title: Caveolin-1 overexpression is associated with hepatocellular carcinoma tumourigenesis and metastasis.
abstract: Caveolin-1 (Cav1) has been implicated in diverse human cancers, yet its role in hepatocellular carcinoma (HCC) tumourigenesis and metastasis remains elusive. In the current study, we aim to provide a comprehensive understanding regarding the functional role of Cav1 in HCC tumourigenesis and metastasis. Cav1 expression was examined in a panel of human HCC cell lines using western blotting analysis and quantitative RT-PCR and human tissues by immunohistochemistry. Cav1 was not detected in normal liver cell line and all non-tumourous liver tissues but exclusively expressed in HCC cell lines and tissues. Dramatic expression of Cav1 was found in metastatic HCC cell lines and tumours, indicating a progressive increase of Cav1 expression along disease progression. Cav1 overexpression was significantly correlated with venous invasion (p = 0.036). To investigate the functions of Cav1 in HCC, Cav1 overexpressing and knockdown stable clones were established in HCC cells and their tumourigenicity and metastatic potential were examined. Overexpression of Cav1 promoted HCC cell growth, motility, and invasiveness, as well as tumourigenicity in vivo. Conversely, knockdown of Cav1 in metastatic HCC cells inhibited the motility and invasiveness and markedly suppressed the tumour growth and metastatic potential in vivo. Collectively, our findings have shown the exclusive expression of Cav1 in HCC cell lines and clinical samples and revealed an up-regulation of Cav1 along HCC progression. The definitive role of Cav1 in promoting HCC tumourigenesis was demonstrated, and we have shown for the first time in a mouse model that Cav1 promotes HCC metastasis.
authors.affiliation: Department of Pathology, The University of Hong Kong, Hong Kong.
authors.forename: Edith Yuk Ting
authors.initials: EY
authors.lastname: Tse
authors.forename: Frankie Chi Fat
authors.initials: FC
authors.lastname: Ko
authors.forename: Edmund Kwok Kwan
authors.initials: EK
authors.lastname: Tung
authors.forename: Lo Kong
authors.initials: LK
authors.lastname: Chan
authors.forename: Terence Kin Wah
authors.initials: TK
authors.lastname: Lee
authors.forename: Elly Sau Wai
authors.initials: ES
authors.lastname: Ngan
authors.forename: Kwan
authors.initials: K
authors.lastname: Man
authors.forename: Alice Sze Tsai
authors.initials: AS
authors.lastname: Wong
authors.forename: Irene Oi-Lin
authors.initials: IO
authors.lastname: Ng
authors.forename: Judy Wai Ping
authors.initials: JW
authors.lastname: Yam
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D006528:Carcinoma, Hepatocellular / Q000235:genetics / Q000401:mortality / Q000556:secondary*; D051242:Caveolin 1 / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D002465:Cell Movement; D049109:Cell Proliferation; D002999:Clone Cells; D004195:Disease Models, Animal; D018450:Disease Progression; D005260:Female; D055785:Gene Knockdown Techniques; D020868:Gene Silencing; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D008099:Liver / Q000378:metabolism / Q000473:pathology; D008113:Liver Neoplasms / Q000235:genetics / Q000401:mortality / Q000473:pathology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D008875:Middle Aged; D009368:Neoplasm Transplantation; D015996:Survival Rate; D015854:Up-Regulation; D055815:Young Adult
chemical_list: D051242:Caveolin 1