title: Glycogen synthase kinase 3 regulates PAX3-FKHR-mediated cell proliferation in human alveolar rhabdomyosarcoma cells.
abstract: Patients with alveolar rhabdomyosarcoma (ARMS) have poorer response to conventional chemotherapy and lower survival rates than those with embryonal RMS (ERMS). To identify compounds that preferentially block the growth of ARMS, we conducted a small-scale screen of 160 kinase inhibitors against the ARMS cell line Rh30 and ERMS cell line RD and identified inhibitors of glycogen synthase kinase 3 (GSK3), including TWS119 as ARMS-selective inhibitors. GSK3 inhibitors inhibited cell proliferation and induced apoptosis more effectively in Rh30 than RD cells. Ectopic expression of fusion protein PAX3-FKHR in RD cells significantly increased their sensitivity to TWS119. Down-regulation of GSK3 by GSK3 inhibitors or siRNA significantly reduced the transcriptional activity of PAX3-FKHR. These results suggest that GSK3 is directly involved in regulating the transcriptional activity of PAX3-FKHR. Also, GSK3 phosphorylated PAX3-FKHR in vitro, suggesting that GSK3 might regulate PAX3-FKHR activity via phosphorylation. These findings support a novel mechanism of PAX3-FKHR regulation by GSK3 and provide a novel strategy to develop GSK inhibitors as anti-ARMS therapies.
authors.affiliation: Department of Chemical Biology and Therapeutics, St Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA.
authors.forename: Fu-Yue
authors.initials: FY
authors.lastname: Zeng
authors.forename: Hanqing
authors.initials: H
authors.lastname: Dong
authors.forename: Jimmy
authors.initials: J
authors.lastname: Cui
authors.forename: Lingling
authors.initials: L
authors.lastname: Liu
authors.forename: Taosheng
authors.initials: T
authors.lastname: Chen
mesh_terms: D000970:Antineoplastic Agents / Q000302:isolation & purification / Q000494:pharmacology*; D049109:Cell Proliferation / Q000187:drug effects*; D004354:Drug Screening Assays, Antitumor; D000071161:Forkhead Box Protein O1; D051858:Forkhead Transcription Factors / Q000378:metabolism*; D038362:Glycogen Synthase Kinase 3 / Q000037:antagonists & inhibitors* / Q000378:metabolism; D006801:Humans; D000072041:PAX3 Transcription Factor; D051761:Paired Box Transcription Factors / Q000378:metabolism*; D010766:Phosphorylation; D047428:Protein Kinase Inhibitors / Q000302:isolation & purification / Q000494:pharmacology*; D011743:Pyrimidines / Q000494:pharmacology; D011758:Pyrroles / Q000494:pharmacology; D018232:Rhabdomyosarcoma, Alveolar / Q000201:enzymology* / Q000473:pathology
chemical_list: D000970:Antineoplastic Agents; C085126:FOXO1 protein, human; D000071161:Forkhead Box Protein O1; D051858:Forkhead Transcription Factors; D000072041:PAX3 Transcription Factor; C489409:PAX3 protein, human; D051761:Paired Box Transcription Factors; D047428:Protein Kinase Inhibitors; D011743:Pyrimidines; D011758:Pyrroles; C547688:TWS 119; D038362:Glycogen Synthase Kinase 3