Reduction of tumorigenesis in androgen receptor overexpressed Huh7 cells through TGF-β induced cellular senescence phenotypes

PURPOSE: Hepatocellular carcinoma (HCC) is a primary malignancy (cancer) of the liver. HCC has been known as androgen-dependent tumor with incidence of five times higher and worse prognosis in male than female. Steroid hormones and their receptors play a major role in the development of many types of human and animal cancers. It has been known that androgen and its receptor (AR) are significantly related with hepatocarcinogenesis both in human and animals, however, the level of AR in hepatoma is variable and their exact effects are still poorly explained. Therefore, we investigated the role of androgen receptor (AR) in HCC development. METHOD: To investigate the potential role of AR in hepatoma, Huh7-AR and Huh7-V cell lines were established by transfection of Huh7 hepatocelluar carcinoma (HCC) cells with human androgen receptor (AR) in pCMV5 and its empty vector, respectively. And their in vivo and in vitro tumorigenesis were evaluated in nude mice as well as in cell culture systems. RESULTS: AR overexpressing Huh7 cells, Huh7-AR, and its control, Huh7-V cells, were established. AR expression was measured by RT-PCR and immunoblot analyses. Huh7-AR cells, which were responsive to 5 alpha-dihydrotestosterone (DHT), revealed a decreased tumorigenecity in nude mice in addition to reduced clonogenicity in vitro, as compared with those of Huh7-V cells; Tumor volume and multiplicity of the HCC development in nude mice and invasiveness of the Huh7-AR cells, measured by Matrigel chamber analysis, were significantly reduced than those of Huh7-V cells. Interestingly, when cultured in the presence of DHT, Huh7-AR cells induced cellular senescence phenotypes, such as SA-beta-galactosidase activity, nuclear actin translocation, cytoplasmic p-Erk1/2 sequestration and reduced telomerase activity. When underlying mechanisms were studied in more detail in the cell culture system with or without DHT, TGF-beta1 mRNA expression was increased in the Huh7-AR cells and HCC tumors in the presence of DHT. At the same time, secretion of TGF-beta 1 was significantly higher in the Huh7-AR cells than that in Huh7-V cells. The effect of TGF-beta 1 on the induction of senescence of Huh7-AR cells was studied by infection of dominant negative TGFbeta-RII adenovirus (TGFbeta RII DN-Ad); The reduced growth rate and other cellular senescence phenotypes were significantly recovered after TGFbeta RII DN-Ad infection, compared with the infection of its control viruses. The above data strongly indicate that androgen receptor inhibits progression of HCC formation by Huh7-AR cells through the induction of senescence phenotypes via TGF-beta 1 expression in the presence of DHT.

Author dc:creator

• 김, 지연

Contributors dc:contributor

• 임, 인경
• 대학원 의학과
• 200124412

• Huh7 hepatoma cells
• Androgen receptor
• Dihydrotestosterone
• Cellular senescence
• TGF-beta1

Language dc:language

en

Identifier

http://dcoll.ajou.ac.kr:9080/dcollection/jsp/common/DcLoOrgPer.jsp?sItemId=000000002079
000000002079

OAI identifier oai:identifier

oai:repository.ajou.ac.kr:201003/1191