摘要
Pancreatic ductal adenocarcinoma(PDAC)has poor prognosis due to limited therapeutic options.This study examines the roles of genome-wide association study identified PDAC-associated genes as therapeutic targets.We have identified HNF4G gene whose silencing most effectively repressed PDAC cell invasiveness.HNF4G overexpression is induced by the deficiency of transcriptional factor and tumor suppressor SMAD4.Increased HNF4G are correlated with SMAD4 deficiency in PDAC tumor samples and associated with metastasis and poor survival time in xenograft animal model and in patients with PDAC(log-rank P=0.036;HR=1.60,95%CI=1.03–2.47).We have found that Metformin suppresses HNF4G activity via AMPK-mediated phosphorylation-coupled ubiquitination degradation and inhibits in vitro invasion and in vivo metastasis of PDAC cells with SMAD4 deficiency.Furthermore,Metformin treatment significantly improve clinical outcomes and survival in patients with SMAD4-deficient PDAC(log-rank P=0.022;HR=0.31,95%CI=0.14–0.68)but not in patients with SMAD4-normal PDAC.Pathway analysis shows that HNF4G may act in PDAC through the cell-cell junction pathway.These results indicate that SMAD4 deficiency-induced overexpression of HNF4G plays a critical oncogenic role in PDAC progression and metastasis but may form a druggable target for Metformin treatment.
基金
We gratefully appreciate Y.L.,Q.C.and L.P.for their assistances in data analysis and T.L.,Y.C.and W.F.for their assistances in preparation of figures.We also thank G.Y.and Y.D.for their assistances in cell lines and animal experiments.This work was supported by National Science Fund for Distinguished Young Scholars(Grant No.81725015 to C.W.)
Beijing Outstanding Young Scientist Program(Grant No.BJJWZYJH01201910023027 to C.W.)
CAMS Innovation Fund for Medical Sciences(CIFMS)(Grant No.2016-I2M-3-019 to D.L.,Grant No.2016-I2M-4-002 to C.W.and Grant No.2016-I2M-1-001 to W.T.).
