METTL3-mediated HSPA9 m6A modification promotes malignant transformation and inhibits cellular senescence by regulating exosomal mortalin protein in cervical cancer.

The role of RNA methyltransferase 3 (METTL3) in tumor progression when tethered to aberrantly expressed oncogenes remains unknown. In especial, the correlation between cervical cancer (CCa)-derived exosomes and m6A methylation in malignant traits of cervical epithelium is currently elusive. Mortalin expression was found to be up-regulated in plasma exosomes isolated from CCa patients. Furthermore, mortalin gained increased mRNA stability and enhanced translation efficiency via the m6A methylation in the HSPA9 mRNA 3'UTR, which was catalysed by METTL3 in CCa cells. Exosomal mortalin overexpression significantly promoted the proliferation, migration and invasion of CCa both in vitro and in vivo. Additionally, exosome-encapsulated mortalin suppressed cellular senescence and facilitated malignant transformation by blocking nuclear transport of p53, thereby preventing the p53-Gadd45A interaction and resulting in inactivation of p53. Our studies demonstrated the significant role of METTL3 mediated exosomal mortalin in malignant transformation and cellular senescence suppression of CCa. Exosomal mortalin could clinically serve as a potential early-diagnosis biomarker and therapeutic target for CCa given its abundance and propensity to be found.

The inhibition of YTHDF3/m6A/LRP6 reprograms fatty acid metabolism and suppresses lymph node metastasis in cervical cancer.

The lipid synthesis of fatty acid (FA) represents a significant hallmark in the occurrence and progression of malignant tumor, which are associated with lymph node (LN) metastasis. Elucidation of the molecular mechanisms underlying LN metastasis could provide therapeutic strategies for cervical cancer (CCa). N6-Methyladenosine (m6A), the most prevalent and abundant RNA modification, exerts specific regulatory control over a series of oncogene expressions. This study demonstrated a clinical correlation between the upregulation of the m6A reader YTHDF3 and LN metastasis, thereby contributing to poor overall survival probability (OS) among CCa patients. The mechanistic investigation revealed that SREBF1 transcriptionally activated YTHDF3 expression by binding to its promoter. Functional experiments demonstrated that the upregulation of YTHDF3 significantly enhanced the in vitro proliferative, migratory, and invasive capacities of CCa cells, while also promoting lymphangiogenesis and facilitating LN metastasis in vivo. Mechanistically, the upregulation of LRP6 through YTHDF3-mediated m6A modification resulted in increased expression of FASN and ACC1, leading to both lipolysis of lipid droplets and synthesis of free fatty acid. Ultimately, this promoted fatty acid metabolism and enhanced LN metastasis by activating the LRP6-YAP-VEGF-C axis, which could induce lymphangiogenesis in CCa. Our study highlighted that YTHDF3 can serve as a promising therapeutic target and predictive biomarker for CCa patients with LN metastasis.

NAT10/ac4C/FOXP1 Promotes Malignant Progression and Facilitates Immunosuppression by Reprogramming Glycolytic Metabolism in Cervical Cancer.

Immunotherapy has recently emerged as the predominant therapeutic approach for cervical cancer (CCa), driven by the groundbreaking clinical achievements of immune checkpoint inhibitors (ICIs), such as anti-PD-1/PD-L1 antibodies. N4-acetylcytidine (ac4C) modification, catalyzed by NAT10, is an important posttranscriptional modification of mRNA in cancers. However, its impact on immunological dysregulation and the tumor immunotherapy response in CCa remains enigmatic. Here, a significant increase in NAT10 expression in CCa tissues is initially observed that is clinically associated with poor prognosis. Subsequently, it is found that HOXC8 activated NAT10 by binding to its promoter, thereby stimulating ac4C modification of FOXP1 mRNA and enhancing its translation efficiency, eventually leading to induction of GLUT4 and KHK expression. Moreover, NAT10/ac4C/FOXP1 axis activity resulted in increased glycolysis and a continuous increase in lactic acid secretion by CCa cells. The lactic acid-enriched tumor microenvironment (TME) further contributed to amplifying the immunosuppressive properties of tumor-infiltrating regulatory T cells (Tregs). Impressively, NAT10 knockdown enhanced the efficacy of PD-L1 blockade-mediated tumor regression in vivo. Taken together, the findings revealed the oncogenic role of NAT10 in initiating crosstalk between cancer cell glycolysis and immunosuppression, which can be a target for synergistic PD-1/PD-L1 blockade immunotherapy in CCa.

Target identification and drug discovery by data-driven hypothesis and experimental validation in ovarian endometriosis.

OBJECTIVE: To identify targets and discover drugs for ovarian endometriosis (OE) DESIGN: A basic study based on a data-driven hypothesis and experimental validation SETTING: Center for Reproductive Medicine PATIENT(S)/ANIMAL(S): Fourteen patients with OE and 7 healthy donors were recruited, and 15 female C57/BL6 mice were involved. INTERVENTION(S): Samples of OE lesions and normal endometrium were obtained. The ITPR1-knockdowned ectopic human endometrial stromal cells (HESCs) were subjected to ribonucleic acid (RNA) sequencing, cell-counting kit-8 (CCK-8) assay, 5-ethynyl-2'-deoxyuridine (EdU) staining, and flow cytometry. Camptothecin was administered to HESCs and in an OE mouse model. MAIN OUTCOME MEASURE(S): ITPR1 expression in OE lesions and normal endometrium, cell proliferation and apoptosis of HESCs with ITPR1 knockdown or camptothecin treatment, and autograft volume in the OE mouse model RESULT(S): Two significant OE-relevant gene modules were identified and involved the PI3K/Akt and aging-relevant pathways. Fifteen hub genes were identified and confirmed, among which the most significant gene, ITPR1, was robustly elevated in OE lesions. RNA sequencing revealed that ITPR1 was highly relevant to cell proliferation and apoptosis, which was further confirmed by CCK-8 assay, EdU staining, and flow cytometry analysis. ITPR1 knockdown inhibited cell proliferation and induced HESC apoptosis. The candidate drugs targeting these modules were screened, among which camptothecin and irinotecan were identified as promising drugs. Both compounds suppressed HESC proliferation and induced apoptosis; ITPR1 expression was suppressed by camptothecin. The therapeutic effect of camptothecin was also validated in the OE mouse model. CONCLUSION(S): This study identified the therapeutic targets and promising drugs for OE and shed light on the use of camptothecin in OE treatment.

Erastin induces ferroptosis via ferroportin-mediated iron accumulation in endometriosis.

STUDY QUESTION: Could erastin activate ferroptosis to regress endometriotic lesions? SUMMARY ANSWER: Erastin could induce ferroptosis to regress endometriotic lesions in endometriosis. WHAT IS KNOWN ALREADY: Ectopic endometrial stromal cells (EESCs) are in an iron overloading microenvironment and tend to be more sensitive to oxidative damage. The feature of erastin-induced ferroptosis is iron-dependent accumulation of lethal lipid reactive oxygen species (ROS). STUDY DESIGN, SIZE, DURATION: Eleven patients without endometriosis and 21 patients with endometriosis were recruited in this study. Primary normal and ectopic endometrial stromal cells were isolated, cultured and subjected to various treatments. The in vivo study involved 10 C57BL/6 female mice to establish the model of endometriosis. PARTICIPANTS/MATERIALS, SETTING, METHODS: The markers of ferroptosis were assessed by cell viability, lipid peroxidation level and morphological changes. The cell viability was measured by colorimetric method, lipid peroxidation levels were measured by flow cytometry, and morphological changes were observed by transmission electron microscopy. Immunohistochemistry and western blot were used to detect ferroportin (FPN) expression. Prussian blue staining and immunofluorescent microscopy of catalytic ferrous iron were semi-quantified the levels of iron. Adenovirus-mediated overexpression and siRNA-mediated knockdown were used to investigate the role of FPN on erastin-induced ferroptosis in EESCs. MAIN RESULTS AND THE ROLE OF CHANCE: EESCs were more susceptible to erastin treatment, compared to normal endometrial stromal cells (NESCs) (P<0.05). Treatment of cultured EESCs with erastin dramatically increased the total ROS level (P<0.05, versus control), lipid ROS level (P<0.05, versus NESCs) and intracellular iron level (P<0.05, versus NESCs). The cytotoxicity of erastin could be attenuated by iron chelator, deferoxamine (DFO), and ferroptosis inhibitors, ferrostatin-1 and liproxstatin-1, (P<0.05, versus erastin) in EESCs. In EESCs with erastin treatment, shorter and condensed mitochondria were observed by electron microscopy. These findings together suggest that erastin is capable to induce EESC death by ferroptosis. However, the influence of erastin on NESCs was slight. The process of erastin-induced ferroptosis in EESCs accompanied iron accumulation and decreased FPN expression. The overexpression of FPN ablated erastin-induced ferroptosis in EESCs. In addition, knockdown of FPN accelerated erastin-induced ferroptosis in EESCs. In a mouse model of endometriosis, we found ectopic lesions were regressed after erastin administration. LARGE SCALE DATA: N/A. LIMITATIONS, REASONS FOR CAUTION: This study was mainly conducted in primary human endometrial stromal cells. Therefore, the function of FPN in vivo need to be further investigated. WIDER IMPLICATIONS OF THE FINDINGS: Our findings reveal that erastin may serve as a potential therapeutic treatment for endometriosis. STUDY FUNDING/COMPETING INTEREST(S): This research did not receive any specific grant from funding agencies in the public, commercial or not-for-profit sectors. The authors declare no conflict of interest.

NR4A1 is Involved in Fibrogenesis in Ovarian Endometriosis.

BACKGROUND/AIMS: Excess fibrosis may lead to chronic pain, scarring, and infertility as endometriosis develops and progresses. The pathogenesis of endometriosis has been linked to transforming growth factor-ß (TGF-ß), the most potent promoter of fibrosis. METHODS: Levels of NR4A1 and P-NR4A1 protein in human endometrial and endometriotic tissue were assessed by western blotting and immunohistochemistry. The expression levels of fibrotic markers in stromal cells were evaluated by real-time PCR. The degree of fibrosis in mouse endometriotic lesions was detected by Masson trichrome and Sirius red staining. RESULTS: The level of phosphorylated-NR4A1 was higher in ovarian endometriotic tissue than in normal endometrium, and long-term TGF-ß1 stimulation phosphorylated NR4A1 in an AKT-dependent manner and then promoted the expression of fibrotic markers. Furthermore, inhibition of NR4A1 in stromal cells increased the TGF-ß1-dependent elevated expression of fibrotic markers, and loss of NR4A1 stimulated fibrogenesis in mice with endometriosis. Additionally, Cytosporone B (Csn-B), an NR4A1 agonist, effectively decreased the TGF-ß1-dependent elevated expression of fibrotic markers in vitro and significantly inhibited fibrogenesis in vivo. CONCLUSION: NR4A1 can regulate fibrosis in endometriosis and may serve as a new target for the treatment of endometriosis.

Long noncoding RNA LINC00152 as a novel predictor of lymph node metastasis and survival in human cancer: a systematic review and meta-analysis.

BACKGROUND: LINC00152, a novel long noncoding RNA (lncRNA), was identified as an oncogene involved various cancers. This study was designed to explore the clinical significance and prognosis role of LINC00152. METHODS: Eligible studies were recruited by a systematic search in PubMed, Web of Science, and Embase up to August 23, 2017. Odds ratios (ORs), hazard ratios (HRs) and 95% confidence interval (95% CI) were pooled using Review Manager 5.3 and STATA 12.0. RESULT: A total of 10 studies with 913 patients were included to evaluate the association between LINC00152 expression and clinicopathological factors, overall survival (OS) and disease-free survivals (DFS). The results indicated that the expression level of LINC00152 was positively correlated with tumor size (OR = 5.19, 95% CI: 2.33-11.52, p < .0001), TNM stage (OR = 3.12, 95% CI: 1.77-5.51, p < .0001) and lymph node metastasis (OR = 3.41, 95% CI: 2.13-5.48, p < .00001). Moreover, elevated LINC00152 could predict unfavorable OS with pooled HR of 1.66 (95% CI: 1.29-2.13, p < .0001) and poor DFS (HR = 2.13, 95% CI: 1.39-3.25, p = .0005) in cancer patients. CONCLUSION: LINC00152 was correlated with advanced clinicopathological features and poor prognosis as a novel predictive biomarker in various cancers.

CRNDE: An important oncogenic long non-coding RNA in human cancers.

Aberrant overexpression of long non-coding RNA CRNDE (Colorectal Neoplasia Differentially Expressed) is confirmed in various human cancers, which is correlated with advanced clinicopathological features and poor prognosis. CRNDE promotes cancer cell proliferation, migration and invasion, and suppresses apoptosis in complicated mechanisms, which result in the initialization and development of human cancers. In this review, we provide an overview of the oncogenic role and potential clinical applications of CRNDE.