title: Expression of YY1 correlates with progression and metastasis in esophageal squamous cell carcinomas.
abstract: OBJECTIVE
  Esophageal squamous cell carcinoma (ESCC) is one of the deadliest cancers worldwide. Yin Yang 1 (YY1) is a ubiquitous and multifunctional zinc-finger transcription factor that plays important biological functions in cell homeostasis and tumorigenesis. The purpose of this study was to investigate the expression of YY1 in different ESCC tissues and the potential relationship with clinicopathological features.
  
  
  METHODS
  One hundred and four ESCC tissues were collected in this study. The protein levels of YY1 were measured by immunohistochemistry. TE-1 cell invasion in vitro was assessed using the Transwell assay.
  
  
  RESULTS
  There were no obvious differences between expression levels in patients over age 64 and those younger than 64, and no noticeable distinction was observed between males and females. However, the YY1 protein level was significantly higher in ESCC tissues with lymph node metastasis than those without lymph node metastasis (P=0.042). Furthermore, the expression of the YY1 protein was stronger in stage III-IV patients than in stage I-II patients (P=0.002), but the protein levels between different histological grades (well, moderate, or poor) showed no statistical significance. Similarly, there was no difference in YY1 expression in patients with or without lymphatic invasion. The Transwell assay revealed that the overexpression of YY1 promoted the invasion ability of TE-1 cells and the inhibition of YY1 could reverse this promotion.
  
  
  CONCLUSIONS
  YY1 expression was associated with TNM stage and lymph node metastasis, suggesting that YY1 can influence human esophageal cancer progression and metastasis.
authors.affiliation: Department of Radiotherapy, Changzhou Tumor Hospital, Soochow University, Changzhou, People's Republic of China.
authors.forename: Judong
authors.initials: J
authors.lastname: Luo
authors.affiliation: Department of Radiotherapy, Changzhou Tumor Hospital, Soochow University, Changzhou, People's Republic of China.
authors.forename: Xin
authors.initials: X
authors.lastname: Jiang
authors.affiliation: Department of Molecular Radiobiology, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima, Japan.
authors.forename: LiLi
authors.initials: L
authors.lastname: Cao
authors.affiliation: Department of Radiotherapy, Changzhou Tumor Hospital, Soochow University, Changzhou, People's Republic of China.
authors.forename: Kejun
authors.initials: K
authors.lastname: Dai
authors.affiliation: School of Radiation Medicine and Protection and Jiangsu Provincial Key Laboratory of Radiation Medicine and Protection, Soochow University, Suzhou, People's Republic of China ; Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions and School for Radiological and Interdisciplinary Sciences (RAD-X), Soochow University, Suzhou, People's Republic of China.
authors.forename: Shuyu
authors.initials: S
authors.lastname: Zhang
authors.affiliation: School of Radiation Medicine and Protection and Jiangsu Provincial Key Laboratory of Radiation Medicine and Protection, Soochow University, Suzhou, People's Republic of China ; Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions and School for Radiological and Interdisciplinary Sciences (RAD-X), Soochow University, Suzhou, People's Republic of China.
authors.forename: Xin
authors.initials: X
authors.lastname: Ge
authors.affiliation: Department of Radiotherapy, Changzhou Tumor Hospital, Soochow University, Changzhou, People's Republic of China.
authors.forename: Xifa
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Department of Radiotherapy, Changzhou Tumor Hospital, Soochow University, Changzhou, People's Republic of China.
authors.forename: Xujing
authors.initials: X
authors.lastname: Lu
keywords: clinicopathological features; immunohistochemistry; invasion; transwell assay