Article Text
Abstract
Background and objectives Cholangiocarcinoma is a devastating cancer of biliary origin with limited treatment options. The growth factor, progranulin, is overexpressed in a number of tumours. The study aims were to assess the expression of progranulin in cholangiocarcinoma and to determine its effects on tumour growth.
Methods The expression and secretion of progranulin were evaluated in multiple cholangiocarcinoma cell lines and in clinical samples from patients with cholangiocarcinoma. The role of interleukin 6 (IL-6)-mediated signalling in the expression of progranulin was assessed using a combination of specific inhibitors and shRNA knockdown techniques. The effect of progranulin on proliferation and Akt activation and subsequent effects of FOXO1 phosphorylation were assessed in vitro. Progranulin knockdown cell lines were established, and the effects on cholangiocarcinoma growth were determined.
Results Progranulin expression and secretion were upregulated in cholangiocarcinoma cell lines and tissue, which were in part via IL-6-mediated activation of the ERK1/2/RSK1/C/EBPβ pathway. Blocking any of these signalling molecules, by either pharmacological inhibitors or shRNA, prevented the IL-6-dependent activation of progranulin expression. Treatment of cholangiocarcinoma cells with recombinant progranulin increased cell proliferation in vitro by a mechanism involving Akt phosphorylation leading to phosphorylation and nuclear extrusion of FOXO1. Knockdown of progranulin expression in cholangiocarcinoma cells decreased the expression of proliferating cellular nuclear antigen, a marker of proliferative capacity, and slowed tumour growth in vivo.
Conclusions Evidence is presented for a role for progranulin as a novel growth factor regulating cholangiocarcinoma growth. Specific targeting of progranulin may represent an alternative for the development of therapeutic strategies.
- IL-6
- C/EBPβ
- FOXO1
- growth factors
- biliary cancer
- autoimmunity
- primary biliary cirrhosis
- autoimmune biliary disease
- primary sclerosing cholangitis
- cholangiocarcinoma
- abdominal surgery
- acute pancreatitis
- bile duct surgery
- acute liver failure
- bile acid metabolism
- cholangiocarcinoma
- biliary physiology
- biliary epithelium
- molecular biology
- bile acid
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- IL-6
- C/EBPβ
- FOXO1
- growth factors
- biliary cancer
- autoimmunity
- primary biliary cirrhosis
- autoimmune biliary disease
- primary sclerosing cholangitis
- cholangiocarcinoma
- abdominal surgery
- acute pancreatitis
- bile duct surgery
- acute liver failure
- bile acid metabolism
- cholangiocarcinoma
- biliary physiology
- biliary epithelium
- molecular biology
- bile acid
Footnotes
See Commentary, p 170
Funding This work was supported by an NIH K01 grant award (DK078532) and an NIH R03 grant award (DK088012) to SD. FB was in part supported by Clonit s.r.l., Milan, Italy. This material is the result of work supported with resources of, and use of facilities at, the Central Texas Veterans Health Care System, Temple, Texas.
Competing interests None.
Ethics approval The ethics committee of the IRCCS Istituto Clinico Humanitas.
Provenance and peer review Not commissioned; externally peer reviewed.