PURPOSE: Histone deactylase inhibitors (HDACi) are a promising new class of anticancer therapeutics; however, little is known about HDACi activity in soft tissue sarcoma (STS), a heterogeneous cohort of mesenchymal origin malignancies. Consequently, we investigated the novel HDACi PCI-24781, alone/in combination with conventional chemotherapy, to determine its potential anti-STS-related effects and the underlying mechanisms involved. EXPERIMENTAL DESIGN: Immunoblotting was used to evaluate the effects of PCI-24781 on histone and nonhistone protein acetylation and expression of potential downstream targets. Cell culture-based assays were utilized to assess the effects of PCI-24781 on STS cell growth, cell cycle progression, apoptosis, and chemosensitivity. Quantitative reverse transcription-PCR, chromatin immunoprecipitation, and reporter assays helped elucidate molecular mechanisms resulting in PCI-24781-induced Rad51 repression. The effect of PCI-24781, alone or with chemotherapy, on tumor and metastatic growth was tested in vivo using human STS xenograft models. RESULTS: PCI-24781 exhibited significant anti-STS proliferative activity in vitro, inducing S phase depletion, G(2)/M cell cycle arrest, and increasing apoptosis. Superior effects were seen when combined with chemotherapy. A PCI-24781-induced reduction in Rad51, a major mediator of DNA double-strand break homologous recombination repair, was shown and may be a mechanism underlying PCI-24781 chemosensitization. We showed that PCI-24781 transcriptionally represses Rad51 through an E2F binding-site on the Rad51 proximal promoter. Although single-agent PCI-24781 had modest effects on STS growth and metastasis, marked inhibition was observed when combined with chemotherapy. CONCLUSIONS: In light of these findings, this novel molecular-based combination may be applicable to multiple STS histologic subtypes, and potentially merits rigorous evaluation in human STS clinical trials.
PURPOSE: Histone deactylase inhibitors (HDACi) are a promising new class of anticancer therapeutics; however, little is known about HDACi activity in soft tissue sarcoma (STS), a heterogeneous cohort of mesenchymal origin malignancies. Consequently, we investigated the novel HDACi PCI-24781, alone/in combination with conventional chemotherapy, to determine its potential anti-STS-related effects and the underlying mechanisms involved. EXPERIMENTAL DESIGN: Immunoblotting was used to evaluate the effects of PCI-24781 on histone and nonhistone protein acetylation and expression of potential downstream targets. Cell culture-based assays were utilized to assess the effects of PCI-24781 on STS cell growth, cell cycle progression, apoptosis, and chemosensitivity. Quantitative reverse transcription-PCR, chromatin immunoprecipitation, and reporter assays helped elucidate molecular mechanisms resulting in PCI-24781-induced Rad51 repression. The effect of PCI-24781, alone or with chemotherapy, on tumor and metastatic growth was tested in vivo using human STS xenograft models. RESULTS:PCI-24781 exhibited significant anti-STS proliferative activity in vitro, inducing S phase depletion, G(2)/M cell cycle arrest, and increasing apoptosis. Superior effects were seen when combined with chemotherapy. A PCI-24781-induced reduction in Rad51, a major mediator of DNA double-strand break homologous recombination repair, was shown and may be a mechanism underlying PCI-24781 chemosensitization. We showed that PCI-24781 transcriptionally represses Rad51 through an E2F binding-site on the Rad51 proximal promoter. Although single-agent PCI-24781 had modest effects on STS growth and metastasis, marked inhibition was observed when combined with chemotherapy. CONCLUSIONS: In light of these findings, this novel molecular-based combination may be applicable to multiple STS histologic subtypes, and potentially merits rigorous evaluation in human STS clinical trials.
Authors: S Thomas; R Aggarwal; T Jahan; C Ryan; T Troung; A M Cripps; P Raha; K T Thurn; S Chen; J A Grabowsky; J Park; J Hwang; A Daud; P N Munster Journal: Ann Oncol Date: 2016-02-21 Impact factor: 32.976
Authors: Gonzalo Lopez; Yechun Song; Ryan Lam; Dennis Ruder; Chad J Creighton; Hemant Kumar Bid; Kate Lynn Bill; Svetlana Bolshakov; Xiaoli Zhang; Dina Lev; Raphael E Pollock Journal: Mol Cancer Res Date: 2015-09-22 Impact factor: 5.852
Authors: William G Kraybill; Jonathan Harris; Ira J Spiro; David S Ettinger; Thomas F DeLaney; Ronald H Blum; David R Lucas; David C Harmon; G Douglas Letson; Burton Eisenberg Journal: Cancer Date: 2010-10-01 Impact factor: 6.860
Authors: Christine M Kivlin; Kelsey L Watson; Ghadah A Al Sannaa; Roman Belousov; Davis R Ingram; Kai-Lieh Huang; Caitlin D May; Svetlana Bolshakov; Sharon M Landers; Azad Abul Kalam; John M Slopis; Ian E McCutcheon; Raphael E Pollock; Dina Lev; Alexander J Lazar; Keila E Torres Journal: Cancer Biol Ther Date: 2015-12-09 Impact factor: 4.742