Comparative genomic analysis of intracranial germ cell tumors - the preliminary study focused on Sonic Hedgehog signaling pathway
WSPOLCZESNA ONKOLOGIA-CONTEMPORARY ONCOLOGY
Authors: Kuleszo, Dominika; Koczkowska, Magdalena; Lipska-Zietkiewicz, Beata S.; Grajkowska, Wieslawa; Adamkiewicz-Drozynska, Elzbieta; Dembowska-Baginska, Bozenna; Ciolkowski, Maciej; Izycka-Swieszewska, Ewa
Abstract
Aim of the study: Examination of copy number changes in a group of intracranial germ cell tumors (GCTs) with particular focus on putative aberrations of the main genes coding SHh pathway proteins. Material and methods: The study was performed on DNA isolated from fresh-frozen tumor tissue samples from eight GCTs, including six intracranial GCTs. The intracranial group consisted of three germinomas, two mature teratomas and one mixed germ cell tumor. Comparative genomic profiling analysis was carried out using microarray-CGH method (Cytosure ISCA UPD 4x180k, OGT). The results were analyzed with Feature Extraction (Agilent Technologies) and Nexus Copy Number (BioDiscovery) softwares. Results and conclusions: Chromosomal aberrations were found in two intracranial germinomas. These tumors were characterized by complex genomic profiles encompassing chromosomes 7, 8, 9, 10, 11, 12, 16, 17 and 19. Common findings were gain at 12p13.33p11.1 of 35 Mbp and gain at 17q11.1q25.3 of 55 Mbp. In one tumor, also SHh (7q36.3), SMO (7q32.1) and GLI3 (7p14.1) copy gains occurred together with 9q21.11q34.3 loss, including PTCH1, all being elements of SHh signaling pathway. Moreover, both tumors showed various copy gain of genes being ligands, regulators, receptors or target genes of SHh (MTSS1; PRKACA and FKBP8) as well as gain of genes of SHh coopting WNT pathway (WNT3, WNT5B, WNT9B in both tumors; WNT16, WNT2 in pineal lesion). Further studies on larger group are needed to characterize SHh-related gene alterations in intracranial GCTs and for searching genotype-phenotype relations.
GANT61 Reduces Hedgehog Molecule (GLI1) Expression and Promotes Apoptosis in Metastatic Oral Squamous Cell Carcinoma Cells
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
Authors: Sacramento de Araujo, Tais Bacelar; Siquara da Rocha, Leonardo de Oliveira; Andion Vidal, Manuela Torres; Cerqueira Coelho, Paulo Lucas; dos Reis, Mitermayer Galvao; de Freitas Souza, Bruno Solano; Pereira Soares, Milena Botelho; Pereira, Thiago Almeida; Della Coletta, Ricardo; Bezerra, Daniel Pereira; Dias, Rosane Borges; Gurgel Rocha, Clarissa Araujo
Abstract
Due to its importance in the pathogenesis of oral squamous cell carcinoma (OSCC), the Hedgehog (HH) pathway is considered a potential therapeutic target. We investigated the effects of GANT61, a GLI inhibitor, on HH gene expression, as well as on metastatic OSCC cell proliferation and death. Following culture in DMEM medium, cytotoxicity of GANT61 against different tumor and non-tumor cell types was assessed by alamarBlue assays. Cytotoxicity analysis revealed that the metastatic HSC3 cell line was the most sensitive (IC50: 36 mu M) to the tested compound. The compound's effects on the expression of HH pathways components were analyzed by qPCR and Western blot; cell viability was analyzed by trypan blue assay and flow cytometry were used to investigate cell cycle phase, morphology, and death patterns in HSC3 cells. A significant reduction in mRNA levels of the GLI1 transcription factor was found after 12 h of treatment withGANT61. Protein expression levels of other HH pathway components (PTCH1, SHH, and Gli1) and HSC3 cell viability also decreased after 24 h of treatment. Cell cycle analysis and death pattern evaluations revealed significantly increased nuclear fragmentation in sub-G1 phase, as well as cell death due to apoptosis. In conclusion, the significantly reduced GLI1 gene expression seen in response to the GLI inhibitor indicates diminished downstream activation in HH pathway components. GANT61 significantly reduced cell viability in the metastatic cell line of OSCC and promoted a significant increase in nuclear fragmentation and cell death by apoptosis.