title: [Biological characteristics of residual leukemic cells and their drug-resistant regrowth].
abstract: OBJECTIVE
  To elucidate the mechanisms of residual leukemia and its drug-resistant regrowth.
  
  
  METHODS
  Bone marrow cells from transplantable mouse leukemia models L615 and L7811 were cultivated in long-term culture system respectively. Daunorubicin (DNR) was added to the systems to mimick in vivo chemotherapy.
  
  
  RESULTS
  Residual leukemic cells on stromal layers escaped DNR killing. They derived from the adherent leukemic cell population, which was heterogeneous with many undifferentiated and dormant cells. They were drug-resistant and expressed bcl-2 gene.
  
  
  CONCLUSIONS
  Bone marrow stromal layer was the vital microenvironment for the residual leukemic cells to survive and regrow, and might increase the drug-resistance by up-regulating bcl-2 gene expression.
authors.affiliation: State Key Laboratory of Experimental Hematology, Institute of Hematology, CAMS and PUMC, Tianjin 300020.
authors.forename: Y
authors.initials: Y
authors.lastname: Ma
authors.forename: Z
authors.initials: Z
authors.lastname: Song
authors.forename: Y
authors.initials: Y
authors.lastname: He
authors.forename: X
authors.initials: X
authors.lastname: Jiang
authors.forename: S
authors.initials: S
authors.lastname: Wang
authors.forename: J
authors.initials: J
authors.lastname: Zhu
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D003630:Daunorubicin / Q000494:pharmacology; D019008:Drug Resistance, Neoplasm; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D019254:Genes, bcl-2 / Q000235:genetics; D007938:Leukemia / Q000235:genetics / Q000473:pathology*; D008297:Male; D051379:Mice; D018365:Neoplasm, Residual
chemical_list: D003630:Daunorubicin