Peltonen, M. | Search bioRxiv

bioRxiv2025

Microtubule Inhibition Triggers MYC-Mediated Immunogenic Cell Death in Breast Cancer

Oncogenic MYC promotes cancer cell proliferation, metabolism, and death, while also driving immunosuppression in the tumour microenvironment, complicating immune-based therapies. To counter MYC-driven immune evasion while leveraging MYC-dependent synthetic lethality (MYC-SL), we identified microtubule-targeting agents, including eribulin, as potent inducers of immunogenic cell death in MYChigh triple-negative breast cancer (TNBC). A screen of 528 oncology compounds using damage-associated molecular pattern (DAMP) reporters revealed that microtubule inhibitors induced key DAMPs, including HMGB1 secretion, calreticulin exposure, and double-stranded DNA release, leading to gasdermin-E associated cell death in MYChigh TNBCs. Immune cell co-culture assays showed immune activation, and patient-derived explant cultures confirmed pro-inflammatory cytokine responses. In vivo, cell-free media from eribulin-treated MYChigh murine TNBCs enhanced tumour protection in vaccination models compared to MYC-knockdown controls, linking MYC-dependent DAMP release to immunogenicity. These findings highlight a dual-function therapeutic strategy: agents that selectively induce MYC-dependent immunogenic cell death can provide both targeted cytotoxicity and local immune stimulation, thereby addressing a key limitation of conventional chemotherapeutics, offering a new approach for MYC-driven cancers.

cancer biology↗

bioRxiv2025

Complex I Drives Glutamine-Dependent TCA Cycle to Support Viability of MYChigh Breast Cancer Cells

In many cancers, stably elevated MYC levels drive persistent and concerted activation of cell growth promoting anabolic programs and the cell cycle in ways that are distinct from normal cells. Therefore, synthetic-lethal strategies to target MYC reprograming of these pathways may identify new selective anticancer therapies for the treatment of MYChigh tumors. Here, we identify enhanced mitochondrial respiration as a hallmark of MYC overexpressing cancer cells. Mitochondrial respiration sustains the TCA cycle by regenerating NAD+ through complex I-mediated oxidation of NADH. Metabolic carbon tracing analysis revealed that MYC shifts TCA cycles carbon source from glucose to glutamine. Inhibition of the glutamine-fueled TCA cycle using NAD+-depleting complex I inhibitors resulted in MYC-dependent synthetic lethality in breast cancer cells. In mouse models of MYChigh tumors, persistent inhibition of tumor growth was achieved through combined inhibition of complex I and glutaminolysis. Our results suggest that the high respiration rate observed in MYChigh cells supports glutamine carbon-enriched TCA cycle, rendering MYChigh tumors selectively vulnerable to inhibitors of mitochondrial respiration and glutaminolysis.

cancer biology↗

bioRxiv2021

Clone expansion of mutation-driven clonal hematopoiesis is associated with aging and metabolic dysfunction in individuals with obesity

AimsHaematopoietic clones caused by somatic mutations with [≥]2% variant allele frequency (VAF), known as clonal haematopoiesis of indeterminate potential (CHIP), increase with age and have been linked to risk of haematological malignancies and cardiovascular disease. Recent observations suggest that smaller clones are also associated with adverse clinical outcomes. Our aims were to determine the prevalence of clonal haematopoiesis driven by clones of variable sizes, and to examine the development of clones over time in relation to age and metabolic dysregulation over up to 20 years in individuals with obesity. Methods and ResultsWe used an ultrasensitive single-molecule molecular inversion probe sequencing assay to identify clonal haematopoiesis driver mutations (CHDMs) in blood samples from individuals with obesity from the Swedish Obese Subjects study. In a single-timepoint dataset with samples from 1050 individuals, we identified 273 candidate CHDMs in 216 individuals, with VAF ranging from 0.01% to 31.15% and CHDM prevalence and clone sizes increasing with age. Longitudinal analysis over 20 years in CHDM-positive samples from 40 individuals showed that small clones can grow over time and become CHIP. VAF increased on average by 7% (range -4% to 27%) per year. Rate of clone growth was positively associated with insulin resistance (R=0.40, P=0.025) and low circulating levels of high-density lipoprotein-cholesterol (HDL-C) (R=-0.68, P=1.74E-05). ConclusionOur results show that haematopoietic clones can be detected and monitored before they become CHIP and indicate that insulin resistance and low HDL-C, well-established cardiovascular risk factors, are associated with clonal expansion in individuals with obesity. Translational perspectivesClonal haematopoiesis-driver mutations are somatic mutations in haematopoietic stem cells that lead to clones detectable in peripheral blood. Haematopoietic clones with a variant allele frequency (VAF) [≥]2%, known as clonal haematopoiesis of indeterminate potential (CHIP), are recognized as an independent cardiovascular risk factor. Here, we show that smaller clones are prevalent, and also correlate with age. Our longitudinal observations in individuals with obesity over 20 years showed that more than half of all clone-positive individuals show growing clones and clones with VAF <2% can grow and become CHIP. Importantly, clone growth was accelerated in individuals with insulin resistance and low high-density lipoprotein-cholesterol (HDL-C). Translational outlook 1: Haematopoietic clones can be detected and monitored before they become CHIP. Translational outlook 2: The association between insulin resistance and low HDL-C with growth of haematopoietic clones opens the possibility that treatments improving metabolism, such as weight loss, may reduce growth of clones and thereby cardiovascular risk. One Sentence SummaryIn obesity, the growth rate of mutation-driven haematopoietic clones increased with insulin resistance and low HDL-C, both known risk factors for cardiovascular disease.

genomics↗