Semi-comprehensive analysis of gene amplification in thymic malignant tumors using multiplex ligation-dependent probe amplification and fluorescence in situ hybridization
INTERNATIONAL JOURNAL OF CLINICAL AND EXPERIMENTAL PATHOLOGY
Authors: Kakegawa, Seiichi; Matsumoto, Isao; Tamura, Masaya; Takata, Munehisa; Yoshida, Shuhei; Saito, Daisuke; Tanaka, Yusuke; Takemura, Hirofumi; Ooi, Akishi
Abstract
Research on the amplification of oncogenes in thymic malignant tumor is limited. In this study, we aimed to determine the gene amplification status of receptor tyrosine kinases and other cell regulator genes in thymic malignant tumors, with a view toward the future introduction of molecular targeted therapy. In addition, we examined the usefulness of multiplex, ligation-dependent probe amplification (MLPA) in the semi-comprehensive detection of these gene amplifications. The participants of this study were nine patients with thymic carcinoma and one patient with atypical carcinoid who underwent resection at our department from 1999 to 2016. Twenty-four oncogenes (MDM4, MYCN, ALK, PDGFRA, KIT, KDR, DHFR, EGFR, MET, SMO, BRAF, FGFR1, MYC, ABL1, RET, CCND1, CCND2, CDK4, MDM2, AURKB, ERBB2, TOP2A, AURKA, AR) were analyzed for amplification by MLPA. In cases where amplification by MLPA was suspected, confirmation was performed by fluorescence in situ hybridization (FISH). Immunostaining for detected oncoproteins and p53 were performed in cases with confirmed oncogene amplification. MYC (2/10, 20%) and MDM2 (1/10,10%) amplifications were detected using MLPA and FISH. Immunostaining in both cases was positive. The MDM2-amplified tumor relapsed and spread rapidly after operation despite the use of post-operative chemo-radiotherapy. MYC amplification may be involved in the carcinogenesis of thymic malignant tumors. In addition, MDM2 amplification may be a concern in the increased malignancy.
Clinical and Molecular Characterization of Adult Glioblastomas in Southern Brazil
JOURNAL OF NEUROPATHOLOGY AND EXPERIMENTAL NEUROLOGY
Authors: Trevisan, Patricia; Graziadio, Carla; Koshiyama Rodrigues, Dayane Bohn; Machado Rosa, Rafael Fabiano; Soares, Fabiano Pasqualotto; Provenzi, Valentina Oliveira; Vieira de Oliveira, Ceres Andreia; Paskulin, Giorgio Adriano; Varella-Garcia, Marileila; Gazzola Zen, Paulo Ricardo
Abstract
We investigated 113 adult Brazilian patients with glioblastoma (GBM) for comparison with patients from distinct geographical areas and evaluation of suitability for novel targeted therapies. Patients were assessed for clinical features and tumor genomic characteristics such as ROS1 and NTRK1 rearrangements, KIT, PDGFRA, and KDR amplification, and RB1 deletion using multicolor fluorescence in situ hybridization. The majority of patients were male (53%), over 40 years (94%), with tumor located in single site (64%), in the right cerebral hemisphere (60%), and underwent partial resection (71%); 14% presented complications after surgery. The main clinical sign at diagnosis was focal abnormality (57%); frontal (31%); and temporal (20%) regions were most commonly affected. Median hospitalization time was 20 days, median survival was 175 days. One tumor was positive for rearrangement in NTRK1 and another in ROS1 (0.9% each). PDGFRA was amplified in 20% of cases, often co-amplified with KDR (>90%) and KIT (>60%). RB1 was deleted in 16% of patients. There was no association between these molecular abnormalities and patient survival. However, older age, complications after surgery, and right-sided tumors were independent variables associated with patient survival. This study contributes information on the molecular profile of glioblastomas in Latin America possibly supporting new target therapies.