title: [Activation of phosphatidylinositol 3-kinase in human breast carcinoma].
abstract: OBJECTIVE
  Phosphatidylinositol 3-kinase (PI3-K) has been implicated in the signaling pathways regulating cell growth by virtue of its activation in response to various mitogenic stimuli, but the role of PI3-K in human tumorigenesis has not yet to be defined. This study was designed to investigate the levels of both PI3-K protein and PI3-K mRNA and the activity of PI3-K in human breast tumors.
  
  
  METHODS
  Western blot, immunoprecipitation, kinase activity assay, and RT-PCR were used to detect the expression and activity of PI3-K in 37 patients with breast cancers.
  
  
  RESULTS
  Significantly increased expression of p85 subunit of PI3-K at levels of both protein and mRNA were found in 32 (86.49%) and 35(94.59%) out of the 37 breast tumors compared with adjacent normal tissue. Significantly higher level of the activity of PI3-kinase was observed in 25(67.57%) out of the 37 cases.
  
  
  CONCLUSIONS
  PI3-K was highly activated in breast tumor tissue compared with adjacent normal tissue, suggesting that PI3-K was involved in the signal transduction of breast tumorigenesis. It may be a potential target for new strategies for the treatment of the patients with breast cancers.
authors.affiliation: Department of Pathology, College of Basic Medical Sciences, China Medical University, Shenyang 110001, P. R. China. yingziz@sohu.com
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.forename: Min
authors.initials: M
authors.lastname: Song
authors.forename: Xiao-yi
authors.initials: XY
authors.lastname: Mi
authors.forename: Hui
authors.initials: H
authors.lastname: Wang
authors.forename: Ji-ye
authors.initials: JY
authors.lastname: Song
mesh_terms: D001943:Breast Neoplasms / Q000201:enzymology* / Q000235:genetics; D018270:Carcinoma, Ductal, Breast / Q000201:enzymology* / Q000235:genetics; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000201:enzymology* / Q000235:genetics; D004789:Enzyme Activation; D005260:Female; D015870:Gene Expression; D006801:Humans; D019869:Phosphatidylinositol 3-Kinases / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger
chemical_list: D012333:RNA, Messenger; D019869:Phosphatidylinositol 3-Kinases