Abstract 3826: HoxA10 gene expression profile correlates with tumorigenic potential of medulloblastoma cell lines.

Abstract

Abstract HOX genes are a family of homeodomain-containing transcription factors defined as master genes of development, altered in cancer cells and thus having implications for tumorigenesis. Developmental genes have been recognized as one of the keys to understanding the tumor progression in some type of cancers. This study aimed to correlate gene expression profile of some HOX genes with the tumorigenic potential of medulloblastoma cell lines (MCL). We used three human MCL, the UW473, UW472 and DAOY and two human cerebellum primary cultures (CPC). The MCL and CPC were characterized morphologically by light microscopy and immunophenotypically by flow cytometry. MCL were assessed by tumorigenic potential infusing 3x106 cells subcutaneously in NUDE mice. MCL and CPC were evaluated for gene expression profile of HOXA3, HOXA10, HOXB3, HOXB4 and HOXB6 genes by quantitative real time PCR. MCL are morphologically heterogeneous (polygonal and fibroblastoid morphology) and the CPC present fibroblastoid morphology. Immunophenotypically, MCL and CPC were similar for some CD markers and showed a high percentage (70-99%) for CD44, CD73, CD105, CD166 and CD29 and low or absence (0-5.3%) for CD144, CD31, CD34, CD45 and CD133. Some differences were observed for CD140b (0.28±0.11%; 6.2±8.3%; 0.78±1.1%; 0.44%), CD24 (52.5±1.7%; 64.6±6.4%; 20.5±6.4%; 1.9%), CD146 (60.4±8.8%; 90.6±3.8%; 34.6±12%; 98.4%), CD73 (77.2±6.9%; 81.4±8.98%; 52,97±12.4%; 99.1%), CD271 (3.3±3.7%; 26.9±16.22%; 0.6±0.8%; 0,26%) and CD90 (3,7±1%; 99.3±0.8%; 88.5±3.3%; 77%) in the UW472, UW473 and DAOY MCL, and CPC respectively. Regarding to tumorigenic potential, among the UW402, UW473 and DAOY MCL, only the DAOY cell line gave rise to tumor nodules that presented histology features similar to medulloblastoma. About gene expression, the HOXA3 gene was 4,027.7±430.9, 283.1±3.8 and 1.4±0.8 times higher expressed in DAOY, UW473 and UW402 MCL respectively when compared to CPC (p<0.0001, p<0.0001, p=0.32), the HOXA10 gene was 22,462.78±26.9, 0.89±0.6 and 1.18±0.7 times (p<0.0001, p=0.82, p=0.77), the HOXB3 gene was 2,867.2±1,318.6, 115.9±12.6 and 67.8±21.9 times (p=0.0074, p<0.0001, p=0.0022), the HOXB4 gene was 5,647.8±567.4, 53.6±24.1 and 60.6±34.6 times (p<0.0001, p=0.0021, p=0.0065), the HOXB6 gene was 2,422.4±579.6, 722.4±58.6 and 1.5±1.2 times (p<0.0001, p<0.0001, p=0.30). Taken together, this study demonstrates that MCL are morphologically heterogeneous and CPC present fibroblastoid morphology. MCL and CPC showed an immunophenotype somewhat different for some markers and DAOY cell line was the only one that gave rise to tumor nodules in NUDE mice. Correlating the tumorigenic potential with HOX gene expression level, the HOXA10 is strongly expressed in DAOY tumorigenic cell line and low expressed in UW402 and UW473 cell lines, suggesting that HOXA10 gene can be related to tumor development in medulloblastoma. Citation Format: Ricardo Bonfim-Silva, Thais Valeria A. C. Pimentel, Elvis T. Valera, Carlos Alberto Scrideli, Fernando S. Ramalho, Hélio Rubens Machado, Dimas Tadeu Covas, Gregory J. Riggins, Angelo A. Cardoso, Aparecida Maria Fontes. HoxA10 gene expression profile correlates with tumorigenic potential of medulloblastoma cell lines. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3826. doi:10.1158/1538-7445.AM2013-3826