Chemical Tags on RNA Take Center Stage in Cancer’s Growth and Immune Evasion

Deep inside every cell, messenger RNA molecules carry chemical decorations that were long dismissed as molecular noise. The most abundant of these, a methyl group attached to the sixth nitrogen atom of adenosine—known as N6-methyladenosine, or m6A—has now emerged as one of the most consequential levers of gene control in human cancer. A comprehensive review published in Molecular Cancer by Tang and colleagues assembles the sprawling evidence that when this modification goes awry, it can fuel uncontrolled proliferation, drive metastasis, rewire tumor metabolism, shield cancer cells from programmed death, and even help tumors hide from the immune system. The authors argue that the m6A axis is no longer a curiosity of RNA biology but a clinically meaningful target, with small-molecule inhibitors and combination immunotherapies already moving through preclinical and early clinical development.

Unlike DNA methylation or histone modification, m6A operates directly on the transcript. It is installed by a writer complex whose catalytic core consists of METTL3 and METTL14, together with accessory factors such as WTAP and VIRMA, and it uses S-adenosylmethionine as the methyl donor. The mark can be removed by erasers—principally the demethylases FTO and ALKBH5—and its consequences are interpreted by reader proteins of the YTH domain family, including YTHDF1, YTHDF2, YTHDF3 and the YTHDC proteins, along with other RNA-binding proteins such as IGF2BP and hnRNPs. Because the methylation event is reversible and does not depend on a fixed sequence motif in the way DNA methylation does, it gives cells a fast, dynamic way to adjust the fate of thousands of transcripts at once. Through these players, m6A influences nearly every stage of an RNA molecule’s life: where it is spliced, whether it exits the nucleus, how long it survives, and how efficiently it is translated into protein.

The review’s central thesis is that dysregulated m6A methylation does not act on random genes. Instead, it converges on the core hallmarks of cancer. In many tumor types, elevated METTL3 stabilizes or boosts translation of oncogenic transcripts such as MYC, pushing cells into sustained proliferation. The same machinery can promote epithelial-mesenchymal transition, the program by which cancer cells become motile and invasive, by modifying transcripts for matrix metalloproteinases, TGF-β pathway components and other regulators of the extracellular matrix, thereby facilitating metastasis. Metabolic rewiring, another hallmark, is also under m6A control: the modification influences hypoxia signaling through HIF-1α and alters lipid and glucose metabolism genes, allowing tumors to adapt to the nutrient-poor, oxygen-starved conditions inside growing masses.

Equally striking is the modification’s grip on cell death pathways. The authors detail how m6A regulators modulate apoptosis—through transcripts such as BCL2, BAX and PUMA—autophagy, via targets including ULK1 and other ATG genes, and increasingly, ferroptosis, the iron-dependent form of cell death governed by factors such as SLC7A11 and GPX4. By tipping the balance of these transcripts, aberrant m6A labeling helps cancer cells survive stresses that would kill a normal cell, from chemotherapy-induced damage to oxidative assault. The review also emphasizes that the same regulator can play opposite roles depending on context: METTL3, for example, acts oncogenic in many carcinomas but has been reported to suppress tumor growth in others, a duality the authors attribute to differences in the target transcript landscape, tissue origin and cellular state.

Beyond the tumor cell itself, the review devotes substantial attention to the tumor immune microenvironment, an area where epitranscriptomics has produced some of its most clinically resonant findings. m6A modification shapes the function of dendritic cells, T cells, natural killer cells, tumor-associated macrophages, myeloid-derived suppressor cells and regulatory T cells, each of which must be precisely balanced for an effective anti-tumor response. When m6A regulators are perturbed, that balance tips toward immune evasion. The modification also directly controls the abundance of immune checkpoint molecules, including PD-L1, the target of a blockbuster class of immunotherapy drugs. In several cancer models, loss of the METTL3–METTL14 complex reduces PD-L1 expression and sensitizes tumors to immune attack, while in other settings erasers such as FTO exert the opposite effect on antitumor immunity—again underscoring the context dependence that pervades this field.

These mechanistic insights carry prognostic weight. The review surveys studies linking expression levels of individual writers, erasers and readers to overall survival, disease-specific survival, progression-free and recurrence-free survival across tumor types, from hepatocellular carcinoma and lung adenocarcinoma to colorectal and pancreatic cancers and acute myeloid leukemia. Aberrant expression of m6A regulators correlates with clinicopathological features such as tumor-node-metastasis stage, and multi-gene signatures built from these regulators show discriminative power in receiver operating characteristic analyses. Data resources such as The Cancer Genome Atlas have been instrumental here, allowing researchers to connect copy number variations and expression changes in m6A genes with patient outcomes. The authors suggest that m6A regulators could serve not only as biomarkers but as stratification tools that predict which patients will benefit from particular therapies, including immune checkpoint inhibitors.

Therapeutic resistance is another arena where the modification leaves fingerprints. The review describes how m6A dynamics influence responses to chemotherapy, targeted agents and radiotherapy by altering the stability of transcripts involved in drug efflux, DNA repair and stress survival. In some cancers, high METTL3 activity protects cells from cisplatin and other cytotoxic drugs; in others, demethylase activity confers resistance by stabilizing survival transcripts. Because immune checkpoint inhibitor response is also modulated through m6A-dependent control of checkpoint ligands and immune cell differentiation, the authors propose that combining m6A-targeted drugs with immunotherapy could convert immunologically cold tumors into responsive ones—a hypothesis supported by preclinical synergy data highlighted in the review.

Translating these observations into drugs is now a major focus. Small-molecule inhibitors of METTL3 have entered development, and inhibitors of FTO have shown activity in acute myeloid leukemia models by restoring tumor-suppressive transcript stability. The authors also discuss emerging modalities such as proteolysis-targeting chimeras, or PROTACs, which degrade rather than inhibit target proteins, and CRISPR-based systems using deactivated Cas13 that can be programmed to remove or install m6A marks at specific transcripts with single-gene precision. Detection technologies have advanced in parallel: methylated RNA immunoprecipitation sequencing, individual-nucleotide-resolution crosslinking methods, glyoxal- and nitrite-mediated sequencing, and single-base elongation- and ligation-based qPCR now allow researchers to map and quantify the modification with increasing resolution, while liquid chromatography-tandem mass spectrometry provides global quantification.

The review is candid about the obstacles standing between this biology and routine clinical practice. Delivering RNA-modifying drugs to the right cells remains the central challenge; lipid nanoparticles, the delivery platform behind mRNA vaccines, are one candidate solution, and small interfering RNA approaches are being explored to silence specific m6A regulators in tumors. Selectivity is another concern, since many m6A substrates are essential for normal tissue function, raising the specter of toxicity. The context-dependent, sometimes contradictory roles of individual regulators mean that therapies will likely need to be matched to tumors in which a given regulator acts oncogenically, reinforcing the push toward personalized oncology. The authors also note that non-coding RNAs—circular RNAs, long non-coding RNAs and microRNA precursors—carry their own m6A marks, adding layers of regulation that are only beginning to be mapped.

What emerges from this synthesis is a picture of cancer as a disease of information as much as of genes. The genome may be intact, but the chemical annotations on its transcripts can be rewritten in ways that produce a malignant phenotype. With the writer, eraser and reader machinery now genetically and pharmacologically tractable, and with immunotherapy providing a clinically validated partner, the m6A axis offers a rare combination of mechanistic depth and therapeutic proximity. The review by Tang and colleagues, published open access in Molecular Cancer, positions aberrant RNA methylation as a frontier where epitranscriptomics, tumor immunology and drug development converge—and where the next decade of cancer research is likely to unfold.

Subject of Research: The role of aberrant N6-methyladenosine RNA modification in cancer progression, immune evasion and therapy

Article Title: The role and clinical impact of aberrant m6A RNA modification in cancer

Article References: Tang, S., Xie, R., Fu, J., Wen, L., Guo, H., Tang, S., Liu, T., Hu, H., Ji, D., Jiang, X., Wang, J., Wang, C., Wang, S., Yang, Y., Liu, C., Yang, Y., Zhou, J., Yu, L., & Zhou, H. (2026). The role and clinical impact of aberrant m6A RNA modification in cancer. Molecular Cancer. https://doi.org/10.1186/s12943-026-02775-7

Image Credits: AI Generated

DOI: 10.1186/s12943-026-02775-7

Keywords: m6A, N6-methyladenosine, RNA modification, epitranscriptomics, METTL3, FTO, ALKBH5, cancer hallmarks, immune evasion, PD-L1, targeted therapy, tumor microenvironment