Epitranscriptomic orchestrations: Unveiling the regulatory paradigm of m6A, A-to-I editing, and m5C in breast cancer via long noncoding RNAs and microRNAs.

Breast cancer (BC) poses a persistent global health challenge, particularly in countries with elevated human development indices linked to factors such as increased life expectancy, education, and wealth. Despite therapeutic progress, challenges persist, and the role of epitranscriptomic RNA modifications in BC remains inadequately understood. The epitranscriptome, comprising diverse posttranscriptional modifications on RNA molecules, holds the potential to intricately modulate RNA function and regulation, implicating dysregulation in various diseases, including BC. Noncoding RNAs (ncRNAs), acting as posttranscriptional regulators, influence physiological and pathological processes, including cancer. RNA modifications in long noncoding RNAs (lncRNAs) and microRNAs (miRNAs) add an extra layer to gene expression control. This review delves into recent insights into epitranscriptomic RNA modifications, such as N-6-methyladenosine (m6A), adenine-to-inosine (A-to-I) editing, and 5-methylcytosine (m5C), specifically in the context of lncRNA and miRNAs in BC, highlighting their potential implications in BC development and progression. Understanding this intricate regulatory landscape is vital for deciphering the molecular mechanisms underlying BC and identifying potential therapeutic targets.

Ibrutinib disrupts blood-tumor barrier integrity and prolongs survival in rodent glioma model.

In malignant glioma, cytotoxic drugs are often inhibited from accessing the tumor site due to the blood-tumor barrier (BTB). Ibrutinib, FDA-approved lymphoma agent, inhibits Bruton tyrosine kinase (BTK) and has previously been shown to independently impair aortic endothelial adhesion and increase rodent glioma model survival in combination with cytotoxic therapy. Yet additional research is required to understand ibrutinib's effect on BTB function. In this study, we detail baseline BTK expression in glioma cells and its surrounding vasculature, then measure endothelial junctional expression/function changes with varied ibrutinib doses in vitro. Rat glioma cells and rodent glioma models were treated with ibrutinib alone (1-10 µM and 25 mg/kg) and in combination with doxil (10-100 µM and 3 mg/kg) to assess additive effects on viability, drug concentrations, tumor volume, endothelial junctional expression and survival. We found that ibrutinib, in a dose-dependent manner, decreased brain endothelial cell-cell adhesion over 24 h, without affecting endothelial cell viability (p < 0.005). Expression of tight junction gene and protein expression was decreased maximally 4 h after administration, along with inhibition of efflux transporter, ABCB1, activity. We demonstrated an additive effect of ibrutinib with doxil on rat glioma cells, as seen by a significant reduction in cell viability (p < 0.001) and increased CNS doxil concentration in the brain (56 ng/mL doxil alone vs. 74.6 ng/mL combination, p < 0.05). Finally, Ibrutinib, combined with doxil, prolonged median survival in rodent glioma models (27 vs. 16 days, p < 0.0001) with brain imaging showing a - 53% versus - 75% volume change with doxil alone versus combination therapy (p < 0.05). These findings indicate ibrutinib's ability to increase brain endothelial permeability via junctional disruption and efflux inhibition, to increase BTB drug entry and prolong rodent glioma model survival. Our results motivate the need to identify other BTB modifiers, all with the intent of improving survival and reducing systemic toxicities.

Adjusting starting points for initial price offers: the example of ibrutinib.

The Inflation Reduction Act of 2022 (IRA) allows the Medicare program to negotiate drug prices beginning in 2024. Based on the guidance in the statute, CMS has selected specific data items to use to adjust initial price offers for 10 drugs in the decision-making process. Although much of the data are publicly available, some of these data items will need to be collected directly from drug companies. A 2019 US House of Representatives Committee on Oversight and Accountability investigative report collected a wide range of data from manufacturers of 12 high-revenue drugs that show what is available from the drug companies, including development costs, marketing, pricing, competition, and patent status. This article focuses on the data obtained for ibrutinib, an oral medication for treating hematologic malignancies, which is one of the only drugs reviewed by the committee that also has been selected for Medicare price negotiation. We examine data that can be obtained only from the drug manufacturer that the IRA has explicitly identified as being used to determine the price and suggest potential negotiation strategies for CMS in response.

TRIM27-Induced Protective Autophagy: A Novel Therapeutic Approach for Pneumonia.

BACKGROUND: Pneumonia is a prevalent respiratory ailment involving complex physiological and pathological mechanisms. The tripartite motif containing 27 (TRIM27) plays a crucial role in regulating inflammation mechanisms. Therefore, the purpose of this study is to further explore the therapeutic potential of TRIM27 in pneumonia, based on its regulatory mechanisms in inflammation and autophagy. METHODS: This study established a mouse pneumonia animal model through lipopolysaccharide (LPS) administration, designating it as the LPS model group. Subsequently, adenovirus-mediated TRIM27 overexpression was implemented in the animals of the LPS model group, creating the TRIM27 treatment group. After a 7-day treatment period, lung tissues from the mice were collected. Various techniques, including immunohistochemistry, quantitative reverse transcription PCR (RT-qPCR), western blot, enzyme-linked immunosorbent assay (ELISA), and electron microscopy were utilized to analyze the impact of TRIM27 overexpression on inflammatory factors, oxidative stress, autophagy, and inflammatory processes in pulmonary tissues. Finally, an in vitro LPS cell model was established, and the effects of TRIM27 overexpression and autophagy inhibition on inflammatory cytokines and autophagosomes in LPS-induced inflammatory cells were examined through RT-qPCR and immunofluorescence techniques. RESULTS: The research findings demonstrate a significant reduction in the elevated levels of interleukin-6 (IL-6), IL-1ß, and Tumor necrosis factor-alpha (TNF-α) induced by LPS with TRIM27 overexpression (p < 0.01). Conversely, the autophagy inhibitor 3-Methyladenine (3-MA) diminished the effects induced by TRIM27 overexpression. Moreover, TRIM27 overexpression enhanced the expression of Microtubule-associated protein 1A/1B light chain 3 (LC3) II/I and Beclin-1 proteins in mice subjected to LPS stimulation (p < 0.01), while reducing the expression of the p62 protein (p < 0.01). The addition of 3-MA, however, decreased Beclin-1 expression and inhibited autophagy (p < 0.01). Additionally, TRIM27 overexpression decreased the expression of NOD-like receptor thermal protein domain associated protein 3 (NLRP3), cleaved caspase-1, IL-1ß, and Gasdermin D N-terminal fragment (GSDMD-N) proteins in LPS-stimulated mice (p < 0.05). TRIM27 overexpression also decreased the levels of malondialdehyde (MDA), Activating Transcription Factor 6 (ATF6), and C/EBP-homologous protein (CHOP), while increasing the levels of superoxide dismutase (SOD) and glutathione (GSH) in mice exposed to LPS (p < 0.01). CONCLUSION: The induction of TRIM27 overexpression emerges as a potential and effective pneumonia treatment. The underlying mechanism may involve inducing protective autophagy, thereby reducing oxidative stress and cell pyroptosis.

Inhibition of SRC-3 as a potential therapeutic strategy for aggressive mantle cell lymphoma.

Mantle cell lymphoma (MCL) has a poor prognosis and high relapse rates despite current therapies, necessitating novel treatment regimens. Inhibition of SRC-3 show effectiveness in vivo and in vitro in other B cell lymphomas. Additionally, previous studies have shown that SRC-3 is highly expressed in the lymph nodes of B cell non-Hodgkin's lymphoma patients, suggesting SRC-3 may play a role in the progression of B cell lymphoma. This study aimed to investigate novel SRC-3 inhibitors, SI-10 and SI-12, in mantle cell lymphoma. The cytotoxic effects of SI-10 and SI-12 were evaluated in vitro and demonstrated dose-dependent cytotoxicity in a panel of MCL cell lines. The in vivo efficacy of SI-10 was confirmed in two ibrutinib-resistant models: an immunocompetent disseminated A20 mouse model of B-cell lymphoma and a human PDX model of MCL. Notably, SI-10 treatment also resulted in a significant extension of survival in vivo with low toxicity in both ibrutinib-resistant murine models. We have investigated SI-10 as a novel anti-lymphoma compound via the inhibition of SRC-3 activity. These findings indicate that targeting SRC-3 should be investigated in combination with current clinical therapeutics as a novel strategy to expand the therapeutic index and to improve lymphoma outcomes.

m6A RNA methylation: The latent string-puller in fibrosis.

Fibrosis is a pathological phenomenon characterized by the aberrant accumulation of extracellular matrix (ECM) in tissues. Fibrosis is a universally age-related disease involving that many organs and is the final stage of many chronic inflammatory diseases, which often threaten the patient's health. Undoubtedly, fibrosis has become a serious economic and health burden worldwide, However, the pathogenesis of fibrosis is complex. Further, the key molecules still remain to be unraveled. Hence, so far, there have been no effective treatments designed against the key targets of fibrosis. The methylation modification on the nitrogen atom at position 6 of adenine (m6A) is the most common mRNA modification in mammals. There is increasing evidence that m6A is actively involved in the pathogenesis of fibrosis. This review aims to highlight m6A-associated mechanisms and functions in several organic fibrosis, which implies that m6A is universal and critical for fibrosis and summarize the outlook of m6A in the treatment of fibrosis. This may light up the unknown aspects of this condition for researchers interested to explore fibrosis further.

Construction and validation of m6A-related diagnostic model for psoriasis.

Background: Psoriasis is a chronic immune-mediated inflammatory disease. N6-methyladenosine (m6A) is involved in numerous biological processes in both normal and diseased states. Herein, we aimed to explore the potential role of m6A regulators in the diagnosis of psoriasis and predict molecular mechanisms by which m6A regulators impact psoriasis. Methods: GSE30999 (170 human skin tissue samples) and GSE13355 (180 human skin tissue samples) were downloaded as the training analysis dataset and validation dataset respectively. M6A-related genes were obtained from the literature and their expression levels in GSE30999 samples were measured to identify M6A-related DEGs between psoriasis lesions (LS) and non-lesional lesions (NL). We identified m6A-related DEGs using differential expression analysis and assessed their interactions through correlation analysis and network construction. A logistic regression analysis followed by LASSO optimization was employed to select m6A-related DEGs for the construction of a diagnostic model. The performance of the model was validated using support vector machine (SVM) methodology with sigmoid kernel function and extensive cross-validation. Additionally, the correlation between m6A-related DEGs and immune cell infiltration was analyzed, as well as the association of these DEGs with psoriasis subtypes. Functional analysis of the m6A-related DEGs included the construction of regulatory networks involving miRNAs, transcription factors (TFs), and small-molecule drugs. The m6A modification patterns were also explored by examining the gene expression differences between psoriasis subtypes and their enriched biological pathways. Finally, the expression of significant m6A regulators involved in the diagnostic model was examined by RT-qPCR. Results: In this study, ten optimal m6A-related DEGs were identified, including FTO, IGF2BP2, METTL3, YTHDC1, ZC3H13, HNRNPC, IGF2BP3, LRPPRC, YTHDC2, and HNRNPA2B1. A diagnostic model based on these m6A-related DEGs was constructed, demonstrating high diagnostic accuracy with an area under the curve (AUC) in GSE30999 and GSE13355 of 0.974 and 0.730, respectively. Meanwhile, the expression level of m6A regulators verified by RT-qPCR was consistent with the results in GSE30999. The infiltration of activated mast cells and NK cells was significantly associated with all ten m6A-related DEGs in psoriasis. Among them, YTHDC1, HNRNPC, and FTO were targeted by most miRNAs and were regulated by nine related TFs. Therefore, patients may benefit from dorsomorphin and cyclosporine therapy. Between the two subgroups, 1,592 DEGs were identified, including LRPPRC and METTL3. These DEGs were predicted to be involved in neutrophil activation, cytokine-cytokine receptor interactions, and chemokine signaling pathways. Conclusions: A diagnostic model based on ten m6A-related DEGs in patients with psoriasis was constructed, which may provide early diagnostic biomarkers and therapeutic targets for psoriasis.

METTL3-mediated m6A modification enhances ZDHHC16 expression in nonsmall- cell lung cancer patients, attenuating ferroptosis by suppressing CREB ubiquitination.

At present, the early diagnosis and treatment of non-small cell lung cancer (NSCLC) is still an urgent problem to be solved worldwide, including in China. The present work investigated the possible protective effect of ZDHHC16 in cell proliferation and metastasis of NSCLC and explored its possible mechanisms. ZDHHC16 expression level in patients with Non-Small-Cell Lung Cancer was up-regulation. ZDHHC16 gene is stabilized by m6A methylation. ZDHHC16 gene reduced ferroptosis of NSCLC by the rehabilitation of the mitochondrial structure. ZDHHC16 promoted CREB expression through the inhibition of CREB Ubiquitination. Confocal microscopy showed that ZDHHC16 reduced the CREB expression of NSCLC. ZDHHC16 up-regulation reduced CREB Ubiquitination, and down-regulation of ZDHHC16 promoted CREB Ubiquitination of NSCLC. CREB Agonists reduced the effects of ZDHHC16 on ferroptosis, not affecting the Warburg effect of NSCLC. CREB inhibitor reduced the effects of si-ZDHHC16 on ferroptosis, not affecting the Warburg effect of NSCLC. METTL3-mediated m6A modification increases ZDHHC16 stability. Our study revealed that the m6A-forming enzyme METTL3 upregulates ZDHHC16 expression in NSCLC patients, leading to the reduction of ferroptosis by inhibiting CREB ubiquitination.

FTO-mediated m6A mRNA demethylation aggravates renal fibrosis by targeting RUNX1 and further enhancing PI3K/AKT pathway.

Chronic kidney disease (CKD) is a global health burden, with ineffective therapies leading to increasing morbidity and mortality. Renal interstitial fibrosis is a common pathway in advanced CKD, resulting in kidney function and structure deterioration. In this study, we investigate the role of FTO-mediated N6-methyladenosine (m6A) and its downstream targets in the pathogenesis of renal fibrosis. M6A modification, a prevalent mRNA internal modification, has been implicated in various organ fibrosis processes. We use a mouse model of unilateral ureteral obstruction (UUO) as an in vivo model and treated tubular epithelial cells (TECs) with transforming growth factor (TGF)-ß1 as in vitro models. Our findings revealed increased FTO expression in UUO mouse model and TGF-ß1-treated TECs. By modulating FTO expression through FTO heterozygous mutation mice (FTO+/- ) in vivo and small interfering RNA (siRNA) in vitro, we observed attenuation of UUO and TGF-ß1-induced epithelial-mesenchymal transition (EMT), as evidenced by decreased fibronectin and N-cadherin accumulation and increased E-cadherin levels. Silencing FTO significantly improved UUO and TGF-ß1-induced inflammation, apoptosis, and inhibition of autophagy. Further transcriptomic assays identified RUNX1 as a downstream candidate target of FTO. Inhibiting FTO was shown to counteract UUO/TGF-ß1-induced RUNX1 elevation in vivo and in vitro. We demonstrated that FTO signaling contributes to the elevation of RUNX1 by demethylating RUNX1 mRNA and improving its stability. Finally, we revealed that the PI3K/AKT pathway may be activated downstream of the FTO/RUNX1 axis in the pathogenesis of renal fibrosis. In conclusion, identifying small-molecule compounds that target this axis could offer promising therapeutic strategies for treating renal fibrosis.

KCTD15 acts as an anti-tumor factor in colorectal cancer cells downstream of the demethylase FTO and the m6A reader YTHDF2.

Potassium Channel Tetramerization Domain Containing 15 (KCTD15) participates in the carcinogenesis of several solid malignancies; however, its role in colorectal cancer (CRC) remains unclear. Here we find that KCTD15 exhibits lower expression in CRC tissues as compared to para-carcinoma tissues. Tetracycline (tet)-induced overexpression and knockdown of KCTD15 confirms KCTD15 as an anti-proliferative and pro-apoptotic factor in CRC both in vitro and in xenografted tumors. N6-methyladenosine (m6A) is known to affect the expression, stabilization, and degradation of RNAs with this modification. We demonstrate that upregulation of fat mass and obesity-associated protein (FTO), a classical m6A eraser, prevents KCTD15 mRNA degradation in CRC cells. Less KCTD15 RNA is recognized by m6A 'reader' YTH N6-Methyladenosine RNA Binding Protein F2 (YTHDF2) in FTO-overexpressed cells. Moreover, KCTD15 overexpression decreases protein expression of histone deacetylase 1 (HDAC1) but increases acetylation of critical tumor suppressor p53 at Lys373 and Lys382. Degradation of p53 is delayed in CRC cells post-KCTD15 overexpression. We further show that the regulatory effects of KCTD15 on p53 are HDAC1-dependent. Collectively, we conclude that KCTD15 functions as an anti-growth factor in CRC cells, and its expression is orchestrated by the FTO-YTHDF2 axis. Enhanced p53 protein stabilization may contribute to KCTD15's actions in CRC cells.

The m6A modification-mediated positive feedback between glycolytic lncRNA SLC2A1-DT and c-Myc promotes tumorigenesis of hepatocellular carcinoma.

Glycolysis exerts a key role in the metabolic reprogramming of cancer. Specific long non-coding RNAs (lncRNAs) have been identified to exhibit oncogenic glycolysis regulation. Nevertheless, the precise mechanisms by which glycolysis-related lncRNAs control hepatocellular carcinoma (HCC) are still unknown. We profiled and analyzed glycolysis-associated lncRNA signatures using HCC specimens from The Cancer Genome Atlas (TCGA) dataset. Considerable upregulation of the glycolysis-related lncRNA SLC2A1-DT was noted in HCC tissues; this upregulation was strongly linked with advanced tumor stage and poor prognosis. Cell culture and animal-related studies indicated that knockdown or overexpression of SLC2A1-DT obviously restrained or promoted glycolysis, propagation, and metastasis in HCC cells. Mechanistically, SLC2A1-DT enhanced the interaction of protein between ß-catenin and YWHAZ, suppressing the binding between ß-catenin and ß-TrCP, an E3 ubiquitin ligase. Thereby, SLC2A1-DT impeded the ß-TrCP-dependent ubiquitination and ß-catenin degradation. The upregulated ß-catenin activated the transcription of c-Myc, which then increased the transcription of glycolytic genes including SLC2A1, LDHA, and HK2. Additionally, we revealed that c-Myc transcriptionally induced the expression of methyltransferase 3 (METTL3), which increased N6-methyladenosine (m6A) modification and stability of SLC2A1-DT in a YTHDF1 dependent manner. Collectively, we show that the lncRNA SLC2A1-DT promotes glycolysis and HCC tumorigenesis by a m6A modification-mediated positive feedback mechanism with glycolytic regulator c-Myc and suggested as an innovative treatment option and indicator for HCC.

m6A methyltransferase METTL14­mediated RP1­228H13.5 promotes the occurrence of liver cancer by targeting hsa­miR­205/ZIK1.

The aim of the present study was to explore the association between N6­methyladenosine (m6A) modification regulatory gene­related long noncoding (lnc)RNA RP1­228H13.5 and cancer prognosis through bioinformatics analysis, as well as the impact of RP1­228H13.5 on cell biology­related behaviors and specific molecular mechanisms. Bioinformatics analysis was used to construct a risk model consisting of nine genes. This model can reflect the survival time and differentiation degree of cancer. Subsequently, a competing endogenous RNA network consisting of 3 m6A­related lncRNAs, six microRNAs (miRs) and 201 mRNAs was constructed. A cell assay confirmed that RP1­228H13.5 is significantly upregulated in liver cancer cells, which can promote liver cancer cell proliferation, migration and invasion, and inhibit liver cancer cell apoptosis. The specific molecular mechanism may be the regulation of the expression of zinc finger protein interacting with K protein 1 (ZIK1) by targeting the downstream hsa­miR­205. Further experiments found that the m6A methyltransferase 14, N6­adenosine­methyltransferase subunit mediates the regulation of miR­205­5p expression by RP1­228H13.5. m6A methylation regulatory factor­related lncRNA has an important role in cancer. The targeting of hsa­miR­205 by RP1­228H13.5 to regulate ZIK1 may serve as a potential mechanism in the occurrence and development of liver cancer.

Depletion of the N6-Methyladenosine (m6A) reader protein IGF2BP3 induces ferroptosis in glioma by modulating the expression of GPX4.

Emerging evidence highlights the multifaceted contributions of m6A modifications to glioma. IGF2BP3, a m6A modification reader protein, plays a crucial role in post-transcriptional gene regulation. Though several studies have identified IGF2BP3 as a poor prognostic marker in glioma, the underlying mechanism remains unclear. In this study, we demonstrated that IGF2BP3 knockdown is detrimental to cell growth and survival in glioma cells. Notably, we discovered that IGF2BP3 regulated ferroptosis by modulating the protein expression level of GPX4 through direct binding to a specific motif on GPX4 mRNA. Strikingly, the m6A modification at this motif was found to be critical for GPX4 mRNA stability and translation. Furthermore, IGF2BP3 knockdown glioma cells were incapable of forming tumors in a mouse xenograft model and were more susceptible to phagocytosis by microglia. Our findings shed light on an unrecognized regulatory function of IGF2BP3 in ferroptosis. The identification of a critical m6A site within the GPX4 transcript elucidates the significance of post-transcriptional control in ferroptosis.

Effect of differentiated direct-to-pharmacy PrEP refill visits supported with client HIV self-testing on clinic visit time and early PrEP continuation.

INTRODUCTION: Delivery of oral pre-exposure prophylaxis (PrEP) is being scaled up in Africa, but clinic-level barriers including lengthy clinic visits may threaten client continuation on PrEP. METHODS: Between January 2020 and January 2022, we conducted a quasi-experimental evaluation of differentiated direct-to-pharmacy PrEP refill visits at four public health HIV clinics in Kenya. Two clinics implemented the intervention package, which included direct-to-pharmacy for PrEP refill, client HIV self-testing (HIVST), client navigator, and pharmacist-led rapid risk assessment and dispensing. Two other clinics with comparable size and client volume served as contemporaneous controls with the usual clinic flow. PrEP continuation was evaluated by visit attendance and pharmacy refill records, and time and motion studies were conducted to determine time spent in the clinics. Dried blood spots were collected to test for tenofovir-diphosphate (TFV-DP) at random visits. We used logistic regression to assess the intervention effect on PrEP continuation and the Wilcoxon rank sum test to assess the effect on clinic time. RESULTS: Overall, 746 clients were enrolled, 366 at control clinics (76 during pre-implementation and 290 during implementation phase), and 380 at direct-to-pharmacy clinics (116 during pre-implementation and 264 during implementation phase). Prior to implementation, the intervention and control clinics were comparable on client characteristics (female: 51% vs. 47%; median age: 33 vs. 33 years) and PrEP continuation (35% vs. 37% at 1 month, and 37% vs. 39% at 3 months). The intervention reduced total time spent at the clinic by 35% (median of 51 minutes at control vs. 33 minutes at intervention clinics; p<0.001), while time spent on HIV testing (20 vs. 20 minutes; p = 0.50) and pharmacy (8 vs. 8 minutes; p = 0.8) was unchanged. PrEP continuation was higher at intervention versus the control clinics: 45% versus 33% at month 1, 34% versus 25% at month 3 and 23% versus 16% at month 6. TFV-DP was detected in 85% (61/72) of samples, similar by the study group (83% vs. 85%). CONCLUSIONS: A client-centred PrEP delivery approach with direct-to-pharmacy PrEP refill visits plus client HIVST significantly reduced clinic visit time by more than one-third and improved PrEP continuation in public health HIV clinics in Kenya.

m6A methylation modification and immune infiltration analysis in osteonecrosis of the femoral head.

Osteonecrosis of the femoral head (ONFH) is a elaborate hip disease characterized by collapse of femoral head and osteoarthritis. RNA N6-methyladenosine (m6A) plays a crucial role in a lot of biological processes within eukaryotic cells. However, the role of m6A in the regulation of ONFH remains unclear. In this study, we identified the m6A regulators in ONFH and performed subtype classification. We identified 7 significantly differentially expressed m6A regulators through the analysis of differences between ONFH and normal samples in the Gene Expression Omnibus (GEO) database. A random forest algorithm was employed to monitor these regulators to assess the risk of developing ONFH. We constructed a nomogram based on these 7 regulators. The decision curve analysis suggested that patients can benefit from the nomogram model. We classified the ONFH samples into two m6A models according to these 7 regulators through consensus clustering algorithm. After that, we evaluated those two m6A patterns using principal component analysis. We assessed the scores of those two m6A patterns and their relationship with immune infiltration. We observed a higher m6A score of type A than that of type B. Finally, we performed a cross-validation of crucial m6A regulatory factors in ONFH using external datasets and femoral head bone samples. In conclusion, we believed that the m6A pattern could provide a novel diagnostic strategy and offer new insights for molecularly targeted therapy of ONFH.

FSH induces EMT in ovarian cancer via ALKBH5-regulated Snail m6A demethylation.

Background: The therapeutic benefits of targeting follicle-stimulating hormone (FSH) receptor in treatment of ovarian cancer are significant, whereas the role of FSH in ovarian cancer progresses and the underlying mechanism remains to be developed. Methods: Tissue microarray of human ovarian cancer, tumor xenograft mouse model, and in vitro cell culture were used to investigate the role of FSH in ovarian carcinogenesis. siRNA, lentivirus and inhibitors were used to trigger the inactivation of genes, and plasmids were used to increase transcription of genes. Specifically, pathological characteristic was assessed by histology and immunohistochemistry (IHC), while signaling pathway was studied using western blot, quantitative RT-PCR, and immunofluorescence. Results: Histology and IHC of human normal ovarian and tumor tissue confirmed the association between FSH and Snail in ovarian cancer metastasis. Moreover, in epithelial ovarian cancer cells and xenograft mice, FSH was showed to promote epithelial mesenchymal transition (EMT) progress and metastasis of ovarian cancer via prolonging the half-life of Snail mRNA in a N6-methyladenine methylation (m6A) dependent manner, which was mechanistically through the CREB/ALKBH5 signaling pathway. Conclusions: These findings indicated that FSH induces EMT progression and ovarian cancer metastasis via CREB/ALKBH5/Snail pathway. Thus, this study provided new insight into the therapeutic strategy of ovarian cancer patients with high level of FSH.

D-2-HG Inhibits IDH1mut Glioma Growth via FTO Inhibition and Resultant m6A Hypermethylation.

IDH1mut gliomas produce high levels of D-2-hydroxyglutarate (D-2-HG), an oncometabolite capable of inhibiting α-ketoglutarate-dependent dioxygenases critical to a range of cellular functions involved in gliomagenesis. IDH1mut gliomas also exhibit slower growth rates and improved treatment sensitivity compared with their IDH1wt counterparts. This study explores the mechanism driving apparent reduced growth in IDH1mut gliomas. Specifically, we investigated the relationship between IDH1mut and the RNA N6-methyladenosine (m6A) demethylases FTO and ALKBH5, and their potential for therapeutic targeting. We investigated the role of D-2-HG and m6A in tumor proliferation/viability using glioma patient tumor samples, patient-derived gliomaspheres, and U87 cells, as well as with mouse intracranial IDH1wt gliomasphere xenografts. Methylation RNA immunoprecipitation sequencing (MeRIP-seq) RNA sequencing was used to identify m6A-enriched transcripts in IDH1mut glioma. We show that IDH1mut production of D-2-HG is capable of reducing glioma cell growth via inhibition of the m6A epitranscriptomic regulator, FTO, with resultant m6A hypermethylation of a set of mRNA transcripts. On the basis of unbiased MeRIP-seq epitranscriptomic profiling, we identify ATF5 as a hypermethylated, downregulated transcript that potentially contributes to increased apoptosis. We further demonstrate how targeting this pathway genetically and pharmacologically reduces the proliferative potential of malignant IDH1wt gliomas, both in vitro and in vivo. Our work provides evidence that selective inhibition of the m6A epitranscriptomic regulator FTO attenuates growth in IDH1wt glioma, recapitulating the clinically favorable growth phenotype seen in the IDH1mut subtype. SIGNIFICANCE: We show that IDH1mut-generated D-2-HG can reduce glioma growth via inhibition of the m6A demethylase, FTO. FTO inhibition represents a potential therapeutic target for IDH1wt gliomas and possibly in conjunction with IDH1mut inhibitors for the treatment of IDH1mut glioma. Future studies are necessary to demonstrate the role of ATF5 downregulation in the indolent phenotype of IDH1mut gliomas, as well as to identify other involved gene transcripts deregulated by m6A hypermethylation.