Cholangiocarcinoma (CCA) is a deadly cancer worldwide and opening the field to new concepts is required to improve the survival of patients. Recently, circular RNAs (circRNAs) emerged in the field of cancer but their role in CCA onset and progression has been poorly investigated. Here, we identified circRNAs regulated by Transforming Growth Factor beta (TGFb) in CCA cell lines, including circRNA-TB1, which expression in CCA tumors is predictive of a poor survival. Functional studies demonstrated that circRNA-TB1 increases tumor cell proliferation, migration, and resistance to gemcitabine-induced apoptosis, and promotes tumor growth in mice. Mechanistically, circRNA-TGFB1 may act as a competitive RNA sponge for miR-338, a tumor suppressor microRNA. More interestingly, circRNA-TB1 is detected in extra-cellular vesicles isolated from the serum of patients with CCA, where it is predictive of a poor prognosis, opening the field to innovative biomarkers.
Hosted by Isabel Fabregat – TGF-beta and cancer Group