m6A modification: a new avenue for anti-cancer therapy

Overexpression of METTL3 in lung cancer cells inhibits radiation-induced bystander effect

BACKGROUND

Radiation-induced bystander effects (RIBE) increase the complexity of radiation therapy (RT). m6A modification is implicated in ionizing radiation damage. This study aims to investigate the RIBE and the mechanism after promoting m6A modification.

METHODS

Lung adenocarcinoma cells were treated to simulate a hypoxic and 0.5 Gy RT environment. The expression levels of METTL3, METTL14, and YTDHF2 were quantified by RT-qPCR. Paracellular clonogenicity and the expression of 53BP1 and γ-H2AX were assessed by immunofluorescence. The proliferative rate was evaluated by CCK-8. Probes were employed to measure ROS levels. Micronucleus formation was evaluated microscopically. m6A-mRNA/lncRNA microarrays, MERIP-PCR, RT-qPCR, and ELISA were utilized to assess m6A modification levels and the expression of inflammatory factors.

RESULTS

m6A modification levels were significantly diminished under hypoxic, low-dose irradiation conditions. The overexpression of METTL3 in irradiated cancer cells resulted in increased clonogenicity and proliferation of paracellular cells, suppressed the rate of micronucleus formation, and reduced DNA damage by modulating the inflammatory response. m6A-mRNA/lncRNA microarray analyses revealed a higher correlation of inflammatory molecules NF-κB and TRAF6. Further analysis demonstrated that the m6A modification levels of inflammation-related factors such as IL-6, TLR4, NF-κB2, and TRAF6 were significantly up-regulated, while their mRNA expression levels were notably decreased. Additionally, the expression of IL-10 and TGF-β was significantly reduced, with no significant changes observed in IL-1 expression.

CONCLUSION

The overexpression of METTL3 facilitated m6A modification and mitigated the inflammatory response, thereby promoting paracellular cloning and proliferation, inhibiting micronucleus formation, alleviating DNA damage, and achieving the objective of suppression of RIBE.

Pulse Activation of Retinoic Acid Receptor Enhances Hematopoietic Stem Cell Homing by Controlling CXCR4 Membrane Presentation

The interplay between metabolic signaling and stem cell biology has gained increasing attention, though the underlying molecular mechanisms remain incompletely elucidated. In this study, we identify and characterize the role of adapalene (ADA), a retinoic acid receptor (RAR) agonist, in modulating the migration behavior of hematopoietic stem cells (HSCs). Our initial findings reveal that ADA treatment suppresses hematopoietic stem and progenitor cell (HSPC) mobilization induced by AMD3100 and G-CSF. Furthermore, we demonstrate that ADA treatment upregulates the surface expression of CXCR4 on HSPCs, resulting in enhanced chemotaxis towards CXCL12. Mechanistically, our study suggests that ADA enhances CXCR4 surface presentation without increasing CXCR4 mRNA levels, pointing towards a non-canonical role of RAR signaling in regulating intracellular trafficking of CXCR4. In vivo experiments show that ADA administration significantly enhances HSC homing efficiency. Additionally, competitive transplantation assays indicate a marked increase in donor chimerism following ADA treatment. These findings highlight the critical role of retinoic acid signaling in regulating HSC homing and suggest its potential for advancing novel HSC-based therapeutic strategies.

Molecular regulators of chemotaxis in human hematopoietic stem cells

Hematopoietic stem cells (HSCs), essential for lifelong blood cell regeneration, are clinically utilized to treat various hematological disorders. These cells originate in the aorta-gonad-mesonephros region, expand in the fetal liver, and mature in the bone marrow. Chemotaxis, involving gradient sensing, polarization, and migration, directs HSCs and is crucial for their homing and mobilization. The molecular regulation of HSC chemotaxis involves chemokines, chemokine receptors, signaling pathways, and cytoskeletal proteins. Recent advances in understanding these regulatory mechanisms have deepened insights into HSC development and hematopoiesis, offering new avenues for therapeutic innovations. Strategies including glucocorticoid receptor activation, modulation of histone acetylation, stimulation of nitric oxide signaling, and interference with m6A RNA modification have shown potential in enhancing CXCR4 expression, thereby improving the chemotactic response and homing capabilities of human HSCs. This review synthesizes current knowledge on the molecular regulation of human HSC chemotaxis and its implications for health and disease.

Emerging epigenetic insights into aging mechanisms and interventions

Epigenetic dysregulation emerges as a critical hallmark and driving force of aging. Although still an evolving field with much to explore, it has rapidly gained significance by providing valuable insights into the mechanisms of aging and potential therapeutic opportunities for age-related diseases. Recent years have witnessed remarkable strides in our understanding of the epigenetic landscape of aging, encompassing pivotal elements, such as DNA methylation, histone modifications, RNA modifications, and noncoding (nc) RNAs. Here, we review the latest discoveries that shed light on new epigenetic mechanisms and critical targets for predicting and intervening in aging and related disorders. Furthermore, we explore burgeoning interventions and exemplary clinical trials explicitly designed to foster healthy aging, while contemplating the potential ramifications of epigenetic influences.

Deciphering RNA m6 A regulation in aging: Perspectives on current advances and future directions

N6 -methyladenosine (m6 A) is a dynamic and reversible RNA modification that has emerged as a crucial player in the life cycle of RNA, thus playing a pivotal role in various biological processes. In recent years, the potential involvement of RNA m6 A modification in aging and age-related diseases has gained increasing attention, making it a promising target for understanding the molecular mechanisms underlying aging and developing new therapeutic strategies. This Perspective article will summarize the current advances in aging-related m6 A regulation, highlighting the most significant findings and their implications for our understanding of cellular senescence and aging, and the potential for targeting RNA m6 A regulation as a therapeutic strategy. We will also discuss the limitations and challenges in this field and provide insights into future research directions. By providing a comprehensive overview of the current state of the field, this Perspective article aims to facilitate further advances in our understanding of the molecular mechanisms underlying aging and to identify new therapeutic targets for aging-related diseases.