A Unique Approach: Biomimetic Graphdiyne-Based Nanoplatform to Treat Prostate Cancer by Combining Cuproptosis and Enhanced Chemodynamic Therapy.

Purpose: Current treatment approaches for Prostate cancer (PCa) often come with debilitating side effects and limited therapeutic outcomes. There is urgent need for an alternative effective and safe treatment for PCa. Methods: We developed a nanoplatform to target prostate cancer cells based on graphdiyne (GDY) and a copper-based metal-organic framework (GDY-CuMOF), that carries the chemotherapy drug doxorubicin (DOX) for cancer treatment. Moreover, to provide GDY-CuMOF@DOX with homotypic targeting capability, we coated the PCa cell membrane (DU145 cell membrane, DCM) onto the surface of GDY-CuMOF@DOX, thus obtaining a biomimetic nanoplatform (DCM@GDY-CuMOF@DOX). The nanoplatform was characterized by using transmission electron microscope, atomic force microscope, X-ray diffraction, etc. Drug release behavior, antitumor effects in vivo and in vitro, and biosafety of the nanoplatform were evaluated. Results: We found that GDY-CuMOF exhibited a remarkable capability to load DOX mainly through π-conjugation and pore adsorption, and it responsively released DOX and generated Cu+ in the presence of glutathione (GSH). In vivo experiments demonstrated that this nanoplatform exhibits remarkable cell-killing efficiency by generating lethal reactive oxygen species (ROS) and mediating cuproptosis. In addition, DCM@GDY-CuMOF@DOX effectively suppresses tumor growth in vivo without causing any apparent side effects. Conclusion: The constructed DCM@GDY-CuMOF@DOX nanoplatform integrates tumor targeting, drug-responsive release and combination with cuproptosis and chemodynamic therapy, offering insights for further biomedical research on efficient PCa treatment.

Aberrant Super-Enhancer Landscape in Enzalutamide-Resistant Prostate Cancer Cells.

Background: Castration-resistant prostate cancer (CRPC), which has developed resistance to next-generation antiandrogens, such as enzalutamide (Enz), is a lethal disease. Furthermore, transcriptional regulation by super enhancers (SEs) is crucial for the growth and spread of prostate cancer, as well as drug resistance. The functions of SEs, a significant class of noncoding DNA cis-regulatory elements, have been the subject of numerous recent studies in the field of cancer research. Materials and Methods: The goal of this research was to identify SEs associated with Enz resistance in C4-2B cells using chromatin immunoprecipitation sequencing and cleavage under targets and tagmentation (CUT&Tag). Using HOMER analysis to predict protein/gene-binding motifs, we identified master transcription factors (TFs) that may bind to SE sites. Using small interfering RNA, WST-1 assays, and qRT-PCR, we then confirmed the associations between TFs of SEs and Enz resistance. Results: A total of 999 SEs were screened from C4-2B EnzR cells in total. Incorporating analysis with RNA-seq data revealed 41 SEs to be strongly associated with the promotion of Enz resistance. In addition, we finally predicted that master TFs bind to SE-binding regions. Subsequently, we selected zinc finger protein 467 (ZFP467) and SMAD family member 3 to confirm the functional connections of master TFs with Enz resistance through SEs (ZNF467). Conclusions: In this study, SMAD3 and ZNF467 were found to be closely related to Enz-resistant CRPC. Our research uncovered a sizable group of SEs linked to Enz resistance in prostate cancer, dissected the mechanisms underlying SE Enz resistance, and shed light on potential clinical uses for SEs.

Individual ingredients of NP-101 (Thymoquinone formula) inhibit SARS-CoV-2 pseudovirus infection.

Thymoquinone TQ, an active ingredient of Nigella Sativa, has been shown to inhibit COVID-19 symptoms in clinical trials. Thymoquinone Formulation (TQF or NP-101) is developed as a novel enteric-coated medication derivative from Nigella Sativa. TQF consists of TQ with a favorable concentration and fatty acids, including palmitic, oleic, and linoleic acids. In this study, we aimed to investigate the roles of individual ingredients of TQF on infection of SARS-CoV-2 variants in-vitro, by utilizing Murine Leukemia Virus (MLV) based pseudovirus particles. We demonstrated that NP-101, TQ, and other individual ingredients, including oleic, linoleic, and palmitic acids inhibited SARS-CoV-2 infection in the MLV-based pseudovirus model. A large, randomized phase 2 study of NP-101 is planned in outpatient COVID-19 patients.

Identification of a 9-gene signature to enhance biochemical recurrence prediction in primary prostate cancer: A benchmarking study using ten machine learning methods and twelve patient cohorts.

Prostate cancer (PCa) is a prevalent malignancy among men worldwide, and biochemical recurrence (BCR) after radical prostatectomy (RP) is a critical turning point commonly used to guide the development of treatment strategies for primary PCa. However, the clinical parameters currently in use are inadequate for precise risk stratification and informing treatment choice. To address this issue, we conducted a study that collected transcriptomic data and clinical information from 1662 primary PCa patients across 12 multicenter cohorts globally. We leveraged 101 algorithm combinations that consisted of 10 machine learning methods to develop and validate a 9-gene signature, named BCR SCR, for predicting the risk of BCR after RP. Our results demonstrated that BCR SCR generally outperformed 102 published prognostic signatures. We further established the clinical significance of these nine genes in PCa progression at the protein level through immunohistochemistry on Tissue Microarray (TMA). Moreover, our data showed that patients with higher BCR SCR tended to have higher rates of BCR and distant metastasis after radical radiotherapy. Through drug target prediction analysis, we identified nine potential therapeutic agents for patients with high BCR SCR. In conclusion, the newly developed BCR SCR has significant translational potential in accurately stratifying the risk of patients who undergo RP, monitoring treatment courses, and developing new therapies for the disease.

Lamin B1: a novel biomarker in adult and pediatric adrenocortical carcinoma.

Adrenocortical carcinoma (ACC) is a malignancy with a poor prognosis and high mortality rate. A high tumor mutational burden (TMB) has been found to be associated with poor prognosis in ACC. Thus, exploring ACC biomarkers based on TMB holds significant importance for patient risk stratification. In our research, we utilized weighted gene coexpression network analysis and an assay for transposase-accessible chromatin with high-throughput sequencing to identify genes associated with TMB. Through the comprehensive analysis of various public datasets, Lamin B1 (LMNB1) was identified as a biomarker associated with a high TMB and low chromatin accessibility. Immunohistochemical staining demonstrated high expression of LMNB1 in ACC compared to noncancerous tissues. Functional enrichment analyses revealed that the function of LMNB1 is associated with cell proliferation and division. Furthermore, cell assays suggested that LMNB1 promotes tumor proliferation and invasion. In addition, mutation analysis suggested that the high expression of LMNB1 is associated with TP53 mutations. Additionally, LMNB1 was highly expressed in the vast majority of solid tumors across cancers. In our immune analysis, we discovered that the high expression of LMNB1 might suppress the infiltration of CD8+ T cells in the ACC microenvironment. In summary, LMNB1 is a predictive factor for the poor prognosis of adult and pediatric ACC. Its high expression in ACC is positively associated with high TMB and lower chromatin accessibility, and it promotes ACC cell proliferation and invasion. Therefore, LMNB1 holds promise as a novel biomarker and potential therapeutic target for ACC.

FKBP10 promotes clear cell renal cell carcinoma progression and regulates sensitivity to the HIF2α blockade by facilitating LDHA phosphorylation.

Renal cell carcinoma (RCC) is one of the three major malignant tumors of the urinary system and originates from proximal tubular epithelial cells. Clear cell renal cell carcinoma (ccRCC) accounts for approximately 80% of RCC cases and is recognized as a metabolic disease driven by genetic mutations and epigenetic alterations. Through bioinformatic analysis, we found that FK506 binding protein 10 (FKBP10) may play an essential role in hypoxia and glycolysis pathways in ccRCC progression. Functionally, FKBP10 promotes the proliferation and metastasis of ccRCC in vivo and in vitro depending on its peptidyl-prolyl cis-trans isomerase (PPIase) domains. Mechanistically, FKBP10 binds directly to lactate dehydrogenase A (LDHA) through its C-terminal region, the key regulator of glycolysis, and enhances the LDHA-Y10 phosphorylation, which results in a hyperactive Warburg effect and the accumulation of histone lactylation. Moreover, HIFα negatively regulates the expression of FKBP10, and inhibition of FKBP10 enhances the antitumor effect of the HIF2α inhibitor PT2385. Therefore, our study demonstrates that FKBP10 promotes clear cell renal cell carcinoma progression and regulates sensitivity to HIF2α blockade by facilitating LDHA phosphorylation, which may be exploited for anticancer therapy.

Peritoneal-directed chimeric oncolytic virus CF17 prevents malignant ascites and improves survival in gastric cancer peritoneal metastases.

Gastric cancer (GC) peritoneal metastasis (PM) is fatal without effective therapy. We investigated CF17, a new replication-competent chimeric poxvirus, against GC cell lines in vitro and PM in an aggressive GCPM mouse model. We performed viral proliferation and cytotoxicity assays on intestinal-type and diffuse-type human GC cell lines following CF17 treatment. At lower MOIs of 0.01, 0.1, there was >80% killing in most cell lines, while in the more aggressive cell lines, killing was seen at higher MOIs of 1.0 and 10.0. We observed reduced peritoneal tumor burden and prolonged survival with intraperitoneal (i.p.) CF17 treatment in nude mice implanted with the resistant GC cell line. At day 91 after treatment, seven of eight mice were alive in the CF17-treated group vs. one of eight mice in the control group. CF17 treatment inhibited ascites formation (0% vs. 62.5% with PBS). Thus, CF17 efficiently infected, replicated in, and killed GC cells in a dose- and time-dependent manner in vitro. In vivo, i.p. CF17 treatment exhibited robust antitumor activity against an aggressive GCPM model to decrease tumor burden, improve survival, and prevent ascites formation. These preclinical results inform the design of future clinical trials of CF17 for peritoneal-directed therapy in GCPM patients.

Phosphodiesterase 2 and Its Isoform a as Therapeutic Targets in the Central Nervous System Disorders.

Cyclic adenosine monophosphates (cAMP) and cyclic guanosine monophosphate (cGMP) are two essential second messengers, which are hydrolyzed by phosphodiesterase's (PDEs), such as PDE-2. Pharmacological inhibition of PDE-2 (PDE2A) in the central nervous system improves cAMP and cGMP signaling, which controls downstream proteins related to neuropsychiatric, neurodegenerative, and neurodevelopmental disorders. Considering that there are no specific treatments for these disorders, PDE-2 inhibitors' development has gained more attention in the recent decade. There is high demand for developing new-generation drugs targeting PDE2 for treating diseases in the central nervous and peripheral systems. This review summarizes the relationship between PDE-2 with neuropsychiatric, neurodegenerative, and neurodevelopmental disorders as well as its possible treatment, mainly involving inhibitors of PDE2.

N6-methyladenosine modified lncRNAs signature for stratification of biochemical recurrence in prostate cancer.

Nonmutational epigenetic reprogramming is a crucial mechanism contributing to the pronounced heterogeneity of prostate cancer (PCa). Among these mechanisms, N6-methyladenosine (m6A)-modified long non-coding RNAs (lncRNAs) have emerged as key players. However, the precise roles of m6A-modified lncRNAs in PCa remain to be elucidated. In this study, methylated RNA immunoprecipitation sequencing (MeRIP-seq) was conducted on primary and metastatic PCa samples, leading to the identification of 21 lncRNAs exhibiting differential methylation and expression patterns. We further established a PCa prognostic signature, named m6A-modified lncRNA score (mLs), based on 9 differential methylated lncRNAs in 4 multicenter cohorts. The high mLs score cohort exhibited a tendency for earlier biochemical recurrence (BCR) compared to the low mLs score cohort. Remarkably, the predictive performance of the mLs score surpassed that of five previously reported lncRNA-based signatures. Functional enrichment analysis underscored a negative correlation between the mLs score and lipid metabolism. Additionally, through MeRIP-qPCR, we pinpointed a hub gene, MIR210HG, which was validated through in vitro and in vivo experiments. These findings collectively illuminate the landscape of m6A-methylated lncRNAs in PCa tissue via MeRIP-seq and harness this information to prognosticate PCa outcomes using the mLs score. Furthermore, our study validates, both experimentally and mechanistically, the facilitative role of MIR210HG in driving PCa progression.

Anti-Tumor Immunogenicity of the Oncolytic Virus CF33-hNIS-antiPDL1 against Ex Vivo Peritoneal Cells from Gastric Cancer Patients.

We studied the immunotherapeutic potential of CF33-hNIS-antiPDL1 oncolytic virus (OV) against gastric cancer with peritoneal metastasis (GCPM). We collected fresh malignant ascites (MA) or peritoneal washings (PW) during routine paracenteses and diagnostic laparoscopies from GC patients (n = 27). Cells were analyzed for cancer cell markers and T cells, or treated with PBS, CF33-GFP, or CF33-hNIS-antiPDL1 (MOI = 3). We analyzed infectivity, replication, cytotoxicity, CD107α upregulation of CD8+ and CD4+ T cells, CD274 (PD-L1) blockade of cancer cells by virus-encoded anti-PD-L1 scFv, and the release of growth factors and cytokines. We observed higher CD45-/large-size cells and lower CD8+ T cell percentages in MA than PW. CD45-/large-size cells were morphologically malignant and expressed CD274 (PD-L1), CD252 (OX40L), and EGFR. CD4+ and CD8+ T cells did not express cell surface exhaustion markers. Virus infection and replication increased cancer cell death at 15 h and 48 h. CF33-hNIS-antiPDL1 treatment produced functional anti-PD-L1 scFv, which blocked surface PD-L1 binding of live cancer cells and increased CD8+CD107α+ and CD4+CD107α+ T cell percentages while decreasing EGF, PDGF, soluble anti-PD-L1, and IL-10. CF33-OVs infect, replicate in, express functional proteins, and kill ex vivo GCPM cells with immune-activating effects. CF33-hNIS-antiPDL1 displays real potential for intraperitoneal GCPM therapy.

Nanoparticle-Mediated Therapy with miR-198 Sensitizes Pancreatic Cancer to Gemcitabine Treatment through Downregulation of VCP-Mediated Autophagy.

Pancreatic ductal adenocarcinoma (PDAC) remains an extremely aggressive disease characterized by rapidly acquired multi-drug resistance, including to first-line chemotherapeutic agent gemcitabine. Autophagy is a process that is often exploited by cancer and is one of several intrinsic factors associated with resistance to gemcitabine. We have previously found that miR-198 acts as a tumor suppressor in PDAC through the targeting of factors including Valosin-containing protein (VCP). VCP has been reported to play an important role in autophagic flux. In this study, we investigated whether the repression of VCP through miR-198 administration disrupts the autophagy process and sensitizes PDAC cells to gemcitabine treatment in vitro. Moreover, we used LGA-PEI (LPNP) nanoparticles to effectively administer miR-198 to tumors in vivo, inducing tumor sensitization to gemcitabine and leading to a significant reduction in tumor burden and metastases and a concomitant downregulation of VCP expression and autophagy maturation. Our results indicate a potential therapeutic strategy for targeting gemcitabine resistant PDAC and establishes the use of LPNPs for effective therapeutic delivery of nucleic acids in vitro and in vivo.

Metformin escape in prostate cancer by activating the PTGR1 transcriptional program through a novel super-enhancer.

The therapeutic efficacy of metformin in prostate cancer (PCa) appears uncertain based on various clinical trials. Metformin treatment failure may be attributed to the high frequency of transcriptional dysregulation, which leads to drug resistance. However, the underlying mechanism is still unclear. In this study, we found evidences that metformin resistance in PCa cells may be linked to cell cycle reactivation. Super-enhancers (SEs), crucial regulatory elements, have been shown to be associated with drug resistance in various cancers. Our analysis of SEs in metformin-resistant (MetR) PCa cells revealed a correlation with Prostaglandin Reductase 1 (PTGR1) expression, which was identified as significantly increased in a cluster of cells with metformin resistance through single-cell transcriptome sequencing. Our functional experiments showed that PTGR1 overexpression accelerated cell cycle progression by promoting progression from the G0/G1 to the S and G2/M phases, resulting in reduced sensitivity to metformin. Additionally, we identified key transcription factors that significantly increase PTGR1 expression, such as SRF and RUNX3, providing potential new targets to address metformin resistance in PCa. In conclusion, our study sheds new light on the cellular mechanism underlying metformin resistance and the regulation of the SE-TFs-PTGR1 axis, offering potential avenues to enhance metformin's therapeutic efficacy in PCa.

An Oncolytic Poxvirus Encoding hNIS, Shows Antitumor Efficacy and Allows Tumor Imaging in a Liver Cancer Model.

Oncolytic viruses (OV) are live viruses that can selectively replicate in cancer cells. We have engineered an OV (CF33) to make it cancer-selective through the deletion of its J2R (thymidine kinase) gene. In addition, this virus has been armed with a reporter gene, human sodium iodide symporter (hNIS), to facilitate noninvasive imaging of tumors using PET. In this study, we evaluated the oncolytic properties of the virus (CF33-hNIS) in liver cancer model, and its usefulness in tumor imaging. The virus was found to efficiently kill liver cancer cells and the virus-mediated cell death exhibited characteristics of immunogenic death based on the analysis of 3 damage-associated molecular patterns: calreticulin, ATP, and high mobility group box-1. Furthermore, local or systemic administration of a single dose of the virus showed antitumor efficacy against a liver cancer xenograft model in mice and significantly increased survival of treated mice. Finally, PET scanning was performed following injection of the radioisotope I-124, for imaging of tumors, and a single dose of virus as low as 1E03 pfu, administered intra-tumorally or intravenously, allowed for PET imaging of tumors. In conclusion, CF33-hNIS is safe and effective in controlling human tumor xenografts in nude mice, and it also facilitates noninvasive imaging of tumors.

Development and validation of a tobacco smoking-related index for predicting overall survival and immunotherapy response in bladder cancer.

Bladder cancer is one of the top five most prevalent cancers in the United States and a major cause of cancer-related mortality worldwide. Meanwhile, tobacco smoking is a well-established modifiable risk factor for bladder cancer, with a population-attributable risk of approximately 50%. But the relationship between the prognosis of bladder cancer and tobacco smoking remains unclear. To further explore the potential relationship between tobacco smoking and bladder cancer prognosis, the bladder cancer dataset from The Cancer Genome Atlas Program was used to build a tobacco smoking-related signature known as the "smoker index" for prognosis prediction. Additionally, we validated the efficacy of the signature with some external datasets. Finally, we preliminarily verified the role of CGB5, the hub gene in the smoker index, through pan-cancer analysis and in vitro assays. The study digs into the underlying connection between tobacco smoking and the prognosis of bladder cancer from a multi-omics perspective.

An oncolytic poxvirus encoding hNIS, shows anti-tumor efficacy and allows tumor imaging in a liver cancer model.

Oncolytic viruses (OVs) are live viruses that can selectively replicate in cancer cells. We have engineered an OV (CF33) to make it cancer-selective through the deletion of its J2R (thymidine kinase) gene. Additionally, this virus has been armed with a reporter gene, human sodium iodide symporter (hNIS), to facilitate non-invasive imaging of tumors using positron emission tomography (PET). In this study we evaluated the oncolytic properties of the virus (CF33-hNIS) in liver cancer model, and its usefulness in tumor imaging. The virus was found to efficiently kill liver cancer cells and the virus-mediated cell death exhibited characteristics of immunogenic death based on the analysis of 3 damage associate molecular patterns (DAMPs): calreticulin, ATP and HMGB1. Furthermore, local or systemic administration of a single dose of the virus showed anti-tumor efficacy against a liver cancer xenograft model in mice and significantly increased survival of treated mice. Lastly, PET scanning was performed following injection of the radioisotope I-124, for imaging of tumors, and a single dose of virus as low as 1E03 pfu, administered intratumorally (I.T.) or intravenously (I.V.), allowed for PET imaging of tumors. In conclusion, CF33-hNIS is safe and effective in controlling human tumor xenografts in nude mice, and it also facilitates non-invasive imaging of tumors.

Identification and verification of an ALYREF-involved 5-methylcytosine based signature for stratification of prostate cancer patients and prediction of clinical outcome and response to therapies.

OBJECTIVES: Due to the heterogeneity of PCa, the clinical indicators used for PCa can't satisfy risk prognostication and personalized treatment. It is imperative to develop novel biomarkers for prognosis prediction and therapy response in PCa. Accumulating evidence shows that non-mutational epigenetic reprogramming, independent from genomic instability and mutation, serves as a newly added hallmark in cancer progression. METHODS: In this study, we integrated multi-center cohorts (N > 1300) to develop a RNA 5-methylcytosine regulator-based signature, the m5C score. We performed unsupervised clustering and LASSO regression to identify novel m5C-related subtypes and calculate the m5C score. Then we assessed the role of m5C cluster and m5C score in several clinical aspects such as prognosis in various molecular subtypes, responses to chemotherapy, androgen receptor signaling inhibitor (ARSI) therapy and immunotherapy in PCa. Finally, we validated the cancer-promoting performance of ALYREF through clinical data analysis and experiments in vivo and in vitro. RESULTS: The investigation revealed that the m5C score could accurately predict the biochemical recurrence (BCR) in different subtypes (the PAM50 subtypes and immunophenotypes) and the responses to chemotherapy, ARSI therapy, and immunotherapy (PD1/PD-L1). A high m5C score indicated a poor BCR prognosis in every subtype of PCa, unfavorable responses in ARSI therapy and immunotherapy (PD1/PD-L1). Moreover, the m5C reader gene termed ALYREF, yielding the highest weighed coefficient, promoted PCa progression through in silico analysis and experimental validations (in vivo and in vitro). CONCLUSIONS: The m5C signature can function in many aspects of PCa, such as the development and prognosis of the disease, and multiple therapy responses. Further, the m5C reader, ALYREF, was identified as a prognostic biomarker and a potential therapeutic target for PCa. The m5C signature could act as a brand-new tool for predicting the prognosis of patients in different molecular subtypes and patients' therapy responses and promoting customized treatments.

Development of the oncolytic virus, CF33, and its derivatives for peritoneal-directed treatment of gastric cancer peritoneal metastases.

BACKGROUND: Gastric cancer (GC) that metastasizes to the peritoneum is fatal. CF33 and its genetically modified derivatives show cancer selectivity and oncolytic potency against various solid tumors. CF33-hNIS and CF33-hNIS-antiPDL1 have entered phase I trials for intratumoral and intravenous treatments of unresectable solid tumors (NCT05346484) and triple-negative breast cancer (NCT05081492). Here, we investigated the antitumor activity of CF33-oncolytic viruses (OVs) against GC and CF33-hNIS-antiPDL1 in the intraperitoneal (IP) treatment of GC peritoneal metastases (GCPM). METHODS: We infected six human GC cell lines AGS, MKN-45, MKN-74, KATO III, SNU-1, and SNU-16 with CF33, CF33-GFP, or CF33-hNIS-antiPDL1 at various multiplicities of infection (0.01, 0.1, 1.0, and 10.0), and performed viral proliferation and cytotoxicity assays. We used immunofluorescence imaging and flow cytometric analysis to verify virus-encoded gene expression. We evaluated the antitumor activity of CF33-hNIS-antiPDL1 following IP treatment (3×105 pfu × 3 doses) in an SNU-16 human tumor xenograft model using non-invasive bioluminescence imaging. RESULTS: CF33-OVs showed dose-dependent infection, replication, and killing of both diffuse and intestinal subtypes of human GC cell lines. Immunofluorescence imaging showed virus-encoded GFP, hNIS, and anti-PD-L1 antibody scFv expression in CF33-OV-infected GC cells. We confirmed GC cell surface PD-L1 blockade by virus-encoded anti-PD-L1 scFv using flow cytometry. In the xenograft model, CF33-hNIS-antiPDL1 (IP; 3×105 pfu × 3 doses) treatment significantly reduced peritoneal tumors (p<0.0001), decreased amount of ascites (62.5% PBS vs 25% CF33-hNIS-antiPDL1) and prolonged animal survival. At day 91, seven out of eight mice were alive in the virus-treated group versus one out of eight in the control group (p<0.01). CONCLUSIONS: Our results show that CF33-OVs can deliver functional proteins and demonstrate effective antitumor activity in GCPM models when delivered intraperitoneally. These preclinical results will inform the design of future peritoneal-directed therapy in GCPM patients.

M6A-modified circRBM33 promotes prostate cancer progression via PDHA1-mediated mitochondrial respiration regulation and presents a potential target for ARSI therapy.

N6-Methyladenosine (m6A) is the most prevalent RNA modification in various types of RNA, including circular RNAs (circRNAs). Mounting evidence has shown that circRNAs may play critical roles in diverse malignancies. However, the biological relevance of m6A modification of circRNAs in prostate cancer (PCa) remains unclear and needs to be elucidated. Our data showed that circRBM33 was m6A-modified and was more highly expressed in PCa cells than in normal cells/tissues. The in vitro and in vivo experiments showed that downregulation/upregulation of circRBM33 inhibited/promoted tumour growth and invasion, respectively. Decreasing m6A levels rescued the tumour-promoting effect of circRBM33. Additionally, once modified by m6A, circRBM33 interacts with FMR1 by forming a binary complex that sustains the mRNA stability of PDHA1, a downstream target gene. Suppressed/overexpressed circRBM33 lowered/enhanced the ATP production, the acetyl-CoA levels and the NADH/NAD+ ratio. Moreover, depletion of circRBM33 significantly increased the response sensitivity to androgen receptor signalling inhibitor (ARSI) therapy, including enzalutamide and darolutamide, in prostate tumours. Our study suggested that the m6A-mediated circRBM33-FMR1 complex can activate mitochondrial metabolism by stabilizing PDHA1 mRNA, which promotes PCa progression, and can attenuate circRBM33 increased ARSI effectiveness in PCa treatment. This newly discovered circRNA may serve as a potential therapeutic target for PCa.

A prognostic signature consisting of N6-methyladenosine modified mRNAs demonstrates clinical potential in prediction of biochemical recurrence and guidance on precision therapy in prostate cancer.

Novel biomarkers are urgently needed to improve the prediction of clinical outcomes and guide personalized treatment for prostate cancer (PCa) patients. However, the role of N6-methyladenosine (m6A) modifications in PCa initiation and progression remains largely elusive. In our study, we collected benign Prostate Hyperplasia (BPH), localized PCa, and metastatic PCa samples from patients and performed methylated RNA immunoprecipitation sequencing (MeRIP-Seq) to map m6A-methylated mRNAs. Furthermore, we developed a prognostic signature based on 239 differentially methylated RNAs and the TCGA-PRAD dataset, which can be used to calculate an m6A-modified mRNA (MMM) score for a PCa patient, validated by independent multi-center cohorts. Our findings revealed that differential m6A modifications were positively correlated with altered expressions of mapped m6A-modified mRNAs. Higher MMM scores were associated with shorter times to biochemical recurrence (BCR) in PCa patients, and the MMM scoring system outperformed three well-established signatures in nine independent validation cohorts, as demonstrated by Kaplan-Meier survival analysis, C-index and ROC. Patients who did not respond to androgen receptor signaling inhibitor (ARSI) therapy and immunotherapy were found to have high MMM scores. Two hub genes, TLE1 and PFKL, were confirmed to have m6A sites through MeRIP-qPCR, and their knockdown promoted PCa cell invasion. Bioinformatics analysis of single-cell databases identified cell types with high transcript abundance levels of these two genes. In summary, our study is the first to perform transcriptome-wide m6A mapping in prostate tissues. The translational potential of a prognostic signature, comprising m6A-methylated mRNAs, in predicting clinical outcomes and therapy responses for PCa patients, is demonstrated.