METTL14 promotes migration and invasion of choroidal melanoma by targeting RUNX2 mRNA via m6A modification

RUNX transcription factors: biological functions and implications in cancer

Runt-related transcription factors (RUNX) are a family of transcription factors that are essential for normal and malignant hematopoietic processes. Their most widely recognized role in malignancy is to promote the occurrence and development of acute myeloid leukemia. However, it is worth noting that during the last decade, studies of RUNX proteins in solid tumors have made considerable progress, suggesting that these proteins are directly involved in different stages of tumor development, including tumor initiation, progression, and invasion. RUNX proteins also play a role in tumor angiogenesis, the maintenance of tumor cell stemness, and resistance to antitumor drugs. These findings have led to the consideration of RUNX as a tumor biomarker. All RUNX proteins are involved in the occurrence and development of solid tumors, but the role of each RUNX protein in different tumors and the major signaling pathways involved are complicated by tumor heterogeneity and the interacting tumor microenvironment. Understanding how the dysregulation of RUNX in tumors affects normal biological processes is important to elucidate the molecular mechanisms by which RUNX affects malignant tumors.

METTL14 drives growth and metastasis of non-small cell lung cancer by regulating pri-miR-93-5p maturation and TXNIP expression

BACKGROUND

Non-small cell lung cancer (NSCLC) is a prevalent and aggressive malignancy responsible for a significant number of cancer-related deaths worldwide. Unraveling the molecular mechanisms governing NSCLC growth and metastasis is crucial for the identification of novel therapeutic targets and the development of effective anti-cancer strategies. One such mechanism of interest is the involvement of METTL14, an RNA methyltransferase implicated in various cellular processes, in NSCLC progression.

OBJECTIVE

The objective of this study was to investigate the role of METTL14 in NSCLC development and metastasis and to elucidate the underlying molecular mechanisms. By understanding the impact of METTL14 on NSCLC pathogenesis, the study aimed to identify potential avenues for targeted therapies in NSCLC treatment.

METHODS

We used bioinformatics and high-throughput transcriptome sequencing analyses to screen regulatory mechanisms affecting NSCLC. The Kaplan-Meier method assessed the correlation between METTL14 expression and the prognosis of NSCLC patients. The effects of manipulated METTL14 on malignant phenotypes of NSCLC cells were examined by colony formation assay, flow cytometry, scratch assay, and Transwell assay. The tumorigenic capacity and metastatic potential of NSCLC cells in vivo were evaluated in nude mice.

RESULTS

METTL14 was overexpressed in NSCLC tissues and cell lines. Its high expression indicated a poor prognosis for NSCLC patients. METTL14 silencing promoted apoptosis and repressed proliferation, migration, and invasion of NSCLC cells. miR-93-5p targeted and inhibited TXNIP. METTL14 increased miR-93-5p expression and matured pri-miR-93-5p through m6A alteration to inhibit TXNIP, thereby inhibiting NSCLC cell apoptosis. By controlling the miR-93-5p/TXNIP axis, METTL14 increased the tumorigenic potential and lung metastasis of NSCLC cells in nude mice.

CONCLUSION

This study revealed a role for METTL14 in the contribution to NSCLC development and metastasis and identified METTL14 as a potential target for NSCLC treatment.

N6-methyladenosine methylation in ophthalmic diseases: From mechanisms to potential applications

N6-methyladenosine (m6A) modification, as the most common modification method in eukaryotes, is widely involved in numerous physiological and pathological processes, such as embryonic development, malignancy, immune regulation, and premature aging. Under pathological conditions of ocular diseases, changes in m6A modification and its metabolism can be detected in aqueous and vitreous humor. At the same time, an increasing number of studies showed that m6A modification is involved in the normal development of eye structures and the occurrence and progress of many ophthalmic diseases, especially ocular neovascular diseases, such as diabetic retinopathy, age-related macular degeneration, and melanoma. In this review, we summarized the latest progress regarding m6A modification in ophthalmic diseases, changes in m6A modification-related enzymes in various pathological states and their upstream and downstream regulatory networks, provided new prospects for m6A modification in ophthalmic diseases and new ideas for clinical diagnosis and treatment.

Roles of RNA Methylations in Cancer Progression, Autophagy, and Anticancer Drug Resistance

RNA methylations play critical roles in RNA processes, including RNA splicing, nuclear export, nonsense-mediated RNA decay, and translation. Regulators of RNA methylations have been shown to be differentially expressed between tumor tissues/cancer cells and adjacent tissues/normal cells. N6-methyladenosine (m6A) is the most prevalent internal modification of RNAs in eukaryotes. m6A regulators include m6A writers, m6A demethylases, and m6A binding proteins. Since m6A regulators play important roles in regulating the expression of oncogenes and tumor suppressor genes, targeting m6A regulators can be a strategy for developing anticancer drugs. Anticancer drugs targeting m6A regulators are in clinical trials. m6A regulator-targeting drugs could enhance the anticancer effects of current chemotherapy drugs. This review summarizes the roles of m6A regulators in cancer initiation and progression, autophagy, and anticancer drug resistance. The review also discusses the relationship between autophagy and anticancer drug resistance, the effect of high levels of m6A on autophagy and the potential values of m6A regulators as diagnostic markers and anticancer therapeutic targets.

METTL3 Promotes the Growth and Invasion of Melanoma Cells by Regulating the lncRNA SNHG3/miR-330-5p Axis

Accumulating evidence indicates that m6A methyltransferase 3 (METTL3) plays a pivotal role in different malignancies including melanoma. However, the function and underlying mechanisms by which METTL3 contributes to the tumorigenesis of melanoma remain undocumented. The association of METTL3 and long noncoding RNA (lncRNA) small nucleolar RNA host gene 3 (SNHG3) with clinicopathological characteristics and prognosis in patients with melanoma was analyzed by real-time quantitative polymerase chain reaction (RT-qPCR), Western blotting, and The Cancer Genome Atlas data sets. The role of METTL3 in melanoma cells was assessed by in vitro and in vivo experiments. The m6A dot blot, methylated RNA immunoprecipitation (MeRIP), and RT-qPCR were used to verify METTL3-mediated m6A modification of lncRNA SNHG3. The effect of METTL3 on lncRNA SNHG3 was determined by luciferase gene reporter assay, RT-qPCR, and Western blotting. We found that METTL3 was upregulated in melanoma tissue samples and associated with poor survival in patients with melanoma. Knockdown of METTL3 suppressed the growth and invasion of melanoma cells in vitro and in vivo, whereas restored expression of METTL3 promoted these effects. Mechanistic investigations showed that knockdown of METTL3 reduced SNHG3 m6A levels and its messenger ribonucleic acid (mRNA) expression levels. SNHG3 could act as a sponge of microRNA (miR)-330-5p to upregulate the expression of CCHC-type zinc finger nucleic acid binding protein (CNBP). SNHG3 overexpression reversed METTL3-knockdown-caused antitumor effects, miR-330-5p upregulation and CNBP downregulation. SNHG3 had a positive correlation with METTL3 expression but a negative correlation with miR-330-5p expression in melanoma tissue samples. In conclusion, our findings demonstrated that METTL3-mediated m6A modification of lncRNA SNHG3 promoted the growth and invasion of melanoma cells by regulating the miR-330-5p/CNBP axis.