Biology subjects

Franich, R.

Publications and source records attributed to Franich, R..

3 recordsLinked to original sources

bioRxiv2026

Menin regulates oncogenic cell identity transcriptional networks in multiple myeloma

Multiple myeloma (MM) is a heterogenous cancer that remains mostly incurable. A unifying feature of MM cells is a highly interconnected network of transcription factors and co-factors that coordinate the activity of super-enhancers to enforce myeloma cell identity. Targeting this network offers a promising avenue for therapeutic intervention across genetically diverse myeloma sub-types. Using integrated molecular and functional genomic approaches we identified Menin as a key driver of oncogenic gene expression in MM cells. Menin and its co-factor KMT2A bind at super-enhancers and maintain expression of essential myeloma genes, including IRF4. We demonstrate that Menin inhibitors, which have recently been approved for treatment of acute myeloid leukaemia, are highly active in myeloma cell lines and in vivo models. Combining Menin inhibitors with other super-enhancer targeting therapies such EP300/CREBBP inhibitors or immunomodulatory drugs (IMiDs) overcomes epigenetic plasticity in cells resistant to single agent treatment.

Cancer Biology↗

bioRxiv2024

Inhibition of heme biosynthesis triggers cuproptosis in acute myeloid leukaemia.

The ubiquitous metabolite heme has diverse enzymatic and signalling functions in most mammalian cells. Cells can salvage heme from the extracellular environment or synthesise heme de novo from succinyl-CoA and glycine through a series of 8 enzymatic reactions catalysed by heme biosynthesis enzymes (HBEs) localised in the mitochondria and the cytosol1,2. Through integrated analyses of mouse models, human cell lines and primary patient samples, we identify de novo heme biosynthesis as a selective dependency in acute myeloid leukaemia (AML). The dependency is underpinned by a propensity of AML cells, and especially leukaemic stem cells (LSCs) to downregulate HBEs. The resultant low heme state upregulates self-renewal genes via the heme sensing transcription factor BACH1, but also places leukaemia cells on the threshold of heme starvation. Genetic or pharmacological inhibition of HBEs induces cuproptosis, a form of programmed cell death caused by copper accumulation and oligomerisation of lipoylated proteins3. Moreover, we identify pathways that are synthetic lethal with heme biosynthesis, including glycolysis, which can be leveraged for combination strategies. Altogether, our work uncovers a heme rheostat that controls gene expression and drug sensitivity in AML and implicates HBE inhibition as a novel cuproptosis trigger.

cancer biology↗

bioRxiv2022

Inhibition of mutant IDH1 promotes cycling of acute myeloid leukemia stem cells

Acute myeloid leukemias (AML) are comprised of multiple cell types with distinct capabilities to propagate the disease and resist therapy. Approximately 20% of AML patients carry gain- of-function mutations in IDH1 or IDH2 that result in over-production of the onco-metabolite 2-HG. Although IDH inhibitors can induce complete morphological remission, almost all patients eventually relapse. Analysis of clinical samples suggests that a population of IDH mutant cells is able to persist during treatment eventually acquiring 2-HG independence and drug resistance. Herein we characterized the molecular and cellular responses to the clinical IDH1 inhibitor AG-120 at high resolution using a novel multi-allelic mouse model of IDH1 mutant AML. We demonstrate that AG-120 exerts cell type-dependent effects on leukemic cells promoting delayed disease regression. Although IDH1 inhibition alone was not able to fully eradicate the disease, we uncovered that it increases cycling of rare leukemic stem cells and triggers transcriptional upregulation of the pyrimidine salvage pathway. Accordingly, AG-120 sensitized IDH1 mutant AML to azacitidine with the combination of AG-120 and azacitidine showing vastly improved efficacy in vivo. Our data highlight the impact of non- genetic heterogeneity on treatment response and provide mechanistic rationale for a drug combination that is being tested in clinical trials. STATEMENT OF SIGNIFICANCEInhibition of mutant IDH1 in AML is insufficient to eliminate the disease but promotes proliferation of quiescent leukemic stem cells. Our data provide a mechanistic explanation for the observed synergy between IDH inhibitors and azacitidine and suggest that IDH inhibitors may also synergize with other drugs that preferentially target actively dividing cells.

cancer biology↗