Biological and Clinical Implications of the Mutational Landscape in Myeloproliferative Neoplasms

Clinical manifestations in MPNs include constitutional symptoms, microvascular disorders, thrombosis and bleeding, splenomegaly secondary to extramedullary hematopoiesis, cytopenia-related symptoms, and progression to acute myeloid leukemia. Dysregulation of the JAK/STAT pathway is the unifying mechanistic hallmark of MPNs and is guided by somatic mutations in driver genes including JAK2, CALR, and MPL. Patients lacking one of these mutations are referred to as triple-negative (TN). Additional mutations in myeloid neoplasm-associated genes (ASXL1, EXH2, SRSF2, U2AF1, IDH1, and IDH2) have also been identified, with established prognostic relevance, particularly in PMF. The increasing knowledge of MPN biology has led to the development of integrated clinical and molecular prognostic scores that allow a more refined stratification. Recently, the therapeutic landscape of MPNs has been revolutionized by the introduction of potent, selective JAK inhibitors (ruxolitinib, fedratinib), that proved effective in controlling disease-related symptoms and splenomegaly, yet leaving unmet critical needs, owing to the lack of disease-modifying activity.

Nowadays, many steps forward have been made on MPNs. However, there is still much work to do. The category of patients with TN MPNs is an unmet diagnostic need: why is the prognosis so poor for TN Myelofibrosis and the outcome better for TN Essential Thrombocythemia patients? What genetic abnormalities do they hide? Are these MPNs, or some other diseases? The phenomenon of loss of sensitivity to ruxolitinib is a challenging therapeutic dilemma and is known to associate with clonal complexity detected at the time of loss of response. Will we be able to predict it in advance and select the best candidates for alternative treatments? These few examples will hopefully reinforce the interest and promote efforts of the scientific community to reach a full understanding and satisfactory treatment of MPNs.

The aim of this Research Topic is to focus on the mutational landscape of MPNs, considering both biological and clinical implications. Findings of interest concerning mutational profile, molecular pathogenesis, animal models, novel treatment approaches, the role of allogeneic hematopoietic stem cell transplantation, and prognosis will be considered for this collection. Original Research, Case Reports, Reviews, and Mini-Reviews are welcomed.

Please note: manuscripts consisting solely of bioinformatics or computational analysis of public genomic or transcriptomic databases which are not accompanied by validation (independent cohort or biological validation in vitro or in vivo) are out of scope for this section and will not be accepted as part of this Research Topic.