title: [Overexpression of SHP-1 Enhances the Sensitivity of K562 Cells to Imatinib].
abstract: OBJECTIVE
  To explore the effect of overexpression of SH2-containing tyrosine phosphatase 1 (SHP-1) on sensitivity of chronic myelogenous 1eukemia (CML) K562 cell line to imatinib and its related mechamism.
  
  
  METHODS
  K562 cells were infected with the lentiviral plasmids containing the specified retroviral vector (pEX-SHP-1-puro-Lv105) or the mock vector (pEX-EGFP-puro-Lv105). The expression of SHP-1 in K562 cells treated with 0.2 µmol/L imatinib (IM) for 72 h was determined by Western blot. After transfection the CCK-8 assay was used to determine the proliferation of the tramfected K562 cells (K562(SHP-1) and K562(EGFP) cells) at 72 h after exposure to different doses of IM, the half inhibitary concentration (IC50) was calculated. The mechanisms of the overexpression effects of SHP-1 and IM on the proliferation in K562 cells was investigated, the BCR-ABL1 activity and the level of tyrosine phosphorylation of CrkL (pCrkL) was measured by flow cytometry; the Western blot was used to detect the expression and activity of these molecules controlling cell growth, including MAPK, AKT, STAT5 and JAK2.
  
  
  RESULTS
  After exposure of K562 cells to 0.08 µmol/L IM for 72 h, there was no significant change of SHP-1 expression in K562 cells. After exposure to 0.2 µmol/L of IM for 72 h, the inhibitory rate of K562(SHP-1) group was higher than that of K562(EGFP) group (P < 0.05), indicating that overexpression of SHP-1 in K562 cells could enhance the proliferation inhtibition effect of IM on K562 cells. The IC50 of IM in K562(SHP-1) cells was the lower as compared with that of K562(EGFP) cells (P < 0.05) after exposure to different concentrations of IM for 72 h. The slope of K562(SHP-1) cells was the largest ranging 0.02 - 0.16 µmol/L of IM. Overexpression of SHP-1 and IM could inhibit the activity BCR-ABL1, MAPK, AKT, STAT5 and JAK2 signaling pathways in the K562 cell line and displayed a synergistic effect.
  
  
  CONCLUSIONS
  SHP-1 inhibits BCR-ABL1, MAPK, AKT, STAT5 and JAK2 signaling pathways in K562 cells, the overexpression of SHP-1 can enhance the sensitivity of K562 cells to IM.
authors.affiliation: Department of Hematology, Harrison International Peace Hospital, Hengshui 053000, Hebei Province, China. E-mail: 1445828799@qq.com.
authors.forename: Ying-Hua
authors.initials: YH
authors.lastname: Li
authors.affiliation: Hengshui Blood Center, Hengshui 053000, Hebei Province, China.
authors.forename: Xue-Dong
authors.initials: XD
authors.lastname: Liu
authors.affiliation: Department of Hematology, Harrison International Peace Hospital, Hengshui 053000, Hebei Province, China.
authors.forename: Xiu-Fen
authors.initials: XF
authors.lastname: Guo
authors.affiliation: Department of Hematology, Harrison International Peace Hospital, Hengshui 053000, Hebei Province, China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Liu
authors.affiliation: Department of Hematology, The Second Hospital of Hebei Medical University, Shijiazhuang 050000, Hebei Province, China.
authors.forename: Jian-Min
authors.initials: JM
authors.lastname: Luo
authors.affiliation: Department of Hematology, Harrison International Peace Hospital, Hengshui 053000, Hebei Province, China.
authors.forename: Zhi-Shang
authors.initials: ZS
authors.lastname: Li
authors.affiliation: Department of Hematology, Harrison International Peace Hospital, Hengshui 053000, Hebei Province, China.
authors.forename: Yong-Xiao
authors.initials: YX
authors.lastname: Zhang
mesh_terms: D049109:Cell Proliferation; D019008:Drug Resistance, Neoplasm; D005822:Genetic Vectors; D006801:Humans; D000068877:Imatinib Mesylate / Q000494:pharmacology*; D020014:K562 Cells / Q000187:drug effects; D010766:Phosphorylation; D053824:Protein Tyrosine Phosphatase, Non-Receptor Type 6 / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D014162:Transfection
chemical_list: D000068877:Imatinib Mesylate; D053824:Protein Tyrosine Phosphatase, Non-Receptor Type 6