METTL17 coordinates ferroptosis and tumorigenesis by regulating mitochondrial translation in colorectal cancer

SIRT7-mediated NRF2 deacetylation promotes antioxidant response and protects against chemodrug-induced liver injury

NRF2 has been recognized as a central hub that neutralizes ROS and restores intracellular redox balance. In addition to KEAP1 mediated ubiquitin-proteasome degradation, post-translational modifications of NRF2 are critical for regulating its nuclear translocation and activation but precise mechanisms underly this regulation remain elusive. In this study, we found that SIRT7 was sufficient and essential for NRF2 nuclear localization and activation. Knockdown of SIRT7 significantly impaired intercellular ROS homeostasis and increased apoptosis in response to oxidative stress including chemodrug treatment. SIRT7 interacted with NRF2 and induced its deacetylation, by which inhibited binding of NRF2 to KEAP1, enhanced NRF2 protein stability and promoted its nuclear translocation. SIRT7 induced NRF2 deacetylation at K443 and K518 sites. Lysine-arginine mutations of these sites (2KR NRF2) significantly reduced KEAP1/NRF2 binding, increased NRF2 nuclear translocation and target gene expression, decreased intercellular ROS level, whereas lysine-glutamine (2KQ) mutant showed similar subcellular localization and functions with WT. Knockdown SIRT7 in hepatocyte exacerbated Oxaliplatin (Oxa) induced hepatic injury and inflammation. While AAV8-NRF2-mediated hepatic NRF2 overexpression or NRF2 agonist significantly prevented Oxa-induced elevation of ALT levels, sinusoidal dilatation and inflammation in SIRT7HKO mice. Our data thus uncovered previously unidentified role of SIRT7 in modulating NRF2 nuclear localization and activation via deacetylation. Activating SIRT7 might offer protection against chemodrug-induced liver injury.

m6A-induced DEAD-box RNA helicase 21 enhances lipid metabolism via 3‑hydroxy-3-methylglutaryl-CoA synthases 1 in colorectal cancer

BACKGROUND

Altered lipid metabolism is a well-known hallmark of cancer. However, the underlying mechanisms of altered lipid metabolism in colorectal cancer (CRC) progression requires further investigation. Previously we have revealed that DEAD-box RNA helicase 21 (DDX21) promotes CRC metastasis via liquid-liquid phase separation. In this study, we identify DDX21 as a novel regulator of lipid metabolism in CRC.

METHODS

In vitro and in vivo assays illustrated the biological role of DDX21 and YTH N6-methyladenosine RNA binding protein 1 (YTHDF1) in CRC lipid metabolism and progression. Bioinformatics analysis, ChIP, meRIP, RIP, RNA stability assay and dual-luciferase reporter assay were applied to explore the underlying molecular mechanisms. The expression levels and prognostic role of YTHDF1/DDX21/HMGCS1 axis in CRC patients were analyzed by immunohistochemical staining and Kaplan-Meier plotter.

RESULTS

DDX21 enhanced CRC progression via promoting lipid metabolism. Mechanistically, YTHDF1 enhanced DDX21 mRNA stability by recognizing its m6A-modified sites. DDX21 further binded to 3‑hydroxy-3-methylglutaryl-CoA synthase 1 (HMGCS1) promoter region and directly activated HMGCS1 transcription. Moreover, our clinical data showed that a simultaneously high expression of YTHDF1, DDX21 and HMGCS1 predicted an unfavorable overall survival in CRC patients.

CONCLUSIONS

Our study demonstrates that the YTHDF1/DDX21/HMGCS1 axis promotes CRC progression via regulating lipid metabolism and DDX21 might be a promising target for CRC therapy.

Mitochondrial Regulation of Ferroptosis in Cancer Cells

Ferroptosis is an iron-dependent nonapoptotic regulated cell death modality characterized by lethal levels of lipid peroxide accumulation and disrupted antioxidant systems. An increasing number of studies have revealed correlations between ferroptosis and the pathophysiology and treatment of cancer. Given the intricate involvement of mitochondria in ferroptosis, as suggested by previous studies, here, we review advances in understanding the roles of mitochondrial quality control and mitochondrial metabolism (including the roles of the TCA cycle, reactive oxygen species, iron metabolism, and lipid metabolism) in cancer-related ferroptosis and outline the molecular mechanism and clinical translation of mitochondria-related ferroptosis in cancer treatment. with the aim of promoting the precise utilization and prevention of ferroptosis in cancer therapeutics.

N7-methylguanosine modification in cancers: from mechanisms to therapeutic potential

N7-methylguanosine (m7G) is an important RNA modification involved in epigenetic regulation that is commonly observed in both prokaryotic and eukaryotic organisms. Their influence on the synthesis and processing of messenger RNA, ribosomal RNA, and transfer RNA allows m7G modifications to affect diverse cellular, physiological, and pathological processes. m7G modifications are pivotal in human diseases, particularly cancer progression. On one hand, m7G modification-associated modulate tumour progression and affect malignant biological characteristics, including sustained proliferation signalling, resistance to cell death, activation of invasion and metastasis, reprogramming of energy metabolism, genome instability, and immune evasion. This suggests that they may be novel therapeutic targets for cancer treatment. On the other hand, the aberrant expression of m7G modification-associated molecules is linked to clinicopathological characteristics, including tumour staging, lymph node metastasis, and unfavourable prognoses in patients with cancer, indicating their potential as tumour biomarkers. This review consolidates the discovery, identification, detection methodologies, and functional roles of m7G modification, analysing the mechanisms by which m7G modification-associated molecules contribute to tumour development, and exploring their potential clinical applications in cancer diagnostics and therapy, thereby providing innovative strategies for tumour identification and targeted treatment.

Mettl15-Mettl17 modulates the transition from early to late pre-mitoribosome

The assembly of the mitoribosomal small subunit involves folding and modification of rRNA, and its association with mitoribosomal proteins. This process is assisted by a dynamic network of assembly factors. Conserved methyltransferases Mettl15 and Mettl17 act on the solvent-exposed surface of rRNA. Binding of Mettl17 is associated with the early assembly stage, whereas Mettl15 is involved in the late stage, but the mechanism of transition between the two was unclear. Here, we integrate structural data from Trypanosoma brucei with mammalian homologs and molecular dynamics simulations. We reveal how the interplay of Mettl15 and Mettl17 in intermediate steps links the distinct stages of small subunit assembly. The analysis suggests a model wherein Mettl17 acts as a platform for Mettl15 recruitment. Subsequent release of Mettl17 allows a conformational change of Mettl15 for substrate recognition. Upon methylation, Mettl15 adopts a loosely bound state which ultimately leads to its replacement by initiation factors, concluding the assembly. Together, our results indicate that assembly factors Mettl15 and Mettl17 cooperate to regulate the biogenesis process, and present a structural data resource for understanding molecular adaptations of assembly factors in mitoribosome.

Epigenetic Effects of Natural Products in Inflammatory Diseases: Recent Findings

Inflammation is an essential step for the etiology of multiple diseases. Clinically, due to the limitations of current drugs for the treatment of inflammatory diseases, such as serious side effects and expensive costs, it is urgent to explore novel mechanisms and medicines. Natural products have received extensive attention recently because of their multi-component and multi-target characteristics. Epigenetic modifications are crucial pathophysiological targets for developing innovative therapies for pharmacological interventions. Investigations examining how natural products improving inflammation through epigenetic modifications are emerging. This review state that natural products relieve inflammation via regulating the gene transcription levels through chromosome structure regulated by histone acetylation levels and the addition or deletion of methyl groups on DNA duplex. They could also exert anti-inflammatory effects by modulating the proteins in typical inflammatory signaling pathways by ubiquitin-related degradation and the effect of glycolysis derived free glycosyls. Studies on epigenetic modifications have the potential to facilitate the development of natural products as therapeutic agents. Future research directed at better understanding of how natural products modulate inflammatory processes through less studied epigenetic modifications including neddylation, SUMOylation, palmitoylation and lactylation, may provide new implications. Meanwhile, higher quality preclinical studies and more powerful clinical evidence are still needed to firmly establish the clinical efficacy of the natural products. Trial Registration: ClinicalTrials.gov Identifier: NCT01764204; ClinicalTrials.gov Identifier: NCT05845931; ClinicalTrials.gov Identifier: NCT04657926; ClinicalTrials.gov Identifier: NCT02330276.

Mitochondrial RNA methylation in cancer

Mitochondria have a complete and independent genetic system with necessary biological energy for cancer occurrence and persistence. Mitochondrial RNA (mt-RNA) methylation, as a frontier in epigenetics, has linked to cancer progression with growing evidences. This review has comprehensively summarized detailed mechanisms of mt-RNA methylation in regulating cancer proliferation, metastasis, and immune infiltration from the mt-RNA methylation sites, biological significance, and its methyltransferases. The mt-RNA methylation also plays a very significant role via epigenetic crosstalk between nucleus and mitochondria. Importantly, the unique structures and functional characteristics of mt-RNA methyltransferases and the potential targeting treatment drugs for cancer are also analyzed. Revealing human mt-RNA methylation regulatory system and the relationship with cancer will contribute to identifying potential biomarkers and therapeutic targets for precise prevention, detection, intervention and treatment in the future.

Recent insights into RNA m5C methylation modification in hepatocellular carcinoma

RNA 5-methylcytosine (m5C) methylation involves the addition of a methyl (-CH3) group to the cytosine (C) base within an RNA molecule, forming the m5C modification. m5C plays a role in numerous essential biological processes, including the regulation of RNA stability, nuclear export, and protein translation. Recent studies have highlighted the importance of m5C in the pathogenesis of various diseases, particularly tumors. Emerging evidence indicates that RNA m5C methylation is intricately implicated in the mechanisms underlying hepatocellular carcinoma (HCC). Dysregulation of m5C-associated regulatory factors is common in HCC and shows significant associations with prognosis, treatment response, and clinicopathological features. This review provides an in-depth analysis of the components and functions of m5C regulators, particularly emphasizing their research advancements in the context of HCC.

Iron homeostasis and ferroptosis in human diseases: mechanisms and therapeutic prospects

Iron, an essential mineral in the body, is involved in numerous physiological processes, making the maintenance of iron homeostasis crucial for overall health. Both iron overload and deficiency can cause various disorders and human diseases. Ferroptosis, a form of cell death dependent on iron, is characterized by the extensive peroxidation of lipids. Unlike other kinds of classical unprogrammed cell death, ferroptosis is primarily linked to disruptions in iron metabolism, lipid peroxidation, and antioxidant system imbalance. Ferroptosis is regulated through transcription, translation, and post-translational modifications, which affect cellular sensitivity to ferroptosis. Over the past decade or so, numerous diseases have been linked to ferroptosis as part of their etiology, including cancers, metabolic disorders, autoimmune diseases, central nervous system diseases, cardiovascular diseases, and musculoskeletal diseases. Ferroptosis-related proteins have become attractive targets for many major human diseases that are currently incurable, and some ferroptosis regulators have shown therapeutic effects in clinical trials although further validation of their clinical potential is needed. Therefore, in-depth analysis of ferroptosis and its potential molecular mechanisms in human diseases may offer additional strategies for clinical prevention and treatment. In this review, we discuss the physiological significance of iron homeostasis in the body, the potential contribution of ferroptosis to the etiology and development of human diseases, along with the evidence supporting targeting ferroptosis as a therapeutic approach. Importantly, we evaluate recent potential therapeutic targets and promising interventions, providing guidance for future targeted treatment therapies against human diseases.

The MEF2A/SNHG16/miR-425-5p/NOTCH2 axis induces gemcitabine resistance by inhibiting ferroptosis in the starving bladder tumor microenvironment

Gemcitabine resistance is one of the leading causes of bladder cancer (BCa) recurrence and progression. The dysregulation of ferroptosis is involved in this process; however, the underlying mechanisms remain unclear. In the current study, we found a prominent increase in long non-coding RNA (lncRNA) small nucleolar RNA host gene 16 (SNHG16) in tumor samples, which was related to advanced tumor grade and poor prognosis. SNHG16 is overexpressed in the starving tumor microenvironment (STME) and induces gemcitabine resistance by inhibiting ferroptosis in BCa. SNHG16 knockdown promotes ferroptosis and increases chemosensitivity to gemcitabine. Mechanistically, the transcription factor MEF2A was markedly upregulated in the STME, facilitating SNHG16 expression. SNHG16 acts as a competing endogenous RNA that sponges miR-425-5p and promotes NOTCH2 expression. SNHG16/miR-425-5p/NOTCH2 is demonstrated, for the first time, to suppress ferroptosis by inducing SLC7A11 and GPX4 expression in vitro and in vivo. Upregulation of miR-425-5p reverses NOTCH2-mediated inhibition of ferroptosis, thereby mitigating gemcitabine resistance. In conclusion, these findings reveal that the STME-activated MEF2A/SNHG16/miR-425-5p/NOTCH2 axis induces gemcitabine resistance by inhibiting ferroptosis and implicate SNHG16 as a potential therapeutic target for chemoresistance.

Dihydroartemisinin Sensitizes Lung Cancer Cells to Cisplatin Treatment by Upregulating ZIP14 Expression and Inducing Ferroptosis

BACKGROUND

Despite significant advances in lung cancer treatment, cisplatin (DDP)-based chemotherapy remains a cornerstone for managing the disease. However, the prevalence of chemoresistance presents a major challenge, limiting its effectiveness and contributing to poor outcomes. This underscores the urgent need for novel therapeutic strategies to overcome chemoresistance and improve chemotherapy efficacy in lung cancer patients. Exploring approaches to sensitize tumors to cisplatin could enhance treatment responses and overall survival rates.

METHODS AND RESULTS

Our study utilized a variety of lung cancer models, including cell lines, mouse models, and patient-derived organoids, to validate the synergistic cytotoxic effects of dihydroartemisinin (DHA) and cisplatin (DDP). When combined with DDP, we demonstrate that DHA is a promising therapeutic agent that effectively triggers ferroptosis in lung cancer cells, offering a potential strategy for overcoming chemoresistance. Mechanistically, the combination of DHA and DDP synergistically enhances ZIP14 expression, modulating iron homeostasis and upregulating oxidative stress, leading to both in vitro and in vivo ferroptosis. Notably, our findings revealed that the sequential administration of DDP followed by DHA significantly increases ZIP14 expression and induces superior therapeutic outcomes compared to the simultaneous administration or DHA followed by DDP. This observation underscores the importance of the drug administration order in optimizing treatment efficacy, providing new insights into enhancing chemotherapy response in lung cancer.

CONCLUSION

Our findings suggest that combining dihydroartemisinin (DHA) with cisplatin (DDP) presents a promising strategy to overcome chemoresistance in lung cancer patients. Importantly, administering DHA during chemotherapy intervals could further optimize treatment outcomes, enhancing the overall efficacy of lung cancer chemotherapy.

RNA m6A modification in ferroptosis: implications for advancing tumor immunotherapy

The pursuit of innovative therapeutic strategies in oncology remains imperative, given the persistent global impact of cancer as a leading cause of mortality. Immunotherapy is regarded as one of the most promising techniques for systemic cancer therapies among the several therapeutic options available. Nevertheless, limited immune response rates and immune resistance urge us on an augmentation for therapeutic efficacy rather than sticking to conventional approaches. Ferroptosis, a novel reprogrammed cell death, is tightly correlated with the tumor immune environment and interferes with cancer progression. Highly mutant or metastasis-prone tumor cells are more susceptible to iron-dependent nonapoptotic cell death. Consequently, ferroptosis-induction therapies hold the promise of overcoming resistance to conventional treatments. The most prevalent post-transcriptional modification, RNA m6A modification, regulates the metabolic processes of targeted RNAs and is involved in numerous physiological and pathological processes. Aberrant m6A modification influences cell susceptibility to ferroptosis, as well as the expression of immune checkpoints. Clarifying the regulation of m6A modification on ferroptosis and its significance in tumor cell response will provide a distinct method for finding potential targets to enhance the effectiveness of immunotherapy. In this review, we comprehensively summarized regulatory characteristics of RNA m6A modification on ferroptosis and discussed the role of RNA m6A-mediated ferroptosis on immunotherapy, aiming to enhance the effectiveness of ferroptosis-sensitive immunotherapy as a treatment for immune-resistant malignancies.

METTL protein family: focusing on the occurrence, progression and treatment of cancer

Methyltransferase-like protein is a ubiquitous enzyme-like protein in the human body, with binding domains for nucleic acids, proteins and other small molecules, and plays an important role in a variety of biological behaviours in normal organisms and diseases, characterised by the presence of a methyltransferase-like structural domain and a structurally conserved SAM-binding domain formed by the seven-stranded β-fold structure in the center of the protein. With the deepening of research, the METTL protein family has been found to be abnormally expressed in a variety of tumor diseases, and the clarification of its relationship with tumor diseases can be used as a molecular therapeutic target and has an important role in the prognosis of tumors. In this paper, we review the structure, biological process, immunotherapy, drug-targeted therapy, and markers of the METTL protein family to provide new ideas for the diagnosis and treatment of tumors.

METTL Family in Healthy and Disease

Transcription, RNA splicing, RNA translation, and post-translational protein modification are fundamental processes of gene expression. Epigenetic modifications, such as DNA methylation, RNA modifications, and protein modifications, play a crucial role in regulating gene expression. The methyltransferase-like protein (METTL) family, a constituent of the 7-β-strand (7BS) methyltransferase subfamily, is broadly distributed across the cell nucleus, cytoplasm, and mitochondria. Members of the METTL family, through their S-adenosyl methionine (SAM) binding domain, can transfer methyl groups to DNA, RNA, or proteins, thereby impacting processes such as DNA replication, transcription, and mRNA translation, to participate in the maintenance of normal function or promote disease development. This review primarily examines the involvement of the METTL family in normal cell differentiation, the maintenance of mitochondrial function, and its association with tumor formation, the nervous system, and cardiovascular diseases. Notably, the METTL family is intricately linked to cellular translation, particularly in its regulation of translation factors. Members represent important molecules in disease development processes and are associated with patient immunity and tolerance to radiotherapy and chemotherapy. Moreover, future research directions could include the development of drugs or antibodies targeting its structural domains, and utilizing nanomaterials to carry miRNA corresponding to METTL family mRNA. Additionally, the precise mechanisms underlying the interactions between the METTL family and cellular translation factors remain to be clarified.

Targeting treatment resistance: unveiling the potential of RNA methylation regulators and TG-101,209 in pan-cancer neoadjuvant therapy

BACKGROUND

Tumor recurrence and mortality rates remain challenging in cancer patients despite comprehensive treatment. Neoadjuvant chemotherapy and immunotherapy aim to eliminate residual tumor cells, reducing the risk of recurrence. However, drug resistance during neoadjuvant therapy is a significant hurdle. Recent studies suggest a correlation between RNA methylation regulators (RMRs) and response to neoadjuvant therapy.

METHODS

Using a multi-center approach, we integrated advanced techniques such as single-cell transcriptomics, whole-genome sequencing, RNA sequencing, proteomics, machine learning, and in vivo/in vitro experiments. Analyzing pan-cancer cohorts, the association between neoadjuvant chemotherapy/immunotherapy effectiveness and RNA methylation using single-cell sequencing was investigated. Multi-omics analysis and machine learning algorithms identified genomic variations, transcriptional dysregulation, and prognostic relevance of RMRs, revealing distinct molecular subtypes guiding pan-cancer neoadjuvant therapy stratification.

RESULTS

Our analysis unveiled a strong link between neoadjuvant therapy efficacy and RNA methylation dynamics, supported by pan-cancer single-cell sequencing data. Integration of omics data and machine learning algorithms identified RMR genomic variations, transcriptional dysregulation, and prognostic implications in pan-cancer. High-RMR-expressing tumors displayed increased genomic alterations, an immunosuppressive microenvironment, poorer prognosis, and resistance to neoadjuvant therapy. Molecular investigations and in vivo/in vitro experiments have substantiated that the JAK inhibitor TG-101,209 exerts notable effects on the immune microenvironment of tumors, rendering high-RMR-expressing pan-cancer tumors, particularly in pancreatic cancer, more susceptible to chemotherapy and immunotherapy.

CONCLUSIONS

This study emphasizes the pivotal role of RMRs in pan-cancer neoadjuvant therapy, serving as predictive biomarkers for monitoring the tumor microenvironment, patient prognosis, and therapeutic response. Distinct molecular subtypes of RMRs aid individualized stratification in neoadjuvant therapy. Combining TG-101,209 adjuvant therapy presents a promising strategy to enhance the sensitivity of high-RMR-expressing tumors to chemotherapy and immunotherapy. However, further validation studies are necessary to fully understand the clinical utility of RNA methylation regulators and their impact on patient outcomes.

New insights into the spleen injury by mitochondrial dysfunction of chicken under polystyrene microplastics stress

Microplastics biological toxicity, environmental persistence and biological chemicals have been paid widespread attention. Microplastics exposed to chicken spleen injury of the specific mechanism is unclear. Thus, we randomly assigned chickens to 4 groups: C (normal diet), L-MPs (1 mg/L), M-MPs (10 mg/L), and H-MPs (100 mg/L), and assessed spleen damage after 42 d of exposure. Morphologically, the boundary between the red and white pulp of the spleen was blurred, along with the expansion of the white pulp. It was further speculated that microplastics induced mitochondrial dynamic homeostasis (Drp1 upgraded, Mfn1, Mfn2, and OPA1 reduced), and provoked the mitochondrial apoptotic pathway (Bcl-2/Bax decreased, cytc, caspase3, and caspase9 raised), resulting in redox imbalance and lipid peroxide accumulation (MDA increased, CAT, GSH, and T-AOC plummeted), and further stimulated ferroptosis (FTH1, GPX4, and SLC7A11 decreased). Here we explored the impact of polystyrene microplastics on the spleen, as well as the programmed death (apoptosis and ferroptosis) involved, and the regulative role of mitochondria in this process. This could be of significant importance in bridging the gap in laboratory research on microplastics-induced spleen injury in chicken.