Myeloproliferative neoplasms (MPN) are chronic haematological malignancies driven by mutations in JAK2, CALR, or MPL that cause constitutive JAK/STAT activation and uncontrolled myeloid proliferation. Interferon-alpha (IFN-α) can induce molecular remissions, yet responses are heterogeneous, frequently gradual and incomplete, highlighting the need for new, rationally designed therapeutic strategies. Preliminary work from our group has shown that IFN-α induces reactive oxygen species, endoplasmic reticulum (ER) stress, and activation of the unfolded protein response (UPR), revealing a stress-linked apoptotic vulnerability that can be enhanced by proteasome inhibition.
This project aims to define the molecular mechanisms that govern IFN-α responses in MPN and exploit these insights to develop rational combination therapies. We will characterise the transcriptomic and proteomic landscape of patient-derived haematopoietic stem and progenitor cells following IFN-α exposure, elucidate how IFN signalling regulates ER stress and UPR activation in JAK2 V617F-positive models, and evaluate synergistic therapeutic combinations in both cell lines and primary patient samples. Together, these studies will provide mechanistic insight into IFN-α–mediated stress signalling and establish preclinical proof-of-concept for combination strategies that enhance the selective eradication of JAK2-mutant clones in MPN
Myeloproliferative neoplasms are a group of chronic blood cancers that arise from clonal disorders of the myeloid stem cell compartment. The main subtypes, polycythaemia vera, essential thrombocythaemia, and myelofibrosis, are characterised by the overproduction of mature myeloid cells which leads to thrombosis, constitutional symptoms, and an increased risk of progression to bone marrow failure or secondary acute leukaemia. Activating mutations in JAK2, CALR, and MPL are present in the majority of patients and drive constant activation of the JAK/STAT pathway, promoting uncontrolled proliferation and survival of myeloid progenitors.
Current treatments are limited in their ability to modify disease progression. Hydroxycarbamide and JAK inhibitors effectively control blood counts and symptoms but do not reliably eradicate the malignant clone. Interferon alpha is an alternative therapy that can achieve molecular remissions, particularly in JAK2 mutant patients, although responses are variable and often require prolonged treatment for modest effects. The molecular basis of these differential responses remains poorly understood. There is therefore a pressing need for new rational therapeutic strategies that enhance the activity of interferon alpha and accelerate elimination of the malignant stem cell population.
Preliminary work has shown that interferon alpha induces oxidative and endoplasmic reticulum stress in JAK2 mutant cell models, leading to activation of the unfolded protein response and apoptosis. These findings suggest that interferon alpha not only drives proliferative exhaustion of mutant stem cells but also creates a stress sensitised state that can be therapeutically exploited. We have further demonstrated synergistic cytotoxicity when interferon alpha is combined with proteasome inhibition, identifying endoplasmic reticulum stress as a promising therapeutic vulnerability.
This project aims to define the molecular mechanisms that connect interferon alpha signalling to activation of the endoplasmic reticulum stress response and to translate these insights into new combination therapies for myeloproliferative neoplasms. It will be delivered through three complementary work packages.
The first work package will characterise the transcriptomic and proteomic landscape of haematopoietic stem and progenitor cells obtained from patients, comparing those exposed and unexposed to interferon alpha. Sorted cell populations will be analysed using RNA sequencing and mass spectrometry to identify genes and pathways regulated by interferon alpha in critical MPN cell populations at clinically relevant IFN dosing.
The second work package will define how IFN signalling leads to induction of the unfolded protein response in JAK2 mutant cells. This will include profiling of STAT1 phosphorylation and nuclear localisation, mapping STAT1 dependent chromatin binding, and validating key transcriptional regulators of endoplasmic reticulum stress using gene editing approaches.
The final work package will evaluate rational combination therapies with interferon alpha in cell line models and primary patient samples. These studies will assess effects on cell viability, apoptosis, and clonogenic potential to identify combinations that enhance depletion of the malignant clone.
Together these studies will provide new mechanistic insights into interferon alpha signalling in myeloproliferative neoplasms and will support the development of more effective combination approaches with disease modifying therapeutic strategies for this group of chronic blood cancers.