摘要
Background:Heterogeneity of leukemia-initiating cells(LICs)is a major obstacle in acute myeloid leukemia(AML)therapy.Accumulated evidence indicates that the coexistence of multiple types of LICs with different pathogenicity in the same individual is a common feature in AML.However,the functional heterogeneity including the drug response of coexistent LICs remains unclear.Therefore,this study aimed to clarify the intra-heterogeneity in LICs that can help predict leukemia behavior and develop more effective treatments.Methods:Spleen cells from the primary Setd2^(-/-)-AML mouse were transplanted into C57BL/6 recipient mice to generate a transplantable model.Flow cytometry was used to analyze the immunophenotype of the leukemic mice.Whole-genome sequencing was conducted to detect secondary hits responsible for leukemia transformation.A serial transplantation assay was used to determine the self-renewal potential of Setd2^(-/-)-AML cells.A limiting-dilution assay was performed to identify the LIC frequency in different subsets of leukemia cells.Bulk and single-cell RNA sequencing were performed to analyze the transcriptional heterogeneity of LICs.Small molecular inhibitor screening and in vivo drug treatment were employed to clarify the difference in drug response between the different subsets of LICs.Results:In this study,we observed an aged Setd2^(-/-)mouse developing AML with co-mutation of Nras^(G12S) and Braf^(K520E).Further investigation identified two types of LICs residing in the c-Kit^(+)B220^(+)Mac-1^(-)and c-Kit^(+)B220^(+)Mac-1^(+)subsets,respectively.In vivo transplantation assay disclosed the heterogeneity in differentiation between the coexistent LICs.Besides,an intrinsic doxorubicinresistant transcriptional signature was uncovered in c-Kit^(+)B220^(+)Mac-1^(+)cells.Indeed,doxorubicin plus cytarabine(DA),the standard chemotherapeutic regimen used in AML treatment,could specifically kill c-Kit^(+)B220^(+)Mac-1^(−)cells,but it hardly affected c-Kit^(+)B220^(+)Mac-1^(+)cells.Transcriptome analysis unveil
基金
National Natural Science Foundation of China,Grant/Award Numbers:81670149,81870102
Samuel Waxman Cancer Research Foundation
Foundation of Key Laboratory of Veterinary Biotechnology,Grant/Award Number:shklab202008。
