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To assess the contribution of rare coding germline genetic variants to prostate cancer risk and severity, we perform here a meta-analysis of 37,184 prostate cancer cases and 331,329 male controls from five cohorts with germline whole exome or genome sequencing data, and one cohort with imputed array data. At the gene level, our case-control collapsing analysis confirms associations between rare damaging variants in four genes and increased prostate cancer risk: SAMHD1, BRCA2 and ATM at the study-wide significance level (P < 1×10 -8 ), and CHEK2 at the suggestive threshold (P < 2.6×10 -6 ). Our case-only analysis, reveals that rare damaging variants in AOX1 are associated with more aggressive disease (OR = 2.60 [1.75-3.83], P = 1.35×10 -6 ), as well as confirming the role of BRCA2 in determining disease severity. At the single-variant level, our study reveals that a rare missense variant in TERT is associated with substantially reduced prostate cancer risk (OR = 0.13 [0.07-0.25], P = 4.67×10 -10 ), and confirms rare non-synonymous variants in a further three genes associated with reduced risk (ANO7, SPDL1, AR) and in three with increased risk (HOXB13, CHEK2, BIK). Altogether, this work provides deeper insights into the genetic architecture and biological basis of prostate cancer risk and severity, with potential implications for clinical risk prediction and therapeutic strategies., Competing Interests: Competing interests: J.M., N.C., O.B., R.D., A.N., A.O., A.A., Q.W., L.A.-D., R.M., B.D., K.C., S.P., M.A.F. are current employees and/or stockholders of AstraZeneca. A.W.Z receives grant funding and consulting fees from AstraZeneca. L.A.M. is on the advisory board and holds equity interest in Convergent Therapeutics. A.M. is a former employee of AstraZeneca and current employee of GSK and a stockholder of AstraZeneca and GSK. C.H. was an employee and stockholder of AZ at the time of study and is a current employee of Debiopharm International. P.W.K. is a co-founder and employee of Convergent Therapeutics. The remaining authors declare no competing interests., (© 2025. The Author(s).)

Purpose: Deleterious germline variants in certain DNA repair genes are risk factors for developing aggressive prostate cancer. The objective was to quantify their prognostic impact after prostate cancer diagnosis., Experimental Design: Men with prostate cancer, predominantly of European ancestry, were included from four cohorts with long-term follow-up. Pathogenic or likely pathogenic germline variants in 26 DNA repair genes were assessed in relation to metastasis-free survival in high-risk localized prostate cancer and to overall survival in metastatic castration-sensitive prostate cancer (mCSPC) and metastatic castration-resistant prostate cancer (mCRPC)., Results: Among 3,525 patients initially diagnosed with nonmetastatic prostate cancer, 2,594 had high-risk localized prostate cancer, 429 had mCSPC, and 502 had mCRPC at inclusion. BRCA2 variant carriers did not have worse metastasis-free survival in high-risk localized prostate cancer [hazard ratio (HR), 1.01; 95% confidence interval (CI), 0.69-1.46] or overall survival in mCSPC (HR, 0.46; 95% CI, 0.14-1.45) or mCRPC (HR, 0.60; 95% CI, 0.31-1.17) compared with noncarriers of DNA repair variants. Among 868 additional patients with de novo metastatic (M1) prostate cancer, BRCA2 variant carriers tended to have worse overall survival (HR, 1.59; 95% CI, 1.01-2.51). BRCA2 prognostic associations were not explained by radiation, PARP inhibitor, or platinum therapy. Results for other genes were limited in precision because variants were less common., Conclusions: Among patients with high-risk or metastatic prostate cancer who were initially diagnosed with and treated for nonmetastatic tumors, germline DNA repair variants in BRCA2 do not confer a substantially worse prognosis., (©2024 American Association for Cancer Research.)

Androgen receptor alterations portend a poor prognosis in patients with advanced prostate cancer. A recent study identified a stemness signature enriched in cell-free DNA from androgen receptor-altered patients, associated with worse outcomes. These findings highlight the potential of epigenomic liquid biopsy tools to discover novel clinically relevant tumor molecular subtypes. See related article by Chauhan et al., p. 151., (©2024 American Association for Cancer Research.)

Background: Fibroblast growth factor receptor (FGFR) inhibitors have significantly improved outcomes for patients with FGFR-altered cholangiocarcinoma, leading to their regulatory approval in multiple countries. However, as with many targeted therapies, acquired resistance limits their efficacy. A comprehensive, multimodal approach is crucial to characterizing resistance patterns to FGFR inhibitors., Patients and Methods: This study integrated data from six investigative strategies: cell-free DNA, tissue biopsy, rapid autopsy, statistical genomics, in vitro and in vivo studies, and pharmacology. We characterized the diversity, clonality, frequency, and mechanisms of acquired resistance to FGFR inhibitors in patients with FGFR-altered cholangiocarcinoma. Clinical samples were analyzed longitudinally as part of routine care across 10 institutions., Results: Among 138 patients evaluated, 77 met eligibility, yielding a total of 486 clinical samples. Patients with clinical benefit exhibited a significantly higher rate of FGFR2 kinase domain mutations compared to those without clinical benefit (65% vs 10%, p<0.0001). We identified 26 distinct FGFR2 kinase domain mutations, with 63% of patients harboring multiple. While IC50 assessments indicated strong potency of pan-FGFR inhibitors against common resistance mutations, pharmacokinetic studies revealed that low clinically achievable drug concentrations may underly polyclonal resistance. Molecular brake and gatekeeper mutations predominated, with 94% of patients with FGFR2 mutations exhibiting one or both, whereas mutations at the cysteine residue targeted by covalent inhibitors were rare. Statistical genomics and functional studies demonstrated that mutation frequencies were driven by their combined effects on drug binding and kinase activity rather than intrinsic mutational processes., Conclusion: Our multimodal analysis led to a model characterizing the biology of acquired resistance, informing the rational design of next-generation FGFR inhibitors. FGFR inhibitors should be small, high-affinity, and selective for specific FGFR family members. Tinengotinib, a novel small molecule inhibitor with these characteristics, exhibited preclinical and clinical activity against key resistance mutations. This integrated approach offers a blueprint for advancing drug resistance research across cancer types., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Background: The PARP inhibitor (PARPi) olaparib is approved for homologous recombination repair (HRR) gene-altered metastatic castration-resistant prostate cancer (mCRPC). However, there is significant heterogeneity in response to PARPi in patients with mCRPC. Better clinical biomarkers are needed to identify patients likely to benefit from PARPi., Methods: Patients with prostate adenocarcinoma and panel sequencing at Dana-Farber Cancer Institute were identified. Mutational signature analysis was performed using SigMA to characterize tumors as HRR deficient (HRD). The validity of SigMA to identify patients likely to benefit from olaparib was compared to the current FDA label (presence of a deleterious alteration in one of 14 HRR genes)., Results: 546 patients were identified, of which 34% were HRD. Among patients with HRR gene alterations, only patients with BRCA2 two-copy loss (2CL) were more likely to be HRD compared to patients without HRR gene alterations (74% vs 31%; P = 9.1 × 10 -7 ). 28 patients with mCRPC received olaparib, of which 13 were HRD and 9 had BRCA2 2CL. SigMA improved upon the current FDA label for predicting PSA50 (sensitivity: 100% vs 90%; specificity: 83% vs 44%; PPV: 77% vs 47%; NPV: 100% vs 89%) and rPFS > 6 months (sensitivity: both 92%; specificity: 93% vs 53%; PPV: 92% vs 63%; NPV: 93% vs 89%). On multivariate analysis, incorporating prognostic clinical factors and HR gene alterations, SigMA-predicted HRD independently associated with improved PSA-PFS (HR = 0.086, p = 0.00082) and rPFS (HR = 0.078, p = 0.0070)., Conclusions: SigMA-predicted HRD may better identify patients likely to benefit from olaparib as compared to the current FDA label. Larger studies are needed for further validation., (© 2024 Wiley Periodicals LLC.)

Background: Androgen deprivation therapy (ADT) in prostate cancer (PCa) has been associated with development of insulin resistance. However, the predominant site of insulin resistance remains unclear., Methods: The ADT & Metabolism Study was a single-center, 24-week, prospective observational study that enrolled ADT-naive men without diabetes who were starting ADT for at least 24 weeks (ADT group, n = 42). The control group comprised men without diabetes with prior history of PCa who were in remission after prostatectomy (non-ADT group, n = 23). Prevalent diabetes mellitus was excluded in both groups using all three laboratory criteria defined in the American Diabetes Association guidelines. All participants were eugonadal at enrollment. The primary outcome was to elucidate the predominant site of insulin resistance (liver or skeletal muscle). Secondary outcomes included assessments of body composition, and hepatic and intramyocellular fat. Outcomes were assessed at baseline, 12, and 24 weeks., Results: At 24 weeks, there was no change in hepatic (1.2; 95% confidence interval [CI], -2.10 to 4.43; p = .47) or skeletal muscle (-3.2; 95% CI, -7.07 to 0.66; p = .10) insulin resistance in the ADT group. No increase in hepatic or intramyocellular fat deposition or worsening of glucose was seen. These changes were mirrored by those observed in the non-ADT group. Men undergoing ADT gained 3.7 kg of fat mass., Conclusions: In men with PCa and no diabetes, 24 weeks of ADT did not change insulin resistance despite adverse body composition changes. These findings should be reassuring for treating physicians and for patients who are being considered for short-term ADT., (© 2024 American Cancer Society.)

Purpose: Histologic transformation to small cell lung cancer (SCLC) is a mechanism of treatment resistance in patients with advanced oncogene-driven lung adenocarcinoma (LUAD) that currently requires histologic review for diagnosis. Herein, we sought to develop an epigenomic cell-free DNA (cfDNA)-based approach to noninvasively detect small cell transformation in patients with EGFR mutant (EGFRm) LUAD., Experimental Design: To characterize the epigenomic landscape of transformed (t)SCLC relative to LUAD and de novo SCLC, we performed chromatin immunoprecipitation sequencing (ChIP-seq) to profile the histone modifications H3K27ac, H3K4me3, and H3K27me3; methylated DNA immunoprecipitation sequencing (MeDIP-seq); assay for transposase-accessible chromatin sequencing; and RNA sequencing on 26 lung cancer patient-derived xenograft (PDX) tumors. We then generated and analyzed H3K27ac ChIP-seq, MeDIP-seq, and whole genome sequencing cfDNA data from 1 mL aliquots of plasma from patients with EGFRm LUAD with or without tSCLC., Results: Analysis of 126 epigenomic libraries from the lung cancer PDXs revealed widespread epigenomic reprogramming between LUAD and tSCLC, with a large number of differential H3K27ac (n = 24,424), DNA methylation (n = 3,298), and chromatin accessibility (n = 16,352) sites between the two histologies. Tumor-informed analysis of each of these three epigenomic features in cfDNA resulted in accurate noninvasive discrimination between patients with EGFRm LUAD versus tSCLC [area under the receiver operating characteristic curve (AUROC) = 0.82-0.87]. A multianalyte cfDNA-based classifier integrating these three epigenomic features discriminated between EGFRm LUAD versus tSCLC with an AUROC of 0.94., Conclusions: These data demonstrate the feasibility of detecting small cell transformation in patients with EGFRm LUAD through epigenomic cfDNA profiling of 1 mL of patient plasma., (©2024 The Authors; Published by the American Association for Cancer Research.)

Background and Objective: BRCA2 mutations in metastatic castration-resistant prostate cancer (mCRPC) confer sensitivity to poly (ADP-ribose) polymerase (PARP) inhibitors. However, additional factors predicting PARP inhibitor efficacy in mCRPC are needed. Preclinical studies support a relationship between speckle-type POZ protein (SPOP) inactivation and PARP inhibitor sensitivity. We hypothesized that SPOP mutations may predict enhanced PARP inhibitor response in BRCA2-altered mCRPC., Methods: We conducted a multicenter retrospective study involving 13 sites. We identified 131 patients with BRCA2-altered mCRPC treated with PARP inhibitors, 14 of which also carried concurrent SPOP mutations. The primary efficacy endpoint was prostate-specific antigen (PSA) response rate (≥50% PSA decline). The secondary endpoints were biochemical progression-free survival (PSA-PFS), clinical/radiographic progression-free survival (PFS), and overall survival (OS). These were compared by multivariable Cox proportional hazard models adjusting for age, tumor stage, baseline PSA level, Gleason sum, prior therapies, BRCA2 alteration types, and co-occurring mutations., Key Findings and Limitations: Baseline characteristics were similar between groups. PSA responses were observed in 60% (70/117) of patients with BRCA2mut/SPOPwt disease and in 86% (12/14) of patients with BRCA2mut/SPOPmut disease (p = 0.06). The median time on PARP inhibitor treatment was 24.0 mo (95% confidence interval [CI] 19.2 mo to not reached) in this group versus 8.0 mo (95% CI 6.1-10.9 mo) in patients with BRCA2 mutation alone (p = 0.05). In an unadjusted analysis, patients with BRCA2mut/SPOPmut disease experienced longer PSA-PFS (hazard ratio [HR] 0.33 [95% CI 0.15-0.72], p = 0.005) and clinical/radiographic PFS (HR 0.4 [95% CI 0.18-0.86], p = 0.02), and numerically longer OS (HR 0.4 [95% CI 0.15-1.12], p = 0.08). In a multivariable analysis including histology, Gleason sum, prior taxane, prior androgen receptor pathway inhibitor, stage, PSA, BRCA2 alteration characteristics, and other co-mutations, patients with BRCA2mut/SPOPmut disease experienced longer PSA-PFS (HR 0.16 [95% CI 0.05-0.47], adjusted p = 0.001), clinical/radiographic PFS (HR 0.28 [95% CI 0.1-0.81], adjusted p = 0.019), and OS (HR 0.19 [95% CI 0.05-0.69], adjusted p = 0.012). In a separate cohort of patients not treated with a PARP inhibitor, there was no difference in OS between patients with BRCA2mut/SPOPmut versus BRCA2mut/SPOPwt disease (HR 0.97 [95% CI 0.40-2.4], p = 0.94). In a genomic signature analysis, Catalog of Somatic Mutations in Cancer (COSMIC) SBS3 scores predictive of homologous recombination repair (HRR) defects were higher for BRCA2mut/SPOPmut than for BRCA2mut/SPOPwt disease (p = 0.04). This was a retrospective study, and additional prospective validation cohorts are needed., Conclusions and Clinical Implications: In this retrospective analysis, PARP inhibitors appeared more effective in patients with BRCA2mut/SPOPmut than in patients with BRCA2mut/SPOPwt mCRPC. This may be related to an increase in HRR defects in coaltered disease., Patient Summary: In this study, we demonstrate that co-alteration of both BRCA2 and SPOP predicts superior clinical outcomes to treatment with poly (ADP-ribose) polymerase (PARP) inhibitors than BRCA2 alteration without SPOP mutation., (Copyright © 2023 European Association of Urology. Published by Elsevier B.V. All rights reserved.)

Renal cell carcinoma with sarcomatoid differentiation (sRCC) is associated with poor survival and a heightened response to immune checkpoint inhibitors (ICIs). Two major barriers to improving outcomes for sRCC are the limited understanding of its gene regulatory programs and the low diagnostic yield of tumor biopsies due to spatial heterogeneity. Herein, we characterized the epigenomic landscape of sRCC by profiling 107 epigenomic libraries from tissue and plasma samples from 50 patients with RCC and healthy volunteers. By profiling histone modifications and DNA methylation, we identified highly recurrent epigenomic reprogramming enriched in sRCC. Furthermore, CRISPRa experiments implicated the transcription factor FOSL1 in activating sRCC-associated gene regulatory programs, and FOSL1 expression was associated with the response to ICIs in RCC in two randomized clinical trials. Finally, we established a blood-based diagnostic approach using detectable sRCC epigenomic signatures in patient plasma, providing a framework for discovering epigenomic correlates of tumor histology via liquid biopsy., Competing Interests: Declaration of interests S.R.V. reports consulting (current or past 3 years) for Jnana Therapeutics, research support from Bayer, and that their spouse is an employee of and holds equity in Kojin Therapeutics. D.A.B. reports honoraria from LM Education/Exchange Services; advisory board fees from Exelixis and AVEO; consulting fees from Merck, Pfizer, and Elephas; equity in Elephas, Fortress Biotech (subsidiary), and CurIOS Therapeutics; personal fees from Schlesinger Associates, Cancer Expert Now, Adnovate Strategies, MDedge, CancerNetwork, Catenion, OncLive, Cello Health BioConsulting, PWW Consulting, Haymarket Medical Network, Aptitude Health, ASCO Post/Harborside, Targeted Oncology, Accolade 2nd.MD, DLA Piper, AbbVie, Compugen, Link Cell Therapies, and Scholar Rock; and research support from Exelixis and AstraZeneca, outside of the submitted work. S.C.B., T.K.C., and M.L.F. are co-founders and shareholders of Precede Biosciences., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

The etiology of prostate cancer, the second most common cancer in men globally, has a strong heritable component. While rare coding germline variants in several genes have been identified as risk factors from candidate gene and linkage studies, the exome-wide spectrum of causal rare variants remains to be fully explored. To more comprehensively address their contribution, we analysed data from 37,184 prostate cancer cases and 331,329 male controls from five cohorts with germline exome/genome sequencing and one cohort with imputed array data from a population enriched in low-frequency deleterious variants. Our gene-level collapsing analysis revealed that rare damaging variants in SAMHD1 as well as genes in the DNA damage response pathway ( BRCA2 , ATM and CHEK2 ) are associated with the risk of overall prostate cancer. We also found that rare damaging variants in AOX1 and BRCA2 were associated with increased severity of prostate cancer in a case-only analysis of aggressive versus non-aggressive prostate cancer. At the single-variant level, we found rare non-synonymous variants in three genes ( HOXB13 , CHEK2 , BIK ) significantly associated with increased risk of overall prostate cancer and in four genes ( ANO7 , SPDL1 , AR , TERT ) with decreased risk. Altogether, this study provides deeper insights into the genetic architecture and biological basis of prostate cancer risk and severity., Competing Interests: Competing Interests J.M., N.C., O.B., R.D., A.N., A.O., A.A., Q.W., L.A.-D., R.M., B.D., K.C., S.P., M.A.F. are current employees and/or stockholders of AstraZeneca. A.W.Z receives grant funding and consulting fees from AstraZeneca. L.A.M. is on the advisory board and holds equity interest in Convergent Therapeutics. A.M. is a former employee of AstraZeneca and current employee of GSK and a stockholder of AstraZeneca and GSK. C.H. was an employee and stockholder of AZ at the time of study. P.W.K. is a co-founder and employee of Convergent Therapeutics.

Introduction/background: Immune checkpoint inhibitors (ICIs) have limited efficacy in prostate cancer (PCa). Better biomarkers are needed to predict responses to ICIs. We sought to demonstrate that a panel-based mutational signature identifies mismatch repair (MMR) deficient (MMRd) PCa and is a biomarker of response to pembrolizumab., Patients and Methods: Clinico-genomic data was obtained for 2664 patients with PCa sequenced at Dana-Farber Cancer Institute (DFCI) and Memorial Sloan Kettering (MSK). Clinical outcomes were collected for patients with metastatic castration-resistant PCa (mCRPC) treated with pembrolizumab at DFCI. SigMA was used to characterize tumors as MMRd or MMR proficient (MMRp). The concordance between MMRd with microsatellite instability (MSI-H) was assessed. Radiographic progression-free survival (rPFS) and overall survival (OS) were collected for patients treated with pembrolizumab. Event-time distributions were estimated using Kaplan-Meier methodology., Results: Across both cohorts, 100% (DFCI: 12/12; MSK: 43/43) of MSI-H tumors were MMRd. However, 14% (2/14) and 9.1% (6/66) of MMRd tumors in the DFCI and MSK cohorts respectively were microsatellite stable (MSS), and 26% (17/66) were MSI-indeterminate in the MSK cohort. Among patients treated with pembrolizumab, those with MMRd (n = 5) versus MMRp (n = 14) mCRPC experienced markedly improved rPFS (HR = 0.088, 95% CI: 0.011-0.70; P = .0064) and OS (HR = 0.11, 95% CI: 0.014-0.80; P = .010) from start of treatment. Four patients with MMRd experienced remissions of >= 2.5 years., Conclusion: SigMA detects additional cases of MMRd as compared to MSI testing in PCa and identifies patients likely to experience durable response to pembrolizumab., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background: Comprehensive profiling of autoantibodies (AAbs) in metastatic urothelial cancer (mUC) has not been performed to date. This may aid in diagnosis of UC, uncover novel therapeutic targets in this disease as well as identify associations between AAbs and response and toxicity to systemic therapies., Methods: We used serum from patients with mUC collected prior to and after systemic therapy (immune checkpoint inhibitor (ICI) or platinum-based chemotherapy (PBC)) at Dana-Farber Cancer Institute. 38 age-matched and sex-matched healthy controls (HCs) from healthy blood donors were also evaluated. The SeroTag immuno-oncology discovery array (Oncimmune) was used, with quantification of the AAb reactivity toward 1132 antigens. Bound AAbs were detected using an anti-immunoglobulin G-specific detection antibody conjugated to the fluorescent reporter dye phycoerythrin. The AAb reactivity was reported as the median fluorescence intensity for each color and sample using a Luminex FlexMAP3D analyzer. Clinical outcomes of interest included radiographic response and development of immune-related adverse events (irAEs). Significance analysis of microarray was used to compare mUC versus HC and radiographic response. Associations with irAE were evaluated using a logistic regression model. P<0.05 was considered statistically significant., Results: 66 patients were included with a median age of 68 years; 54 patients (82%) received ICI and 12 patients (18%) received PBC. Compared with HCs, AAbs against the cancer/testis antigens (CTAG1B, CTAG2, MAGEB18), HSPA1A, TP53, KRAS, and FGFR3 were significantly elevated in patients with mUC. AAbs against BRCA2, TP53, and CTNBB1 were associated with response, and those against BICD2 and UACA were associated with resistance to ICI therapy. AAbs against MITF, CDH3, and KDM4A were associated with development of irAEs in patient who received an ICI. A higher variance in pre-to-post treatment fold change in AAb levels was seen in patients treated with ICI versus PBC and was associated with response to ICI., Conclusions: This is the first report of comprehensive AAb profiling of patients with mUC and identified key AAbs that were elevated in patients with mUC versus HCs as well as AAbs associated with therapeutic response to ICI. These findings are hypothesis generating and further mechanistic studies evaluating humoral immunity in UC are required., Competing Interests: Competing interests: PR: research funding (to institution) from Lilly, Bayer, and Telix and speaker’s fees from OncLive. BAM: consulting fees from BMS, Eisai, Exelixis, Gilead, Pfizer, and Seagen and research funding (to institution) from BMS, Exelixis, Pfizer, and Seagen. JEB: speaker honoraria from Guardant Health; consulting fees from Guardant Health, Genome Medical, Oncotect, Precede, TracerDx, Musculo, and JucaBio; equity in Cityblock Health, Genome Medical, Oncotect, Precede, TracerDx, and Musculo; and filed an institutional patent on methods to detect neuroendocrine prostate cancer through tissue-informed cell-free DNA methylation analysis. GS: in advisory board of BMS, Genentech, EMD Serono, Merck, AstraZeneca, Sanofi, Seattle Genetics/Astellas, AstraZeneca, Exelixis, Janssen, Bicycle Therapeutics, Pfizer, Gilead, Scholar Rock, G1 Therapeutics, Eli Lilly/Loxo Oncology, Infinity Pharmaceuticals, Lucence Health, IMV, Vial, Syapse, Tempus, Ellipses Pharma, PrecisCa, and Primum; in consultant/scientific advisory board of Suba Therapeutics, Syapse, Servier, Merck, and Syncorp; received research support (to institution) from Sanofi, AstraZeneca, Gilead, Helsinn, Lucence, BMS, EMD Serono, and Jazz Therapeutics; received speaker's fees from Seagen, Gilead, Natera, Exelixis, Janssen, Bayer, and Aveo; received data safety monitoring committee honorarium from Mereo; received writing/editor fees from UpToDate, Practice Update, and Onviv; and spouse employed in Myriad. PB, BAA, ER, JG, AS-S, ALK, MB, and H-DZ are employees of Oncimmune., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: The antibody-drug conjugates sacituzumab govitecan (SG) and enfortumab vedotin (EV) are standard monotherapies for metastatic urothelial carcinoma (mUC). Given the different targets and payloads, we evaluated the safety and efficacy of SG + EV in a phase I trial in mUC (NCT04724018)., Patients and Methods: Patients with mUC and Eastern Cooperative Oncology Group performance status ≤1 who had progressed on platinum and/or immunotherapy were enrolled. SG + EV were administered on days 1 + 8 of a 21-day cycle until progression or unacceptable toxicity. Primary endpoint was the incidence of dose-limiting toxicities during cycle 1. The number of patients treated at each of four pre-specified dose levels (DLs) and the maximum tolerated doses in combination (MTD) were determined using a Bayesian Optimal Interval design. Objective response, progression-free survival, and overall survival were secondary endpoints., Results: Between May 2021 and April 2023, 24 patients were enrolled; 1 patient never started therapy and was excluded from the analysis. Median age was 70 years (range 41-88 years); 11 patients received ≥3 lines of therapy. Seventy-eight percent (18/23) of patients experienced grade ≥3 adverse event (AE) regardless of attribution at any DL, with one grade 5 AE (pneumonitis possibly related to EV). The recommended phase II doses are SG 8 mg/kg with EV 1.25 mg/kg with granulocyte colony-stimulating factor support; MTDs are SG 10 mg/kg with EV 1.25 mg/kg. The objective response rate was 70% (16/23, 95% confidence interval 47% to 87%) with three complete responses; three patients had progressive disease as best response. With a median follow-up of 14 months, 9/23 patients have ongoing response including 6 responses lasting over 12 months., Conclusions: The combination of SG + EV was assessed at different DLs and a safe dose for phase II was identified. The combination had encouraging activity in patients with mUC with high response rates, including clinically significant complete responses. Additional study of this combination is warranted., Competing Interests: Disclosure BAM reports consulting fees from BMS, Eisai, Exelixis, Gilead, Pfizer, SeaGen and research funding to institution from BMS, Exelixis, Pfizer, SeaGen. GPS reports consulting fees from, Genentech, EMD Serono, Merck, Astrazeneca, Sanofi, Seattle Genetics/Astellas, Astrazeneca, Exelixis, Janssen, Bicycle Therapeutics, Pfizer, Gilead, Scholar Rock, G1 Therapeutics, Eli Lilly/Loxo Oncology, Infinity Pharmaceuticals, Lucence Health, IMV, Vial, Syapse, Tempus, Ellipses Pharma, PrecisCa, Primum. He serves on scientific advisory board for Suba Therapeutics, Syapse, Servier, Merck, Syncorp and reports research support to institution from Sanofi, Astrazeneca, Gilead, Helsinn, Lucence, BMS, EMD Serono, Jazz Therapeutics. He is a paid speaker for BIO – INFORMAÇÃO BRASILEIRA DE ONCOLOGIA Ltda, OLE Forum (Mexico), Seagen, Gilead, Natera, Exelixis, Janssen, Bayer, Aveo and serves on data safety monitoring committee honorarium for Mereo. His spouse is employed by Myriad. XG reports consulting fees from Bayer, Flare Therapeutics, Myovant, PathAI, PureTech Bio, Silverback Therapeutics. CMM reports consulting fees from Aadi Bioscience, Synthekine and research funding to institution from BMS. XXW reports consulting fees from Novartis and research funding to institution from BMS. JEB reports speaker honoraria from Guardant Health with consulting fees from Guardant Health, Genome Medical, Oncotect, Precede, TracerDx, Musculo, JucaBio. He has equity in Cityblock Health, Genome Medical, Oncotect, Precede, TracerDx, Musculo and institutional patent filed on methods to detect neuroendocrine prostate cancer through tissue-informed cell-free DNA methylation analysis. SAB reports consulting fees from BMS, Eisai, Exelixis, Seagen. PKR reports research funding to institution from Bayer, Telix, and Lilly. MDM reports scientific advisory boards for Merck and Janssen. TKC reports consulting fees from Alkermes, AstraZeneca, Aravive, Aveo, Bayer, Bristol Myers-Squibb, Calithera, Circle Pharma, Deciphera Pharmaceuticals, Eisai, EMD Serono, Exelixis, GlaxoSmithKline, Gilead, HiberCell, IQVA, Infinity, Ipsen, Jansen, Kanaph, Lilly, Merck, Nikang, Nuscan, Novartis, Oncohost, Pfizer, Roche, Sanofi/Aventis, Scholar Rock, Surface Oncology, Takeda, Tempest, Up-To-Date, CME events (Peerview, OncLive, MJH, CCO and others), outside the submitted work. He has institutional patents filed on molecular alterations and immunotherapy response/toxicity, and ctDNA and equity in Tempest, Pionyr, Osel, Precede Bio, CureResponse, InnDura Therapeutics, Primium. He is supported in part by the Dana-Farber/Harvard Cancer Center Kidney SPORE (2P50CA101942-16) and Program 5P30CA006516-56, the Kohlberg Chair at Harvard Medical School and the Trust Family, Michael Brigham, Pan Mass Challenge, Hinda, Arthur Marcus Fund, and Loker Pinard Funds for Kidney Cancer Research at DFCI. JB reports personal and institutional financial interests with Genentech, Pfizer, Bristol-Myers Squibb, AstraZeneca, Merck, Takeda, Eisai, Scholar Rock, Surface Oncology, Gilead, Ipsen, and Pierre-Fabre, trial sponsorship through Associació per a la Recerca Oncológia (APRO), royalties from UpToDate, stocks from Rainier Therapeutics, and a nonfinancial interest as President of APRO. All other authors have declared no conflicts of interest., (Copyright © 2023 European Society for Medical Oncology. Published by Elsevier Ltd. All rights reserved.)

Although circulating tumor DNA (ctDNA) assays are increasingly used to inform clinical decisions in cancer care, they have limited ability to identify the transcriptional programs that govern cancer phenotypes and their dynamic changes during the course of disease. To address these limitations, we developed a method for comprehensive epigenomic profiling of cancer from 1 ml of patient plasma. Using an immunoprecipitation-based approach targeting histone modifications and DNA methylation, we measured 1,268 epigenomic profiles in plasma from 433 individuals with one of 15 cancers. Our assay provided a robust proxy for transcriptional activity, allowing us to infer the expression levels of diagnostic markers and drug targets, measure the activity of therapeutically targetable transcription factors and detect epigenetic mechanisms of resistance. This proof-of-concept study in advanced cancers shows how plasma epigenomic profiling has the potential to unlock clinically actionable information that is currently accessible only via direct tissue sampling., (© 2023. The Author(s), under exclusive licence to Springer Nature America, Inc.)

Advanced prostate cancers comprise distinct phenotypes, but tumor classification remains clinically challenging. Here, we harnessed circulating tumor DNA (ctDNA) to study tumor phenotypes by ascertaining nucleosome positioning patterns associated with transcription regulation. We sequenced plasma ctDNA whole genomes from patient-derived xenografts representing a spectrum of androgen receptor active (ARPC) and neuroendocrine (NEPC) prostate cancers. Nucleosome patterns associated with transcriptional activity were reflected in ctDNA at regions of genes, promoters, histone modifications, transcription factor binding, and accessible chromatin. We identified the activity of key phenotype-defining transcriptional regulators from ctDNA, including AR, ASCL1, HOXB13, HNF4G, and GATA2. To distinguish NEPC and ARPC in patient plasma samples, we developed prediction models that achieved accuracies of 97% for dominant phenotypes and 87% for mixed clinical phenotypes. Although phenotype classification is typically assessed by IHC or transcriptome profiling from tumor biopsies, we demonstrate that ctDNA provides comparable results with diagnostic advantages for precision oncology., Significance: This study provides insights into the dynamics of nucleosome positioning and gene regulation associated with cancer phenotypes that can be ascertained from ctDNA. New methods for classification in phenotype mixtures extend the utility of ctDNA beyond assessments of somatic DNA alterations with important implications for molecular classification and precision oncology. This article is highlighted in the In This Issue feature, p. 517., (©2022 The Authors; Published by the American Association for Cancer Research.)

Background: PARP (poly(ADP-ribose) polymerase) inhibitors (PARPi) are now standard of care in metastatic castrate-resistant prostate cancer (mCRPC) patients with select mutations in DNA damage repair (DDR) pathways, but patients with ATM- and BRCA2 mutations may respond differently to PARPi. We hypothesized that differences may also exist in response to taxanes, which may inform treatment sequencing decisions., Methods: mCRPC patients (N = 158) with deleterious ATM or BRCA2 mutations who received taxanes, PARPi, or both were retrospectively identified from 11 US academic centers. Demographic, treatment, and survival data were collected. Kaplan-Meier analyses were performed and Cox hazard ratios (HR) were calculated for progression-free survival (PFS) as well as overall survival (OS), from time of first taxane or PARPi therapy., Results: Fifty-eight patients with ATM mutations and 100 with BRCA2 mutations were identified. Fourty-four (76%) patients with ATM mutations received taxane only or taxane before PARPi, while 14 (24%) received PARPi only or PARPi before taxane. Patients with ATM mutations had longer PFS when taxane was given first versus PARPi given first (HR: 0.74 [95% confidence interval [CI]: 0.37-1.50]; p = 0.40). Similarly, OS was longer in patients with ATM mutations who received taxane first (HR: 0.56 [CI: 0.20-1.54]; p = 0.26). Among patients with BRCA2 mutations, 51 (51%) received taxane first and 49 (49%) received PARPi first. In contrast, patients with BRCA2 mutations had longer PFS when PARPi was given first versus taxane given first (HR: 0.85 [CI: 0.54-1.35]; p = 0.49). Similarly, OS was longer in patients with BRCA2 mutations who received PARPi first (HR: 0.75 [CI: 0.41-1.37]; p = 0.35)., Conclusions: Our retrospective data suggest differential response between ATM and BRCA2 mutated prostate cancers in terms of response to PARPi and to taxane chemotherapy. When considering the sequence of PARPi versus taxane chemotherapy for mCRPC with DDR mutations, ATM, and BRCA2 mutation status may be helpful in guiding choice of initial therapy., (© 2022 The Authors. The Prostate published by Wiley Periodicals LLC.)

While the mutational and transcriptional landscapes of renal cell carcinoma (RCC) are well-known, the epigenome is poorly understood. We characterize the epigenome of clear cell (ccRCC), papillary (pRCC), and chromophobe RCC (chRCC) by using ChIP-seq, ATAC-Seq, RNA-seq, and SNP arrays. We integrate 153 individual data sets from 42 patients and nominate 50 histology-specific master transcription factors (MTF) to define RCC histologic subtypes, including EPAS1 and ETS-1 in ccRCC, HNF1B in pRCC, and FOXI1 in chRCC. We confirm histology-specific MTFs via immunohistochemistry including a ccRCC-specific TF, BHLHE41. FOXI1 overexpression with knock-down of EPAS1 in the 786-O ccRCC cell line induces transcriptional upregulation of chRCC-specific genes, TFCP2L1, ATP6V0D2, KIT, and INSRR, implicating FOXI1 as a MTF for chRCC. Integrating RCC GWAS risk SNPs with H3K27ac ChIP-seq and ATAC-seq data reveals that risk-variants are significantly enriched in allelically-imbalanced peaks. This epigenomic atlas in primary human samples provides a resource for future investigation., (© 2023. The Author(s).)

Background: Targeted therapies have transformed clinical management of advanced biliary tract cancer (BTC). Cell-free DNA (cfDNA) analysis is an attractive approach for cancer genomic profiling that overcomes many limitations of traditional tissue-based analysis. We examined cfDNA as a tool to inform clinical management of patients with advanced BTC and generate novel insights into BTC tumor biology., Patients and Methods: We analyzed next-generation sequencing data of 2068 cfDNA samples from 1671 patients with advanced BTC generated with Guardant360. We carried out clinical annotation on a multi-institutional subset (n = 225) to assess intra-patient cfDNA-tumor concordance and the association of cfDNA variant allele fraction (VAF) with clinical outcomes., Results: Genetic alterations were detected in cfDNA in 84% of patients, with targetable alterations detected in 44% of patients. Fibroblast growth factor receptor 2 (FGFR2) fusions, isocitrate dehydrogenase 1 (IDH1) mutations, and BRAF V600E were clonal in the majority of cases, affirming these targetable alterations as early driver events in BTC. Concordance between cfDNA and tissue for mutation detection was high for IDH1 mutations (87%) and BRAF V600E (100%), and low for FGFR2 fusions (18%). cfDNA analysis uncovered novel putative mechanisms of resistance to targeted therapies, including mutation of the cysteine residue (FGFR2 C492F) to which covalent FGFR inhibitors bind. High pre-treatment cfDNA VAF was associated with poor prognosis and shorter response to chemotherapy and targeted therapy. Finally, we report the frequency of promising targets in advanced BTC currently under investigation in other advanced solid tumors, including KRAS G12C (1.0%), KRAS G12D (5.1%), PIK3CA mutations (6.8%), and ERBB2 amplifications (4.9%)., Conclusions: These findings from the largest and most comprehensive study to date of cfDNA from patients with advanced BTC highlight the utility of cfDNA analysis in current management of this disease. Characterization of oncogenic drivers and mechanisms of therapeutic resistance in this study will inform drug development efforts to reduce mortality for patients with BTC., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)

African-American (AA) men are more likely to be diagnosed with and die from prostate cancer than European American (EA) men. Despite the central role of the androgen receptor (AR) transcription factor in prostate cancer, little is known about the contribution of epigenetics to observed racial disparities. We performed AR chromatin immunoprecipitation sequencing on primary prostate tumors from AA and EA men, finding that sites with greater AR binding intensity in AA relative to EA prostate cancer are enriched for lipid metabolism and immune response genes. Integration with transcriptomic and metabolomic data demonstrated coinciding upregulation of lipid metabolism gene expression and increased lipid levels in AA prostate cancer. In a metastatic prostate cancer cohort, upregulated lipid metabolism associated with poor prognosis. These findings offer the first insights into ancestry-specific differences in the prostate cancer AR cistrome. The data suggest a model whereby increased androgen signaling may contribute to higher levels of lipid metabolism, immune response, and cytokine signaling in AA prostate tumors. Given the association of upregulated lipogenesis with prostate cancer progression, our study provides a plausible biological explanation for the higher incidence and aggressiveness of prostate cancer observed in AA men., Significance: With immunotherapies and inhibitors of metabolic enzymes in clinical development, the altered lipid metabolism and immune response in African-American men provides potential therapeutic opportunities to attenuate racial disparities in prostate cancer., (©2022 The Authors; Published by the American Association for Cancer Research.)

Purpose: Guidelines recommend somatic and germline testing for men with advanced prostate cancer (PCa). Barriers to widespread implementation result in underutilization of germline testing. Somatic testing alone risks missing pathogenic germline variants (PGVs). We sought to determine whether the addition of germline testing to tumor-only sequencing improves detection of PGVs in men with advanced PCa. Secondarily, we sought to define the added value of combining somatic and germline testing to optimize detection of clinically actionable alterations., Patients and Methods: We analyzed results of independent germline testing and tumor-only sequencing from 100 men with advanced PCa from a prospective clinical trial (ClinicalTrials.gov identifier: NCT03328091). The primary outcome was the proportion of PGVs not reported with tumor-only sequencing. The secondary outcome was the association of locus-specific loss of heterozygosity for PGVs in homologous recombination genes with clinical-genomic features., Results: In the 100 men who underwent germline testing and tumor-only sequencing, 24 PGVs were identified, 17 of which were clinically actionable, in 23 patients. Tumor-only sequencing failed to report four (17%) of the PGVs. One additional PGV (4.2%) had variant allele frequency on tumor-sequencing below the threshold for follow-up germline testing. When integrating tumor-only sequencing with germling testing results, 33% of patients harbored clinically actionable alterations. Rates of locus-specific loss of heterozygosity were higher for BRCA2 PGVs in castration-resistant PCa than PGVs in other homologous recombination genes in hormone-sensitive PCa ( P = .029)., Conclusion: Tumor-only sequencing failed to report more than 20% of PGVs in men with advanced PCa. These findings strongly support guideline recommendations for universal germline and somatic testing in this population. Combining tumor and germline sequencing doubled the chance of detecting a clinically actionable alteration.

Inherited genetic mutations can significantly increase the risk for prostate cancer (PC), may be associated with aggressive disease and poorer outcomes, and can have hereditary cancer implications for men and their families. Germline genetic testing (hereditary cancer genetic testing) is now strongly recommended for patients with advanced/metastatic PC, particularly given the impact on targeted therapy selection or clinical trial options, with expanded National Comprehensive Cancer Network guidelines and endorsement from multiple professional societies. Furthermore, National Comprehensive Cancer Network guidelines recommend genetic testing for men with PC across the stage and risk spectrum and for unaffected men at high risk for PC based on family history to identify hereditary cancer risk. Primary care is a critical field in which providers evaluate men at an elevated risk for PC, men living with PC, and PC survivors for whom germline testing may be indicated. Therefore, there is a critical need to engage and educate primary care providers regarding the role of genetic testing and the impact of results on PC screening, treatment, and cascade testing for family members of affected men. This review highlights key aspects of genetic testing in PC, the role of clinicians, with a focus on primary care, the importance of obtaining a comprehensive family history, current germline testing guidelines, and the impact on precision PC care. With emerging evidence and guidelines, clinical pathways are needed to facilitate integrated genetic education, testing, and counseling services in appropriately selected patients. There is also a need for providers to understand the field of genetic counseling and how best to collaborate to enhance multidisciplinary patient care., (© 2022 The Authors. CA: A Cancer Journal for Clinicians published by Wiley Periodicals LLC on behalf of American Cancer Society.)

HOXB13, a homeodomain transcription factor, critically regulates androgen receptor (AR) activities and androgen-dependent prostate cancer (PCa) growth. However, its functions in AR-independent contexts remain elusive. Here we report HOXB13 interaction with histone deacetylase HDAC3, which is disrupted by the HOXB13 G84E mutation that has been associated with early-onset PCa. Independently of AR, HOXB13 recruits HDAC3 to lipogenic enhancers to catalyze histone deacetylation and suppress lipogenic regulators such as fatty acid synthase. Analysis of human tissues reveals that the HOXB13 gene is hypermethylated and downregulated in approximately 30% of metastatic castration-resistant PCa. HOXB13 loss or G84E mutation leads to lipid accumulation in PCa cells, thereby promoting cell motility and xenograft tumor metastasis, which is mitigated by pharmaceutical inhibition of fatty acid synthase. In summary, we present evidence that HOXB13 recruits HDAC3 to suppress de novo lipogenesis and inhibit tumor metastasis and that lipogenic pathway inhibitors may be useful to treat HOXB13-low PCa., (© 2022. The Author(s), under exclusive licence to Springer Nature America, Inc.)

Purpose: Neuroendocrine prostate cancer (NEPC) is a resistance phenotype that emerges in men with metastatic castration-resistant prostate adenocarcinoma (CR-PRAD) and has important clinical implications, but is challenging to detect in practice. Herein, we report a novel tissue-informed epigenetic approach to noninvasively detect NEPC., Experimental Design: We first performed methylated immunoprecipitation and high-throughput sequencing (MeDIP-seq) on a training set of tumors, identified differentially methylated regions between NEPC and CR-PRAD, and built a model to predict the presence of NEPC (termed NEPC Risk Score). We then performed MeDIP-seq on cell-free DNA (cfDNA) from two independent cohorts of men with NEPC or CR-PRAD and assessed the accuracy of the model to predict the presence NEPC., Results: The test cohort comprised cfDNA samples from 48 men, 9 with NEPC and 39 with CR-PRAD. NEPC Risk Scores were significantly higher in men with NEPC than CR-PRAD (P = 4.3 × 10-7) and discriminated between NEPC and CR-PRAD with high accuracy (AUROC 0.96). The optimal NEPC Risk Score cutoff demonstrated 100% sensitivity and 90% specificity for detecting NEPC. The independent, multi-institutional validation cohort included cfDNA from 53 men, including 12 with NEPC and 41 with CR-PRAD. NEPC Risk Scores were significantly higher in men with NEPC than CR-PRAD (P = 7.5×10-12) and perfectly discriminated NEPC from CR-PRAD (AUROC 1.0). Applying the predefined NEPC Risk Score cutoff to the validation cohort resulted in 100% sensitivity and 95% specificity for detecting NEPC., Conclusions: Tissue-informed cfDNA methylation analysis is a promising approach for noninvasive detection of NEPC in men with advanced prostate cancer., (©2021 American Association for Cancer Research.)

Translocation renal cell carcinoma (tRCC) is a poorly characterized subtype of kidney cancer driven by MiT/TFE gene fusions. Here, we define the landmarks of tRCC through an integrative analysis of 152 patients with tRCC identified across genomic, clinical trial, and retrospective cohorts. Most tRCCs harbor few somatic alterations apart from MiT/TFE fusions and homozygous deletions at chromosome 9p21.3 (19.2% of cases). Transcriptionally, tRCCs display a heightened NRF2-driven antioxidant response that is associated with resistance to targeted therapies. Consistently, we find that outcomes for patients with tRCC treated with vascular endothelial growth factor receptor inhibitors (VEGFR-TKIs) are worse than those treated with immune checkpoint inhibitors (ICI). Using multiparametric immunofluorescence, we find that the tumors are infiltrated with CD8 + T cells, though the T cells harbor an exhaustion immunophenotype distinct from that of clear cell RCC. Our findings comprehensively define the clinical and molecular features of tRCC and may inspire new therapeutic hypotheses., Competing Interests: Declaration of interests Z.B.: research funding from Bristol-Myers Squibb & Genentech/imCORE; honoraria from UpToDate. X.G.: advisory board for Exelixis, Bayer and Guardant Health. D.A.B.: non-financial support from Bristol Myers Squibb, honoraria from LM Education/Exchange Services, advisory board fees from Exelixis and Aveo, and consulting/personal fees from Octane Global, Defined Health, Dedham Group, Adept Field Solutions, Slingshot Insights, Blueprint Partnerships, Charles River Associates, Trinity Group, and Insight Strategy outside of the submitted work. N.I.V.: advisory board to Sanofi/Genzyme, Oncocyte, and Lilly. M.S.H.: consultant, Janssen Pharmaceuticals and UpToDate. R.H.: research funding from Novartis. B.A.M.: consultant for Bayer, Astellas, AstraZeneca, Seattle Genetics, Exelixis, Nektar, Pfizer, Janssen, Genentech, Eisai, Dendreon, Bristol Myers Squibb, Calithera, and EMD Serono; research funding to the institution from Bristol Myers Squibb, Calithera, Exelixis, and Seattle Genetics. A.S.F.: consultant, Olympus America, Inc.; honoraria, Roche, Janssen; advisory board, Vessi Medical. C.J.W.: equity holder of BioNTech, Inc; research funding from Pharmacyclics. D.F.M.: honoraria from BMS, Pfizer, Merck, Alkermes, Inc., EMD Serono, Eli Lilly and Company, Iovance, Eisai, Inc., Werewolf Therapeutics, and Calithera Biosciences; research support from BMS, Merck, Genentech, Pfizer, Exelixis, X4 Pharma, and Alkermes, Inc. D.Y.C.H.: consultancies and research funding from Pfizer, Novartis, BMS, Merck, Eisai, Ipsen, and Exelixis. S.S.: grants from Exelixis, grants from Bristol-Myers Squibb, personal fees from Merck, grants and personal fees from AstraZeneca, personal fees from CRISPR Therapeutics, personal fees from NCI, and personal fees from AACR; a patent for Biogenex with royalties paid. E.M.V.A.: advisory/consulting, Tango Therapeutics, Genome Medical, Invitae, Enara Bio, Janssen, Manifold Bio, Monte Rosa; research support, Novartis, BMS; equity, Tango Therapeutics, Genome Medical, Syapse, Enara Bio, Manifold Bio, Microsoft, Monte Rosa; patents, institutional patents filed on chromatin mutations and immunotherapy response and methods for clinical interpretation. T.K.C.: research (institutional and personal), Alexion, Analysis Group, AstraZeneca, Aveo, Bayer, Bristol Myers-Squibb/ER Squibb and Sons, LLC, Calithera, Cerulean, Corvus, Eisai, Exelixis, F. Hoffmann-La Roche, Foundation Medicine, Inc., Genentech, GlaxoSmithKline, Ipsen, Lilly, Merck, Novartis, Peloton, Pfizer, Prometheus Labs, Roche, Roche Products Limited, Sanofi/Aventis, Takeda, and Tracon; consulting/honoraria or advisory role, Alexion, Analysis Group, AstraZeneca, Aveo, Bayer, Bristol Myers-Squibb/ER Squibb and Sons, LLC, Cerulean, Corvus, Eisai, EMD Serono, Exelixis, Foundation Medicine, Inc., Genentech, GlaxoSmithKline, Heron Therapeutics, Infinity Pharma, Ipsen, Jansen Oncology, IQVIA, Lilly, Merck, NCCN, Novartis, Nuscan, Peloton, Pfizer, Pionyr, Prometheus Labs, Roche, Sanofi/Aventis, Surface Oncology, Tempest, and Up-to-Date; CME-related events (e.g., OncLIve, PVI, MJH Life Sciences); NCI GU Steering Committee; stock ownership, Pionyr and Tempest; patents filed, royalties, or other intellectual properties, related to biomarkers of immune checkpoint blockers and ctDNA; travel, accommodations, expenses, medical writing in relation to consulting, advisory roles, or honoraria; no speaker’s bureau. S.R.V.: consulting, MPM Capital and Vida Ventures; spouse is an employee of and holds equity in Kojin Therapeutics. All other authors report no competing interests., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Introduction: Novel non-steroidal anti-androgens (NSAA) are increasingly part of the management of prostate cancer. We aimed to quantify and compare the neurologic side effects of NSAA agents., Materials and Methods: Phase III randomized controlled trials evaluating NSAAs in the treatment of prostate cancer were selected by two reviewers independently in MEDLINE. A random-effects model and the Mantel-Haenszel method were used. The Odds Ratio (OR) and its 95 % confidence interval were computed. The primary endpoints were the rates of neurologic adverse events., Results: Eight phase III trials evaluating novel NSAAs (vs. non-NSAAs) were included. Fatigue (OR:1.66 [1.32-2.08]), falls (OR:1.76 [1.25-2.49]), headache (OR:1.74 [1.42-2.14]), and dizziness (OR:1.70 [1.33-2.19]) were found to be significantly associated with NSAA use., Conclusions: NSAAs are associated with an increase in various neurologic adverse events. When NSAAs are prescribed, neurologic adverse event prevention and management strategies should be discussed and implemented., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Background: Intense neoadjuvant androgen deprivation therapy (ADT) before radical prostatectomy (RP) is an investigational approach to reduce recurrence rates in men with high-risk localized prostate cancer (PCa). The impact of germline DNA damage repair (gDDR) gene alterations on response to intense neoadjuvant ADT is not known., Objective: To evaluate the prevalence of gDDR alterations among men with localized PCa at high risk of recurrence and evaluate their impact on response to intense neoadjuvant ADT., Design, Setting, and Participants: We performed germline panel sequencing for 201 men with intermediate- and high-risk localized PCa from five randomized multicenter clinical trials of intense neoadjuvant ADT before RP., Intervention: Intense neoadjuvant ADT followed by RP., Outcome Measurements and Statistical Analysis: The prevalence of pathogenic gDDR alterations and their association with exceptional pathologic response (complete response or minimal residual disease, defined as residual tumor with the largest cross-section dimension ≤5 mm) to intense neoadjuvant ADT and rates of post-RP biochemical recurrence., Results and Limitations: Pathogenic gDDR alterations were detected in 19 (9.5%) of the 201 PCa patients. The most frequently altered genes were BRCA2 (n = 6; 3.0%) and ATM (n = 4; 2.0%). Patients with gDDR alterations exhibited similar rates of exceptional pathologic response (26% vs 22%), pT3 disease (42% vs 53%), lymph node involvement (5.3% vs 10%), extraprostatic extension (35% vs 54%), and positive margins (5.3% vs 13%) to patients without gDDR alterations (all p > 0.05). The 3-yr biochemical recurrence-free survival was also similar at 45% (95% confidence interval 7.9-78%) for men with gDDR alterations and 55% (95% confidence interval 44-64%) for men without gDDR alterations., Conclusions: gDDR alterations are common among men with intermediate- and high-risk localized PCa. Men with gDDR alterations appear to have a comparable response to intense neoadjuvant ADT to that among men without gDDR alterations and should not be excluded from consideration for this treatment approach., Patient Summary: Intense therapy to inhibit the production of androgen hormones (eg, testosterone) before surgery may minimize the risk of cancer recurrence for men with high-risk localized prostate cancer. Inherited mutations in certain DNA repair genes are associated with particularly high rates of recurrence. We found that men with these mutations respond equally well to this intense androgen inhibition before surgery as men without the mutations., (Copyright © 2021. Published by Elsevier B.V.)

Background: Many systemic therapies for advanced prostate cancer work by disrupting androgen receptor signaling. Androgen indifferent prostate cancer (AIPC) variants, including aggressive variant prostate cancer (AVPC), neuroendocrine prostate cancer (NEPC), and double-negative prostate cancer (DNPC), are increasingly common and often overlapping resistance phenotypes following treatment with androgen receptor signaling inhibitors in men with metastatic castration-resistant prostate cancer and are associated with poor outcomes. Understanding the underlying biology and identifying effective therapies for AIPC is paramount for improving survival for men with prostate cancer., Methods: In this review, we summarize the current knowledge on AIPC variants, including our current understanding of the clinical, morphologic, and molecular features as well as current therapeutic approaches. We also explore emerging therapies and biomarkers aimed at improving outcomes for men with AIPC., Results and Conclusions: Establishing consensus definitions, developing novel biomarkers for early and accurate detection, further characterization of molecular drivers of each phenotype, and developing effective therapies will be critical to improving outcomes for men with AIPC. Significant progress has been made toward defining the clinical and molecular characteristics of AVPC, NEPC, and DNPC. Novel diagnostic approaches, including cell-free DNA, circulating tumor cells, and molecular imaging are promising tools for detecting AIPC in clinical practice. Building on previous treatment advances, several clinical trials are underway evaluating novel therapeutic approaches in patients with AIPC informed by an understanding of variant-specific biology. In this review, we discuss how these recent and ongoing studies will help to improve diagnosis, prognosis, and therapy for men with AIPC., (© 2021. The Author(s), under exclusive licence to Springer Nature Limited part of Springer Nature.)

Rising homelessness, especially among older adults, has significant ramifications for our health care system. People experiencing homelessness tend to experience worse health and poorer access to needed health care than people with stable housing. Commonwealth Care Alliance (CCA), a not-for-profit payer and provider that offers health plans to people dually eligible for Medicare and Medicaid, sought to address homelessness among its beneficiaries through a partnership with a local community-based housing organization, Hearth. This partnership led to many CCA members gaining access to permanent supportive housing in a setting in which CCA and Hearth could monitor and address their medical, social, and behavioral needs. It also provided an opportunity to examine health care utilization and cost trends associated with permanent supportive housing. Our experience demonstrates that a community-based partnership can effectively address homelessness among older adults with significant medical needs and may be associated with reduced health care expenditures., Competing Interests: Disclosures Suhas Gondi and Caroline Berchuck report prior employment at Commonwealth Care Alliance, Inc. Lauren Easton, Leah Smith, and Henry Burden are current employees of Commonwealth Care Alliance, Inc. Mark Hinderlie is President and CEO of Hearth, Inc. Rebecca T. Brown is a member of the board of directors for Hearth, Inc. The authors have no other relevant conflicts of interest to disclose.

Two poly (ADP-ribose) polymerase (PARP) inhibitors (olaparib and rucaparib) are US Food and Drug Administration-approved for patients with metastatic castration-resistant prostate cancer (mCRPC) harboring BRCA1 / 2 mutations, but the relative efficacy of PARP inhibition in BRCA1 - versus BRCA2 -altered mCRPC is understudied., Methods: We conducted a multicenter retrospective analysis involving 12 sites. We collected genomic and clinical data from 123 patients with BRCA1 / 2 -altered mCRPC who were treated with PARP inhibitors. The primary efficacy end point was the prostate-specific antigen (PSA) response (≥ 50% PSA decline) rate. Secondary end points were PSA progression-free survival (PSA-PFS), clinical or radiographic PFS, and overall survival. We compared clinical outcomes, and other genomic characteristics, among BRCA1 - versus BRCA2 -altered mCRPC., Results: A total of 123 patients (13 BRCA1 and 110 BRCA2 ) were included. PARP inhibitors used were olaparib (n = 116), rucaparib (n = 3), talazoparib (n = 2), and veliparib (n = 2). At diagnosis, 72% of patients had Gleason 8-10 disease. BRCA1 patients were more likely to have metastatic disease at presentation (69% v 37%; P = .04). Age, baseline PSA, metastatic distribution, and types of previous systemic therapies were similar between groups. There were equal proportions of germline mutations (51% v 46%; P = .78) in both groups. BRCA1 patients had more monoallelic (56% v 41%; P = .49) and concurrent TP53 (55% v 36%; P = .32) mutations. PSA 50 responses in BRCA1 - versus BRCA2 -altered patients were 23% versus 63%, respectively ( P = .01). BRCA2 patients achieved longer PSA-PFS (HR, 1.94; 95% CI, 0.92 to 4.09; P = .08), PFS (HR, 2.08; 95% CI, 0.99 to 4.40; P = .05), and overall survival (HR, 3.01; 95% CI, 1.32 to 6.83; P = .008). Biallelic (compared with monoallelic) mutations, truncating (compared with missense) mutations, and absence of a concurrent TP53 mutation were associated with PARP inhibitor sensitivity., Conclusion: PARP inhibitor efficacy is diminished in BRCA1 - versus BRCA2 -altered mCRPC. This is not due to an imbalance in germline mutations but might be related to more monoallelic mutations and/or concurrent TP53 alterations in the BRCA1 group., Competing Interests: Emmanuel S. Antonarakis Honoraria: Sanofi, Dendreon, Medivation, Janssen Biotech, ESSA, Astellas Pharma, Merck, AstraZeneca, Clovis Oncology Consulting or Advisory Role: Sanofi, Dendreon, Janssen Biotech, ESSA, Merck, AstraZeneca, Clovis Oncology, Lilly, Bayer Research Funding: Janssen Biotech, Johnson & Johnson, Sanofi, Dendreon, Aragon Pharmaceuticals, Exelixis, Millennium, Genentech, Novartis, Astellas Pharma, Tokai Pharmaceuticals, Merck, AstraZeneca, Clovis Oncology, Constellation Pharmaceuticals Patents, Royalties, Other Intellectual Property: Coinventor of a biomarker technology that has been licensed to Qiagen Travel, Accommodations, Expenses: Sanofi, Dendreon, Medivation No other potential conflicts of interest were reported. Emmanuel S. Antonarakis Honoraria: Sanofi, Dendreon, Medivation, Janssen Biotech, ESSA, Astellas Pharma, Merck, AstraZeneca, Clovis Oncology Consulting or Advisory Role: Sanofi, Dendreon, Janssen Biotech, ESSA, Merck, AstraZeneca, Clovis Oncology, Lilly, Bayer Research Funding: Janssen Biotech, Johnson & Johnson, Sanofi, Dendreon, Aragon Pharmaceuticals, Exelixis, Millennium, Genentech, Novartis, Astellas Pharma, Tokai Pharmaceuticals, Merck, AstraZeneca, Clovis Oncology, Constellation Pharmaceuticals Patents, Royalties, Other Intellectual Property: Coinventor of a biomarker technology that has been licensed to Qiagen Travel, Accommodations, Expenses: Sanofi, Dendreon, Medivation No other potential conflicts of interest were reported., (© 2021 by American Society of Clinical Oncology.)

Lineage plasticity, the ability of a cell to alter its identity, is an increasingly common mechanism of adaptive resistance to targeted therapy in cancer. An archetypal example is the development of neuroendocrine prostate cancer (NEPC) after treatment of prostate adenocarcinoma (PRAD) with inhibitors of androgen signaling. NEPC is an aggressive variant of prostate cancer that aberrantly expresses genes characteristic of neuroendocrine (NE) tissues and no longer depends on androgens. Here, we investigate the epigenomic basis of this resistance mechanism by profiling histone modifications in NEPC and PRAD patient-derived xenografts (PDXs) using chromatin immunoprecipitation and sequencing (ChIP-seq). We identify a vast network of cis-regulatory elements (N~15,000) that are recurrently activated in NEPC. The FOXA1 transcription factor (TF), which pioneers androgen receptor (AR) chromatin binding in the prostate epithelium, is reprogrammed to NE-specific regulatory elements in NEPC. Despite loss of dependence upon AR, NEPC maintains FOXA1 expression and requires FOXA1 for proliferation and expression of NE lineage-defining genes. Ectopic expression of the NE lineage TFs ASCL1 and NKX2-1 in PRAD cells reprograms FOXA1 to bind to NE regulatory elements and induces enhancer activity as evidenced by histone modifications at these sites. Our data establish the importance of FOXA1 in NEPC and provide a principled approach to identifying cancer dependencies through epigenomic profiling.

Sarcomatoid and rhabdoid (S/R) renal cell carcinoma (RCC) are highly aggressive tumors with limited molecular and clinical characterization. Emerging evidence suggests immune checkpoint inhibitors (ICI) are particularly effective for these tumors, although the biological basis for this property is largely unknown. Here, we evaluate multiple clinical trial and real-world cohorts of S/R RCC to characterize their molecular features, clinical outcomes, and immunologic characteristics. We find that S/R RCC tumors harbor distinctive molecular features that may account for their aggressive behavior, including BAP1 mutations, CDKN2A deletions, and increased expression of MYC transcriptional programs. We show that these tumors are highly responsive to ICI and that they exhibit an immune-inflamed phenotype characterized by immune activation, increased cytotoxic immune infiltration, upregulation of antigen presentation machinery genes, and PD-L1 expression. Our findings build on prior work and shed light on the molecular drivers of aggressivity and responsiveness to ICI of S/R RCC.

Purpose: Plasma cell-free DNA (cfDNA) variant analysis is commonly used in many cancer subtypes. Cell-free methylated DNA immunoprecipitation sequencing (cfMeDIP-seq) has shown high sensitivity for cancer detection. To date, studies have not compared the sensitivity of both methods in a single cancer subtype., Methods: cfDNA from 40 metastatic RCC (mRCC) patients was subjected to targeted panel variant analysis. For 34 of 40, cfMeDIP-seq was also performed. A separate cohort of 38 mRCC patients were used in cfMeDIP-seq analysis to train an RCC classifier., Results: cfDNA variant analysis detected 21 candidate variants in 11 of 40 mRCC patients (28%), after exclusion of 2 germline variants and 6 variants reflecting clonal hematopoiesis. Among 23 patients with parallel tumor sequencing, cfDNA analysis alone identified variants in 9 patients (39%), while cfDNA analysis focused on tumor sequencing variant findings improved the sensitivity to 52%. In 34 mRCC patients undergoing cfMeDIP-seq, cfDNA variant analysis identified variants in 7 (21%), while cfMeDIP-seq detected all mRCC cases (100% sensitivity) with 88% specificity in 34 control subjects. In 5 patients with cfDNA variants and serial samples, variant frequency correlated with response to therapy., Conclusion: cfMeDIP-seq is significantly more sensitive for mRCC detection than cfDNA variant analysis. However, cfDNA variant analysis may be useful for monitoring response to therapy.

Prior data have variably implicated the inactivation of the mammalian SWItch/Sucrose Non-Fermentable (mSWI/SNF) complex with increased tumor sensitivity to immune checkpoint inhibitors (ICI). Herein, we examined the association between mSWI/SNF variants and clinical outcomes to ICIs. We correlated somatic loss-of-function (LOF) variants in a predefined set of mSWI/SNF genes ( ARID1A, ARID1B, SMARCA4, SMARCB1, PBRM1 , and ARID2 ) with clinical outcomes in patients with cancer treated with systemic ICIs. We identified 676 patients from Dana-Farber Cancer Institute (DFCI, Boston, MA) and 848 patients from a publicly available database from Memorial Sloan Kettering Cancer Center (MSKCC, New York, NY) who met the inclusion criteria. Multivariable analyses were conducted and adjusted for available baseline factors and tumor mutational burden. Median follow-up was 19.6 (17.6-22.0) months and 28.0 (25.0-29.0) months for the DFCI and MSKCC cohorts, respectively. Seven solid tumor subtypes were examined. In the DFCI cohort, LOF variants of mSWI/SNF did not predict improved overall survival (OS), time-to-treatment failure (TTF), or disease control rate. Only patients with renal cell carcinoma with mSWI/SNF LOF showed significantly improved OS and TTF with adjusted HRs (95% confidence interval) of 0.33 (0.16-0.7) and 0.49 (0.27-0.88), respectively, and this was mostly driven by PRBM1 In the MSKCC cohort, where only OS was captured, LOF mSWI/SNF did not correlate with improved outcomes across any tumor subtype. We did not find a consistent association between mSWI/SNF LOF variants and improved clinical outcomes to ICIs, suggesting that mSWI/SNF variants should not be considered as biomarkers of response to ICIs., (©2020 American Association for Cancer Research.)

Importance: Preexisting mental health disorders (MHDs) are associated with increased mortality in people diagnosed with cancer, yet few data exist on the efficacy of interventions to mitigate this disparity., Objective: To evaluate the association of participation in mental health treatment programs (MHTPs), housing support programs, or employment support programs with stage at cancer diagnosis, receipt of stage-appropriate treatment, and mortality among patients with a preexisting MHD., Design, Setting, and Participants: This retrospective, population-based cohort study included 55 315 veterans in the Veterans Affairs Central Cancer Registry (VACCR) who had newly diagnosed non-small cell lung cancer (NSCLC) from September 30, 2000, to December 31, 2011. Data were analyzed from January 15, 2017, to March 17, 2020., Exposures: Mental health disorders, including schizophrenia, bipolar disorder, depressive disorder, posttraumatic stress disorder, and substance use disorder., Main Outcomes and Measures: Stage at cancer diagnosis, receipt of stage-appropriate cancer treatment, all-cause mortality, and lung cancer-specific mortality., Results: Of 55 315 veterans with a new diagnosis of NSCLC included in the analysis (98.1% men; mean [SD] age, 68.1 [9.8] years), 18 229 had a preexisting MHD, among whom participation in MHTPs was associated with a lower likelihood of being diagnosed in a late stage (odds ratio [OR], 0.62; 95% CI, 0.58-0.66; P < .001), a higher likelihood of receiving stage-appropriate treatment (OR, 1.55; 95% CI, 1.26-1.89; P < .001), lower all-cause mortality (adjusted hazard ratio [AHR], 0.74; 95% CI, 0.72-0.77; P < .001), and lower lung cancer-specific mortality (AHR, 0.77; 95% CI, 0.74-0.80; P < .001). Likewise, participation in housing and employment support programs was associated with similar improvements in all outcomes described above., Conclusions and Relevance: In veterans with preexisting MHDs diagnosed with NSCLC, participation in MHTPs and housing and employment support programs was associated with improved lung cancer-related outcomes. This study might be the first to demonstrate significant improvement in cancer mortality for patients with MHDs who participate in MHTPs, housing support programs, or employment support programs. This work supports substantial literature that investment in mental health and social needs can improve health outcomes and highlights the importance of further research to identify, evaluate, and implement interventions to improve outcomes for patients with MHDs who are diagnosed with cancer.

Improving early cancer detection has the potential to substantially reduce cancer-related mortality. Cell-free methylated DNA immunoprecipitation and high-throughput sequencing (cfMeDIP-seq) is a highly sensitive assay capable of detecting early-stage tumors. We report accurate classification of patients across all stages of renal cell carcinoma (RCC) in plasma (area under the receiver operating characteristic (AUROC) curve of 0.99) and demonstrate the validity of this assay to identify patients with RCC using urine cell-free DNA (cfDNA; AUROC of 0.86).

Purpose: To date, there has not been a large, systematic evaluation of the prevalence of germline risk variants in urothelial carcinoma (UC)., Methods: We evaluated the frequency of germline pathogenic and likely pathogenic variants in 1038 patients with high-risk UC who underwent targeted clinical germline testing. Case-control enrichment analysis was performed to screen for pathogenic variant enrichment in 17 DNA repair genes in 1038 UC patients relative to cancer-free individuals., Results: Among 1038 patients with UC, the cumulative frequency of patients with pathogenic variants was 24%; 18.6% of patients harbored ≥1 actionable germline variant with preventive or therapeutic utility. MSH2 (34/969, 3.5%) and BRCA1/2 (38/867, 4.4%) germline variants had the highest frequency. Germline variants in DNA damage repair genes accounted for 78% of pathogenic germline variants. Compared to the cancer-free cohort, UC patients had significant variant enrichment in MSH2 (odds ratio [OR]: 15.4, 95% confidence interval [CI]: 7.1-32.7, p < 0.0001), MLH1 (OR: 15.9, 95% CI: 4.4-67.7, p < 0.0001), BRCA2 (OR: 5.7, 95% CI: 3.2-9.6, p < 0.0001), and ATM (OR: 3.8, 95% CI: 1.8-8.3, p = 0.02)., Conclusion: In this study, 24% of UC patients harbored pathogenic germline variants and 18.6% had clinically actionable variants. MLH1 and MSH2 were validated as UC risk genes while ATM and BRCA2 were highlighted as potential UC predisposition genes. This work emphasizes the utility of germline testing in selected high-risk UC cohorts.

Introduction: This case highlights the importance of getting a thorough workup for acute kidney injury before assigning a diagnosis., Case Presentation: A 68-year-old male was referred to our clinic after a recent outside hospitalization for septic knee arthritis and acute kidney injury requiring hemodialysis. He had chronic kidney disease presumed secondary to diabetes with baseline GFR 50 mL/min. He complained of fatigue and weight loss. Vital signs were within normal limits. Exam was notable for trace ankle edema, healed right knee scar, and right internal jugular hemodialysis catheter. Medications included amlodipine, aspirin, atorvastatin, furosemide, sevelamer, and cephalexin. Calculated creatinine clearance was 6 mL/min with urine output 2 L/day. Urinalysis showed 1+ protein, 2+ glucose, and fine granular casts. Clinical impression was ischemic acute tubular necrosis in recovery phase. However, when he did not improve and continued requiring dialysis, further workup showed elevated serum κ free light chains and urine Bence-Jones protein. Renal biopsy showed κ light chain crystalline tubulopathy, interstitial inflammation, and extensive fibrosis. Subsequent bone marrow biopsy showed 15% κ-restricted plasma cells. Multiple myeloma was diagnosed, and chemotherapy initiated. With decrease in κ light chain burden, kidney function improved, and patient was able to come off dialysis., Conclusion: This case describes a rare presentation of κ light chain crystalline tubulopathy and illustrates the value of a comprehensive evaluation for acute kidney injury to enable prompt diagnosis and therapy.
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Context: Naloxone distribution has historically been implemented in a community-based, expanded public health model; however, there is now a need to further explore primary care clinic-based naloxone delivery to effectively address the nationwide opioid epidemic., Objective: To create a general medicine infrastructure to identify patients with high-risk opioid use and provide 25% of this population with naloxone autoinjector prescription and training within a 6-month period., Design: The quality improvement study was conducted at an outpatient clinic serving 1238 marginally housed veterans with high rates of comorbid substance use and mental health disorders. Patients at high risk of opioid-related adverse events were identified using the Stratification Tool for Opioid Risk Management and were contacted to participate in a one-on-one, 15-minute, hands-on naloxone training led by nursing staff., Main Outcome Measures: The number of patients identified at high risk and rates of naloxone training/distribution., Results: There were 67 patients identified as having high-risk opioid use. None of these patients had been prescribed naloxone at baseline. At the end of the intervention, 61 patients (91%) had been trained in the use of naloxone. Naloxone was primarily distributed by licensed vocational nurses (42/61, 69%)., Conclusion: This study demonstrates the feasibility of high-risk patient identification and of a primary care-based and nursing-championed naloxone distribution model. This delivery model has the potential to provide access to naloxone to a population of patients with opioid use who may not be engaged in mental health or specialty care.

Purpose: Retinal pigment epithelial (RPE) cell death is an important feature of the advanced forms of AMD. Complement alternative pathway (AP) activation is associated with RPE cell death in AMD. In this study, we developed a new model to initiate AP activation on RPE cells and investigated the cellular mechanisms modulating AP activation-mediated RPE cell death., Methods: An anti-RPE antibody was developed. A spontaneously arising human RPE cell line (ARPE-19) and donor RPE cells were primed with this antibody followed by stimulation with 6% C1q-depleted human serum (C1q-Dep) to activate AP. Complement activation was evaluated by flow cytometry and immunofluorescent staining. Cellular response to complement activation was examined by measurement of intracellular calcium and adenosine triphosphate (ATP) release. Cell viability was assessed by Sytox orange, tetrazolium salt, and lactate dehydrogenase release assays., Results: Alternative pathway complement-mediated RPE cell death was associated with membrane attack complex formation and a rapid rise in intracellular calcium followed by release of ATP. Downregulation of membrane complement regulatory proteins and protein kinase C (PKC) inhibition increased cell susceptibility to complement attack. Pretreatment of RPE cells with either hydrogen peroxide or hydroquinone enhanced cell death. Chronic repetitive treatment of RPE cells with low levels of oxidants also enhanced complement-mediated cell death., Conclusions: Activation of complement through the alternative pathway induces sublytic and lytic phases of complement attack on RPE cells, leading to cell death modulated by extracellular calcium, membrane complement regulatory proteins, and intracellular signaling mechanisms. Single-dose oxidant exposure and low-dose repetitive oxidant exposure rendered RPE cells more susceptible to complement-mediated death.

Purpose: Retinal pigment epithelial (RPE) cell death occurs early in the pathogenesis of age-related macular degeneration (AMD) and Stargardt's disease. Emerging evidence suggests that all-trans-retinal (atRal) and alternative complement pathway (AP) activation contribute to RPE cell death in both of these retinal disorders. The aim of this study was to investigate the combined effect of atRal and AP activation on RPE cell viability., Methods: RPE cells were treated with atRal and then incubated with a complement-fixing antibody followed by stimulation with C1q-depleted serum to activate AP. Cell viability was assessed by tetrazolium salt and lactate dehydrogenase release assays. Changes in cell surface CD46 and CD59 expression were assessed by flow cytometry. Cells were pretreated with the antioxidant resveratrol, and C1q-depleted serum was incubated with an anti-C5 antibody prior to initiating AP attack to determine the protective effects of antioxidant therapy and complement inhibition, respectively., Results: Both atRal and AP activation independently caused RPE cell death. When AP attack was initiated following atRal treatment, a synergistic increase in cell death was observed. Following 24-hour atRal treatment, CD46 and CD59 expression decreased, corresponding temporally to increased susceptibility to AP attack. Resveratrol and the anti-C5 antibody both protected against AP-induced cell death following atRal exposure and were most effective when used in combination., Conclusions: atRal sensitizes RPE cells to AP attack, which may be mediated in part by atRal-induced downregulation of CD46 and CD59. Despite increased susceptibility to AP attack following exposure to atRal, resveratrol and anti-C5 antibody effectively prevent AP-mediated cell death.

Cell-based screening can facilitate the rapid identification of compounds inducing complex cellular phenotypes. Advancing a compound toward the clinic, however, generally requires the identification of precise mechanisms of action. We previously found that epidermal growth factor receptor (EGFR) inhibitors induce acute myeloid leukemia (AML) differentiation via a non-EGFR mechanism. In this report, we integrated proteomic and RNAi-based strategies to identify their off-target, anti-AML mechanism. These orthogonal approaches identified Syk as a target in AML. Genetic and pharmacological inactivation of Syk with a drug in clinical trial for other indications promoted differentiation of AML cells and attenuated leukemia growth in vivo. These results demonstrate the power of integrating diverse chemical, proteomic, and genomic screening approaches to identify therapeutic strategies for cancer.