title: Arsenic trioxide prevents osteosarcoma growth by inhibition of GLI transcription via DNA damage accumulation.
abstract: The Hedgehog pathway is activated in various types of malignancies. We previously reported that inhibition of SMO or GLI prevents osteosarcoma growth in vitro and in vivo. Recently, it has been reported that arsenic trioxide (ATO) inhibits cancer growth by blocking GLI transcription. In this study, we analyzed the function of ATO in the pathogenesis of osteosarcoma. Real-time PCR showed that ATO decreased the expression of Hedgehog target genes, including PTCH1, GLI1, and GLI2, in human osteosarcoma cell lines. WST-1 assay and colony formation assay revealed that ATO prevented osteosarcoma growth. These findings show that ATO prevents GLI transcription and osteosarcoma growth in vitro. Flow cytometric analysis showed that ATO promoted apoptotic cell death. Comet assay showed that ATO treatment increased accumulation of DNA damage. Western blot analysis showed that ATO treatment increased the expression of γH2AX, cleaved PARP, and cleaved caspase-3. In addition, ATO treatment decreased the expression of Bcl-2 and Bcl-xL. These findings suggest that ATO treatment promoted apoptotic cell death caused by accumulation of DNA damage. In contrast, Sonic Hedgehog treatment decreased the expression of γH2AX induced by cisplatin treatment. ATO re-induced the accumulation of DNA damage attenuated by Sonic Hedgehog treatment. These findings suggest that ATO inhibits the activation of Hedgehog signaling and promotes apoptotic cell death in osteosarcoma cells by accumulation of DNA damage. Finally, examination of mouse xenograft models showed that ATO administration prevented the growth of osteosarcoma in nude mice. Because ATO is an FDA-approved drug for treatment of leukemia, our findings suggest that ATO is a new therapeutic option for treatment of patients with osteosarcoma.
authors.affiliation: Department of Orthopaedic Surgery, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan.
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Nakamura
authors.forename: Satoshi
authors.initials: S
authors.lastname: Nagano
authors.forename: Hiroko
authors.initials: H
authors.lastname: Nagao
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Ishidou
authors.forename: Masahiro
authors.initials: M
authors.lastname: Yokouchi
authors.forename: Masahiko
authors.initials: M
authors.lastname: Abematsu
authors.forename: Takuya
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Setsuro
authors.initials: S
authors.lastname: Komiya
authors.forename: Takao
authors.initials: T
authors.lastname: Setoguchi
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics; D000077237:Arsenic Trioxide; D001152:Arsenicals / Q000494:pharmacology* / Q000627:therapeutic use; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002945:Cisplatin / Q000494:pharmacology; D004249:DNA Damage / Q000235:genetics*; D053823:Hedgehog Proteins / Q000378:metabolism; D006801:Humans; D051379:Mice; D012516:Osteosarcoma / Q000188:drug therapy / Q000235:genetics / Q000473:pathology; D010087:Oxides / Q000494:pharmacology* / Q000627:therapeutic use; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects*; D000071676:Zinc Finger Protein GLI1
chemical_list: D001152:Arsenicals; C400551:GLI1 protein, human; D053823:Hedgehog Proteins; D010087:Oxides; D014157:Transcription Factors; D000071676:Zinc Finger Protein GLI1; D002945:Cisplatin; D000077237:Arsenic Trioxide