N6-methyladenosine (m6A) writer METTL5 represses the ferroptosis and antitumor immunity of gastric cancer

METTL5-mediated m6A modification of SLC7A11 promotes cervical cancer by inhibiting ferroptosis

Ferroptosis could suppress the viability of cervical cancer cells and trigger their death, thereby offering a unique perspective for exploring novel therapeutic approach for cervical cancer. Here, this study tried to explore the role of N6-methyladenosine (m6A) methyltransferase methyltransferase-like 5 (METTL5) on cervical cancer ferroptosis. Elevated METTL5 functioned as an oncogene in cervical cancer tumorigenesis by inhibiting the ferroptosis. Mechanistically, METTL5 was verified to target SLC7A11 and installed the m6A methylation on SLC7A11 mRNA. Moreover, YTHDF3 bound with the m6A site of SLC7A11 mRNA to enhance SLC7A11 mRNA stability. Rescue assays confirmed that METTL5/YTHDF3/SLC7A11 axis inhibited the ferroptosis of cervical cancer cells. In vivo, METTL5 silencing repressed the tumor growth of cervical cancer cells, as well as reducing the SLC7A11. In conclusion, these data inspired that METTL5-mediated m6A modification of SLC7A11 promoted cervical cancer by inhibiting ferroptosis, providing a novel insight for cervical cancer.

Scutellarin suppresses ovarian cancer progression by targeting METTL5

Scutellarin, a natural compound extracted from Scutellaria barbata, has demonstrated antitumor activity in various cancers. However, its role in ovarian cancer has not been fully explored. This study aims to evaluate the therapeutic potential and underlying mechanisms of Scutellarin in ovarian cancer. The effects of Scutellarin on cell proliferation and migration were assessed in ovarian cancer cell lines including SKOV3, A2780, OVCAR3, and OVCAR8. Patient-derived ovarian cancer organoids were used to further validate the in vitro findings. Calcein-AM and PI staining were used to analyze cell viability, and ATP assays were performed to assess organoid activity. Western blot was used to evaluate the regulation of METTL5 protein by Scutellarin. The gene and protein expression levels of METTL5 and their association with ovarian cancer prognosis were assessed using the databases The Human Protein Atlas (HPA), Gene Expression Profiling Interactive Analysis 2 (GEPIA2), TNMplot, KM-plotter and The Cancer Genome Atlas (TCGA). The functional role of METTL5 was assessed by transwell migration and colony formation assays, and its involvement in Scutellarin's mechanism of action was confirmed by rescue experiments using wound healing and transwell assays. Scutellarin significantly inhibited the proliferation and migration of ovarian cancer cells. In organoid models, Scutellarin markedly reduced organoid growth, induced cell damage, and decreased ATP levels. Compared to normal ovarian tissue, ovarian cancer tissue exhibited elevated RNA and protein expression levels of METTL5. High METTL5 expression was associated with poorer prognosis in ovarian cancer patients and promoted the migration and clonogenicity of ovarian cancer cells. Scutellarin downregulated METTL5 expression, and rescue experiments demonstrated that Scutellarin inhibited ovarian cancer migration by targeting METTL5. Scutellarin demonstrates potent, broad-spectrum anti-tumor activity in ovarian cancer cell lines, potentially mediated through targeting METTL5. These findings suggest a novel and promising therapeutic strategy for ovarian cancer treatment.

METTL5 triggers the ferroptosis of cardiomyocytes in sepsis-induced myocardial injury

Sepsis frequently precipitates a spectrum of serious organ dysfunction syndromes, notably inducing severe cardiac insufficiency. Emerging evidence have linked the roles of N6-methyladenosine (m6A) modification and ferroptosis to sepsis-induced myocardial injury. However, the potential mechanism of m6A regulator methyltransferase-like 5 (METTL5) in sepsis-induced myocardial injury is still unclear. In vivo rats' sepsis model, lipopolysaccharide (LPS) administration increased the level of METTL5 and m6A modification enrichment. In LPS-induced cardiomyocytes, METTL5 silencing (shRNA-METTL5) alleviated the lipid ROS accumulation, MDA, or iron overload, which also promoted cardiomyocytes' proliferation. The data indicated that METTL5 acted as a driver of ferroptosis in sepsis-induced myocardial injury. Mechanistically, METTL5 installed the m6A modification of NRF2 mRNA, and YTHDF2 targeted NRF2 mRNA to trigger its degradation. NRF2 could repress the ferroptosis in LPS-induced cardiomyocytes. Thus, METTL5 consequently accelerated the ferroptosis in sepsis-induced myocardial injury via YTHDF2/NRF2 axis and m6A-dependent manner. In summary, the findings revealed the function of METTL5 on LPS-induced cardiomyocytes ferroptosis, providing a potential therapeutic target for sepsis-induced myocardial injury.

The human 18S rRNA m6A methyltransferase METTL5 promotes tumorigenesis via DEPDC1 in lung squamous cell carcinoma

Background

N6-Methyladenosine (m6A) is one of the post-transcriptional modifications and abnormal m6A is critical for cancer initiation, progression, metastasis in Lung squamous cell carcinoma (LUSC). Ribosomal RNA (rRNA) accounts for most of the total cellular RNA, however, the functions and molecular mechanisms underlying rRNA modifications in LUSC remained largely unclear.

Methods

High-throughput library screening identifies the key m6A regulator METTL5 in LUSC. Cell and animal experiments were used to identify that METTL5 promoted LUSC tumorigenesis to enhance DEP domain containing 1 (DEPDC1) translation via m6A modification.

Results

We showed that the N6-methyladenosine (m6A) methyltransferase METTL5 was an independent risk factor in LUSC and was associated with poor prognosis of patients. Notedly, overexpression METTL5 promoted LUSC tumorigenesis in an m6A modification, while METTL5 knockdown markedly inhibited proliferation and migratory ability of tumor cells in vitro and in vivo. Mechanistically, METTL5 promoted LUSC tumorigenesis via m6a methyltransferase to increase the translation of DEPDC1.

Conclusion

Our results revealed that METTL5 enhances DEPDC1 translation to contribute to tumorigenesis and poor prognosis, providing a potential prognostic biomarker and therapeutic target for LUSC.

The role of N(6)-methyladenosine (m6a) modification in cancer: recent advances and future directions

N(6)-methyladenosine (m6A) modification is the most abundant and prevalent internal modification in eukaryotic mRNAs. The role of m6A modification in cancer has become a hot research topic in recent years and has been widely explored. m6A modifications have been shown to regulate cancer occurrence and progression by modulating different target molecules. This paper reviews the recent research progress of m6A modifications in cancer and provides an outlook on future research directions, especially the development of molecularly targeted drugs. See also the graphical abstract(Fig. 1).

IGF2BP1 accelerates the aerobic glycolysis to boost its immune escape in hepatocellular carcinoma microenvironment

INTRODUCTION

Energy metabolism abnormity emerges as a crucial factor that facilitates tumorigenesis by accelerating aerobic glycolysis. However, the function of N6-methyladenosine (m6A) on hepatocellular carcinoma (HCC) aerobic glycolysis and immune escape is still unclear. Here, this investigation was intended to elucidate the regulation of m6A 'reader' IGF2BP1 involved in HCC aerobic glycolysis and immune escape.

METHODS

The aerobic glycolysis was tested by glucose uptake, lactate, ATP generation and ECAR. The CD8+ T cell-mediated killing effect was tested by cytotoxicity, IFN-γ and granzyme B. The molecular interaction was confirmed by luciferase reporter assay, immunoprecipitation assay and chromatin immunoprecipitation (ChIP)-PCR.

RESULTS

Elevated IGF2BP1 expression was associated with poor prognosis in HCC patients. Functionally, IGF2BP1 emerged as an oncogenic factor that accelerated HCC aerobic glycolysis (glucose uptake, lactate, ATP generation and ECAR) and oxaliplatin resistance. Meanwhile, IGF2BP1 repressed the activated CD8+ T cell-mediated killing effect (cytotoxicity, IFN-γ and granzyme B) and apoptosis of HCC cells, indicating a suppressed cytotoxic T-cell response. By recognizing and binding to the m6A-modified sites on c-Myc mRNA, IGF2BP1 enhanced the stability of c-Myc mRNA, consequently upregulating c-Myc expression. In addition, transcription factor c-Myc targeted the programmed death ligand 1 (PD-L1) promoter region to strengthen its transcription.

DISCUSSION

Taken together, this study illustrates IGF2BP1 as a potential therapeutic target in HCC, aiming to disrupt the interplay between aberrant metabolism and immune escape.