摘要:
Constitutive JAK/STAT pathway activation is crucial in the pathogenesis of BCR::ABL1-negative myeloproliferative neoplasms (MPN), but has not yet been linked to interferon (IFN)-gamma signaling and tumor microenvironment. Human JAK2 V617F-mutated cell lines, 265 bone marrow biopsies (BMB) of two MPN cohorts, and 50 non-neoplastic BMB, revealed an intrinsic activation of IFN-gamma signaling, which was confirmed by public RNA expression data. In vitro analysis of JAK2-mutated cell lines showed an activation of IFN-gamma signaling pathway in the absence of IFN-gamma in the cell supernatants. In addition, a heterogeneous, but increased expression of IFN-gamma signaling components was found in BMB of JAK2-mutated samples with the highest expression in lymphocytes and monocytes, accompanied by increased tumor infiltrating lymphocytes (TIL). Unsupervised clustering identified a prognostic favorable cluster in both patient cohorts characterized by augmented IFN-gamma signaling and TILs. This cluster was enriched with JAK2-mutated, JAK-inhibition naive MPN, mainly essential thrombocythemia and polycythemia vera with mild bone marrow fibrosis. Moreover, in silico data confirmed the link between JAK2 mutations and increased IFN-gamma signaling. Multivariate Cox regression revealed TILs to be the strongest prognostic marker. In conclusion, JAK2-mutated MPN exhibit an intrinsic activation of IFN-gamma signaling associated with changes in the BM TME and patients' *** activation of the Janus kinases and signal transducer and activator of transcription (JAK/STAT) signaling pathway mainly mediated by mutations in the JAK2, CALR and MPL genes in pluripotent hematopoietic stem cells (HSC) is crucial for the pathogenesis of BCR::ABL1-negative myeloproliferative neoplasms (MPN). Despite the activation of JAK/STAT signaling and its influence on the proliferation of malignant cells is well studied in patient samples and JAK2- and CALR-mutated cell systems, there exists li