277 466

Cited 0 times in

RASSF1A-mediated amphiregulin regulation in hepatocellular carcinoma via Hippo pathway

Other Titles
 간세포암종에서 Hippo pathway를 통한 RASSF1A의 AREG 발현 조절 
Authors
 안의용 
Issue Date
2012
Description
Dept. of Medical Science/석사
Abstract
Ras association domain family 1 isoform A (RASSF1A) is a tumor suppressor and its methylation is involved in many human cancers including hepatocellular carcinoma (HCC). RASSF1A induces tumor suppressive effect by phosphorylation and activation of Hippo pathway kinase cascade.The activated kinase cascade leads to inhibition of yes-associated protein (YAP), a potent transcription coactivator playing a critical role as an oncogeniccomponent inducing tumorigenic effect in the Hippo pathway. Amphiregulin (AREG) is one of the target genes of YAPthat induces cell proliferation and anti-apoptoticeffect on cancer cells. Here, we demonstratethe regulation of AREG by RASSF1Aoverexpression through the Hippo pathway. Methylation of RASSF1A was examined in HepG2, Hep3B, Huh7, SK-Hep1, and PLC/PRF/5 HCC cells. Overexpression of RASSF1A reduced cell proliferation significantly in Hep3B and SK-Hep1 cells at 24h, 48h, and 72h and PLC/PRF/5 cells at 48h and 72h (p<0.05). RASSF1A overexpression also induced apoptosis in SK-Hep1 (p< 0.05) and PLC/PRF/5 cells. Phosphorylation of MST1/2 and YAP, which is a component of the Hippo pathway, was detected in Hep3B, SK-Hep1, and PLC/PRF/5 cells with overexpressed RASSF1A. As a result, we have also examined reduced AREG expressionin Hep3B, SK-Hep1, and PLC/PRF/5 cellswith overexpressed RASSF1A. Furthermore, in human liver tissues, RASSF1A expression was higher in non-tumor liver tissues than in HCC tissues,but AREG and YAP expressionswere higher in HCC tissues than in non-tumor liver tissues.Our results suggest that RASSF1A expression in HCC cells inhibit cell proliferation and induce apoptosis. Increased phosphorylation of MST and YAP in HCC cells with overexpressed RASSF1A, revealedthe activation of the Hippo pathway. We have also found the decrease of AREG levels in HCC cells with overexpressed RASSF1A, explaining the inhibition of YAP, which is a transcription coactivator of AREG. From the in vivo study results, we have showed that the detection of RASSF1A, YAP, and AREG in HCC tissues support the regulation of AREG by RASSF1A. Thus, our results support that RASSF1A-mediated downregulation of AREG activates the tumor suppressive Hippo pathway by phosphorylation of YAP.
Files in This Item:
T012043.pdf Download
Appears in Collections:
1. College of Medicine (의과대학) > Others (기타) > 2. Thesis
URI
https://ir.ymlib.yonsei.ac.kr/handle/22282913/133801
사서에게 알리기
  feedback

qrcode

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

Browse

Links