title: Arsenic trioxide potentiates the anti-cancer activities of sorafenib against hepatocellular carcinoma by inhibiting Akt activation.
abstract: Sorafenib is the standard first-line systemic drug for advanced hepatocellular carcinoma (HCC), but it also induces the activation of Akt, which contributes to the mechanisms for the resistance to sorafenib. Arsenic trioxide (ATO) is a currently clinically used anticancer drug and displays its anticancer activities by inhibiting Akt activation. Therefore, we hypothesized that ATO may potentiate the anti-cancer activities of sorafenib against HCC. The results have demonstrated that ATO synergized with sorafenib to inhibit the proliferation and promote the apoptosis of HCC cells by diminishing the increased activation of Akt by sorafenib. ATO was shown to inhibit the expression or activation of Akt downstream factors, including glycogen synthase kinase (GSK)-3β, mammalian target of rapamycin (mTOR), ribosomal protein S6 kinase (S6K), and eukaryotic translation initiation factor 4E-binding protein 1 (4EBP1), which regulate cell apoptosis and were upregulated or activated by sorafenib. Both sorafenib and ATO downregulated the expression of cyclin D1, resulting in HCC cells arrested at G0/G1 phase. ATO downregulated the expression of Bcl-2 and Bcl-xL and upregulated the expression of Bax, indicating that ATO could induce the apoptosis of HCC cells through the intrinsic pathways; but sorafenib showed little effects on these proteins of Bcl-2 family. ATO synergized with sorafenib to suppress the growth of HCC tumors established in mice by inhibiting the proliferation and inducing the apoptosis of HCC cells in situ. These results indicate that ATO may be a potential agent that given in combination with sorafenib acts synergistically for treating HCC.
authors.affiliation: Department of General Surgery, The Fourth Affiliated Hospital of Harbin Medical University, Harbin, 150001, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Zhai
authors.forename: Xian
authors.initials: X
authors.lastname: Jiang
authors.forename: Changjun
authors.initials: C
authors.lastname: He
authors.forename: Dali
authors.initials: D
authors.lastname: Zhao
authors.forename: Lixin
authors.initials: L
authors.lastname: Ma
authors.forename: Lishan
authors.initials: L
authors.lastname: Xu
authors.forename: Hongchi
authors.initials: H
authors.lastname: Jiang
authors.forename: Xueying
authors.initials: X
authors.lastname: Sun
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D000077237:Arsenic Trioxide; D001152:Arsenicals / Q000008:administration & dosage*; D006528:Carcinoma, Hepatocellular / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D049109:Cell Proliferation / Q000187:drug effects; D004357:Drug Synergism; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D056945:Hep G2 Cells; D006801:Humans; D008113:Liver Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D051379:Mice; D009363:Neoplasm Proteins / Q000096:biosynthesis; D009536:Niacinamide / Q000008:administration & dosage / Q000031:analogs & derivatives*; D010087:Oxides / Q000008:administration & dosage*; D010671:Phenylurea Compounds / Q000008:administration & dosage*; D051057:Proto-Oncogene Proteins c-akt / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D000077157:Sorafenib
chemical_list: D001152:Arsenicals; D009363:Neoplasm Proteins; D010087:Oxides; D010671:Phenylurea Compounds; D009536:Niacinamide; D000077157:Sorafenib; D051057:Proto-Oncogene Proteins c-akt; D000077237:Arsenic Trioxide