MiR-4521 perturbs FOXM1-mediated DNA damage response in breast cancer

Inhibition of mitochondrial genome-encoded mitomiR-3 contributes to ZEB1 mediated GPX4 downregulation and pro-ferroptotic lipid metabolism to induce ferroptosis in breast cancer cells

Ferroptosis, an iron-dependent form of regulated cell death driven by lipid peroxidation, represents a unique vulnerability in cancer cells. However, current ferroptosis-inducing therapies face clinical limitations due to poor cancer cell specificity, systemic toxicity, and off-target effects. Therefore, a deeper understanding of molecular regulators of ferroptosis sensitivity is critical for developing targeted therapies. The metabolic plasticity of cancer cells determines their sensitivity to ferroptosis. While mitochondrial dysfunction contributes to metabolic reprogramming in cancer, its role in modulating ferroptosis remains poorly characterized. Previously, studies have identified that mitochondrial genome also encodes several non-coding RNAs. We identified 13 novel mitochondrial genome-encoded miRNAs (mitomiRs) that are aberrantly overexpressed in triple-negative breast cancer (TNBC) cell lines and patient tumors. We observed higher levels of mitomiRs in basal-like triple-negative breast cancer (TNBC) cells compared to mesenchymal stem-like TNBC cells. Strikingly, 11 of these mitomiRs directly target the 3'UTR of ZEB1, a master regulator of epithelial-to-mesenchymal transition (EMT). Using mitomiR-3 mimic, inhibitor and sponges, we demonstrated its role as a key regulator of ZEB1 expression in TNBC cells. Inhibition of mitomiR-3 via sponge construct in basal-like TNBC, MDA-MB-468 cells, promoted ZEB1 upregulation and induced a mesenchymal phenotype. Further, mitomiR-3 inhibition in TNBC cells contributed to reduced cancer cell proliferation, migration, and invasion. Mechanistically, mitomiR-3 inhibition in TNBC cells promote metabolic reprogramming toward pro-ferroptotic pathways, including iron accumulation, increased polyunsaturated fatty acid (PUFA) metabolites, and lipid peroxidation, contributing to ferroptotic cell death via ZEB1-mediated downregulation of GPX4, a critical ferroptosis defense enzyme. We observed that mitomiR-3 inhibition significantly suppressed tumor growth in vivo. Our identified mitomiR-3 has low expression in normal breast cells, minimizing potential off-target toxicity, making them a promising target for pro-ferroptotic cancer therapy. Our study reveals a novel link between mitochondrial miRNAs and ferroptosis sensitivity in TNBC paving a way for miRNA-based therapeutics.

The Role of the Fox Gene in Breast Cancer Progression

Forkhead box (FOX) genes are a family of transcription factors that participate in many biological activities, from early embryogenesis to the formation of organs, and from regulation of glucose metabolism to regulation of longevity. Given the extensive influence in the multicellular process, FOX family proteins are responsible for the progression of many types of cancers, especially lung cancer, breast cancer, prostate cancer, and other cancers. Breast cancer is the most common cancer among women, and 2.3 million women were diagnosed in 2020. So, various drugs targeting the FOX signaling pathway have been developed to inhibit breast cancer progression. While the role of the FOX family gene in cancer development has not received enough attention, discovering more potential drugs targeting the FOX signaling pathway is urgently demanded. Here, we review the main members in the FOX gene family and summarize their signaling pathway, including the regulation of the FOX genes and their effects on breast cancer progression. We hope this review will emphasize the understanding of the role of the FOX gene in breast cancer and inspire the discovery of effective anti-breast cancer medicines targeting the FOX gene in the future.

MiR-509-3p promotes gastric cancer development by activating FOXM1-mediated p38/MK2 pathway

Gastric cancer (GC), a malignant tumor, is highly prevalent, particularly in Asia. miR-509-3p plays a crucial role in regulating tumorigenesis, but its mechanism in GC remains unclear. Potential targets of miR-509-3p were identified through database analyses (miRWalk, TargetScan, ENCORI, and TCGA). The binding site between miR-509-3p and forkhead box protein M1 (FOXM1) was confirmed using a dual-luciferase assay. CCK-8, EdU, Transwell, wound healing assays, flow cytometry, and Western blot analysis were employed to examine changes in proliferation, migration, invasion, apoptosis, FOXM1, and the p38 MAPK (p38)/MAPK-activated protein kinase 2 (MK2) pathway in GC cells (MNK-45 and HGC-27) after miR-509-3p overexpression or knockdown, FOXM1 overexpression, and application of the p38 pathway agonist Anisomycin. The size and weight of subcutaneous xenografts were measured, and the effects of miR-509-3p overexpression were analyzed through histopathological staining (Tunel immunofluorescence, HE staining, Ki67, and FOXM1 immunohistochemistry). The results showed that overexpression of miR-509-3p suppressed proliferation, migration, and invasion, while accelerating apoptosis. Knockdown of miR-509-3p promoted malignant progression. miR-509-3p inhibited GC by regulating FOXM1-mediated p38/MK2 pathway activation, and miR-509-3p mimics restrained tumor growth in vivo through this pathway. In conclusion, miR-509-3p suppresses GC malignant progression by regulating FOXM1-mediated p38/MK2 pathway activation.

Epigenetic regulation of DNA repair gene program by Hippo/YAP1-TET1 axis mediates sorafenib resistance in HCC

Hepatocellular carcinoma (HCC) is a malignancy that occurs worldwide and is generally associated with poor prognosis. The development of resistance to targeted therapies such as sorafenib is a major challenge in clinical cancer treatment. In the present study, Ten-eleven translocation protein 1 (TET1) was found to be highly expressed in sorafenib-resistant HCC cells and knockdown of TET1 can substantially improve the therapeutic effect of sorafenib on HCC, indicating the potential important roles of TET1 in sorafenib resistance in HCC. Mechanistic studies determined that TET1 and Yes-associated protein 1 (YAP1) synergistically regulate the promoter methylation and gene expression of DNA repair-related genes in sorafenib-resistant HCC cells. RNA sequencing indicated the activation of DNA damage repair signaling was extensively suppressed by the TET1 inhibitor Bobcat339. We also identified TET1 as a direct transcriptional target of YAP1 by promoter analysis and chromatin-immunoprecipitation assays in sorafenib-resistant HCC cells. Furthermore, we showed that Bobcat339 can overcome sorafenib resistance and synergized with sorafenib to induce tumor eradication in HCC cells and mouse models. Finally, immunostaining showed a positive correlation between TET1 and YAP1 in clinical samples. Our findings have identified a previously unrecognized molecular pathway underlying HCC sorafenib resistance, thus revealing a promising strategy for cancer therapy.

GTSE1 promotes nasopharyngeal carcinoma proliferation and angiogenesis by upregulating STMN1

BACKGROUND

Nasopharyngeal carcinoma (NPC) is a malignant tumor with poor survival rate. G2 and S phase-expressed-1 (GTSE1) takes part in the progression of diverse tumors as an oncogene, but its role and potential mechanism in NPC remain unknown.

METHODS

The GTSE1 expression was analyzed by western blot in NPC tissues and cells. Knock-down experiments were conducted to determine the function of GTSE1 in NPC by cell counting kit-8, the 5-ethynyl-2'-deoxyuridine (EdU) incorporation experiment, cell scratch wound-healing experiment, transwell assays, tube forming experiment and western blot. In addition, the in vivo role of GTSE1 was addressed in tumor-bearing mice.

RESULTS

The expression of was increased in NPC. Silencing of GTSE1 suppressed cell viability, the percent of EdU positive cells, and the number of invasion cells and tubes, but enhanced the scratch ratio in NPC cells. Mechanically, downregulation of GTSE1 decreased the expressions of FOXM1 and STMN1, which were restored with the upregulation of FOXM1. Increased expression of STMN1 reversed the effects of the GTSE1 silencing on proliferation, migration, invasion and angiogenesis of NPC cells. Furthermore, knockdown of GTSE1 repressed the tumor volume and tumor weight of xenografted mice.

CONCLUSION

GTSE1 was highly expressed in NPC, and silencing of GTSE1 ameliorated the malignant processes of NPC cells by upregulating STMN1, suggesting a possible therapeutical target for NPC.

In vivo validation of the functional role of MicroRNA-4638-3p in breast cancer bone metastasis

PURPOSE

Skeletal metastases are increasingly reported in metastatic triple-negative breast cancer (BC) patients. We previously reported that TGF-β1 sustains activating transcription factor 3(ATF3) expression and is required for cell proliferation, invasion, and bone metastasis genes. Increasing studies suggest the critical regulatory function of microRNAs (miRNAs) in governing BC pathogenesis. TGF-β1 downregulated the expression of miR-4638-3p, which targets ATF3 in human BC cells (MDA-MB-231). In the present study, we aimed to identify the functional role of miR-4638-3p in BC bone metastasis by the caudal artery injection of the MDA-MB-231 cells overexpressing mir-4638 in the mice.

METHODS

MDA-MB-231 cells overexpressing miR-4638 were prepared by stable transfections. Reverse transcriptase quantitative PCR was carried out to determine the expression of endogenous miR-4638-3p and bone resorption marker genes. X-ray, micro-CT, and Hematoxylin & Eosin studies were used to determine osteolytic lesions, trabecular structure, bone mineral density, and micrometastasis of cells.

RESULTS

The mice injected with MDA-MB-231 cells overexpressing miR-4638-3p decreased the expression of bone resorption marker genes, compared to MDA-MB-231 cells injection. Reduced osteolytic lesions and restored bone density by MDA-MB-231 cells overexpressing miR-4638-3p were observed. Similarly, the mice injected with MDA-MB-231 cells overexpressing miR-4638-3p showed a better microarchitecture of the trabecular network. A few abnormal cells seen in the femur of MDA-MB-231 cells-injected mice were not found in MDA-MB-231 cells overexpressing miR-4638.

CONCLUSION

The identified functional role of ATF3 targeting miR-4638-3p in BC bone metastasis in vivo suggests its candidature as BC therapeutics in the future.

Mesenchymal Stem Cells from Familial Alzheimer's Patients Express MicroRNA Differently

Alzheimer's disease (AD) is a progressive neurodegenerative disorder and the predominant form of dementia globally. No reliable diagnostic, predictive techniques, or curative interventions are available. MicroRNAs (miRNAs) are vital to controlling gene expression, making them valuable biomarkers for diagnosis and prognosis. This study examines the transcriptome of olfactory ecto-mesenchymal stem cells (MSCs) derived from individuals with the PSEN1(A431E) mutation (Jalisco mutation). The aim is to determine whether this mutation affects the transcriptome and expression profile of miRNAs and their target genes at different stages of asymptomatic, presymptomatic, and symptomatic conditions. Expression microarrays compare the MSCs from mutation carriers with those from healthy donors. The results indicate a distinct variation in the expression of miRNAs and mRNAs among different symptomatologic groups and between individuals with the mutation. Using bioinformatics tools allows us to identify target genes for miRNAs, which in turn affect various biological processes and pathways. These include the cell cycle, senescence, transcription, and pathways involved in regulating the pluripotency of stem cells. These processes are closely linked to inter- and intracellular communication, vital for cellular functioning. These findings can enhance our comprehension and monitoring of the disease's physiological processes, identify new disorder indicators, and develop innovative treatments and diagnostic tools for preventing or treating AD.