Erschienen in:
01.08.2010 | Original Article
PinX1 Inhibits Telomerase Activity in Gastric Cancer Cells Through Mad1/c-Myc Pathway
verfasst von:
Hong-bin Wang, Xing-wei Wang, Gang Zhou, Wei-qiang Wang, Yong-gang Sun, Shi-ming Yang, Dian-chun Fang
Erschienen in:
Journal of Gastrointestinal Surgery
|
Ausgabe 8/2010
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Abstract
Introduction
The aim of this study was to investigate the role of Mad1/c-Myc in telomerase regulation in gastric cancer cells in order to gain insight into telomerase activity and to evaluate PinX1 as a putative inhibitor of gastric cancer.
Methods
PinX1 and PinX1siRNA eukaryotic expression vectors were constructed by recombinant technology and transfected into gastric carcinoma cells using Lipofectamine™ 2000. Telomerase activity was measured by the telomeric repeat amplification protocol. Apoptosis of gastric cancer cells was analyzed by flow cytometry and transmission electron microscopy. Reverse transcription-polymerase chain reaction and Western blotting were used to assess the expression levels of PinX1 and Mad1/c-Myc.
Results
We found that PinX1-negative gastric cancer cells showed significantly higher telomerase activity than did the PinX1-postive cells. PinX1-transfection reduced telomerase activity in PinX1-negative gastric cancer cells and exhibited an upregulation of Mad1 and downregulation of c-Myc expression. Pinx1 RNAi treatment led to downregulation of Mad1 and upregulation of c-Myc.
Conclusion
Suppression of telomerase activity mediated by PinX1 is involved in the Mad1/c-Myc pathway.