Contribution of RIZ1 to regulation of proliferation and migration of a liver fluke-related cholangiocarcinoma cell.

Retinoblastoma-interacting zinc finger gene (RIZ1) is a tumor suppressor gene which is highly inactivated by promoter hypermethylation in patients with liver fluke-related cholangiocarcinoma (CCA). Epigenetic aberration of this gene might withdraw the ability to restrain tumor cell proliferation and migration. We aimed to define the role of RIZ1 on cell proliferation and migration in CCA cell line. Small interference RNA (siRNA) was used to knock down the expression of RIZ1 in a CCA-derived cell line in which cell proliferation and cell migration were performed. A predominant nuclear localization of RIZ1 was observed. Reduction of RIZ1 by siRNA augmented cell proliferation and migration. The result suggested that RIZ1 might play a role in regulating cell proliferation and migration in CCA. Reduction of RIZ1 expression may aggravate the progression of CCA.