Overexpression of Plk1 promotes malignant progress in human esophageal squamous cell carcinoma

  • Chunling ZhaoEmail author
  • Lei Gong
  • Wentong Li
  • Limei Chen
Original Paper



Plk1, belonging to a family of serine/threonine kinases, is involved in spindle formation and chromosome segregation during mitosis and therefore, in the regulation of cell cycle. Plk1 was found to be overexpressed in various human tumors. In the present work, we investigated the expression of human esophageal squamous cell carcinoma (ESCC) to determine whether Plk1 has a role in malignant progress.


Immunohistochemistry and Western blotting were performed to define the expressions of Plk1 in ESCC tissues and normal adjacent tissues. Transfection of cells with small interference RNA, growth suppression assay, and Transwell assay were used to determine the potential role of Plk1 in ESCC malignant progress.


Plk1 was overexpressed in 69.6% of the ESCC tissues. In addition, the extent of Plk1 expression was closely correlated with differentiation grades and invasiveness in ESCC. We also found that the downregulation of endogenous Plk1 in human ESSC cell lines Eca-109 and EC9706 significantly decreased cells proliferation and migrating ability.


Our results show that Plk1 expression is elevated in ESCC tissues and is associated with differentiation grades and invasiveness in ESCC, indicating that overexpression of Plk1 may play an important role in carcinogenesis and malignant progress of ESCC.


Plk1 Overexpression ESCC Small interfering RNA Proliferation Migration 



This research was supported in part by grants from doctoral Science Foundation in Weifang Medical University (200710023).

Conflict of interest statement

The authors declare that we have no conflict of interest.


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Copyright information

© Springer-Verlag 2009

Authors and Affiliations

  • Chunling Zhao
    • 1
    Email author
  • Lei Gong
    • 2
  • Wentong Li
    • 1
  • Limei Chen
    • 1
  1. 1.Basic Medicine DepartmentWeifang Medical UniversityWeifangPeople’s Republic of China
  2. 2.Medical SchoolShandong UniversityJinanPeople’s Republic of China

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