The emerging roles and mechanism of m6a in breast cancer progression

Identification of N6-Methyladenosine-Associated lncRNAs and Analysis of Prognostic Signature in Breast Cancer

Breast cancer represents the predominant malignant neoplasm in women, posing significant threats to both life and health. N6-methyladenosine (m6A) methylation, the most prevalent RNA modification, plays a crucial role in cancer development. This study aims to delineate the prognostic implications of m6A-associated long non-coding RNAs (m6AlncRNAs) and identify potential m6AlncRNA candidates as novel therapeutic targets for breast cancer. Through univariate Cox, Least Absolute Shrinkage and Selection Operator and multiple Cox regression analysis, m6AlncRNA was analyzed and a risk-prognosis model was constructed. Kaplan-Meier analysis, principal component analysis and nomogram were used to evaluate the risk model. Finally, we screened candidate lncRNAs and validated them in breast cancer cell lines. m6AlncRNAs were stratified into three subtypes, and their associations with survival outcomes and immune infiltrating capacities were systematically analyzed. Subsequently, breast cancer patients were stratified into high and low-risk groups based on median risk scores, revealing distinct clinical characteristics, tumor immunoinvasive profiles, tumor mutation burden, and survival probabilities. Additionally, a prognostic model was established, highlighting three promising candidate lncRNAs: ECE1-AS1, NDUFA6-DT, and COL4A2-AS1. This study investigated the prognostic implications of m6A-associated long non-coding RNAs (m6AlncRNAs) and developed a prognostic risk model to identify three potential m6AlncRNA candidates. These findings provide valuable insights into the potential application of these m6AlncRNAs in guiding immunotherapeutic strategies for breast cancer.

The lncRNAMALAT1-WTAP axis: a novel layer of EMT regulation in hypoxic triple-negative breast cancer

Early metastatic disease development is one characteristic that defines triple-negative breast cancer (TNBC) as the most aggressive breast cancer (BC) subtype. Numerous studies have identified long non-coding RNAs (lncRNA) as critical players in regulating tumor progression and metastasis formation. Here, we show that MALAT1, a long non-coding RNA known to promote various features of BC malignancy, such as migration and neo angiogenesis, regulates TNBC cell response to hypoxia. By profiling MALAT1-associated transcripts, we discovered that lncRNA MALAT1 interacts with the mRNA encoding WTAP protein, previously reported as a component of the N6-methyladenosine (m6A) modification writer complex. In hypoxic conditions, MALAT1 positively regulates WTAP protein expression, which influences the response to hypoxia by favoring the transcription of the master regulators HIF1α and HIF1β. Furthermore, WTAP stimulates BC cell migratory ability and the expression of N-Cadherin and Vimentin, hallmarks of epithelial-to-mesenchymal transition (EMT). In conclusion, this study highlights the functional axis comprising MALAT1 and WTAP as a novel prognostic marker of TNBC progression and as a potential target for the development of therapeutic approaches for TNBC treatment.

Emerging roles of interactions between ncRNAs and other epigenetic modifications in breast cancer

Up till the present moment, breast cancer is still the leading cause of cancer-related death in women worldwide. Although the treatment methods and protocols for breast cancer are constantly improving, the long-term prognosis of patients is still not optimistic due to the complex heterogeneity of the disease, multi-organ metastasis, chemotherapy and radiotherapy resistance. As a newly discovered class of non-coding RNAs, ncRNAs play an important role in various cancers. Especially in breast cancer, lncRNAs have received extensive attention and have been confirmed to regulate cancer progression through a variety of pathways. Meanwhile, the study of epigenetic modification, including DNA methylation, RNA methylation and histone modification, has developed rapidly in recent years, which has greatly promoted the attention to the important role of non-coding RNAs in breast cancer. In this review, we carefully and comprehensively describe the interactions between several major classes of epigenetic modifications and ncRNAs, as well as their different subsequent biological effects, and discuss their potential for practical clinical applications.

Gene signature of m6A RNA regulators in diagnosis, prognosis, treatment, and immune microenvironment for cervical cancer

Continuing studies imply that m⁶A RNA modification is involved in the development of cervical cancer (CC), but lack strong support on recurrence and diagnosis prediction. In this research, a comprehensive analysis of 33 m⁶A regulators was performed to fulfill them. Here, we performed diagnostic and prognosis models and identified key regulators, respectively. Then the CC patients were separated into two clusters in accordance with 33 regulators, and participants in the cluster 1 had a worse prognosis. Subsequently, the m⁶AScore was calculated to quantify the m⁶A modification pattern based on regulators and we found that patients in cluster 1 had higher m⁶AScore. Afterwards, immune microenvironment, cell infiltration, escape analyses and tumor burden mutation analyses were executed, and results showed that m⁶AScore was correlated with them, but to a limited extent. Interestingly, HLAs and immune checkpoint expression, and immunophenoscore in patients with high-m⁶AScores were significantly lower than those in the low-m⁶AScore group. These suggested the m⁶AScores might be used to predict the feasibility of immunotherapy in patients. Results provided a distinctive perspective on m⁶A modification and theoretical basis for CC diagnosis, prognosis, clinical treatment strategies, and potential mechanism exploration.

Identification and verification of IGFBP3 and YTHDC1 as biomarkers associated with immune infiltration and mitophagy in hypertrophic cardiomyopathy

Background: Hypertrophic cardiomyopathy (HCM) is the main cause of sudden cardiac death among young adults, yet its pathogenesis remains vague. N6-methyladenosine (m6A) methylation modification was involved in various cardiovascular diseases such as coronary heart disease and heart failure, although its influence on HCM remains unclear. This study aimed to explore the potential role of m6A in the diagnosis and pathogenesis of HCM.

Methods: GSE36961 including 106 HCM and 39 controls was used in the study. The HCM-related m6A regulators were selected using support vector machine recursive feature elimination and random forest algorithm. A significant gene signature was then established using least absolute shrinkage and selection operator and then verified by GSE130036. Subgroup classification of HCM was performed based on the expression of m6A biomarkers. Gene set variation analysis was employed to explore the functional difference between distinct subgroups. Weighted gene co-expression network analysis was used to determine the m6A-related hub module. Single-sample gene set enrichment analysis was conducted to assess the immune and mitophagy features between subgroups. Besides, transfection of recombinant plasmids with targeted genes into H9c2 cells was performed to further verify the function of the significant biomarkers.

Results: Significant difference existed in m6A landscape between HCM and control patients, among which IGFBP3 and YTHDC1 were identified as the independent biomarkers of HCM. Highly infiltrated immune cells (MDSC, macrophages, etc.), more enriched immune-related pathways (TNFα signaling via NFκB and IL6-JAK-STAT3 signaling) and cardiac remodeling-associated pathways (epithelial mesenchymal transition, angiogenesis, etc.) were identified in the subgroup with higher IGFBP3. Consistently, overexpression of IGFBP3 in H9c2 cells led to upregulation of extracellular-matrix-related genes (COL1A2, COL3A1 and MMP9) and inflammation-related genes (TNFα and IL6). Besides, higher YTHDC1 expression seemed to be consistent with less-activated mitophagy (PINK1-PRKN mediated mitophagy) and energy metabolism. Further experiments demonstrated that overexpression of YTHDC1 resulted in up-regulation of PINK and PRKN in cardiomyocytes, which are essential genes mediating mitophagy.

Conclusion: Two m6A readers (IGFBP3 and YTHDC1) well distinguished HCM and may facilitate clinical diagnosis. IGFBP3 may play a role in the immune-microenvironments and remodeling of cardiac tissues, while YTHDC1 may influence mitophagy and energy metabolism in HCM.