Combination Therapy Of Bcl-2 Inhibitor With Other Drugs In Patients With Acute Myeloid Leukemia:A Clinical And Bioinformatic Study

Objective:1.To estimate the efficacy and safety of combination regimens with B-cell lymphoma 2（Bcl-2）inhibitors among patients with acute myeloid leukemia（AML）,and identify the factors affecting the efficacy of patients.2.To explore the mechanisms associated with Venetoclax resistance and predict drugs that can reverse resistance.Methods:1.A retrospective study of the clinical data of 46 patients,including 16 patients with primary AML,14 patients with relapsed refractory AML,7 patients with minimal residual disease（MRD）after complete remission（CR）and 9 patients with secondary acute myeloid leukemia（sAML）and myelodysplastic syndrome（MDS）,who were received Bcl-2 inhibitor-based combinational therapy at the Department of Hematology of the First Hospital of Lanzhou University from March 2020 to December 2021.Among the 46 patients,34 received Venetoclax combined with azacitidine chemotherapy and 3 combined with FLT3 inhibitor;12 received Venetoclax combined with other chemotherapy regimens.The clinical data of the 46 patients were retrospectively analyzed to assess the treatment efficacy and safety,and to analyze the factors affecting the efficacy.2.We compared the RNA-sequencing profiles from high-throughput gene expression databases between parental cells and venetoclax resistant cells and further screened for common differential expressed genes（DEGs）using R software and related packages.Subsequently,we performed enrichment analysis,constructed protein-protein interaction networks,obtained hub genes,predicted differential gene transcription factors,explored drug resistance-related pathways and regulatory mechanisms,and predicted drugs that could reverse resistance through public databases.Results:1.Assessment of the efficacy of Bcl-2 inhibitors in combination with chemotherapy in AML（1）The overall response rate（ORR）was 69%in the 16 primary elderly AML patients;57%in the 14 patients with relapsed refractory AML,78%in the 6 patients with sAML and 3 patients with MDS and CR_MRD-was obtained in 6 of 7（86%）CR_MRD+cases.（2）Clinical traits such as age,gender,cytogenetic risk stratification,prognostic risk classification,history of hypomethylating agents,and gene mutations were not significantly correlated with complete remission or complete remission with incomplete hematologic recovery and ORR,and the differences were not found to be statistically significant.（3）The major adverse effects of Bcl-2 inhibitor-based combination therapy was myelosuppression.Adverse effects were tolerated with appropriate symptomatic supportive therapy.2.A bioinformatic-based study of drug resistance to Bcl-2 inhibitor in AMLForty-eight common DEGs are mainly involved in biological processes such as mRNA metabolic processes,translation initiation,nonsense-mediated mRNA decay,and are mainly related to signaling pathways such as ribosomes and cellular senescence.Furthermore,we constructed PPI network and screened for 10 hub genes associated with venetoclax resistance.To explore the potential coregulatory relationships,transcription factors were screened out.JUND can be involved in drug resistance both as gene and as transcription factor.A drug prediction analysis identified 10 drug candidates including decitabine and sorafenib that may improve Venetoclax resistance.Conclusions:1.Assessment of the efficacy of Bcl-2 inhibitors in combination with chemotherapy in AML（1）Bcl-2-based combination therapy has shown positive efficacy in AML patients,especially in CR_MRD+and primary AML patients demonstrating outstanding efficacy.（2）Conventional adverse effect factors,such as age and prognostic risk classification,did not correlate significantly with the efficacy of Bcl-2 inhibitor-based combination therapy.（3）Bone marrow suppression is the most common adverse effect of Bcl-2-based combination therapy2.A bioinformatic-based study of drug resistance to Bcl-2 inhibitor in AML（1）Forty-eight differentially expressed genes were obtained in MOLM13 and MV4-11 parental cells and Venetoclax-resistant cells and they are mainly involved in biological processes such as mRNA metabolic processes,translation initiation,nonsense-mediated mRNA decay,and are mainly related to signaling pathways such as ribosomes and cellular senescence.（2）With 20 predicted transcription factors,of which CDKN1A as a target gene is regulated by almost all predicted transcription factors,JUND can be involved in drug resistance both as gene and as transcription factor.（3）Drug prediction analysis showed that sorafenib,decitabine and other drugs can act on common DEGs and can reverse Venetoclax resistance.