The combined restoration of miR-424-5p and miR-142-3p effectively inhibits MCF-7 breast cancer cell line via modulating apoptosis, proliferation, colony formation, cell cycle and autophagy

MicroRNA-based interventions in aberrant cell cycle diseases: Therapeutic strategies for cancers, central nervous system disorders and comorbidities

Malignant tumors and central nervous system (CNS) disorders are intricately linked to a process known as "aberrant cell cycle re-entry," which plays a critical role in the progression of these diseases. Addressing the dysregulation in cell cycles offers a promising therapeutic approach for cancers and CNS disorders. MicroRNAs (miRNAs) play a crucial role as regulators of gene expression in cell cycle transitions, presenting a promising therapeutic avenue for treating these disorders and their comorbidities. This review consolidates the progress made in the last three years regarding miRNA-based treatments for diseases associated with aberrant cell cycle re-entry. It encompasses exploring fundamental mechanisms and signaling pathways influenced by miRNAs in cancers and CNS disorders, particularly focusing on the therapeutic effects of exosome-derived miRNAs. The review also identifies specific miRNAs implicated in comorbidity of cancers and CNS disorders, discusses the future potential of miRNA reagents in managing cell cycle-related diseases.

Star-PAP controls oncogene expression through primary miRNA 3'-end formation to regulate cellular proliferation and tumour formation

Star-PAP is a non-canonical poly(A) polymerase that is down regulated in breast cancer. While Star-PAP down regulation impairs target mRNA polyadenylation, paradoxically, we see up regulation of a large number of oncogenes on Star-PAP knockdown. Using two breast cancer cells (MCF7 with high Star-PAP, and MDA-MB-231 with negligible Star-PAP level), we discover that Star-PAP negatively regulates oncogene expression and subsequently cellular proliferation. This regulation is compromised with Star-PAP mutant of 3'-end processing function (serine 6 to alanine, S6A phospho-mutation). Concomitantly, xenograft mice model using MDA-MB-231 cells reveals a reduction in the tumour formation on ectopic Star-PAP expression that is ameliorated by S6A mutation. We find that Star-PAP control of target oncogene expression is independent of Star-PAP-mediated alternative polyadenylation or target mRNA 3'-end formation. We demonstrate that Star-PAP regulates target oncogenes through cellular miRNAs (miR-421, miR-335, miR-424, miR-543, miR-205, miR-34a, and miR-26a) that are down regulated in breast cancer. Analysis of various steps in miRNA biogenesis pathway reveals that Star-PAP regulates 3'-end formation and synthesis of primary miRNA (host) transcripts that is dependent on S6 phosphorylation thus controlling mature miRNA generation. Using mimics and inhibitors of two target miRNAs (miR-421 and miR-424) after Star-PAP depletion in MCF7 or ectopic expression in MDA-MB-231 cells, we demonstrate that Star-PAP controls oncogene expression and cellular proliferation through targeting miRNAs that regulates tumour formation. Our study establishes a novel mechanism of oncogene expression independent of alternative polyadenylation through Star-PAP-mediated miRNA host transcript polyadenylation that regulates breast cancer progression.

miR-142-3p/5p role in cancer: From epigenetic regulation to immunomodulation

MicroRNAs (miRNAs) play critical roles in cancer pathobiology, acting as regulators of gene expression and pivotal drivers of tumorigenesis. It is believed that miRNAs act through canonical mechanisms, involving the binding of mature miRNAs to target messenger RNAs (mRNAs) and subsequent repression of protein translation or degradation of target mRNAs. miR-142-3p/5p has been extensively studied and established as a key regulator in various malignancies. Recent discoveries have revealed miR-142-3p/5p serve as either oncogene or tumor suppressor in cancer. By targeting epigenetic factor and cancer-related signaling pathway, miR-142-3p/5p can regulate wide range of downstream genes. The immune modulatory role of miR-142-3p/5p has been shown in various cancers, which provides significant insight into immunosuppression and tumor escape from the immune response. Exosomes with miR-142-3p/5p facilitate cell communication and can affect cancer cell behavior, offering potential therapeutic, and diagnosis applications in cancer therapy. In this review, for the first time, we comprehensively summarize the current knowledge regarding mentioned functions of miR-142-3p/5p in cancer pathobiology.

Role of miR-424 in the carcinogenesis

Recent studies have revealed the impact of microRNAs (miRNAs) in the carcinogenic process. miR-424 is a miRNA whose role in this process is being to be identified. Experiments in the ovarian cancer, cervical cancer, hepatocellular carcinoma, neuroblastoma, breast cancer, osteosarcoma, intrahepatic cholangiocarcinoma, prostate cancer, endometrial cancer, non-small cell lung cancer, hemangioma and gastric cancer have reported down-regulation of miR-424. On the other hand, this miRNA has been found to be up-regulated in melanoma, laryngeal and esophageal squamous cell carcinomas, glioma, multiple myeloma and thyroid cancer. Expression of this miRNA is regulated by methylation status of its promoter. Besides, LINC00641, CCAT2, PVT1, LIN00657, LINC00511 and NNT-AS1 are among lncRNAs that act as molecular sponges for miR-424, thus regulating its expression. Moreover, several members of SNHG family of lncRNAs have been found to regulate expression of miR-424. This miRNA is also involved in the regulation of E2F transcription factors. The current review aims at summarization of the role of miR-424 in the process of cancer evolution and its impact on clinical outcome of patients in order to find appropriate markers for malignancies.

Plasma-derived exosomal miRNA profiles reveal potential epigenetic pathogenesis of premature ovarian failure

The role of plasma-derived exosomal miRNA in premature ovarian failure (POF) remains unclear. This study aimed to investigate the epigenetic pathogenesis of POF through exosomal miRNA sequencing. Exosomes were isolated and characterized from six POF patients and four healthy individuals using nanoparticle tracking analysis, transmission electron microscopy and western blot analysis. Exosomal miRNA sequencing was performed to identify differentially expressed miRNAs with |fold change| greater than 1.5 and p value less than 0.05. Bioinformatics analysis in GSE39501 dataset and our sequencing data was conducted to investigate underlying mechanisms of POF. The functional role of hsa-miR-19b-3p was assessed using CCK8, western blot, flow cytometry and fluorescence staining. The regulatory effect of hsa-miR-19b-3p on BMPR2 was investigated through miRNA transfection, qPCR analysis, and luciferase reporter assay. Statistical significance was determined using t-tests and one-way ANOVA (p < 0.05). Exosomal miRNA sequencing revealed 18 dysregulated miRNAs in POF patients compared to healthy controls. Functional enrichment analysis demonstrated their involvement in cell growth, oocyte meiosis and PI3K-Akt signaling pathways. Moreover, the constructed miRNA-mRNA network unveiled potential regulatory mechanisms underlying POF, particularly implicating hsa-miR-19b-3p in the regulation of BMPR2. In vitro assays conducted on KGN cells confirmed that hsa-miR-19b-3p promoted apoptosis, as evidenced by reduced cell viability, decayed mitochondrial membrane potential and increased apoptotic rate, thereby supporting its role in POF. Notably, hsa-miR-19b-3p was found to significantly downregulate BMPR2 expression via targeting its 3'UTR, while co-expression analysis revealed strong associations between BMPR2 and POF-related processes. This study sheds light on the epigenetic pathogenesis of POF by investigating exosomal miRNA profiles. Particularly, hsa-miR-19b-3p emerged as a potential regulator of BMPR2 and demonstrated its functional significance in POF through modulation of apoptosis.

Modulation of AKT Pathway-Targeting miRNAs for Cancer Cell Treatment with Natural Products

Many miRNAs are known to target the AKT serine-threonine kinase (AKT) pathway, which is critical for the regulation of several cell functions in cancer cell development. Many natural products exhibiting anticancer effects have been reported, but their connections to the AKT pathway (AKT and its effectors) and miRNAs have rarely been investigated. This review aimed to demarcate the relationship between miRNAs and the AKT pathway during the regulation of cancer cell functions by natural products. Identifying the connections between miRNAs and the AKT pathway and between miRNAs and natural products made it possible to establish an miRNA/AKT/natural product axis to facilitate a better understanding of their anticancer mechanisms. Moreover, the miRNA database (miRDB) was used to retrieve more AKT pathway-related target candidates for miRNAs. By evaluating the reported facts, the cell functions of these database-generated candidates were connected to natural products. Therefore, this review provides a comprehensive overview of the natural product/miRNA/AKT pathway in the modulation of cancer cell development.

MicroRNAs: A Link between Mammary Gland Development and Breast Cancer

Breast cancer is among the most common cancers in women, second to skin cancer. Mammary gland development can influence breast cancer development in later life. Processes such as proliferation, invasion, and migration during mammary gland development can often mirror processes found in breast cancer. MicroRNAs (miRNAs), small, non-coding RNAs, can repress post-transcriptional RNA expression and can regulate up to 80% of all genes. Expression of miRNAs play a key role in mammary gland development, and aberrant expression can initiate or promote breast cancer. Here, we review the role of miRNAs in mammary development and breast cancer, and potential parallel roles. A total of 32 miRNAs were found to be expressed in both mammary gland development and breast cancer. These miRNAs are involved in proliferation, metastasis, invasion, and apoptosis in both processes. Some miRNAs were found to have contradictory roles, possibly due to their ability to target many genes at once. Investigation of miRNAs and their role in mammary gland development may inform about their role in breast cancer. In particular, by studying miRNA in development, mechanisms and potential targets for breast cancer treatment may be elucidated.

Obesity as a Risk Factor for Breast Cancer-The Role of miRNA

Breast cancer (BC) is the most common cancer diagnosed among women in the world, with an ever-increasing incidence rate. Due to the dynamic increase in the occurrence of risk factors, including obesity and related metabolic disorders, the search for new regulatory mechanisms is necessary. This will help a complete understanding of the pathogenesis of breast cancer. The review presents the mechanisms of obesity as a factor that increases the risk of developing breast cancer and that even initiates the cancer process in the female population. The mechanisms presented in the paper relate to the inflammatory process resulting from current or progressive obesity leading to cell metabolism disorders and disturbed hormonal metabolism. All these processes are widely regulated by the action of microRNAs (miRNAs), which may constitute potential biomarkers influencing the pathogenesis of breast cancer and may be a promising target of anti-cancer therapies.