Objective Acute myeloid leukemia(AML)is an aggressive hematological malignancy characterized by abnormal myeloid blast expansion.Recent studies have demonstrated that circular RNAs play a role in AML pathogenesis.In t...Objective Acute myeloid leukemia(AML)is an aggressive hematological malignancy characterized by abnormal myeloid blast expansion.Recent studies have demonstrated that circular RNAs play a role in AML pathogenesis.In this study,we aimed to investigate the clinical significance of circ_0012152 in AML and elucidate its underlying molecular mechanism in the pathogenesis of this condition.Methods Circ_0012152 expression was detected by quantitative real-time polymerase chain reaction in samples obtained from 247 patients with AML and 40 healthy controls.A systematic analysis of clinical characteristics and prognostic factors was also conducted.Cell growth was assessed using the Cell Counting Kit-8(CCK-8)assay,and apoptosis and cell cycle progression were evaluated by flow cytometry.Moreover,RNA pull-down was performed to identify target microRNAs,and transcriptome RNA sequencing and bioinformatics analyses were utilized to identify downstream mRNA targets.Results Circ_0012152 was significantly upregulated in samples from patients with AML and served as an independent adverse prognostic factor for overall survival(OS)(hazard ratio:2.357;95%confidence interval 1.258–4.415).The circ_0012152 knockdown reduced cell growth,increased apoptosis,and inhibited cell cycle progression in AML cell lines.RNA pull-down and sequencing identified miR-652-3p as a target microRNA of circ_0012152.Cell growth inhibition by circ_0012152 knockdown was significantly relieved by miR-652-3p inhibitors.We suggested that miR-652-3p targeted SOX4,as the decrease in SOX4 expression resulting from circ_0012152 knockdown was upregulated by miR-652-3p inhibitors in AML cells.Conclusion Circ_0012152 is an independent poor prognostic factor for OS in AML,and it promotes AML cell growth by upregulating SOX4 through miR-652-3p.展开更多
BACKGROUND The Coexistence of myeloid and lymphoid malignancies is rare.Myeloid leukemia occurs more frequently as a secondary event in patients receiving chemotherapy agents for lymphoid malignancies.Synchronous diag...BACKGROUND The Coexistence of myeloid and lymphoid malignancies is rare.Myeloid leukemia occurs more frequently as a secondary event in patients receiving chemotherapy agents for lymphoid malignancies.Synchronous diagnoses of diffuse large B-cell lymphoma(DLBCL),acute myeloid leukemia(AML),and untreated lymphoplasmacytic lymphoma/Waldenström macroglobulinemia(LPL/WM)in the same patient have not been reported.Here we report one such case.CASE SUMMARY An 89-year-old man had a chest wall mass histopathologically diagnosed as DLBCL.The bone marrow and peripheral blood contained two groups of cells.One group of cells fulfilled the criteria of AML,and the other revealed the features of small B lymphocytic proliferative disorder,which we considered LPL/WM.Multiple chromosomal or genetic changes were detected in bone marrow mononuclear cells,including ATM deletion,CCND1 amplification,mutations of MYD88(L265P)and TP53,WT1 overexpression,and fusion gene of BIRC2-ARAP1,as well as complex chromosomal abnormalities.The patient refused chemotherapy because of old age and died of pneumonia 1 mo after the final diagnosis.CONCLUSION The coexistence of DLBCL,AML,and untreated LPL/WM in the same patient is extremely rare,which probably results from multiple steps of genetic abnormalities.Asymptomatic LPL/WM might have occurred first,then myelodysplastic syndromerelated AML developed,and finally aggressive DLBCL arose.Therefore,medical staff should pay attention to this rare phenomenon to avoid misdiagnoses.展开更多
FMS-like tyrosine kinase 3(FLT3) is classified as a type Ⅲ receptor tyrosine kinase, which exerts a key role in regulation of normal hematopoiesis. FLT3 mutation is the most common genetic mutation in acute myeloid l...FMS-like tyrosine kinase 3(FLT3) is classified as a type Ⅲ receptor tyrosine kinase, which exerts a key role in regulation of normal hematopoiesis. FLT3 mutation is the most common genetic mutation in acute myeloid leukemia(AML) and represents an attractive therapeutic target. Targeted therapy with FLT3 inhibitors in AML shows modest promising results in current ongoing clinical trials suggesting the complexity of FLT3 targeting in therapeutics. Importantly, resistance to FLT3 inhibitors may explain the lack of overwhelming response and could obstruct the successful treatment for AML. Here, we summarize the molecular mechanisms of primary resistance and acquired resistance to FLT3 inhibitors and discuss the strategies to circumvent the emergency of drug resistance and to develop novel treatment intervention.展开更多
FMS-like tyrosine kinase 3(FLT3)mutation is strongly associated with poor prognosis in acute myeloid leukemia(AML).Though many FLT3 inhibitors have been developed for clinical application with 34%-56%complete remissio...FMS-like tyrosine kinase 3(FLT3)mutation is strongly associated with poor prognosis in acute myeloid leukemia(AML).Though many FLT3 inhibitors have been developed for clinical application with 34%-56%complete remission rate,patients would develop resistance sooner or later after initial response to tyrosine kinase inhibitors(TKIs),such as gilteritinib.And increasing studies have shown that several resistance related mutations of FLT3 emerged during the AML progression.Thus,further investigation is warranted for these FLT3mu,AML patients to achieve a better treatment outcome.4-Hydroxyphenyl retinamide(4-HPR)has been investigated extensively in animal models and clinical trials as an anticancer/chemopreventive agent and is currently used for protection against cancer development/recurrence,with minimal side effects.In this study,we performed gene-set enrichment analysis and found that down-regulated genes induced by 4-HPR were associated with FLT3-ITD gene sets.CD34+ AML stem/progenitor cells separated from 32 AML samples were treated with 4-HPR.Correlation analysis showed that AML cells with FLT3-ITD genetic alteration were more sensitive to 4-HPR treatment than those without FLT3-ITD.Next,we treated 22 primary AML cells with 4-HPR and found that 4-HPR was more toxic to AML cells with FLT3-ITD.These results indicated that 4-HPR was preferentially cytotoxic to all FLT3-ITD AML cells irrespective of stem/progenitor cells or blast cells.4-HPR-induced reactive oxygen species(ROS)production and NF-kB inhibition might be the reason of 4-HPR selectivity on FLT3 mutated AML cells.展开更多
BACKGROUND Leukemic hematopoietic cells acquire enhanced self-renewal capacity and impaired differentiation.The emergence of symptomatic leukemia also requires the acquisition of a clonal proliferative advantage.Untre...BACKGROUND Leukemic hematopoietic cells acquire enhanced self-renewal capacity and impaired differentiation.The emergence of symptomatic leukemia also requires the acquisition of a clonal proliferative advantage.Untreated leukemia patients usually experience an aggressive process.However,spontaneous remission occasionally occurs in patients with acute myeloid leukemia(AML),most frequently after recovery from a febrile episode,and this is generally attributed to the triggering of antineoplastic immunity.There may be another explanation for the spontaneous remission as implicated in this paper.CASE SUMMARY A 63-year-old Chinese man presented with high fever,abdominal pain and urticaria-like skin lesions.He was diagnosed with AML-M4 with t(8;21)(q22;q22)/RUNX1-RUNX1T1 based on morphological,immunological,cytogenetic and molecular analyses.He had a complex chromosome rearrangement of 48,XY,t(8;21)(q22;q22),+13,+13[9]/49,idem,+mar[9]/49,idem,+8[2].He also had a mutated tyrosine kinase domain in fms-like tyrosine kinase 3 gene.He was treated with antibiotics and glucocorticoids for gastrointestinal infection and urticaria-like skin lesions.The infection and skin lesions were quickly resolved.Unexpectedly,he achieved hematological remission along with resolution of the febrile episode,gastrointestinal symptoms and skin lesions.Notably,after relapse,repeating these treatments resulted in a return to hematological remission.Unfortunately,he demonstrated strong resistance to antibiotic and glucocorticoid treatment after the second relapse and died of sepsis from bacterial infection with multidrug resistance.The main clinical feature of this patient was that symptomatic AML emerged with flaring of the gut inflammatory disorder and it subsided after resolution of the inflammation.Learning from the present case raises the possibility that in a subgroup of AML patients,the proliferative advantage of leukemia cells may critically require the presence of inflammatory stresses.CONCLUSION Inflammatory stresses,most likely arising from gastrointestinal infection,may sustain the growth and survival advantage of leukemic cells.展开更多
Oxidative stress, a pervasive condition of increased number of reactive oxygen species, is now recognized to be prominent feature of various diseases and their progression. The relationship between antioxidants and le...Oxidative stress, a pervasive condition of increased number of reactive oxygen species, is now recognized to be prominent feature of various diseases and their progression. The relationship between antioxidants and levels of well-known markers of oxidative stress, measured as lipid peroxides and oxidized proteins reflect health indices. The aim of this study is to evaluate the extent of oxidative stress and antioxidant status in acute and chronic myeloid leukemia patients. The present study included 60 patients selected using standard questionnaire based on age, family history, Body Mass Index (BMI), dietary intake, with no other complications and 30 age and sex-matched healthy subjects. The median age of myeloid leukemia patients was 43 years and that of controls was 42 years. Out of 60 myeloid leukemia patients, 30 were in acute and 30 were in chronic state. Oxidative stress and antioxidant status were evaluated in the patients and in the controls by assessing standard oxidative stress markers viz. plasma and erythrocyte lipid peroxide levels in terms of malondialdehyde and oxidized proteins as protein carbonyls whereas antioxidant status was assessed in terms of serum non enzymatic antioxidant levels. There was a significant increase (p 0.01) in plasma and erythrocyte lipid peroxidation and protein oxidation in acute and chronic myeloid leukemia patients as compared to healthy subjects. Antioxidant status as indicated by the levels of non-enzymatic antioxidants viz. erythrocyte reduced glutathione (GSH), serum β carotene, vitamin A & C and ceruloplasmin was found to be significantly decreased (p 0.01) in both the leukemia patients as compared to healthy participants. However, chronic myeloid leukemia patients had significantly (p 0.05) higher oxidative stress and lower antioxidant status as compared to acute myeloid leukemia patients.展开更多
FMS-like tyrosine kinase 3(FLT3)is a viable and important therapeutic target for acute myeloid leukemia(AML).FLT3 internal tandem duplication(FLT3-ITD)mutations have been identified in approximately 30%of AML patients...FMS-like tyrosine kinase 3(FLT3)is a viable and important therapeutic target for acute myeloid leukemia(AML).FLT3 internal tandem duplication(FLT3-ITD)mutations have been identified in approximately 30%of AML patients,and are associated with unfavorable prognosis,higher risk of relapse,drug resistance,and poor clinical outcome.Even FLT3 inhibitors have demonstrated promising efficacy,they cannot cure AML or even significantly extend the lives of patients with FLT3-ITD mutations.This is partly because of poor water solubility,insufficient membrane penetration and short half-life of small molecule inhibitors.Besides,the presence of enzymes like CYP3A4 in bone marrow accelerate the elimination and metabolism of FLT3 inhibitors,resulting in low plasma concentrations and side effects.Here we report the erythrocyte membrane-camouflaged FLT3 inhibitor nanoparticles to enhance FLT3-ITD AML treatment.Briefly,we physically coextruded red blood cell(RBC)membrane vesicles with nanoparticles derived from FLT3 inhibitor F30 to obtain F30@RBC-M,which exhibited comparable potent FLT3-ITD inhibitory effects compared to free F30 in vitro,while displaying a higher potent antitumor efficacy in xenograft models due to the prolonged circulation properties.Furthermore,administration of F30@RBC-M significantly extended the survival of mice in a transplanted mouse model than F30 free drug.These findings suggest that RBC membrane-coated nanoparticles derived from FLT3 inhibitors hold promise as a tool to enhance the therapeutic efficacy to treat FLT3-ITD AML.展开更多
FMS-related tyrosine kinase 3(FLT3)mutations,present in about 25%-30%of acute myeloid leukemia(AML)patients,constitute one of the most frequently detected mutations in these patients.The binding of FLT3L to FLT3 activ...FMS-related tyrosine kinase 3(FLT3)mutations,present in about 25%-30%of acute myeloid leukemia(AML)patients,constitute one of the most frequently detected mutations in these patients.The binding of FLT3L to FLT3 activates the phosphatidylinositol 3-kinase(PI3K)and RAS pathways,producing increased cell proliferation and the inhibition of apoptosis.Two types of FLT3 mutations exist:FLT3-ITD and FLT3-TKD(point mutations in D835 and I836 or deletion of codon I836).A class of drugs,tyrosine-kinase inhibitors(TKI),targeting mutated FLT3,is already available with 1st and 2nd generation molecules,but only midostaurin and gilteritinib are currently approved.However,the emergence of resistance or the selection of clones not responding to FLT3 inhibitors has become an important clinical dilemma,as the duration of clinical responses is generally limited to a few months.This review analyzes the insights into mechanisms of resistance to TKI and poses a particular view on the clinical relevance of this phenomenon.Has resistance been overlooked?Indeed,FLT3 inhibitors have significantly contributed to reducing the negative impact of FLT3 mutations on the prognosis of AML patients who are no longer considered at high risk by the European LeukemiaNet(ELN)2022.Finally,several ongoing efforts to overcome resistance to FLT3-inhibitors will be presented:new generation FLT3 inhibitors in monotherapy or combined with standard chemotherapy,hypomethylating drugs,or IDH1/2 inhibitors,Bcl2 inhibitors;novel anti-human FLT3 monoclonal antibodies(e.g.,FLT3/CD3 bispecific antibodies);FLT3-CAR T-cells;CDK4/6 kinase inhibitor(e.g.,palbociclib).展开更多
基金supported by grants from the Natural Science Foundation of Zhejiang Province(No.LY20H080001)Medical and Health Science and Technology Projects of Zhejiang Province(No.2021KY997,No.2022KY306,No.2022KY316,No.2023KY263).
文摘Objective Acute myeloid leukemia(AML)is an aggressive hematological malignancy characterized by abnormal myeloid blast expansion.Recent studies have demonstrated that circular RNAs play a role in AML pathogenesis.In this study,we aimed to investigate the clinical significance of circ_0012152 in AML and elucidate its underlying molecular mechanism in the pathogenesis of this condition.Methods Circ_0012152 expression was detected by quantitative real-time polymerase chain reaction in samples obtained from 247 patients with AML and 40 healthy controls.A systematic analysis of clinical characteristics and prognostic factors was also conducted.Cell growth was assessed using the Cell Counting Kit-8(CCK-8)assay,and apoptosis and cell cycle progression were evaluated by flow cytometry.Moreover,RNA pull-down was performed to identify target microRNAs,and transcriptome RNA sequencing and bioinformatics analyses were utilized to identify downstream mRNA targets.Results Circ_0012152 was significantly upregulated in samples from patients with AML and served as an independent adverse prognostic factor for overall survival(OS)(hazard ratio:2.357;95%confidence interval 1.258–4.415).The circ_0012152 knockdown reduced cell growth,increased apoptosis,and inhibited cell cycle progression in AML cell lines.RNA pull-down and sequencing identified miR-652-3p as a target microRNA of circ_0012152.Cell growth inhibition by circ_0012152 knockdown was significantly relieved by miR-652-3p inhibitors.We suggested that miR-652-3p targeted SOX4,as the decrease in SOX4 expression resulting from circ_0012152 knockdown was upregulated by miR-652-3p inhibitors in AML cells.Conclusion Circ_0012152 is an independent poor prognostic factor for OS in AML,and it promotes AML cell growth by upregulating SOX4 through miR-652-3p.
基金Supported by the National Natural Science Foundation of China,No.81700130Nanjing Medical University Science and Technology Development Fund.
文摘BACKGROUND The Coexistence of myeloid and lymphoid malignancies is rare.Myeloid leukemia occurs more frequently as a secondary event in patients receiving chemotherapy agents for lymphoid malignancies.Synchronous diagnoses of diffuse large B-cell lymphoma(DLBCL),acute myeloid leukemia(AML),and untreated lymphoplasmacytic lymphoma/Waldenström macroglobulinemia(LPL/WM)in the same patient have not been reported.Here we report one such case.CASE SUMMARY An 89-year-old man had a chest wall mass histopathologically diagnosed as DLBCL.The bone marrow and peripheral blood contained two groups of cells.One group of cells fulfilled the criteria of AML,and the other revealed the features of small B lymphocytic proliferative disorder,which we considered LPL/WM.Multiple chromosomal or genetic changes were detected in bone marrow mononuclear cells,including ATM deletion,CCND1 amplification,mutations of MYD88(L265P)and TP53,WT1 overexpression,and fusion gene of BIRC2-ARAP1,as well as complex chromosomal abnormalities.The patient refused chemotherapy because of old age and died of pneumonia 1 mo after the final diagnosis.CONCLUSION The coexistence of DLBCL,AML,and untreated LPL/WM in the same patient is extremely rare,which probably results from multiple steps of genetic abnormalities.Asymptomatic LPL/WM might have occurred first,then myelodysplastic syndromerelated AML developed,and finally aggressive DLBCL arose.Therefore,medical staff should pay attention to this rare phenomenon to avoid misdiagnoses.
基金Supported by the Singapore National Research Foundation and the Ministry of Education under the Research Center of Excellence Program(to Chng WJ)NMRC Clinician-Scientist IRG Grant,No.CNIG11nov38(to Zhou J)+1 种基金supported by NMRC Clinician Scientist Investigator awardsupported by the RNA Biology Center at CSI Singapore,NUS,from funding by the Singapore Ministry of Education’s Tier 3 grants,No.MOE2014-T3-1-006
文摘FMS-like tyrosine kinase 3(FLT3) is classified as a type Ⅲ receptor tyrosine kinase, which exerts a key role in regulation of normal hematopoiesis. FLT3 mutation is the most common genetic mutation in acute myeloid leukemia(AML) and represents an attractive therapeutic target. Targeted therapy with FLT3 inhibitors in AML shows modest promising results in current ongoing clinical trials suggesting the complexity of FLT3 targeting in therapeutics. Importantly, resistance to FLT3 inhibitors may explain the lack of overwhelming response and could obstruct the successful treatment for AML. Here, we summarize the molecular mechanisms of primary resistance and acquired resistance to FLT3 inhibitors and discuss the strategies to circumvent the emergency of drug resistance and to develop novel treatment intervention.
基金This work was partially funded by the National Natural Science Foundation of China(No.81300401)St.Baldrick’s Foundation International Scholar(No.581580)+1 种基金Natural Science Foundation of Guangdong Province(No.2015A030313460)Guangzhou Women and Children’s Medical Center(No.IP-2008-001 and No.GCP-2019-006).
文摘FMS-like tyrosine kinase 3(FLT3)mutation is strongly associated with poor prognosis in acute myeloid leukemia(AML).Though many FLT3 inhibitors have been developed for clinical application with 34%-56%complete remission rate,patients would develop resistance sooner or later after initial response to tyrosine kinase inhibitors(TKIs),such as gilteritinib.And increasing studies have shown that several resistance related mutations of FLT3 emerged during the AML progression.Thus,further investigation is warranted for these FLT3mu,AML patients to achieve a better treatment outcome.4-Hydroxyphenyl retinamide(4-HPR)has been investigated extensively in animal models and clinical trials as an anticancer/chemopreventive agent and is currently used for protection against cancer development/recurrence,with minimal side effects.In this study,we performed gene-set enrichment analysis and found that down-regulated genes induced by 4-HPR were associated with FLT3-ITD gene sets.CD34+ AML stem/progenitor cells separated from 32 AML samples were treated with 4-HPR.Correlation analysis showed that AML cells with FLT3-ITD genetic alteration were more sensitive to 4-HPR treatment than those without FLT3-ITD.Next,we treated 22 primary AML cells with 4-HPR and found that 4-HPR was more toxic to AML cells with FLT3-ITD.These results indicated that 4-HPR was preferentially cytotoxic to all FLT3-ITD AML cells irrespective of stem/progenitor cells or blast cells.4-HPR-induced reactive oxygen species(ROS)production and NF-kB inhibition might be the reason of 4-HPR selectivity on FLT3 mutated AML cells.
基金Supported by the Specialized Scientific Research Fund Projects of The Medical Group of Qingdao University,No. YLJT20201002
文摘BACKGROUND Leukemic hematopoietic cells acquire enhanced self-renewal capacity and impaired differentiation.The emergence of symptomatic leukemia also requires the acquisition of a clonal proliferative advantage.Untreated leukemia patients usually experience an aggressive process.However,spontaneous remission occasionally occurs in patients with acute myeloid leukemia(AML),most frequently after recovery from a febrile episode,and this is generally attributed to the triggering of antineoplastic immunity.There may be another explanation for the spontaneous remission as implicated in this paper.CASE SUMMARY A 63-year-old Chinese man presented with high fever,abdominal pain and urticaria-like skin lesions.He was diagnosed with AML-M4 with t(8;21)(q22;q22)/RUNX1-RUNX1T1 based on morphological,immunological,cytogenetic and molecular analyses.He had a complex chromosome rearrangement of 48,XY,t(8;21)(q22;q22),+13,+13[9]/49,idem,+mar[9]/49,idem,+8[2].He also had a mutated tyrosine kinase domain in fms-like tyrosine kinase 3 gene.He was treated with antibiotics and glucocorticoids for gastrointestinal infection and urticaria-like skin lesions.The infection and skin lesions were quickly resolved.Unexpectedly,he achieved hematological remission along with resolution of the febrile episode,gastrointestinal symptoms and skin lesions.Notably,after relapse,repeating these treatments resulted in a return to hematological remission.Unfortunately,he demonstrated strong resistance to antibiotic and glucocorticoid treatment after the second relapse and died of sepsis from bacterial infection with multidrug resistance.The main clinical feature of this patient was that symptomatic AML emerged with flaring of the gut inflammatory disorder and it subsided after resolution of the inflammation.Learning from the present case raises the possibility that in a subgroup of AML patients,the proliferative advantage of leukemia cells may critically require the presence of inflammatory stresses.CONCLUSION Inflammatory stresses,most likely arising from gastrointestinal infection,may sustain the growth and survival advantage of leukemic cells.
文摘Oxidative stress, a pervasive condition of increased number of reactive oxygen species, is now recognized to be prominent feature of various diseases and their progression. The relationship between antioxidants and levels of well-known markers of oxidative stress, measured as lipid peroxides and oxidized proteins reflect health indices. The aim of this study is to evaluate the extent of oxidative stress and antioxidant status in acute and chronic myeloid leukemia patients. The present study included 60 patients selected using standard questionnaire based on age, family history, Body Mass Index (BMI), dietary intake, with no other complications and 30 age and sex-matched healthy subjects. The median age of myeloid leukemia patients was 43 years and that of controls was 42 years. Out of 60 myeloid leukemia patients, 30 were in acute and 30 were in chronic state. Oxidative stress and antioxidant status were evaluated in the patients and in the controls by assessing standard oxidative stress markers viz. plasma and erythrocyte lipid peroxide levels in terms of malondialdehyde and oxidized proteins as protein carbonyls whereas antioxidant status was assessed in terms of serum non enzymatic antioxidant levels. There was a significant increase (p 0.01) in plasma and erythrocyte lipid peroxidation and protein oxidation in acute and chronic myeloid leukemia patients as compared to healthy subjects. Antioxidant status as indicated by the levels of non-enzymatic antioxidants viz. erythrocyte reduced glutathione (GSH), serum β carotene, vitamin A & C and ceruloplasmin was found to be significantly decreased (p 0.01) in both the leukemia patients as compared to healthy participants. However, chronic myeloid leukemia patients had significantly (p 0.05) higher oxidative stress and lower antioxidant status as compared to acute myeloid leukemia patients.
基金supported by the National Natural Science Foundation of China(No.32222046,China)the Sichuan Science and Technology Program(Nos.2022NSFSC0823,2023NSFSC193,2022NSFSC0793,China)the 1·3·5 Project for Disciplines of Excellence,West China Hospital,Sichuan University(No.ZYJC21022,China).
文摘FMS-like tyrosine kinase 3(FLT3)is a viable and important therapeutic target for acute myeloid leukemia(AML).FLT3 internal tandem duplication(FLT3-ITD)mutations have been identified in approximately 30%of AML patients,and are associated with unfavorable prognosis,higher risk of relapse,drug resistance,and poor clinical outcome.Even FLT3 inhibitors have demonstrated promising efficacy,they cannot cure AML or even significantly extend the lives of patients with FLT3-ITD mutations.This is partly because of poor water solubility,insufficient membrane penetration and short half-life of small molecule inhibitors.Besides,the presence of enzymes like CYP3A4 in bone marrow accelerate the elimination and metabolism of FLT3 inhibitors,resulting in low plasma concentrations and side effects.Here we report the erythrocyte membrane-camouflaged FLT3 inhibitor nanoparticles to enhance FLT3-ITD AML treatment.Briefly,we physically coextruded red blood cell(RBC)membrane vesicles with nanoparticles derived from FLT3 inhibitor F30 to obtain F30@RBC-M,which exhibited comparable potent FLT3-ITD inhibitory effects compared to free F30 in vitro,while displaying a higher potent antitumor efficacy in xenograft models due to the prolonged circulation properties.Furthermore,administration of F30@RBC-M significantly extended the survival of mice in a transplanted mouse model than F30 free drug.These findings suggest that RBC membrane-coated nanoparticles derived from FLT3 inhibitors hold promise as a tool to enhance the therapeutic efficacy to treat FLT3-ITD AML.
文摘FMS-related tyrosine kinase 3(FLT3)mutations,present in about 25%-30%of acute myeloid leukemia(AML)patients,constitute one of the most frequently detected mutations in these patients.The binding of FLT3L to FLT3 activates the phosphatidylinositol 3-kinase(PI3K)and RAS pathways,producing increased cell proliferation and the inhibition of apoptosis.Two types of FLT3 mutations exist:FLT3-ITD and FLT3-TKD(point mutations in D835 and I836 or deletion of codon I836).A class of drugs,tyrosine-kinase inhibitors(TKI),targeting mutated FLT3,is already available with 1st and 2nd generation molecules,but only midostaurin and gilteritinib are currently approved.However,the emergence of resistance or the selection of clones not responding to FLT3 inhibitors has become an important clinical dilemma,as the duration of clinical responses is generally limited to a few months.This review analyzes the insights into mechanisms of resistance to TKI and poses a particular view on the clinical relevance of this phenomenon.Has resistance been overlooked?Indeed,FLT3 inhibitors have significantly contributed to reducing the negative impact of FLT3 mutations on the prognosis of AML patients who are no longer considered at high risk by the European LeukemiaNet(ELN)2022.Finally,several ongoing efforts to overcome resistance to FLT3-inhibitors will be presented:new generation FLT3 inhibitors in monotherapy or combined with standard chemotherapy,hypomethylating drugs,or IDH1/2 inhibitors,Bcl2 inhibitors;novel anti-human FLT3 monoclonal antibodies(e.g.,FLT3/CD3 bispecific antibodies);FLT3-CAR T-cells;CDK4/6 kinase inhibitor(e.g.,palbociclib).
