"Beyond the Genetic Blueprint: Disrupting the Epitranscriptomic Code in Myeloproliferative Neoplasms"

Philadelphia chromosome-negative myeloproliferative neoplasms (MPNs), including polycythemia vera, essential thrombocythemia, and primary myelofibrosis, are driven by canonical JAK2, CALR, or MPL mutations that constitutively activate JAK-STAT signaling. Yet, the clinical reality reveals a sobering paradox: JAK inhibitors modify symptoms but fail to eradicate the malignant clone, reduce mutant allele burden, or reverse fibrosis. This therapeutic ceiling suggests that oncogenic signaling alone cannot explain disease persistence, progression, or transformation to secondary acute myeloid leukemia. Emerging evidence iMPLicates epitranscriptomics, the dynamic chemical modification of RNA, as an underexplored but fundamentally critical layer of regulatory control in MPN pathobiology. RNA modifications, particularly N6-methyladenosine (m⁶A), are orchestrated by specialized "writers" (METTL3/METTL14), "erasers" (FTO/ALKBH5), and "readers" (YTHDF/IGF2BP proteins) that collectively govern transcript stability, translation, splicing, and localization. In MPNs, this machinery is transcriptionally dysregulated rather than mutated, creating a feed-forward oncogenic loop wherein JAK-STAT signaling upregulates m⁶A writers, which in turn stabilize and translate key oncogenes (MYC, BCL2, JAK2 itself) while suppressing tumor suppressors. Moreover, metabolic shifts during disease progression, particularly IDH1/2 mutations that generate the oncometabolite 2-hydroxyglutarate, may alter α-ketoglutarate-dependent RNA demethylase activity and thereby provide a plausible link between metabolic remodeling and epitranscriptomic dysregulation during leukemic transformation. This review synthesizes the biological rationale, mechanistic evidence, and emerging therapeutic strategies targeting epitranscriptomic regulators in MPNs. We propose that epitranscriptomic remodeling represents both a driver of clonal fitness and a therapeutic vulnerability, positioning RNA modification pathways as promising frontiers for disease-modifying intervention in these recalcitrant malignancies.