Genomic Characterization of Peritoneal Mesothelioma Reveals Recurrent Loss of 6, 9, and 22 Chromosomal Material
LA Shatat, JA Bridge, Z Gatalica, JM Hagenkord. Creighton University, Omaha, NE; University of Nebraska Medical Center, Omaha, NE
Background: Malignant mesothelioma is a rare aggressive tumor that arises from serosal surfaces. Peritoneal mesothelioma is four times less common than its pleural counterpart. Previous genomic studies performed on pleural tumors showed deletions of 1p21-22, 3p21, 4q, 6q, 9p21, 13q13-14,and 14q have been repeatedly observed, while monosomy 22 was the most frequent numerical change. However cytogenetic studies of peritoneal mesotheliomas are few.
Design: In an effort to characterize potential genomic alterations in peritoneal mesothelioma, representative peritoneal mesothelioma samples from four male patients (age range 50-73 years) were subjected to both conventional cytogenetic and SNP (single nucleotide polymorphism) array karyotyping analyses. The former was conducted on fresh tissue per standard protocol and the latter on DNA extracted from corresponding formalin-fixed, paraffin-embedded tissue using Affymetrix 250K Nsp arrays. Results were compared to the literature.
Results: Complex numerical and/or structural abnormalities affecting all chromosomes except chromosome 21 were identified using these two complementary methodologic approaches. Loss of all or a portion of the short and long arms of chromosomes 5 and 6, respectively, was seen in 3 of 4 cases. Deletion of chromosomes 9 and 22 were seen in 2/4 cases.
Conclusions: Peritoneal mesotheliomas show complex cytogenetic abnormalities similar to those previously described for pleural-based tumors. Conventional culture based karytoyping and a novel virtual karyotyping using SNP arrays are complementary methods which, when combined, can provide a more targeted analysis of oncogenes and tumor suppressor genes involved in the pathogenesis of peritoneal mesotheliomas.
Category: Pan-genomic/Pan-proteomic Approaches to Diseases
Monday, March 22, 2010 1:00 PM
Poster Session II # 231, Monday Afternoon