutant SF3B1. Through an unbiased screen, we identified epigenetic factors in the Sin3/HDAC complex, which, when modulated, normalize transcription defects and their downstream effects. Our findings shed light on the mechanisms by which oncogenic mutant spliceosomes impact chromatin organization through their effects on RNAPII transcription elongation and present a rationale for targeting the Sin3/HDAC complex as a potential therapeutic strategy., Highlights: Oncogenic mutations of SF3B1 and U2AF1 cause a gene-body RNAPII elongation defectRNAPII transcription elongation defect leads to transcription replication conflicts, DNA damage response, and changes to chromatin organization and H3K4me3 marksThe transcription elongation defect is linked to disruption of the early spliceosome formation through impaired interaction of HTATSF1 with mutant SF3B1.Changes to chromatin organization reveal potential therapeutic strategies by targeting the Sin3/HDAC pathway.

BRCA1-mediated homologous recombination is an important DNA repair mechanism that is the target of FDA-approved PARP inhibitors, yet details of BRCA1-mediated functions remain to be fully elucidated. Similarly, immune checkpoint molecules are targets of FDA-approved cancer immunotherapies, but the biological and mechanistic consequences of their application are incompletely understood. We show here that the immune checkpoint molecule PD-L1 regulates homologous recombination in cancer cells by promoting BRCA1 nuclear foci formation and DNA end resection. Genetic depletion of tumor PD-L1 reduced homologous recombination, increased nonhomologous end joining, and elicited synthetic lethality to PARP inhibitors olaparib and talazoparib in vitro in some, but not all, BRCA1 wild-type tumor cells. In vivo, genetic depletion of tumor PD-L1 rendered olaparib-resistant tumors sensitive to olaparib. In contrast, anti-PD-L1 immune checkpoint blockade neither enhanced olaparib synthetic lethality nor improved its efficacy in vitro or in wild-type mice. Tumor PD-L1 did not alter expression of BRCA1 or its cofactor BARD1 but instead coimmunoprecipitated with BARD1 and increased BRCA1 nuclear accumulation. Tumor PD-L1 depletion enhanced tumor CCL5 expression and TANK-binding kinase 1 activation in vitro, similar to known immune-potentiating effects of PARP inhibitors. Collectively, these data define immune-dependent and immune-independent effects of PARP inhibitor treatment and genetic tumor PD-L1 depletion. Moreover, they implicate a tumor cell-intrinsic, immune checkpoint-independent function of PD-L1 in cancer cell BRCA1-mediated DNA damage repair with translational potential, including as a treatment response biomarker., Significance: PD-L1 upregulates BRCA1-mediated homologous recombination, and PD-L1-deficient tumors exhibit BRCAness by manifesting synthetic lethality in response to PARP inhibitors, revealing an exploitable therapeutic vulnerability and a candidate treatment response biomarker. See related commentary by Hanks, p. 2069., (©2022 American Association for Cancer Research.)

Uterine fibroid (UF) driver mutations in Mediator complex subunit 12 (MED12) trigger genomic instability and tumor development through unknown mechanisms. Herein, we show that MED12 mutations trigger aberrant R-loop-induced replication stress, suggesting a possible route to genomic instability and a novel therapeutic vulnerability in this dominant UF subclass. Immunohistochemical analyses of patient-matched tissue samples revealed that MED12 mutation-positive UFs, compared to MED12 mutation-negative UFs and myometrium, exhibited significantly higher levels of R-loops and activated markers of Ataxia Telangiectasia and Rad3-related (ATR) kinase-dependent replication stress signaling in situ. Single molecule DNA fiber analysis revealed that primary cells from MED12 mutation-positive UFs, compared to those from patient-matched MED12 mutation-negative UFs and myometrium, exhibited defects in replication fork dynamics, including reduced fork speeds, increased and decreased numbers of stalled and restarted forks, respectively, and increased asymmetrical bidirectional forks. Notably, these phenotypes were recapitulated and functionally linked in cultured uterine smooth muscle cells following chemical inhibition of Mediator-associated CDK8/19 kinase activity that is known to be disrupted by UF driver mutations in MED12. Thus, Mediator kinase inhibition triggered enhanced R-loop formation and replication stress leading to an S-phase cell cycle delay, phenotypes that were rescued by overexpression of the R-loop resolving enzyme RNaseH. Altogether, these findings reveal MED12-mutant UFs to be uniquely characterized by aberrant R-loop induced replication stress, suggesting a possible basis for genomic instability and new avenues for therapeutic intervention that involve the replication stress phenotype in this dominant UF subtype., (© 2022. The Author(s).)

Drugs that block the activity of the methyltransferase EZH2 are in clinical development for the treatment of non-Hodgkin lymphomas harboring EZH2 gain-of-function mutations that enhance its polycomb repressive function. We have previously reported that EZH2 can act as a transcriptional activator in castration-resistant prostate cancer (CRPC). Now we show that EZH2 inhibitors can also block the transactivation activity of EZH2 and inhibit the growth of CRPC cells. Gene expression and epigenomics profiling of cells treated with EZH2 inhibitors demonstrated that in addition to derepressing gene expression, these compounds also robustly down-regulate a set of DNA damage repair (DDR) genes, especially those involved in the base excision repair (BER) pathway. Methylation of the pioneer factor FOXA1 by EZH2 contributes to the activation of these genes, and interaction with the transcriptional coactivator P300 via the transactivation domain on EZH2 directly turns on the transcription. In addition, CRISPR-Cas9-mediated knockout screens in the presence of EZH2 inhibitors identified these BER genes as the determinants that underlie the growth-inhibitory effect of EZH2 inhibitors. Interrogation of public data from diverse types of solid tumors expressing wild-type EZH2 demonstrated that expression of DDR genes is significantly correlated with EZH2 dependency and cellular sensitivity to EZH2 inhibitors. Consistent with these findings, treatment of CRPC cells with EZH2 inhibitors dramatically enhances their sensitivity to genotoxic stress. These studies reveal a previously unappreciated mechanism of action of EZH2 inhibitors and provide a mechanistic basis for potential combination cancer therapies., Competing Interests: Competing interest statement: N.S. receives research grant funding from AstraZeneca. J.E.B. is an executive and shareholder of Novartis AG and has been a founder and shareholder of SHAPE (acquired by Medivir), Acetylon (acquired by Celgene), Tensha (acquired by Roche), Syros, Regency, and C4 Therapeutics. P.W.K. serves on the scientific advisory board (SAB) of BIND Biosciences, BN Immunotherapeutics, GE Healthcare, Janssen, New England Research Institutes, OncoCellMDX, Progenity, Sanofi, and Thermo Fisher. He shares investment interests in Context Therapeutics, Druggability Technologies Holdings Ltd. (DRGT), Placon, Seer Biosciences, and Tarveda Therapeutics. He also serves on the Data and Safety Monitoring Board (DSMB) of Genetch and Merck. X.S.L. is a cofounder, board member, SAB, and consultant of GV20 Oncotherapy and its subsidiaries. M.B. is a consultant to and receives sponsored research support from Novartis and is a consultant to MPM Capital and serves on the SAB of Kronos Bio, H3 Biomedicine, and GV20 Oncotherapy., (Copyright © 2022 the Author(s). Published by PNAS.)