Prostate cancer (PCa) demonstrates notable disease heterogeneity, with African American men (AAM) experiencing a higher incidence and increased mortality rates compared to their European American (EAM) counterparts. While social determinants of health are key contributors to these differences, underlying biological differences remain important drivers of disease severity and outcomes. In the current work, we aimed to explore the interplay between stress mediated reactive oxygen species and inflammatory signaling in promoting progression of PCa in AAM. The study used a retrospective race-matched Genomic Resource Intelligent Discovery (GRID) database (NCT02609269) (n = 8,626), and the prospective VANDAAM study (NCT02723734) (n = 243) to identify hallmarks of oxidative stress and inflammatory signaling in PCa from AAM. We demonstrate that DNA damage repair (DDR) pathway genes are significantly downregulated in AAM-derived PCa, with sustained γH2AX phosphorylation following radiotherapy confirming impaired DNA damage resolution. Transcriptomic analyses further revealed that mitochondrial electron transport chain (ETC) Complex I and Complex III genes are among the most differentially downregulated in AAM, functionally resulting in elevated basal mitochondrial ROS and enhanced sensitivity to ETC inhibition. These mitochondrial ROS-mediated changes promoted lipid peroxidation, plasma membrane remodeling, and extracellular release of ATP and its immunosuppressive metabolite adenosine, selectively in AAM-derived cells and patient-derived explants. Reduced ETC expression further correlated with upregulation of immunosuppressive gene signatures. These findings establish a novel mechanistic framework linking impaired DDR to mitochondrial ETC dysregulation, elevated ROS, and immunosuppressive signature in PCa from AAM, highlighting potential therapeutic targets to address racial disparities in this high-risk population.

Abstract Background Adjuvant treatment with PD-1 inhibitors for 12 months has been the established standard of care for patients with resected stage IIB-IV cutaneous melanoma. In other solid tumours (e.g. breast and colorectal), a shorter duration of adjuvant chemotherapy has been shown to be non-inferior with improved toxicity profile. More recently, neoadjuvant immunotherapy with immune checkpoint inhibitors for clinically detectable stage III and stage IV disease has been introduced. There is no clear biological rationale for the chosen duration, and no studies have investigated duration of adjuvant treatment with immune checkpoint inhibitors. A reduced duration of adjuvant therapy could lead to less toxicity from reduced drug exposure, patients returning to normal life sooner, significantly lower drug costs and better healthcare resource utilization. There remains significant interest from patients and clinicians to address this important question. Methods Grand SLAM is a prospective phase III randomised, controlled international multi-centre non-inferiority study. The primary objective is to investigate if short (6 months) has equal efficacy as long (12 months) duration of (neo-)adjuvant immune checkpoint inhibition in relation to distant metastasis-free survival and relapse-free survival at landmark analysis at 2 years. After radical surgery of stage IIB-C, III or IV cutaneous melanoma, patients are randomly assigned 1:1 to short or long adjuvant treatment with either nivolumab or pembrolizumab. Patients who have received neoadjuvant treatment with major pathological response are excluded. The sample size of 1,880 patients was determined based on a non-inferiority margin of 4%, a significance level of 0.045 and 80% statistical power. An interim analysis will be conducted when 2/3 of patients are accrued. Biomarkers and the role of food supplements for relapse (MelKo) will be investigated in prespecified substudies. Discussion This is the first randomised study to assess a shorter duration of adjuvant anti PD-1 antibody in cutaneous melanoma patients. As of March 2026, the study is recruiting patients in the Nordic countries. Centres in other countries will open shortly. Trial registration NCT06488482. Date of registration: 2024-06-10.

Abstract BACKGROUND: Tumor-specific T cells are often characterized by reduced TCR signaling due to central and peripheral tolerance pathways that limit their responsiveness. These signals are further weakened by insufficient co-stimulation and active co-inhibitory pathways, collectively establishing a high threshold for activation. The integration of antigen recognition with co-stimulatory and inhibitory cues ultimately determines whether a T cell becomes activated or remains tolerant. Early TCR signaling must therefore be precisely regulated to prevent autoreactivity while still supporting protective immunity. Although phosphorylation and ubiquitination are well-established regulators of proximal TCR signaling, additional post-translational mechanisms remain less defined. SIRT2, a cytosolic NAD+-dependent deacetylase with emerging roles in immune regulation, has not been examined in the context of TCR signaling. METHODS: We evaluated proximal TCR signaling events in wild-type and SIRT2-deficient T cells using flow cytometry, immunoblotting, calcium flux assays, and RNA-sequencing. SIRT2-associated pathways were defined by mapping its interactome and acetylated substrates through mass spectrometry and immunoprecipitation. We screened LCK post-translational modifications by mass spectrometry and assessed SIRT2 enzymatic activity using an HPLC-based deacetylase assay. Conformational effects of LCK modification were examined using fluorescence-polarization binding assays and AlphaFold structural modeling. SIRT2 was deleted in human tumor infiltrating lymphocytes (TILs) via CRISPR/Cas9, and the impact of SIRT2 targeting was tested in lung cancer patient-derived xenograft models reconstituted with autologous TILs. RESULTS: SIRT2 deficiency amplified proximal TCR signaling, leading to elevated phosphorylation of early signaling mediators and increased calcium flux in both naïve and anergic T cells. Loss of SIRT2 also altered thymic selection dynamics and expanded TCR repertoire diversity. Mechanistically, SIRT2 interacted with and deacetylated LCK, the initiating kinase of proximal TCR signaling. Mass spectrometry identified lysine K228 in the LCK linker region as a SIRT2-regulated deacetylation site that governs LCK conformation and kinase activity. Functionally, SIRT2 inhibition in exhausted mouse and human TILs restored TCR signaling capacity and improved anti-tumor responses. CONCLUSION: Here we identify SIRT2-regulated deacetylation of LCK as a previously unrecognized mechanism that sets the strength and threshold of proximal TCR signaling. Accordingly, SIRT2 targeting reverses the exhausted phenotype of tumor-reactive T cells. Citation Format: Imene Hamaidi, Pingyan Cheng, Soo Young Jun, Min-Hsuan Wang, Min Zhang, Odesha Taylor, Luis Lopez-bailon, Ismail Can, Bin Fang, Anders Berglund, Bradford Perez, Ben Creelan, Andriy Marusyk, Virginia Shapiro, Haitao Ji, Jose R. Conejo-Garcia, Sungjune Kim. Sirt2 dictates TCR activation thresholds through post-translational control of LCK conformational state [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 4250.

INTRODUCTION:Hepatocellular carcinoma (HCC) development in patients with metabolic dysfunction-associated steatotic liver disease (MASLD) is a growing health concern, but the underlying mechanisms are not fully understood. Epigenetic aging biomarkers, reflecting cellular and tissue aging, have been linked to various age-related pathologies, but their association with MASLD-HCC is unknown. We investigated associations between five epigenetic aging biomarkers and MASLD-HCC risk. METHODS:We performed whole blood DNA methylation assay (Infinium 850k array) and calculated principal components-based (PC) versions of HorvathAge, HannumAge, PhenoAge and GrimAge and the DunedinPACE aging rate. We further calculated relative age accelerations for PCHorvathAge, PCHannumAge, PCPhenoAge and PCGrimAge. The aging biomarkers were modelled as continuous variables and categorised into tertiles based on distributions among controls. Associations between each aging biomarker and MASLD-HCC were examined using logistic regression, calculating odds ratios (ORs) and 95% confidence intervals (CIs), adjusting for covariates. RESULTS:Data on 272 MASLD-HCC cases and 316 cancer-free MASLD controls recruited from six sites and matched on chronological age, sex and study site were analysed. Higher relative age accelerations of PCPhenoAge (ORT3 vs. T1 = 2.25, 95% CI: 1.45-3.50; ORcontinuous = 1.04, 95% CI: 1.02-1.07, p = 0.009), PCGrimAge (ORT3 vs. T1 = 3.97, 95% CI: 2.41-6.64; ORcontinuous = 1.16, 95% CI: 1.10-1.24, p = 8.76 × 10-07) and DunedinPACE (ORT3 vs. T1 = 3.45, 95% CI: 2.17-5.55; ORcontinuous = 1.72, 95% CI: 1.43-2.10, p = 2.58 × 10-08) were associated with MASLD-HCC, but not PCHorvathAge or PCHannumAge. CONCLUSION:Higher relative age accelerations of PCPhenoAge, PCGrimAge and DunedinPACE aging rate are associated with risk of MASLD-HCC. These aging biomarkers could improve HCC risk assessment and facilitate risk stratification in patients with MASLD.

Trastuzumab is an effective treatment for HER2-positive cancers that has known cardiotoxic properties. Discovering biomarkers that assess cardiotoxicity risk before trastuzumab therapy is essential for protecting the cardiovascular health of cancer patients. To examine the associations between pre-treatment epigenetic age acceleration, circulating leukocyte composition, and candidate single nucleotide polymorphisms (SNPs) with cardiotoxicity risk in breast cancer patients receiving trastuzumab. Among a retrospective cohort of HER2-positive breast cancer patients treated with trastuzumab at Moffitt Cancer Center, we profiled blood DNA methylation and genetic profiles. Epigenetic clocks and circulating leukocyte subsets were derived from MethylationEPIC BeadChip data, and candidate SNPs were measured using the Global Screening Array. Cardiotoxicity events (i.e., reductions in left ventricular ejection fraction, symptomatic heart failure), were identified in medical records. Logistic regression models, adjusted for traditional risk factors, estimated odds ratios (ORs) for biomarker associations with cardiotoxicity risk. Among 157 patients selected for this study, 39 (25

Background: In a previous study, we explored real-world programmed death-ligand 1 (PD-L1) testing and treatment patterns for patients with advanced non-small cell lung cancer (NSCLC) in the era of immune-oncology. The present study aimed to investigate overall survival (OS) with PD-(L)1 inhibitors with longer-term follow-up in the Swedish setting. Materials and methods: Data were extracted from the Swedish National Lung Cancer Registry for patients with NSCLC stage IIIB-IV and ECOG performance status (PS) 0–2 who initiated first-line systemic treatment from 1-April-2017 to 30-June-2021 with data cut-off 30-June-2022. OS and Kaplan–Meier estimates were calculated from start of the PD-(L)1 inhibitor therapy, with subgroups based on nonsquamous/squamous (NSQ/SQ) histology, and further by PS, and PD-L1 status (available from 1-January-2018) provided sufficient sample size. Results: We identified 784 (NSQ:590/SQ:194) patients treated with first-line PD-(L)1 inhibitor monotherapy and 369 (NSQ:305/SQ:64) patients receiving combination regimens. Median OS (95% confidence interval [CI]) was 15.2 (12.4–17.7) and 12.9 (10.6–15.8) months with monotherapy and 17.0 (13.6–23.9) and 18.0 (13.9-NA) months with combination regimens for NSQ/SQ patients. In PS2, median OS with monotherapy was 5.0 (3.7–7.1) and 8.9 (6.2–12.9) months for NSQ/SQ patients (n = 138/59), 5.3 (3.6–13.4) months with combination regimens in NSQ (n = 58) and not evaluable in SQ patients. For PS0-1 patients with tumor cell PD-L1 expression ≥50%, the median OS for NSQ was 23.8 (17.7–29.3) and 27.3 (21.6-NA) months for monotherapy/combination therapy (n = 281/55), while the median OS for combination regimens for PD-L1 <1% and 1–49% was 18.6 (12.1–26.9) and 15.9 (10.8–26.7) months (NSQ; n = 65/87). Interpretation: Real-world OS in Swedish patients receiving first-line PD-(L)1 inhibitor-based regimens was consistent with that observed in clinical trials. Moderate OS rates were observed in PS2, with limited sample sizes. Further research is needed in these patients, as well as in high PD-L1, given the slightly longer OS for combination therapy compared to monotherapy seen for NSQ.

Supplementary Figure from Characterization of Epigenomic Alterations in HPV16+ Head and Neck Squamous Cell Carcinomas

Background Papillary renal cell carcinoma (pRCC) is the second most common kidney cancer subtype, yet our understanding of its tumor immune microenvironment (TIME) remains limited. Objective We utilized multiplex immunofluorescence (mIF) and spatial transcriptomics (ST) to evaluate immune cell architecture in pRCC contrasted with clear cell RCC (ccRCC). Methods Localized RCC tumors (16 pRCC, 70 ccRCC) underwent mIF using markers for T cells, B cells, and tumor-associated macrophages (TAMs). Spatial data in both tumor and stromal compartments of the TIME were collected. A post hoc recurrence free survival analysis (RFS) was performed using Cox proportional hazard models. Single-cell ST was performed on a subset of samples, utilizing probes against 960 transcripts. Cell density, cell spatial clustering, and spatially varying gene expression were analyzed. Results Immune cell density was statistically lower in pRCC amongst functional CD8T cells, while cell clustering was higher amongst M2-like macrophages. Using ST, two genes ( CCL18 , GPNMB ) were enriched in clustered M2-like macrophages in pRCC (FDR < 0.001) and are known markers of lipid-associated TAMs (LAMs). Conclusion Compared to ccRCC, pRCC has greater M2-like macrophage clustering. Using ST, M2-like macrophage clustering corresponds with lipid associated TAMs (LAMs), and therapeutics against this myeloid subset are currently being tested in pRCC.

Glioblastoma (GBM) is a highly aggressive brain tumor characterized by its ability to evade the immune system, hindering the efficacy of current immunotherapies. Recent research has highlighted the important role of immunosuppressive macrophages in the tumor microenvironment (TME) in driving this immune evasion. In this study, we are the first to identify THEMIS2 as a key regulator of tumor-associated macrophage (TAM)-mediated immunosuppression in GBM. We found that a high THEMIS2 expression is associated with poor patient outcomes and increased infiltration of immune cells, particularly macrophages. Functional analyses revealed THEMIS2’s critical involvement in immune-related pathways, including immune response activation, mononuclear cell differentiation, and the positive regulation of cytokine production. Additionally, single-cell RNA sequencing data demonstrated that macrophages with a high THEMIS2 expression were associated with increased phagocytosis, immune suppression, and enhanced tumor growth. These findings suggest that THEMIS2 could serve as both a prognostic marker and a therapeutic target for enhancing anti-tumor immunity in GBM.

Supplementary Table S4 lists oncogenes and tumor suppressor genes analyzed for changes in translation efficiency (TE) following depletion of eIF5A or DHPS, related to Fig. 5E.

ABSTRACT:The radiation sensitivity index (RSI) and 12-chemokine gene expression signature (12CK GES) are two gene expression signatures (GES) that were previously developed to predict tumor radiation sensitivity or identify the presence of tertiary lymphoid structures in tumors, respectively. To advance the use of these GESs into clinical trial evaluation, their assays must be assessed within the context of the Clinical Laboratory Improvement Amendments (CLIA) process. Using HG-U133Plus2.0 arrays, we first established CLIA laboratory proficiency. Then the accuracy (limit of detection and macrodissection impact), precision (variability by time and operator), sample type (surgery vs. biopsy), and concordance with a reference laboratory were evaluated. RSI and 12CK GES were reproducible (RSI: 0.01 mean difference, 12CK GES: 0.17 mean difference) and precise with respect to time and operator. Taken together, the reproducibility analysis of the scores indicated a median RSI difference of 0.06 (6.47% of range) across samples and a median 12CK GES difference of 0.92 (12.29% of range). Experiments indicated that the lower limit of input RNA is 5 ng. Reproducibility with a second CLIA laboratory demonstrated reliability with the median RSI score difference of 0.065 (6% of full range) and 12CK GES difference of 0.93 (12% of observed range). Overall, under CLIA, RSI and 12CK GES were demonstrated by the Moffitt Cancer Center Advanced Diagnostic Laboratory to be reproducible GESs for clinical usage. SIGNIFICANCE:The RSI and 12CK GES are two GESs that predict tumor radiation sensitivity or the presence of tertiary lymphoid structures in tumors, respectively. These GESs were assessed within the CLIA process for future clinical use. We established proficiency, reproducibility, and reliability characteristics for both signatures in a controlled setting, indicating these GESs are suitable for validation within future clinical trials.

Supplementary Table S3 lists 665 shared differentially translated transcripts (DTT) identified following depletion of eIF5A or DHPS, related to Fig. 5C.

12021 Background: Anthracyclines are effective chemotherapeutic agents for treating breast cancer but are associated with significant risks of chemotherapy-related cardiac dysfunction (CTRCD). Current predictors of CTRCD, including patient demographics and clinical characteristics, are insufficient for accurately assessing cardiotoxicity risk before treatment initiation. Here, we examine CTRCD risk associations with pre-treatment DNA methylation (DNAm)-derived biomarkers of biological age, called “epigenetic clocks,” and circulating leukocyte composition. Methods: A retrospective cohort of 137 newly diagnosed breast cancer patients who received anthracycline-based therapy was sampled from the Total Cancer Care cohort at Moffitt Cancer Center. DNAm profiles were assayed using MethylationEPIC v2 BeadChips on pretreatment whole blood samples and used to derive six biological age metrics and percentages of twelve circulating leukocyte subsets. CTRCD events occurring within one year of treatment initiation were identified through medical records and defined as either a reduction in left ventricular ejection fraction (≥10%) or symptomatic heart failure. Logistic regression models, adjusted for chronological age and traditional cardiotoxicity risk factors (e.g., hypertension, diabetes, baseline ejection fraction, and cumulative anthracycline dose), estimated odds ratios (ORs) for associations between DNAm biomarkers and CTRCD. Results: Among 137 newly diagnosed breast cancer patients (mean age: 54 years; 94% white), 33 (24%) experienced CTRCD. In age-adjusted models, the percentage of circulating naïve CD4+ T cells was inversely associated with CTRCD risk, and Horvath18 AgeAccel was positively associated with CTRCD risk, but these associations did not reach statistical significance after additional adjustment for other cardiotoxicity risk factors. In fully adjusted models, a higher percentage of circulating eosinophils was positively associated with CTRCD risk (OR: 1.49; 95% CI: 1.02, 2.24; P = 0.04). Conclusions: A higher percentage of circulating eosinophils appears to be a novel risk factor for CTRCD in breast cancer patients. While eosinophils may contribute to CTRCD susceptibility through mechanisms such as creating a pro-inflammatory environment in cardiac tissue, further studies are needed to clarify the role of eosinophils and confirm these findings. Typically, monocyte/macrophage-mediated pathways, including IL-6 and other cytokines, are thought to play a central role in anthracycline-related cardiac injury, but eosinophil-mediated effects may represent an alternative or complementary pathway. Integrating DNAm biomarker and leukocyte composition assessments into clinical workflows could improve CTRCD risk stratification in newly diagnosed breast cancer patients.

Supplementary Tables S1, S2, S5-S13 includes Supplementary Tables S1, S2, S5-S13. Supplementary Table S1 provides a summary of BL and DHL patient demographics for the immunohistochemistry study presented in Fig. 1, E and F. Supplementary Table S2 lists the MYC-dysregulated genes whose expression is significantly altered following depletion of eIF5A or DHPS, related to Fig. 4F. Supplementary Table S5 shows DHPS GISTIC count and survival of select TCGA PanCancer datasets, related to Fig. 7J. Supplementary Table S6 shows the genetic mouse models used in this study, related to Methods. Supplementary Table S7 shows the mouse and human cell lines used in this study, related to Methods. Supplementary Table S8 lists the antibodies used in this study, related to Methods. Supplementary Table S9 lists reagents used in this study, related to Methods. Supplementary Table S10 summarizes the plasmids used in this study, related to Methods. Supplementary Table S11 lists the sequences of the oligonucleotides used in this study, related to Methods. Supplementary Table S12 lists accession numbers and publicly deposited data from this study, related to Methods. Supplementary Table S13 lists software and algorithms used in this study, related to Methods.

Abstract Spatial transcriptomics (ST) is a powerful tool for understanding tissue biology and disease mechanisms. However, the advanced data analysis and programming skills required can hinder researchers from realizing the full potential of ST. To address this, we developed spatialGE, a web application that simplifies the analysis of ST data. The application spatialGE provided a user-friendly interface that guides users without programming expertise through various analysis pipelines, including quality control, normalization, domain detection, phenotyping, and multiple spatial analyses. It also enabled comparative analysis among samples and supported various ST technologies. The utility of spatialGE was demonstrated through its application in studying the tumor microenvironment of two data sets: 10× Visium samples from a cohort of melanoma metastasis and NanoString CosMx fields of vision from a cohort of Merkel cell carcinoma samples. These results support the ability of spatialGE to identify spatial gene expression patterns that provide valuable insights into the tumor microenvironment and highlight its utility in democratizing ST data analysis for the wider scientific community. Significance: The spatialGE web application enables user-friendly exploratory analysis of spatial transcriptomics data by using a point-and-click interface to guide users from data input to discovery of spatial patterns, facilitating hypothesis generation.

Glioblastoma (GBM) is a highly treatment-resistant malignancy characterized by its poor prognosis and intrinsic resistance to therapy, driven largely by glioblastoma stem cells (GSCs) and an immunosuppressive tumor microenvironment (TME). This dual resistance plays a significant role in the failure of current treatment strategies. Consequently, there is an urgent need for novel therapeutic approaches that can effectively target GSCs while simultaneously reshaping the TME to promote anti-tumor immunity. In this study, we investigated the dual therapeutic potential of Xevinapant, a lead SMAC mimetic, through a combination of in vitro, in vivo, and single-cell transcriptomic analyses. We found that Xevinapant demonstrated potent anti-tumor activity through inducing dose-dependent apoptosis and significantly reduced cell viability in both human and mouse GSCs. In vivo administration of Xevinapant led to significant tumor suppression and extended overall survival in orthotopic models. Notably, our single-cell RNA sequencing result revealed that Xevinapant activated immune effector cell responses, contributing to the reprogramming of the immunosuppressive TME. Immune cell activation (both lymphoid and myeloid lineages) was further validated by flow cytometry using tumor-derived cells. To overcome potential therapeutic resistance, we derived Xevinapant-specific gene expression signatures and queried the LINCS database to identify small molecules with synergistic effects. Our analysis identified a promising compound ST-059620 that, when used in combination with Xevinapant, enhanced therapeutic efficacy and overcame resistance. Taken together, our findings highlight the dual mechanism of action of Xevinapant in targeting both tumor-intrinsic and microenvironmental resistance mechanisms. These results support the continued clinical development of Xevinapant and provide a strong rationale for combination strategies aimed at improving treatment efficacy in GBM.

While cancer immunotherapies have revolutionized treatment, their efficacy remains limited for most patients, highlighting tumors' capacity to evade immune detection. Epigenetic modifications, particularly DNA methylation, play a pivotal role in silencing immune-related pathways, thereby facilitating immune escape. By modulating gene expression, methylation disrupts immune activation, contributing to reduced tumor immunogenicity. This study examines the methylation landscape of co-stimulatory and immune checkpoint genes across various cancers to elucidate how these changes influence immune responses. Using The Cancer Genome Atlas (TCGA), we analyzed methylation and gene expression profiles across diverse cancer types. Data from 8,186 solid tumors and 745 adjacent normal tissues were processed via t-distributed stochastic neighbor embedding (t-SNE) with 247 probes targeting 20 immune-related genes. Principal component analysis (PCA) was applied to capture methylation variability across 8,931 tumor and normal samples. To explore the effects of methylation on immune gene expression, we analyzed data from 26 epithelial cancer cell lines treated with 5-azacitidine, a demethylating agent, using the GSE57342 dataset. Post-treatment changes in gene expression were assessed, and survival analyses from prior studies were used to explore clinical correlations. We identified distinct methylation patterns in immune synapse genes, differentiating tumors from adjacent normal tissues. Co-stimulatory genes such as CD40 were hypermethylated in tumors, correlating with decreased expression, whereas immune checkpoint genes like PDL1 and HHLA2 were hypomethylated, correlating with increased expression. This inverse relationship between methylation and gene expression underscores the transcriptional regulatory role of DNA methylation. Treatment with 5-azacitidine reversed hypermethylation in co-stimulatory genes, including CD40, potentially enhancing immune recognition. Methylation levels of these genes were also associated with T cell infiltration into the tumor microenvironment and predicted better outcomes in melanoma patients, underscoring their clinical relevance. This study demonstrates that DNA methylation of immune synapse genes contributes to tumor immune evasion by modulating immune gene expression. Targeting these epigenetic alterations represents a promising strategy to restore tumor immunogenicity and improve immunotherapy outcomes, particularly when combined with immune checkpoint inhibitors. Reversing methylation-driven immune suppression could strengthen the immune response and enhance clinical outcomes for cancer patients. Imene Hamaidi, Anders Berglund, Matthew Mills, Ryan M. Putney, James J. Mulé, Sungjune Kim. DNA methylation of immune synapse genes drives tumor immune evasion [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 4831.

Introduction:Puerto Rican (PR) Hispanic/Latino (H/L) men are an understudied population that has the highest prostate cancer (PCa) specific mortality among other Hispanic populations. Little information is known about the higher mortality in PR H/L men. It is thought that epigenetic changes in key genes may play a critical role in aggressive tumors. Methods:We aimed to identify key 5-hydroxymethylcytosine (5hmC) changes in PR H/L men with aggressive PCa. We performed sequencing analysis using the 5hmC-enriched DNA from 22 prostate tumors and 24 adjacent normal FFPE samples. Results:We identified 808 differentially methylated genes (DMGs) in tumors compared to adjacent normal tissues. These genes suggest key mechanisms, including upregulated signatures of negative Androgen Receptor (AR) regulation, Wnt/β-catenin pathway activation, and downregulation of tumor suppressor genes. Pathway analysis of DMGs demonstrated that DNA repair pathway was most upregulated in tumors. Since 5hmC abundance positively correlates with gene expression levels, we further investigated 808 DMGs in TCGA PCa gene expression data. Further, we identified 59 DMGs with significant gene expression changes in the same direction. Additionally, we identified 111 aggressiveness-related DMGs, of which, two hypomethylated genes (CCDC122, NUDT15) and four hypermethylated genes (PVT1, RPL30, TRMT12, UBR5) were found to be altered at transcriptomic level in a concordant manner in PR H/L PCa patients. Aberrant 5hmC and GE changes in these six genes were also associated with progression-free survival in the mixed PCa population. Discussion:The 5hmC modifications and associated gene expression changes in these six genes could be linked to the highest prostate cancer (PCa)-specific mortality in PR H/L men. In conclusion, our study identified 59 DMGs showing concordant epigenetic and transcriptomic changes in tumor tissues and 111 DMGs showing association with aggressive PCa among PR H/L men. Our findings have significant implications for understanding these key genes' molecular mechanisms, which may drive PCa progression and mortality in this population. This will help in developing potential biomarkers or therapeutic targets for personalized treatment strategies in this high-risk subgroup. Future research will explore how these genes contribute to PCa-specific mortality through molecular analyses, with plans to validate them in a larger validation cohort.

Supplementary Figures S1-S7 includes Supplementary Figure S1-S7 and the figure legend for each figure. Supplementary Fig. S1 shows that the polyamine-hypusine circuit is activated in many human cancers including MYC-driven lymphoma. Supplementary Fig. S1 is related to Fig. 1. Supplementary Fig. S2 shows that inhibition of DHPS enzyme activity, or silencing eIF5A or DHPS, suppresses the growth of mouse MYC-driven lymphoma. Supplementary Fig. S2 is related to Fig. 2. Supplementary Fig. S3 shows that hypusinated eIF5A (eIF5AHyp) contributes to the tumorigenic potential and maintenance of MYC-driven lymphoma. Supplementary Fig. S3 is related to Fig. 3. Supplementary Fig. S4 shows the effects of eIF5A or DHPS depletion on the transcriptional landscape of MYC-driven lymphoma. Supplementary Fig. S4 is related to Fig. 4. Supplementary Fig. S5 shows that depletion of eIF5A or DHPS impairs the translation efficiency of subsets of mRNA in MYC-driven lymphoma. Supplementary Fig. S5 is related to Fig. 5. Supplementary Fig. S6 shows the validation of select eIF5AHyp translation targets identified by the multi-omics analyses, and that the translation of key regulatory cell cycle factors is controlled by hypusinated eIF5A. Supplementary Fig. S6 is related to Fig. 6. Supplementary Fig. S7 shows that hypusinated eIF5A is essential for the development of MYC-driven lymphoma. Supplementary Fig. S7 is related to Fig. 7.