title: [Resistance of leukemia KG1a cells with positive N-cadherin in phase G(0) against killing activity of VP16].
abstract: Drug resistance is an important character of leukemic stem cells. To explore the mechanism of the chemotherapy resistance of N-cadherin positive leukemia cells, the quiescent state of N-cadherin positive leukemia cells was determined by flow cytometry and the relationship of G(0) phase cell ratio with the chemotherapy resistance was analyzed. After KG1a cells were induced to enter cell cycle, the G(0) phase cell ratio and the sensitivity of cells to VP16 were determined. Finally the quiescent state and drug resistance properties of KG1a cells were determined after inhibiting N-cadherin-mediated cell-cell interaction by EGTA treatment. The results showed that the G(0) phase cell ratio in N-cadherin positive KG1a cells was higher than that in N-cadherin negative KG1a cells. After KG1a cells were induced to enter cell cycle, the G(0) phase cell ratio was decreased significantly and the sensitivity of KG1a cells to VP16 increased. Following EGTA treatment for 24 hours, the G(0) phase cell ratio decreased and the drug-sensitivity was enhanced significantly. It is concluded that N-cadherin-mediated adhesion keeps N-cadherin positive leukemia cells in quiescent state of G(0) phase, thus protect these leukemia cells against VP16 chemotherapy.
authors: Institute of Hematology & Blood Disease Hospital, Chinese Academy of Medical Sciences, Tianjin, China.
authors: Kan
authors: K
authors: He
authors: Pei
authors: P
authors: Yu
authors: Hai-Yan
authors: HY
authors: Xing
authors: Yan
authors: Y
authors: Li
authors: Zheng
authors: Z
authors: Tian
authors: Min
authors: M
authors: Wang
authors: Ke-Jing
authors: KJ
authors: Tang
authors: Qing
authors: Q
authors: Rao
mesh_terms: D015703:Antigens, CD / Q000378:metabolism*; D017209:Apoptosis / Q000187:drug effects; D015820:Cadherins / Q000378:metabolism*; D045744:Cell Line, Tumor; D005047:Etoposide / Q000494:pharmacology* / Q000627:therapeutic use; D005434:Flow Cytometry; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000188:drug therapy; D016192:Resting Phase, Cell Cycle / Q000187:drug effects*
chemical_list: D015703:Antigens, CD; C050361:CDH2 protein, human; D015820:Cadherins; D005047:Etoposide