Candidate Cancer Driver Mutations in Distal Regulatory Elements and Long-Range Chromatin Interaction Networks.

A comprehensive catalog of cancer driver mutations is essential for understanding tumorigenesis and developing therapies. Exome-sequencing studies have mapped many protein-coding drivers, yet few non-coding drivers are known because genome-wide discovery is challenging. We developed a driver discovery method, ActiveDriverWGS, and analyzed 120,788 cis-regulatory modules (CRMs) across 1,844 whole tumor genomes from the ICGC-TCGA PCAWG project. We found 30 CRMs with enriched SNVs and indels (FDR < 0.05). These frequently mutated regulatory elements (FMREs) were ubiquitously active in human tissues, showed long-range chromatin interactions and mRNA abundance associations with target genes, and were enriched in motif-rewiring mutations and structural variants. Genomic deletion of one FMRE in human cells caused proliferative deficiencies and transcriptional deregulation of cancer genes CCNB1IP1, CDH1, and CDKN2B, validating observations in FMRE-mutated tumors. Pathway analysis revealed further sub-significant FMREs at cancer genes and processes, indicating an unexplored landscape of infrequent driver mutations in the non-coding genome.

Tyrosine phosphatase SHP-2 mediates C-type lectin receptor-induced activation of the kinase Syk and anti-fungal TH17 responses.

Fungal infection stimulates the canonical C-type lectin receptor (CLR) signaling pathway via activation of the tyrosine kinase Syk. Here we identify a crucial role for the tyrosine phosphatase SHP-2 in mediating CLR-induced activation of Syk. Ablation of the gene encoding SHP-2 (Ptpn11; called 'Shp-2' here) in dendritic cells (DCs) and macrophages impaired Syk-mediated signaling and abrogated the expression of genes encoding pro-inflammatory molecules following fungal stimulation. Mechanistically, SHP-2 operated as a scaffold, facilitating the recruitment of Syk to the CLR dectin-1 or the adaptor FcRγ, through its N-SH2 domain and a previously unrecognized carboxy-terminal immunoreceptor tyrosine-based activation motif (ITAM). We found that DC-derived SHP-2 was crucial for the induction of interleukin 1ß (IL-1ß), IL-6 and IL-23 and anti-fungal responses of the TH17 subset of helper T cells in controlling infection with Candida albicans. Together our data reveal a mechanism by which SHP-2 mediates the activation of Syk in response to fungal infection.

E-cadherin bridges cell polarity and spindle orientation to ensure prostate epithelial integrity and prevent carcinogenesis in vivo.

Cell polarity and correct mitotic spindle positioning are essential for the maintenance of a proper prostate epithelial architecture, and disruption of the two biological features occurs at early stages in prostate tumorigenesis. However, whether and how these two epithelial attributes are connected in vivo is largely unknown. We herein report that conditional genetic deletion of E-cadherin, a key component of adherens junctions, in a mouse model results in loss of prostate luminal cell polarity and randomization of spindle orientations. Critically, E-cadherin ablation causes prostatic hyperplasia which progresses to invasive adenocarcinoma. Mechanistically, E-cadherin and the spindle positioning determinant LGN interacts with the PDZ domain of cell polarity protein SCRIB and form a ternary protein complex to bridge cell polarity and cell division orientation. These findings provide a novel mechanism by which E-cadherin acts an anchor to maintain prostate epithelial integrity and to prevent carcinogenesis in vivo.

Carbon Monoxide Impairs CD11b+Ly-6Chi Monocyte Migration from the Blood to Inflamed Pancreas via Inhibition of the CCL2/CCR2 Axis.

Acute pancreatitis (AP) is a sterile inflammation, in which inflammatory monocytes (CD11b+Ly-6Chi) are recruited into the inflamed tissue at the onset of disease. Monocyte infiltration and activation at the site of inflammation are critical to the pathogenesis of AP. Our previous studies have shown a protective role for CO in AP, which is partially mediated by inhibition of macrophage activation via TLR4 signaling. In the current study, to gain a better understanding of CO's therapeutic effect, we further investigated whether CO could affect inflammatory monocyte trafficking during AP. In a mouse model of AP, we found that treatment with CO-releasing molecule-2 (CORM-2) impaired recruitment of inflammatory monocytes, but not that of neutrophils, from peripheral blood to inflamed pancreas. During the early stage of AP, a single dose of CORM-2 decreased pancreatic CCL2 and soluble ICAM-1 expression. In addition, using in vivo and in vitro experiments, we found that CORM-2 had the ability to inhibit CD11b+Ly-6Chi monocyte migration via blockade of CCR2 endocytosis. Notably, we showed that CORM-2 inhibited CCR2 endocytosis of inflammatory monocytes (CD14hiCD16-) from AP patients. Taken together, our results highlighted CO's effect on inflammatory monocyte trafficking, shedding additional light on its therapeutic potential in AP.

A Src family kinase-Shp2 axis controls RUNX1 activity in megakaryocyte and T-lymphocyte differentiation.

Hematopoietic development occurs in complex microenvironments and is influenced by key signaling events. Yet how these pathways communicate with master hematopoietic transcription factors to coordinate differentiation remains incompletely understood. The transcription factor RUNX1 plays essential roles in definitive hematopoietic stem cell (HSC) ontogeny, HSC maintenance, megakaryocyte (Mk) maturation, and lymphocyte differentiation. It is also the most frequent target of genetic alterations in human leukemia. Here, we report that RUNX1 is phosphorylated by Src family kinases (SFKs) and that this occurs on multiple tyrosine residues located within its negative regulatory DNA-binding and autoinhibitory domains. Retroviral transduction, chemical inhibitor, and genetic studies demonstrate a negative regulatory role of tyrosine phosphorylation on RUNX1 activity in Mk and CD8 T-cell differentiation. We also demonstrate that the nonreceptor tyrosine phosphatase Shp2 binds directly to RUNX1 and contributes to its dephosphorylation. Last, we show that RUNX1 tyrosine phosphorylation correlates with reduced GATA1 and enhanced SWI/SNF interactions. These findings link SFK and Shp2 signaling pathways to the regulation of RUNX1 activity in hematopoiesis via control of RUNX1 multiprotein complex assembly.

A MicroRNA302-367-Erk1/2-Klf2-S1pr1 Pathway Prevents Tumor Growth via Restricting Angiogenesis and Improving Vascular Stability.

RATIONALE: Angiogenic hypersprouting and leaky vessels are essential for tumor growth. MicroRNAs have unique therapeutic advantages by targeting multiple pathways of tumor-associated angiogenesis, but the function of individual miRNAs of miR302-367 cluster in angiogenesis and tumors has not yet been fully evaluated. OBJECTIVE: To investigate the functions of miR302-367 in developmental angiogenesis and tumor angiogenesis and explore the molecular mechanisms of microRNA for the treatment of pathological neovascularization-related diseases. METHODS AND RESULTS: Here, we show that miR302-367 elevation in endothelial cells reduces retinal sprouting angiogenesis and promotes vascular stability in vivo, ex vivo, and in vitro. Erk1/2 is identified as direct target of miR302-367, and downregulation of Erk1/2 on miR302-367 elevation in endothelial cells increases the expression of Klf2 and in turn S1pr1 and its downstream target VE-cadherin, suppressing angiogenesis and improving vascular stability. Conversely, both pharmacological blockade and genetic deletion of S1pr1 in endothelial cells reverse the antiangiogenic and vascular stabilizing effect of miR302-367 in mice. Tumor angiogenesis shares features of developmental angiogenesis, and endothelial specific elevation of miR302-367 reduces tumor growth by restricting sprout angiogenesis and decreasing vascular permeability via the same Erk1/2-Klf2-S1pr1 pathways. CONCLUSIONS: MiR302-367 regulation of an Erk1/2-Klf2-S1pr1 pathway in the endothelium advances our understanding of angiogenesis, meanwhile also provides opportunities for therapeutic intervention of tumor growth.

Shp2 and Pten have antagonistic roles in myeloproliferation but cooperate to promote erythropoiesis in mammals.

Previous data suggested a negative role of phosphatase and tensin homolog (Pten) and a positive function of SH2-containing tyrosine phosphatase (Shp2)/Ptpn11 in myelopoiesis and leukemogenesis. Herein we demonstrate that ablating Shp2 indeed suppressed the myeloproliferative effect of Pten loss, indicating directly opposing functions between pathways regulated by these two enzymes. Surprisingly, the Shp2 and Pten double-knockout mice suffered lethal anemia, a phenotype that reveals previously unappreciated cooperative roles of Pten and Shp2 in erythropoiesis. The lethal anemia was caused collectively by skewed progenitor differentiation and shortened erythrocyte lifespan. Consistently, treatment of Pten-deficient mice with a specific Shp2 inhibitor suppressed myeloproliferative neoplasm while causing anemia. These results identify concerted actions of Pten and Shp2 in promoting erythropoiesis, while acting antagonistically in myeloproliferative neoplasm development. This study illustrates cell type-specific signal cross-talk in blood cell lineages, and will guide better design of pharmaceuticals for leukemia and other types of cancer in the era of precision medicine.

A candidate gastric stem/progenitor cell marker revealed by genome-wide analysis.

Despite the important role of the gastric stem cell in tissue homeostasis and gastric carcinogenesis, its residence and identity remain poorly understood. In a recent paper in The Journal of Pathology, Vange et al suggest ASPM as a candidate stem/progenitor cell marker for oxyntic glands. Identification of ASPM was achieved by genome-wide gene expression analysis of the micro-dissected isthmus zone, where the majority of stem/progenitor cells are believed to reside. ASPM-positive cells, scattered in the proliferative isthmus region, do not express most differentiated cell markers and are largely quiescent. Together with ASPM, 11 other genes that are uniquely expressed in the isthmus zone constitute a regulatory network downstream of the core transcription factor E2F1. The authors further demonstrated that up-regulation of E2F1 and ASPM is associated with gastric cancers. This study provides novel candidates for future lineage-tracing experiments that will lead to the ultimate discovery of bona fide gastric stem cell markers. Additionally, the E2F1-ASPM axis may represent a new mechanism for gastric carcinogenesis.

Nonreceptor tyrosine phosphatase Shp2 promotes adipogenesis through inhibition of p38 MAP kinase.

The molecular mechanism underlying adipogenesis and the physiological functions of adipose tissue are not fully understood. We describe here a unique mouse model of severe lipodystrophy. Ablation of Ptpn11/Shp2 in adipocytes, mediated by aP2-Cre, led to premature death, lack of white fat, low blood pressure, compensatory erythrocytosis, and hepatic steatosis in Shp2(fat-/-) mice. Fat transplantation partially rescued the lifespan and blood pressure in Shp2(fat-/-) mice, and administration of leptin also restored partially the blood pressure of mutant animals with endogenous leptin deficiency. Consistently, homozygous deletion of Shp2 inhibited adipocyte differentiation from embryonic stem (ES) cells. Biochemical analyses suggest a Shp2-TAO2-p38-p300-PPARγ pathway in adipogenesis, in which Shp2 suppresses p38 activation, leading to stabilization of p300 and enhanced PPARγ expression. Inhibition of p38 restored adipocyte differentiation from Shp2(-/-) ES cells, and p38 signaling is also suppressed in obese patients and obese animals. These results illustrate an essential role of adipose tissue in mammalian survival and physiology and also suggest a common signaling mechanism involved in adipogenesis and obesity development.

Proteomic Comparison and MRM-Based Comparative Analysis of Metabolites Reveal Metabolic Shift in Human Prostate Cancer Cell Lines.

One of the major challenges in prostate cancer therapy remains the development of effective treatments for castration-resistant prostate cancer (CRPC), as the underlying mechanisms for its progression remain elusive. Previous studies showed that androgen receptor (AR) is crucially involved in regulation of metabolism in prostate cancer (PCa) cells throughout the transition from early stage, androgen-sensitive PCa to androgen-independent CRPC. AR achieves such metabolic rewiring directively either via its transcriptional activity or via interactions with AMP-activated protein kinase (AMPK). However, due to the heterogeneous expression and activity status of AR in PCa cells, it remains a challenge to investigate the links between AR status and metabolic alterations. To this end, we compared the proteomes of three pairs of androgen-sensitive (AS) and androgen-independent (AI) PCa cell lines, namely, PC3-AR(+)/PC3, 22Rv1/Du145, and LNCaP/C42B, using an iTRAQ labeling approach. Our results revealed that most of the differentially expressed proteins between each pair function in metabolism, indicating a metabolic shift between AS and AI cells, as further validated by multiple reaction monitoring (MRM)-based quantification of nucleotides and relative comparison of fatty acids between these cell lines. Furthermore, increased adenylate kinase isoenzyme 1 (AK1) in AS relative to AI cells may result in activation of AMPK, representing a major regulatory factor involved in the observed metabolic shift in PCa cells.

TRIM59 is up-regulated in gastric tumors, promoting ubiquitination and degradation of p53.

BACKGROUND & AIMS: Little is known about factors that promote gastric carcinogenesis. We analyzed multiple microarray data sets for messenger RNAs (mRNAs) that were increased significantly in human gastric tumor samples, compared with the adjacent normal gastric tissue. We found expression of tripartite motif 59 (TRIM59), which encodes a putative ubiquitin ligase, to be increased, and investigated its effects in gastric cancer cell lines. METHODS: We analyzed microarray data sets from the Oncomine database. We used quantitative polymerase chain reaction and immunoblotting to measure levels of TRIM59 mRNA and protein in 50 human gastric cancer and paired normal tissues, obtained from Renji Hospital and the First Affiliated Hospital of Nanchang University, in China. We also measured protein levels in the gastric epithelial cell line GES-1; the cancer cell lines MKN45, AGS, SGC7901, BGC823, Snu5, N87, and Snu1; and in tissue arrays of 108 human gastric tumors. TRIM59 was knocked down and overexpressed in gastric cancer cell lines, and the effects on proliferation, clone formation, migration, and growth of xenograft tumors in nude mice were assessed. TRIM59-related signaling pathways were examined by immunoblotting and quantitative polymerase chain reaction. We analyzed interactions among TRIM59, P53, and ubiquitin in immunoprecipitation studies. RESULTS: Levels of TRIM59 mRNA and protein were increased significantly in gastric tumors compared with nontumor tissues; increased levels were associated with advanced tumor stage and shorter patient survival times. TRIM59 knockdown reduced proliferation, clone formation, and migration of gastric cancer cell lines, as well as growth of xenograft tumors in nude mice; overexpression of TRIM59 had the opposite effects. TRIM59 interacted physically with P53, increasing its ubiquitination and degradation. Increased levels of TRIM59 in human gastric tumors correlated with reduced expression of P53 target genes. CONCLUSIONS: The putative ubiquitin ligase TRIM59 is up-regulated in human gastric tumors compared with nontumor tissues. Levels of TRIM59 correlate with tumor progression and patient survival times. TRIM59 interacts with P53, promoting its ubiquitination and degradation, and TRIM59 might promote gastric carcinogenesis via this mechanism.

Modulation of fatty acid synthase degradation by concerted action of p38 MAP kinase, E3 ligase COP1, and SH2-tyrosine phosphatase Shp2.

The Src-homology 2 (SH2) domain-containing tyrosine phosphatase Shp2 has been known to regulate various signaling pathways triggered by receptor and cytoplasmic tyrosine kinases. Here we describe a novel function of Shp2 in control of lipid metabolism by mediating degradation of fatty acid synthase (FASN). p38-phosphorylated COP1 accumulates in the cytoplasm and subsequently binds FASN through Shp2 here as an adapter, leading to FASN-Shp2-COP1 complex formation and FASN degradation mediated by ubiquitination pathway. By fasting p38 is activated and stimulates FASN protein degradation in mice. Consistently, the FASN protein levels are dramatically elevated in mouse liver and pancreas in which Shp2/Ptpn11 is selectively deleted. Thus, this study identifies a new activity for Shp2 in lipid metabolism.

Inhibiting Endothelial Cell-Mediated T Lymphocyte Apoptosis with Integrin-Targeting Peptide-Drug Conjugate Filaments for Chemoimmunotherapy of Triple-Negative Breast Cancer.

Tumor-associated endothelial cells (TECs) limit antitumor immunity via inducing apoptosis of infiltrating T lymphocytes through a Fas ligand (FasL) mediated mechanism. Herein, this work creates a peptide-drug conjugate (PDC) by linking 7-ethyl-10-hydroxycamptothecin (SN38) to hydrophilic segments with either RGDR or HKD motif at their C-terminus through a glutathione-responsive linker. The PDCs spontaneously assemble into filaments in aqueous solution. The PDC filaments containing 1% of SN38-RGDR (SN38-HKD/RGDR) effectively target triple-negative breast cancer (TNBC) cells and TECs with upregulated expression of integrin, and induce immunogenic cell death (ICD) of tumor cells and FasL downregulation of TECs. SN38-HKD/RGDR increases infiltration, activity, and viability of CD8+ T cells, and thus inhibits the growth of primary tumors and pulmonary metastasis. This study highlights the synergistic modulation of cancerous cells and TECs with integrin-targeting PDC filaments as a promising strategy for TNBC chemoimmunotherapy.

Chemical conjugation mitigates immunotoxicity of chemotherapy via reducing receptor-mediated drug leakage from lipid nanoparticles.

Immunotoxicity remains a major hindrance to chemotherapy in cancer therapy. Nanocarriers may alleviate the immunotoxicity, but the optimal design remains unclear. Here, we created two variants of maytansine (DM1)-loaded synthetic high-density lipoproteins (D-sHDL) with either physically entrapped (ED-sHDL) or chemically conjugated (CD-sHDL) DM1. We found that CD-sHDL showed less accumulation in the tumor draining lymph nodes (DLNs) and femur, resulting in a lower toxicity against myeloid cells than ED-sHDL via avoiding scavenger receptor class B type 1 (SR-B1)-mediated DM1 transportation into the granulocyte-monocyte progenitors and dendritic cells. Therefore, higher densities of lymphocytes in the tumors, DLNs, and blood were recorded in mice receiving CD-sHDL, leading to a better efficacy and immune memory of CD-sHDL against colon cancer. Furthermore, liposomes with conjugated DM1 (CD-Lipo) showed lower immunotoxicity than those with entrapped drug (ED-Lipo) through the same mechanism after apolipoprotein opsonization. Our findings highlight the critical role of drug loading patterns in dictating the biological fate and activity of nanomedicine.

Cumulative Lifetime Violence and Bacterial Vaginosis Infection in Sexually Transmitted Infections: Findings From a Retrospective Cohort Study Among Black Women at Risk for HIV.

Introduction: Bacterial vaginosis is the most common vaginal condition among women of reproductive age and has been associated with sexually transmitted infections. This study examines the association between cumulative lifetime violence exposure, bacterial vaginosis, and sexually transmitted infections among Black women at risk for HIV. Methods: HIV-negative Black women in a retrospective cohort study (N=230) completed survey questions on cumulative violence (exposure to sexual or physical abuse before age 18 years and exposure to intimate partner violence or sexual violence [partner or other] after age 18 years and past year), bacterial vaginosis (lifetime and past year), and sexually transmitted infection diagnosis (lifetime and past year). Logistic regression models estimated the associations between cumulative violence, bacterial vaginosis, and sexually transmitted infections. Bacterial vaginosis was examined as a moderator in the association between cumulative violence and sexually transmitted infections. Results: Many women reported cumulative violence exposure (40%), lifetime bacterial vaginosis diagnosis (53%), and lifetime sexually transmitted infection diagnosis (73%). Cumulative violence experience was significantly associated with increased adjusted odds of lifetime bacterial vaginosis diagnosis (AOR=1.98; 95% CI=1.10, 3.54). Lifetime bacterial vaginosis diagnosis (AOR=2.76; 95% CI=1.45, 5.22) and past-year bacterial vaginosis diagnosis (AOR=2.16; 95% CI=1.14, 4.10) were significantly associated with increased odds of lifetime sexually transmitted infection diagnosis. Lifetime bacterial vaginosis diagnosis (AOR=2.10; 95% CI=1.19, 3.70) and past-year bacterial vaginosis diagnosis (AOR=3.00; 95% CI=1.70, 5.31) were significantly associated with past-year sexually transmitted infection diagnosis. Lifetime bacterial vaginosis infection significantly increased the odds of lifetime sexually transmitted infection diagnosis with increasing cumulative violence exposure. Conclusions: Our findings support educating and screening Black women who experience cumulative violence for bacterial vaginosis to reduce the risk of untreated bacterial vaginosis and sexually transmitted infections.

moPepGen: Rapid and Comprehensive Proteoform Identification.

Gene expression is a multi-step transformation of biological information from its storage form (DNA) into functional forms (protein and some RNAs). Regulatory activities at each step of this transformation multiply a single gene into a myriad of proteoforms. Proteogenomics is the study of how genomic and transcriptomic variation creates this proteoform diversity, and is limited by the challenges of modeling the complexities of gene-expression. We therefore created moPepGen, a graph-based algorithm that comprehensively enumerates proteoforms in linear time. moPepGen works with multiple technologies, in multiple species and on all types of genetic and transcriptomic data. In human cancer proteomes, it detects and quantifies previously unobserved noncanonical peptides arising from germline and somatic genomic variants, noncoding open reading frames, RNA fusions and RNA circularization. By enabling efficient identification and quantitation of previously hidden proteins in both existing and new proteomic data, moPepGen facilitates all proteogenomics applications. It is available at: https://github.com/uclahs-cds/package-moPepGen.

Zeb1-controlled metabolic plasticity enables remodeling of chromatin accessibility in the development of neuroendocrine prostate cancer.

Cell plasticity has been found to play a critical role in tumor progression and therapy resistance. However, our understanding of the characteristics and markers of plastic cellular states during cancer cell lineage transition remains limited. In this study, multi-omics analyses show that prostate cancer cells undergo an intermediate state marked by Zeb1 expression with epithelial-mesenchymal transition (EMT), stemness, and neuroendocrine features during the development of neuroendocrine prostate cancer (NEPC). Organoid-formation assays and in vivo lineage tracing experiments demonstrate that Zeb1+ epithelioid cells are putative cells of origin for NEPC. Mechanistically, Zeb1 transcriptionally regulates the expression of several key glycolytic enzymes, thereby predisposing tumor cells to utilize glycolysis for energy metabolism. During this process, lactate accumulation-mediated histone lactylation enhances chromatin accessibility and cellular plasticity including induction of neuro-gene expression, which promotes NEPC development. Collectively, Zeb1-driven metabolic rewiring enables the epigenetic reprogramming of prostate cancer cells to license the adeno-to-neuroendocrine lineage transition.

The N6-methyladenosine Epitranscriptomic Landscape of Lung Adenocarcinoma.

Comprehensive m6A epitranscriptome profiling of primary tumors remains largely uncharted. Here, we profiled the m6A epitranscriptome of 10 non-neoplastic lung (NL) tissues and 51 lung adenocarcinoma (LUAD) tumors, integrating the corresponding transcriptome, proteome and extensive clinical annotations. We identified distinct clusters and genes that were exclusively linked to disease progression through m6A modifications. In comparison with NL tissues, we identified 430 transcripts to be hypo-methylated and 222 to be hyper-methylated in tumors. Among these genes, EML4 emerged as a novel metastatic driver, displaying significant hyper-methylation in tumors. m6A modification promoted the translation of EML4, leading to its widespread overexpression in primary tumors. Functionally, EML4 modulated cytoskeleton dynamics through interacting with ARPC1A, enhancing lamellipodia formation, cellular motility, local invasion, and metastasis. Clinically, high EML4 protein abundance correlated with features of metastasis. METTL3 small molecule inhibitor markedly diminished both EML4 m6A and protein abundance, and efficiently suppressed lung metastases in vivo.

Kit-Shp2-Kit signaling acts to maintain a functional hematopoietic stem and progenitor cell pool.

The stem cell factor (SCF)/Kit system has served as a classic model in deciphering molecular signaling events in the hematopoietic compartment, and Kit expression is a most critical marker for hematopoietic stem cells (HSCs) and progenitors. However, it remains to be elucidated how Kit expression is regulated in HSCs. Herein we report that a cytoplasmic tyrosine phosphatase Shp2, acting downstream of Kit and other RTKs, promotes Kit gene expression, constituting a Kit-Shp2-Kit signaling axis. Inducible ablation of PTPN11/Shp2 resulted in severe cytopenia in BM, spleen, and peripheral blood in mice. Shp2 removal suppressed the functional pool of HSCs/progenitors, and Shp2-deficient HSCs failed to reconstitute lethally irradiated recipients because of defects in homing, self-renewal, and survival. We show that Shp2 regulates coordinately multiple signals involving up-regulation of Kit expression via Gata2. Therefore, this study reveals a critical role of Shp2 in maintenance of a functional HSC/progenitor pool in adult mammals, at least in part through a kinase-phosphatase-kinase cascade.

TRIM59 is suppressed by androgen receptor and acts to promote lineage plasticity and treatment-induced neuroendocrine differentiation in prostate cancer.

The incidence of treatment-induced neuroendocrine prostate cancer (t-NEPC) has been greatly increasing after the usage of secondgeneration androgen receptor (AR) pathway inhibitors (ARPIs). Neuroendocrine differentiation (NED) is closely associated with ARPI treatment failure and poor prognosis in prostate cancer (PCa) patients. However, the molecular mechanisms of NED are not fully understood. Here we report that upregulation of TRIM59, a TRIM family protein, is strongly correlated with ARPI treatment mediated NED and shorter patient survival in PCas. AR binds to TRIM59 promoter and represses its transcription. ARPI treatment leads to a reversal of repressive epigenetic modifications on TRIM59 gene and the transcriptional restraint on TRIM59 by AR. Upregulated TRIM59 then drives the NED of PCa by enhancing the degradation of RB1 and P53 and upregulating downstream lineage plasticity-promoting transcription factor SOX2. Altogether, TRIM59 is negatively regulated by AR and acts as a key driver for NED in PCas. Our study provides a novel prognostic marker for PCas and shed new light on the molecular pathogenesis of t-NEPC, a deadly variant of PCa.