Abstract A13: Genome-wide transcriptional analysis of HDAC inhibition-induced apoptosis in synovial sarcoma

Introduction: Conventional cytotoxic therapies for synovial sarcoma provide limited benefit, and no drugs specifically targeting its driving SS18-SSX fusion oncoprotein are currently available. HDAC inhibition has been shown in previous studies to disrupt the driving complex implicated in synovial sarcoma, resulting in apoptosis induction.

Methods: Transcriptome analysis was undertaken in a panel of six human synovial sarcoma cell lines in order to uncover potential mechanisms of cell death following HDAC inhibition. By comparison studies with five additional publicly available related expression datasets, common class effects resulting from HDAC inhibition were investigated. Five human synovial sarcoma tumor samples were profiled by RNA-seq for comparison. A mouse model of synovial sarcoma was treated by HDAC inhibition and tumors were profiled for apoptotic markers.

Results: Cell cycle arrest, differentiation, and response to oxygen-containing species and cell death were common biologic responses among the panel of post-HDAC inhibitor expression studies. Specific to synovial sarcoma, reactivation of repressed tumor suppressor CDKN2A and induction of proapoptotic transcriptional patterns results in apoptosis and decreased tumor burden in vivo.

Conclusion: HDAC inhibition impedes SS18-SSX-mediated transcriptional deregulation, allowing for reactivation of normal cell cycle regulatory and apoptotic pathways. This study provides mechanistic support for a particular susceptibility of synovial sarcoma to HDAC inhibition as a means of potential clinical treatment.

Citation Format: Aimee N. Laporte, Neal M. Poulin, Alireza Lorzadeh, Xiu Qing Wang, Ryan Vander werff, Jared J. Barrott, Michelle Moska, Christopher Hughes, Gregg Morin, Kevin B. Jones, Martin Hirst, T. Michael Underhill, Torsten O. Nielsen. Genome-wide transcriptional analysis of HDAC inhibition-induced apoptosis in synovial sarcoma [abstract]. In: Proceedings of the AACR Conference on Advances in Sarcomas: From Basic Science to Clinical Translation; May 16-19, 2017; Philadelphia, PA. Philadelphia (PA): AACR; Clin Cancer Res 2018;24(2_Suppl):Abstract nr A13.

Cytogenetic Examination of South American Tapirs, Tapirus Terrestris (Perissodactyla, Tapiridae), from the Wroclaw Zoological Garden

Cytogenetic Examination of South American Tapirs, Tapirus terrestris (Perissodactyla, Tapiridae) from the Wroclaw Zoological Garden. Kosowska, B., Strzała, T., Moska, M., Ratajszczak, R., Dobosz, T. - Seven lowland tapirs (Tapirus terrestris) from Wrocław ZOO (three females and four males), differing from each other with exterior and sexual behaviour were verified with cytogenetic analysis in order to check their taxonomic status. Cytogenetic analysis was done using two alternative methods of blood collection: 1) conventionally with venepuncture, and 2) with blood sucking bugs from the Reduviidae family. Lymphocytes capable of growing were obtained only with conventional method of blood sampling. Karyotypes and karyograms of all analyzed tapirs were created using classical cytogenetic methods of chromosomes staining. All possessed karyograms had diploid chromosome number equal 80 (2n = 80). Homologous chromosomes did not differ between each other with quantity, size, centromeres location, length of arms, G bands and all were classified as proper karyograms of Tapirus terrestris species representatives. The X chromosomes as well as the first pair of chromosomes (both metacentric), were the largest among all analyzed, respectively. All remaining 38 pairs of chromosomes were acrocentric with Y chromosome as the smallest one (in males’ karyograms). Blood collected with blood sucking bugs proved to be unsuitable for cell culture. None of the seven established cultures was effective as lymphocytes obtained with this method did not show growth potential in prepared media. Thus, blood collected from the tapirs via Dipetalogaster maxima species did not show usefulness for cytogenetic studies due to the inability of cells to proliferation, even after a relatively short period of time elapsed since the blood sampling (1 to 2 hours).