title: Clinicopathological significance of STAT4 in hepatocellular carcinoma and its effect on cell growth and apoptosis.
abstract: BACKGROUND
  Recent studies showed that signal transducer and activator of transcription 4 (STAT4) was downregulated in hepatocellular carcinoma (HCC) tissues. However, the role of STAT4 in HCC is still unknown. The aim of this study is to explore the association between STAT4 expression and other clinicopathological features in HCC and to test the effect of STAT4 on cell growth and apoptosis in vitro.
  
  
  METHODS
  STAT4 was evaluated by immunohistochemistry in 171 HCC and corresponding paraneoplastic liver, 37 cirrhosis, and 33 normal liver tissues. Association between STAT4 and clinicopathological parameters was analyzed. Meta-analysis on STAT4 in cancer was performed. The effect of STAT4 small interfering RNA (siRNA) on cell growth and cell apoptosis was also detected.
  
  
  RESULTS
  Positive rate of STAT4 was 29.2% (50/171) in HCC tissues, 53.2% (91/171) in paraneoplastic liver tissues, 64.9% (24/37) in cirrhosis tissues, and 72.7% (24/33) in normal liver tissues. STAT4 was upregulated in younger patients who were female, with single tumor node, early TNM stage, without portal vein tumor embolus, and α-fetoprotein (AFP)-positive tumors compared with the groups comprising older patients, males, and those with multiple tumor nodes, advanced TNM stage, with portal vein tumor embolus, and AFP negative tumors. Meta-analysis showed STAT4 was correlated with TNM stage (OR =0.50, 95% CI =0.30, 0.83, P=0.008) and age (OR =0.58, 95% CI =0.38, 0.95, P=0.032) in malignant tissues, and with AFP level (OR =1.76, 95% CI =1.06, 2.94, P=0.03) in HCC. STAT4 siRNA promoted growth and suppressed apoptosis of HepG2 cells.
  
  
  CONCLUSIONS
  STAT4 might play a vital role in development of HCC, via influencing cell growth and apoptosis, as a tumor suppressor.
authors.affiliation: Department of General Surgery, Western Branch, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi Zhuang Autonomous Region, People's Republic of China.
authors.forename: Jianjun
authors.initials: J
authors.lastname: Li
authors.affiliation: Department of Pathology, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi Zhuang Autonomous Region, People's Republic of China.
authors.forename: Lu
authors.initials: L
authors.lastname: Liang
authors.affiliation: Department of Pathology, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi Zhuang Autonomous Region, People's Republic of China.
authors.forename: Yongru
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Pathology, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi Zhuang Autonomous Region, People's Republic of China.
authors.forename: Yihuan
authors.initials: Y
authors.lastname: Luo
authors.affiliation: Department of Pathology, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi Zhuang Autonomous Region, People's Republic of China.
authors.forename: Xiaona
authors.initials: X
authors.lastname: Liang
authors.affiliation: Department of Pathology, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi Zhuang Autonomous Region, People's Republic of China.
authors.forename: Dianzhong
authors.initials: D
authors.lastname: Luo
authors.affiliation: Department of Pathology, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi Zhuang Autonomous Region, People's Republic of China.
authors.forename: Zhenbo
authors.initials: Z
authors.lastname: Feng
authors.affiliation: Department of Pathology, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi Zhuang Autonomous Region, People's Republic of China.
authors.forename: Yiwu
authors.initials: Y
authors.lastname: Dang
authors.affiliation: Department of Medical Oncology, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi Zhuang Autonomous Region, People's Republic of China.
authors.forename: Lihua
authors.initials: L
authors.lastname: Yang
authors.affiliation: Department of Pathology, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi Zhuang Autonomous Region, People's Republic of China.
authors.forename: Gang
authors.initials: G
authors.lastname: Chen
keywords: HCC; STAT4; clinicopathological features; hepatocellular carcinoma; immunohistochemistry; in vitro; meta-analysis; signal transducers and activators of transcription 4