[1900] Recurrent Cytogenetic Alterations in Radiation Induced (RI) Abdominal Malignant Mesothelioma (AMM).
Anthony N Sireci, Brynn Levy, Taub Robert, JL Chen, Nahum Odelia, Borczuk C Alain. Columbia University Medical Center, New York, NY
Background: Abdominal malignant mesothelioma (AMM) is a rare tumor of the peritoneum that has been linked to asbestos exposure and past radiation therapy to the abdomen. Other than patient history, there is no established method to differentiate the two etiologies. We describe recurrent copy number alterations that differ between RI tumors and other AMM.
Design: Needle-dissected tumor from 7 RI AMM tumors (cases) and 34 non-RI tumors (controls) were studied for copy number (CN) alteration (Affymetrix SNParray 6.0). CN data were analyzed using NEXUS software. A list of CN alterations that significantly predicted radiation exposure at p<0.025 was compiled. All tumors were of epithelioid morphology.
Results: Loci of CN alterations associated with tumor etiology were identified. Potential genes of interest within these loci include those involved in cell signaling, cell cycle regulation, cellular cytoskeleton, transcription/translation modification, metabolism, protein ubiquitination and cell stress response.
| Chromosome | Alteration | Distributions | No. of Genes Involved |
|---|---|---|---|
| 1p | Loss | 3/7 RI, 3/34 ctrl | 10 |
| 3p | Loss | 3/7 RI, 8/34 ctrl | 3 |
| 3p | Loss | 4/7 RI, 2/34 ctrl | 8 |
| 3q | Loss | 5/7 RI, 9/34 ctrl | 1 |
| 3q | Loss | 2/7 RI, 0 ctrl | 15 |
| 3q | Gain | 2/7 RI, 0 ctrl | 4 |
| 3q | Loss; Gain | 4/7 RI, 2/34 ctrl; 3/7 RI, 1/34 ctrl | 1 |
| 3q | Gain | 2/7 RI, 0/34 ctrl | 9 |
| 15q | Loss; Gain | 3/7 RI, 2/34 ctrl; 0/7 RI, 9/34 ctrl | 1 |