VIRMA/IGF2BP3-mediated ANLN upregulation promotes intrahepatic cholangiocarcinoma growth by forming a positive feedback loop with RhoA/YAP1/TEAD1 signaling pathway

The prognosis of patients with intrahepatic cholangiocarcinoma (ICC) remains poor owing to the lack of effective targeted therapeutic strategies. Thus, the exploration of the molecular pathogenesis of ICC is urgently required. The cytoskeleton protein, anillin (ANLN), has been reported to contribute to various tumor growth by participating in cytokinesis via RhoA signaling. However, the exact physiological role and potential regulatory mechanism of ANLN in ICC are still not well understood. Based on spindle-related genes, integrated bioinformatic analyses identified ANLN as a potential candidate target for ICC. ANLN was elevated in ICC and predicted worse survival. Mechanistically, VIRMA-mediated m6A modification and IGF2BP3-dependent interaction collectively accounted for the upregulation of ANLN by maintaining its mRNA stability. Furthermore, the combination of ANLN and VIRMA or IGF2BP3 offered a greater predictive value than each marker alone in a large ICC cohort. Functional studies indicated that ANLN was involved in cancer cell proliferation and cell cycle. ANLN knockdown induced cytokinesis failure, DNA damage, and apoptosis in ICC cells. In addition to discovering the crucial role of ANLN in cytokinesis via RhoA activation, we also illustrated that ANLN restrained the Hippo pathway by enhancing the activity of RhoA signaling, which together contributed to ANLN-mediated tumor-promoting effects on ICC. Furthermore, YAP1-TEAD1 transcriptionally activated ANLN, subsequently establishing a self-reinforcing loop between ANLN and Hippo pathway, which was mediated by RhoA signaling as an intermediate regulatory node. Importantly, two clinical drugs, the RhoA inhibitor simvastatin and the YAP1/TEAD inhibitor verteporfin were determined to be the disruptors of this feed-forward signaling axis, inhibiting ICC tumor growth. These findings reveal the vital function of ANLN in ICC growth and provide promising treatment strategies for ICC.