Biology subjects

DiNardo, C.

Publications and source records attributed to DiNardo, C..

3 recordsLinked to original sources

bioRxiv2020

Leukemia stemness and co-occurring mutations drive resistance to IDH inhibitors in acute myeloid leukemia

Allosteric inhibitors of mutant IDH1 or IDH2 induce terminal differentiation of the mutant leukemic blasts and provide durable clinical responses in approximately 40% of acute myeloid leukemia (AML) patients with the mutations. However, primary resistance and acquired resistance to the drugs are major clinical issues. To understand the molecular underpinnings of clinical resistance to IDH inhibitors (IDHi), we performed multipronged genomic analyses (DNA sequencing, RNA sequencing and cytosine methylation profiling) in longitudinally collected specimens from 68 IDH1- or IDH2-mutant AML patients treated with the inhibitors. The analysis revealed that leukemia stemness is a major driver of primary resistance to IDHi, whereas selection of mutations in RUNX1/CEBPA or RAS-RTK pathway genes was the main driver of acquired resistance to IDHi, along with BCOR, homologous IDH gene, and TET2. These data suggest that targeting stemness and certain high-risk co-occurring mutations may overcome resistance to IDHi in AML.

cancer biology↗

bioRxiv2020

Clinicopathologic Correlates and Natural History of Atypical Chronic Myeloid Leukemia

There is limited data on the clonal mechanisms underlying leukemogenesis, prognostic factors, and optimal therapy for atypical chronic myeloid leukemia (aCML). We evaluated the clinicopathological features, outcomes, and responses to therapy of 65 patients with aCML. Median age was 67 years (range 46-89). The most frequently mutated genes included ASXL1 (83%), SRSF2 (68%), and SETBP1 (58%). Mutations in SETBP1, SRSF2, TET2, and GATA2 tended to appear within dominant clones, with frequent SRSF2 and SETBP1 codominance, while other RAS pathway mutations were more likely to appear as minor clones. Acquisition of new, previously undetectable mutations at transformation was observed in 63% of evaluable patients, the most common involving signaling pathway mutations. Hypomethylating agents were associated with the highest response rates and duration. With a median overall survival of 25 months (95% CI 20-30), intensive chemotherapy was associated with worse OS than other treatment modalities, and allogeneic stem cell transplantation was the only therapy associated with improved outcomes (HR 0.044, 95% CI 0.035-0.593, p=0.007). Age, platelet count, BM blast percentage, and serum LDH levels were independent predictors of survival and were integrated in a multivariable model which allowed to predict 1-year and 3-year survival.

cancer biology↗

bioRxiv2020

Polygenic mutations model the pleiotropic disease of Fanconi Anemia

Fanconi Anemia (FA) is a prototypic genetic disease signified by heterogeneous phenotypes including cancer, bone marrow failure, short stature, congenital abnormalities, infertility, sub-mendelian birth rate, genome instability and high cellular sensitivity to cancer therapeutics1-4. Clinical diagnosis is confirmed by identifying biallelic, homo- or hemizygous mutations in any one of twenty-three FANC genes1,5. Puzzlingly, inactivation of one single Fanc gene in mice fails to faithfully model the human disease manifestations6-8. We here delineate a preclinical Fanc mouse model with mutations in two genes, Fancd1/Brca2 and Fanco/Rad51c, that recapitulates the severity and heterogeneity of the human disease manifestations including death by cancer at young age. Surprisingly, these grave phenotypes cannot be explained by the sum of phenotypes seen in mice with single gene inactivation, which are unremarkable. In contrast to expectations from classic epistasis analysis of genetic pathways, the data instead reveal an unexpected functional synergism of polygenic Fanc mutations. Importantly in humans, whole exome sequencing uncovers that FANC co-mutation in addition to the identified inactivating FANC gene mutation is a frequent event in FA patients. Collectively, the data establish a concept of polygenic stress as an important contributor to disease manifestations, with implications for molecular diagnostics.

cancer biology↗