title: [Growth inhibition effect of matrine on K562 cells mediated by IL-6/JAK/STAT3 signaling pathway].
abstract: OBJECTIVE
  To investigate the molecular mechanism of the growth inhibitory effect of matrine on K562 cells in JAK/STAT3 mediated signal pathway.
  
  
  METHODS
  Western blot analyses were performed to investigate the differential expression of JAK2, STAT3, phosphor-STAT3 (Tyr705 & Ser727) and phosphor-JAK2 proteins after matrine treatment in K562 cells with or without human recombinant interleukin 6 (IL-6) pretreatment. The expression of STAT3 response gene products such as Bcl-xL, Cyclin D1 and c-Myc, were investigated by Western blot and quantitative real time RT-PCR (qRT-PCR). Expression of IL-6, a potent upstream activating factor of JAK/STAT3 pathway, was analyzed by both real time qRT-PCR and ELISA.
  
  
  RESULTS
  Western blot revealed that matrine treatment resulted in a strong down-regulation of phosphor-STAT3 both in Tyr705 and Ser727 sites or phosphor-JAK2 proteins expression without significant effects on the total STAT3 and JAK2 proteins. The expression of phosphor-Tyr705 STAT3 and phosphor-Ser727 STAT3 was decreased to 0.370 ± 0.172 in K562 cells treated with 0.5 mg/ml matrine for 48 h, respectively, from 0.690 ± 0.119 and 1.150 ± 0.263 in control cells, accompanied with a dramatical down-regulation of phosphor-JAK2 from 0.670 ± 0.137 to 0.049 ± 0.057 (P<0.05). In addition, it was found that the expression of Bcl-xL, Cyclin D1, c-Myc was decreased both at the transcription and protein level in K562 cells after matrine treatment. Matrine treatment resulted in a significant decrease in the expression level of IL-6 in K562 cells from (35.1 ± 1.93) to (10.74 ± 1.83) and (8.66 ± 1.24) pg/ml at the dose of 0.5 and 0.8 mg/ml, respectively (p<0.05). Matrine treatment could diminish the up-regulation of STAT3, JAK2, phosphor-STAT3 and phosphor-JAK2 protein following pretreatment with IL-6 in K562 cells.
  
  
  CONCLUSIONS
  Matrine exerts its anti-leukemia effect by interfering with the JAK2/STAT3 signaling pathway. The inhibition of IL-6 expression may play a pivotal role in the disruption of JAK/STAT pathway by matrine.
authors.affiliation: Department of Hematology, the First Affiliated Hospital of Nanjing Medical University, Jiangsu Provincial Hospital, Nanjing 210029, China.
authors.forename: Lingdi
authors.initials: L
authors.lastname: Ma
authors.affiliation: Department of Hematology, the First Affiliated Hospital of Nanjing Medical University, Jiangsu Provincial Hospital, Nanjing 210029, China.
authors.forename: Zhichao
authors.initials: Z
authors.lastname: Zhu
authors.affiliation: Department of Hematology, the First Affiliated Hospital of Nanjing Medical University, Jiangsu Provincial Hospital, Nanjing 210029, China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Sun
authors.affiliation: Department of Hematology, the First Affiliated Hospital of Nanjing Medical University, Jiangsu Provincial Hospital, Nanjing 210029, China.
authors.forename: Lijia
authors.initials: L
authors.lastname: Jiang
authors.affiliation: Department of Hematology, the First Affiliated Hospital of Nanjing Medical University, Jiangsu Provincial Hospital, Nanjing 210029, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Bai
authors.affiliation: Department of Hematology, the First Affiliated Hospital of Nanjing Medical University, Jiangsu Provincial Hospital, Nanjing 210029, China.
authors.forename: Xuzhang
authors.initials: X
authors.lastname: Lu
authors.affiliation: Department of Hematology, the First Affiliated Hospital of Nanjing Medical University, Jiangsu Provincial Hospital, Nanjing 210029, China.
authors.forename: Min
authors.initials: M
authors.lastname: Zhou
authors.affiliation: Department of Hematology, the First Affiliated Hospital of Nanjing Medical University, Jiangsu Provincial Hospital, Nanjing 210029, China.
authors.forename: Sixuan
authors.initials: S
authors.lastname: Qian
authors.affiliation: Department of Hematology, the First Affiliated Hospital of Nanjing Medical University, Jiangsu Provincial Hospital, Nanjing 210029, China.
authors.forename: Jianyong
authors.initials: J
authors.lastname: Li
mesh_terms: D000470:Alkaloids; D015536:Down-Regulation; D006801:Humans; D015850:Interleukin-6; D053614:Janus Kinase 2; D020014:K562 Cells; D011807:Quinolizines; D050796:STAT3 Transcription Factor; D015398:Signal Transduction; D015854:Up-Regulation; D000093842:Matrines
chemical_list: D000470:Alkaloids; C508600:IL6 protein, human; D015850:Interleukin-6; D011807:Quinolizines; D050796:STAT3 Transcription Factor; C494086:STAT3 protein, human; C507924:JAK2 protein, human; D053614:Janus Kinase 2; D000093842:Matrines