No conflicts of interest were declared.
Constant allelic alteration on chromosome 16p (TSC2 gene) in perivascular epithelioid cell tumour (PEComa): genetic evidence for the relationship of PEComa with angiomyolipoma†
Article first published online: 11 DEC 2007
Copyright © 2007 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
The Journal of Pathology
Volume 214, Issue 3, pages 387–393, February 2008
How to Cite
Pan, C.-C., Chung, M.-Y., Ng, K.-F., Liu, C.-Y., Wang, J.-S., Chai, C.-Y., Huang, S.-H., Chen, P.-H. and Ho, D. (2008), Constant allelic alteration on chromosome 16p (TSC2 gene) in perivascular epithelioid cell tumour (PEComa): genetic evidence for the relationship of PEComa with angiomyolipoma. J. Pathol., 214: 387–393. doi: 10.1002/path.2289
- Issue published online: 10 JAN 2008
- Article first published online: 11 DEC 2007
- Accepted manuscript online: 11 DEC 2007 12:00AM EST
- Manuscript Accepted: 6 OCT 2007
- Manuscript Revised: 16 SEP 2007
- Manuscript Received: 24 JUL 2007
- Veterans General Hospitals University System of Taiwan Joint Research Program, Tsou's Foundation. Grant Number: VGHUST95-P7-35
- perivascular epithelioid cell tumour;
- tuberous sclerosis;
- loss of heterozygosity
Perivascular epithelioid cell tumours (PEComas) are a family of tumours including classic angiomyolipoma, lymphangioleiomyomatosis, and clear epithelioid cell tumours reported under a variety of names such as epithelioid angiomyolipoma, pulmonary and extrapulmonary clear cell sugar tumour, and PEComa. Our previous comparative genomic hybridization study of PEComas demonstrated recurrent chromosomal aberrations including deletions on chromosome 16p, where the TSC2 gene is located. In this study, we focused on the alteration of chromosome 16p, including TSC2. We collected ten sporadic and two tuberous sclerosis complex-associated PEComas, as well as 14 sporadic classic hepatic and renal angiomyolipomas (AMLs) as controls. We used 16 microsatellite markers distributed along chromosome 16p to test for allelic imbalances on chromosome 16p and at TSC2, and two markers for TSC1. Furthermore, we carried out immunohistochemical staining for phospho-p706K, phospho-AKT, and phospho-S6 to evaluate the effect of TSC2 alterations on the mTOR signalling pathway. Loss of heterozygosity (LOH) was found in 11 PEComas and involved the region of the TSC2 locus in seven. Six classic angiomyolipomas had allelic changes at chromosome 16p. Microsatellite instability was detected in two PEComas. The incidence of genetic aberrations was significantly higher in the PEComa group. Only one PEComa showed LOH at the TSC1 locus. Eleven PEComas and 13 AMLs revealed elevated phospho-p70S6K accompanied by reduced phospho-AKT. Five PEComas and eight classic angiomyolipomas were positive for phospho-S6. The phosphorylation profile indicates functional activation of the mTOR pathway through a disrupted TSC1/2 complex. Our observations of frequent deletion of TSC2 and the mTOR signalling pathway provide evidence that the oncogenetic lineage of PEComa, as a distinct TSC2-linked neoplasm, is similar to that of angiomyolipoma. Copyright © 2007 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.