title: Involvement of PI3K/PTEN/AKT/mTOR pathway in invasion and metastasis in hepatocellular carcinoma: Association with MMP-9.
abstract: OBJECTIVE
  To investigate the status of Phosphatidylinositol 3-kinase (PI3K)/PTEN/AKT/mammalian target of rapamycin (mTOR) pathway and its correlation with clinicopathological features and matrix metalloproteinase-2, -9 (MMP-2, 9) in human hepatocellular carcinoma (HCC).
  
  
  METHODS
  PTEN, Phosphorylated AKT (p-AKT), Phosphorylated mTOR (p-mTOR), MMP-2, MMP-9 and Ki-67 expression levels were evaluated by immunohistochemistry on tissue microarrays containing 200 HCCs with paired adjacent non-cancerous liver tissues. PTEN, MMP-2 and MMP-9 mRNA levels were determined by real-time RT-PCR in 36 HCCs. The relationships between PI3K/PTEN/AKT/mTOR pathway and clinicopathological factors and MMP-2, 9 were analyzed in HCC.
  
  
  RESULTS
  In HCC, PTEN loss and overexpression of p-AKT and p-mTOR were associated with tumor grade, intrahepatic metastasis, vascular invasion, TNM stage and high Ki-67 labeling index (P < 0.05). PTEN loss was correlated with p-AKT, p-mTOR and MMP-9 overexpression. Furthermore, PTEN and MMP-2, 9 mRNA levels were down-regulated and up-regulated in HCC compared with paired non-cancerous liver tissues, respectively (P < 0.01). PTEN, MMP-2 and MMP-9 mRNA levels were correlated with tumor stage and metastasis. There was an inverse correlation between PTEN and MMP-9 mRNA expression. However, PI3K/PTEN/AKT/mTOR pathway was not correlated with MMP-2.
  
  
  CONCLUSIONS
  PI3K/PTEN/AKT/mTOR pathway, which is activated in HCC, is involved in invasion and metastasis through up-regulating MMP-9 in HCC.
authors.affiliation: Department of Hepatobiliary Surgery , The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China.
authors.forename: Jing-Song
authors.initials: JS
authors.lastname: Chen
authors.forename: Qian
authors.initials: Q
authors.lastname: Wang
authors.forename: Xin-Hui
authors.initials: XH
authors.lastname: Fu
authors.forename: Xiao-Hui
authors.initials: XH
authors.lastname: Huang
authors.forename: Xi-Lin
authors.initials: XL
authors.lastname: Chen
authors.forename: Liang-Qi
authors.initials: LQ
authors.lastname: Cao
authors.forename: Lian-Zhou
authors.initials: LZ
authors.lastname: Chen
authors.forename: Hao-Xiang
authors.initials: HX
authors.lastname: Tan
authors.forename: Wen
authors.initials: W
authors.lastname: Li
authors.forename: Jiong
authors.initials: J
authors.lastname: Bi
authors.forename: Long-Juan
authors.initials: LJ
authors.lastname: Zhang