Mutation Patterns Predict Drug Sensitivity in Acute Myeloid Leukemia.

The inherent genetic heterogeneity of acute myeloid leukemia (AML) has challenged the development of precise and effective therapies. The objective of this study was to elucidate the genomic basis of drug resistance or sensitivity, identify signatures for drug response prediction, and provide resources to the research community. We performed targeted sequencing, high-throughput drug screening, and single-cell genomic profiling on leukemia cell samples derived from patients with AML. Statistical approaches and machine learning models were applied to identify signatures for drug response prediction. We also integrated large public datasets to understand the co-occurring mutation patterns and further investigated the mutation profiles in the single cells. The features revealed in the co-occurring or mutual exclusivity pattern were further subjected to machine learning models. We detected genetic signatures associated with sensitivity or resistance to specific agents, and identified five co-occurring mutation groups. The application of single-cell genomic sequencing unveiled the co-occurrence of variants at the individual cell level, highlighting the presence of distinct subclones within patients with AML. Using the mutation pattern for drug response prediction demonstrates high accuracy in predicting sensitivity to some drug classes, such as MEK inhibitors for RAS-mutated leukemia. Our study highlights the importance of considering the gene mutation patterns for the prediction of drug response in AML. It provides a framework for categorizing patients with AML by mutations that enable drug sensitivity prediction.

Qin G ，Dai J ，Chien S ，Martins TJ ，Loera B ，Nguyen QH ，Oakes ML ，Tercan B ，Aguilar B ，Hagen L ，McCune J ，Gelinas R ，Monnat RJ Jr ，Shmulevich I ，Becker PS ... -  《-》

Clonal Selection with RAS Pathway Activation Mediates Secondary Clinical Resistance to Selective FLT3 Inhibition in Acute Myeloid Leukemia.

Gilteritinib is a potent and selective FLT3 kinase inhibitor with single-agent clinical efficacy in relapsed/refractory FLT3-mutated acute myeloid leukemia (AML). In this context, however, gilteritinib is not curative, and response duration is limited by the development of secondary resistance. To evaluate resistance mechanisms, we analyzed baseline and progression samples from patients treated on clinical trials of gilteritinib. Targeted next-generation sequencing at the time of AML progression on gilteritinib identified treatment-emergent mutations that activate RAS/MAPK pathway signaling, most commonly in NRAS or KRAS. Less frequently, secondary FLT3-F691L gatekeeper mutations or BCR-ABL1 fusions were identified at progression. Single-cell targeted DNA sequencing revealed diverse patterns of clonal selection and evolution in response to FLT3 inhibition, including the emergence of RAS mutations in FLT3-mutated subclones, the expansion of alternative wild-type FLT3 subclones, or both patterns simultaneously. These data illustrate dynamic and complex changes in clonal architecture underlying response and resistance to mutation-selective tyrosine kinase inhibitor therapy in AML. SIGNIFICANCE: Comprehensive serial genotyping of AML specimens from patients treated with the selective FLT3 inhibitor gilteritinib demonstrates that complex, heterogeneous patterns of clonal selection and evolution mediate clinical resistance to tyrosine kinase inhibition in FLT3-mutated AML. Our data support the development of combinatorial targeted therapeutic approaches for advanced AML.See related commentary by Wei and Roberts, p. 998.This article is highlighted in the In This Issue feature, p. 983.

McMahon CM ，Ferng T ，Canaani J ，Wang ES ，Morrissette JJD ，Eastburn DJ ，Pellegrino M ，Durruthy-Durruthy R ，Watt CD ，Asthana S ，Lasater EA ，DeFilippis R ，Peretz CAC ，McGary LHF ，Deihimi S ，Logan AC ，Luger SM ，Shah NP ，Carroll M ，Smith CC ，Perl AE ... -  《-》

Genetic biomarkers of drug resistance: A compass of prognosis and targeted therapy in acute myeloid leukemia.

Acute myeloid leukemia (AML) is a highly aggressive hematological malignancy with complex heterogenous genetic and biological nature. Thus, prognostic prediction and targeted therapies might contribute to better chemotherapeutic response. However, the emergence of multidrug resistance (MDR) markedly impedes chemotherapeutic efficacy and dictates poor prognosis. Therefore, prior evaluation of chemoresistance is of great importance in therapeutic decision making and prognosis. In recent years, preclinical studies on chemoresistance have unveiled a compendium of underlying molecular basis, which facilitated the development of targetable small molecules. Furthermore, routing genomic sequencing has identified various genomic aberrations driving cellular response during the course of therapeutic treatment through adaptive mechanisms of drug resistance, some of which serve as prognostic biomarkers in risk stratification. However, the underlying mechanisms of MDR have challenged the certainty of the prognostic significance of some mutations. This review aims to provide a comprehensive understanding of the role of MDR in therapeutic decision making and prognostic prediction in AML. We present an updated genetic landscape of the predominant mechanisms of drug resistance with novel targeted therapies and potential prognostic biomarkers from preclinical and clinical chemoresistance studies in AML. We particularly highlight the unfolded protein response (UPR) that has emerged as a critical regulatory pathway in chemoresistance of AML with promising therapeutic horizon. Futhermore, we outline the most prevalent mutations associated with mechanisms of chemoresistance and delineate the future directions to improve the current prognostic tools. The molecular analysis of chemoresistance integrated with genetic profiling will facilitate decision making towards personalized prognostic prediction and enhanced therapeutic efficacy.

Long L ，Assaraf YG ，Lei ZN ，Peng H ，Yang L ，Chen ZS ，Ren S ... -  《-》

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

Wang F ，Morita K ，DiNardo CD ，Furudate K ，Tanaka T ，Yan Y ，Patel KP ，MacBeth KJ ，Wu B ，Liu G ，Frattini M ，Matthews JA ，Little LD ，Gumbs C ，Song X ，Zhang J ，Thompson EJ ，Kadia TM ，Garcia-Manero G ，Jabbour E ，Ravandi F ，Bhalla KN ，Konopleva M ，Kantarjian HM ，Andrew Futreal P ，Takahashi K ... -  《-》

Reversal of acquired drug resistance in FLT3-mutated acute myeloid leukemia cells via distinct drug combination strategies.

FMS-like tyrosine kinase-3 (FLT3) internal tandem duplication (FLT3-ITD) mutations are common in patients with acute myeloid leukemia (AML). These patients regularly develop resistance to FLT3 inhibitors suggesting that targeted combination drug strategies are needed to enhance AML therapy efficacy. Acquired point mutations of FLT3-ITD gene were screened using cDNA-based sequencing approach in vitro sorafenib-resistant cells, which were developed by long-term exposure of Ba/F3-ITD to increasing doses of sorafenib, and in FLT3-ITD mutated AML patients, who developed relapse following sorafenib therapy. Drug effects (e.g., proliferation inhibition, apoptosis induction, and changes in signal transduction protein expression) were assessed in AML cells harboring the point mutations in vitro and in FLT3-ITD-mutated AML patient samples. We identified several acquired point mutations in the tyrosine kinase domains (TKD) of the FLT3 gene in sorafenib-resistant murine leukemia cell line carrying human FLT3-ITD mutations, which were also detected in two of four sorafenib-resistant patient samples. Engineering these point mutations into Ba/F3-ITD cells generated sublines that demonstrated varying degrees of sorafenib [a type II tyrosine kinase inhibitor (TKI)] resistance. A similar pattern of resistance could be observed by exposing these sublines to the other type II TKIs AC220 and MLN518. However, these sublines retained sensitivity to the type I TKIs PKC412 or crenolanib. The combination of crenolanib with sorafenib demonstrated marked cytotoxic effects in all of the sorafenib-resistant sublines. These combination strategies could be clinically important in reversing acquired resistance to FLT3 inhibition in AML.

Zhang W ，Gao C ，Konopleva M ，Chen Y ，Jacamo RO ，Borthakur G ，Cortes JE ，Ravandi F ，Ramachandran A ，Andreeff M ... -  《-》