2. Academic Validation
  3. Exosomal microRNA-20b-5p contributes to cytarabine resistance in acute myeloid leukemia via the microtubule-associated serine/threonine kinase-like-phosphatidylinositol 3-kinase-protein kinase B signaling axis

Exosomal microRNA-20b-5p contributes to cytarabine resistance in acute myeloid leukemia via the microtubule-associated serine/threonine kinase-like-phosphatidylinositol 3-kinase-protein kinase B signaling axis

  • Int J Biol Macromol. 2025 Dec;333(Pt 2):148750. doi: 10.1016/j.ijbiomac.2025.148750.
Aoshuang Huang 1,  Li Wang 2,  Ying Chen 2,  Zihao Zhao 3,  Wei Cheng 2,  WeiWei Cheng 2,  Bingqing Cheng 2,  Hai Guo 4,  Ya Li 2,  Jiumei Cai 5,  Jinghui Yang 6,  Xue Zou 7,  Jishi Wang 8
Affiliations

Affiliations

  • 1 Department of Hematology, Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou, China; Department of Clinical Medicine, Guizhou Medical University, Guiyang, Guizhou, China; Hematopoietic Stem Cell Transplantation Center of Guizhou Province, Key Laboratory of Hematological Disease Diagnostic & Treat Centre of Guizhou Province, Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou, China. Electronic address: [email protected].
  • 2 Department of Hematology, Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou, China; Hematopoietic Stem Cell Transplantation Center of Guizhou Province, Key Laboratory of Hematological Disease Diagnostic & Treat Centre of Guizhou Province, Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou, China.
  • 3 Department of Orthopedics, Affiliated Guiyang Public Health Clinical Center of Guizhou Medical University, Guiyang, Guizhou, China.
  • 4 Department of Hematology, Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou, China; Department of Clinical Medicine, Guizhou Medical University, Guiyang, Guizhou, China; Hematopoietic Stem Cell Transplantation Center of Guizhou Province, Key Laboratory of Hematological Disease Diagnostic & Treat Centre of Guizhou Province, Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou, China.
  • 5 Department of Neurosurgery, Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou, China.
  • 6 Department of Ultrasound, Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou, China.
  • 7 Clinical Research Center, Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou, China.
  • 8 Department of Hematology, Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou, China; Department of Clinical Medicine, Guizhou Medical University, Guiyang, Guizhou, China; Hematopoietic Stem Cell Transplantation Center of Guizhou Province, Key Laboratory of Hematological Disease Diagnostic & Treat Centre of Guizhou Province, Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou, China. Electronic address: [email protected].
PMID: 41197693 DOI: 10.1016/j.ijbiomac.2025.148750
Abstract

Background: Cytarabine (Ara-C) resistance limits durable remission in acute myeloid leukemia (AML). A working model posits that exosomal miR-20b-5p promotes resistance by repressing MASTL and sustaining PI3K-AKT signaling.

Methods: Ara-C-resistant sublines were generated. Exosomes were purified and validated by TEM, NTA, and immunoblotting. Functional transfer used exosome-depleted serum with GW4869 and EV-depleted medium controls. MASTL targeting was tested with 3'-UTR dual-luciferase reporters and biotinylated-miRNA pull-down. Proteomics profiled pathways. Xenograft studies evaluated in vivo effects; MK-2206 probed Akt dependence.

Results: Resistant-cell exosomes reduced Ara-C sensitivity of matched parental cells, and were enriched for miR-20b-5p; controls had no effect. Reporter and pull-down assays supported direct binding to the MASTL 3'-UTR, with reduced MASTL mRNA/protein and increased p-PI3K/p-AKT. Re-expression of MASTL lacking the 3'-UTR and Akt inhibition each partially reversed signaling and drug-response phenotypes. In relapsed blasts, a miRNA inhibitor restored MASTL and lowered p-PI3K. In vivo, leukemia-derived exosomes increased leukemic burden, consistent with an exosomal miR-20b-5p-MASTL-PI3K-AKT axis.

Conclusions: Exosomal miR-20b-5p represses MASTL, remodels PI3K-AKT, and attenuates Ara-C responses in AML models. Seed-mutant reporters and 3'-UTR-independent rescue support target specificity. Findings are mechanistic and hypothesis-generating; clinical relevance requires confirmation in primary blasts and prospective validation.

Keywords

Acute myeloid leukemia; Cytarabine resistance; Exosomes; MASTL; PI3K–AKT signaling; miR-20b-5p.

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