title: Bone morphogenetic protein-9 induces epithelial to mesenchymal transition in hepatocellular carcinoma cells.
abstract: Epithelial-mesenchymal transition (EMT) is an important mechanism to initiate cancer invasion and metastasis. Bone morphogenetic protein (BMP)-9 is a member of the transforming growth factor (TGF)-β superfamily. It has been suggested to play a role in cancer development in some non-hepatic tumors. In the present study, two hepatocellular carcinoma (HCC) lines, HLE and HepG2, were treated with BMP-9 in vitro, and phenotypic changes and cell motility were analyzed. In situ hybridization (ISH) and immunohistochemical analyses were performed with human HCC tissue samples in order to assess expression levels of BMP-9. In vivo, BMP-9 protein and mRNA were expressed in all the tested patients to diverse degrees. At the protein level, mildly positive (1 + ) BMP-9 staining could be observed in 25/41 (61%), and moderately to strongly positive (2 + ) in 16/41 (39%) of the patients. In 27/41 (65%) patients, the BMP-9 protein expression level was consistent with the mRNA expression level as measured by ISH. In those patients with 2 + protein level, nuclear pSmad1 expression in cancer cells was also significantly increased. Expression of BMP-9 was positively related to nuclear Snail expression and reversely correlated to cell surface E-cadherin expression, although this did not reach statistical significance. Expression levels of BMP-9 were significantly associated with the T stages of the investigated tumors and high levels of BMP-9 were detected by immunofluorescence especially at the tumor borders in samples from an HCC mouse model. In vitro, BMP-9 treatment caused a reduction of E-cadherin and ZO-1 and an induction of Vimentin and Snail expression. Furthermore, cell migration was enhanced by BMP-9 in both HCC cell lines. These results imply that EMT induced by BMP-9 is related to invasiveness of HCC.
authors.affiliation: Department of Medicine II, Section Molecular Hepatology - Alcohol Associated Diseases, Medical Faculty Mannheim at Heidelberg University, Mannheim, Germany.
authors.forename: Qi
authors.initials: Q
authors.lastname: Li
authors.forename: Xing
authors.initials: X
authors.lastname: Gu
authors.forename: Honglei
authors.initials: H
authors.lastname: Weng
authors.forename: Shahrouz
authors.initials: S
authors.lastname: Ghafoory
authors.forename: Yan
authors.initials: Y
authors.lastname: Liu
authors.forename: Teng
authors.initials: T
authors.lastname: Feng
authors.forename: Johanna
authors.initials: J
authors.lastname: Dzieran
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.forename: Iryna
authors.initials: I
authors.lastname: Ilkavets
authors.forename: Marianna
authors.initials: M
authors.lastname: Kruithof-de Julio
authors.forename: Stefan
authors.initials: S
authors.lastname: Munker
authors.forename: Alexander
authors.initials: A
authors.lastname: Marx
authors.forename: Albrecht
authors.initials: A
authors.lastname: Piiper
authors.forename: Eduardo
authors.initials: E
authors.lastname: Augusto Alonso
authors.forename: Norbert
authors.initials: N
authors.lastname: Gretz
authors.forename: Chunfang
authors.initials: C
authors.lastname: Gao
authors.forename: Stefan
authors.initials: S
authors.lastname: Wölfl
authors.forename: Steven
authors.initials: S
authors.lastname: Dooley
authors.forename: Katja
authors.initials: K
authors.lastname: Breitkopf-Heinlein
mesh_terms: D015820:Cadherins / Q000378:metabolism; D006528:Carcinoma, Hepatocellular / Q000378:metabolism* / Q000473:pathology*; D045744:Cell Line, Tumor; D058750:Epithelial-Mesenchymal Transition; D005260:Female; D055427:Growth Differentiation Factor 2; D006801:Humans; D008113:Liver Neoplasms / Q000378:metabolism* / Q000473:pathology*; D008297:Male; D008875:Middle Aged
chemical_list: D015820:Cadherins; D055427:Growth Differentiation Factor 2