Abstract
Tuberous sclerosis complex (TSC) is an autosomal-dominant disease that is caused by mutations in either the TSC1 or TSC2 gene. Smooth muscle-like cells (ASMs) were isolated from an angiomyolipoma of a patient with TSC. These cells lacked tuberin, were labeled by both HMB45 and CD44v6 antibodies, and had constitutive S6 phosphorylation. The cells bear a germline TSC2 intron 8-exon 9 junction mutation, but DNA analysis and polymerase chain reaction amplification failed to demonstrate loss of heterozygosity. Testing for an epigenetic alteration, we detected methylation of the TSC2 promoter. Its biological relevance was confirmed by tuberin expression and a reduction in HMB45 labeling and S6 constitutive phosphorylation after exposure to the chromatin-remodeling agents, trichostatin A and 5-azacytidine. These cells were named TSC2 -/meth ASMs. Their proliferation required epidermal growth factor in the medium as previously described for TSC2-/- ASMs. Blockade of epidermal growth factor with monoclonal antibodies caused the death of TSC2 -/meth ASMs. In addition, rapamycin effectively blocked the proliferation of these cells. Our data show for the first time that methylation of the TSC2 promoter might cause a complete loss of tuberin in TSC2 cells , and that the pathogenesis of angiomyolipomas might also originate from epigenetic defects in smooth muscle cells. Additionally, the effect of chromatin-remodeling agents in these cells suggests a further avenue for the treatment of TSC as well as lymphangioleiomyomatosis.
| Original language | English |
|---|---|
| Pages (from-to) | 2150-2159 |
| Number of pages | 10 |
| Journal | American Journal of Pathology |
| Volume | 174 |
| Issue number | 6 |
| DOIs | |
| Publication status | Published - Jun 2009 |
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ASJC Scopus subject areas
- Pathology and Forensic Medicine
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The methylation of the TSC2 promoter underlies the abnormal growth of TSC2 angiomyolipoma-derived smooth muscle cells. / Lesma, Elena; Sirchia, Silvia Maria; Ancona, Silvia; Carelli, Stephana; Bosari, Silvano; Ghelma, Filippo; Montanari, Emanuele; Di Giulio, Anna Maria; Gorio, Alfredo.
In: American Journal of Pathology, Vol. 174, No. 6, 06.2009, p. 2150-2159.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - The methylation of the TSC2 promoter underlies the abnormal growth of TSC2 angiomyolipoma-derived smooth muscle cells
AU - Lesma, Elena
AU - Sirchia, Silvia Maria
AU - Ancona, Silvia
AU - Carelli, Stephana
AU - Bosari, Silvano
AU - Ghelma, Filippo
AU - Montanari, Emanuele
AU - Di Giulio, Anna Maria
AU - Gorio, Alfredo
PY - 2009/6
Y1 - 2009/6
N2 - Tuberous sclerosis complex (TSC) is an autosomal-dominant disease that is caused by mutations in either the TSC1 or TSC2 gene. Smooth muscle-like cells (ASMs) were isolated from an angiomyolipoma of a patient with TSC. These cells lacked tuberin, were labeled by both HMB45 and CD44v6 antibodies, and had constitutive S6 phosphorylation. The cells bear a germline TSC2 intron 8-exon 9 junction mutation, but DNA analysis and polymerase chain reaction amplification failed to demonstrate loss of heterozygosity. Testing for an epigenetic alteration, we detected methylation of the TSC2 promoter. Its biological relevance was confirmed by tuberin expression and a reduction in HMB45 labeling and S6 constitutive phosphorylation after exposure to the chromatin-remodeling agents, trichostatin A and 5-azacytidine. These cells were named TSC2 -/meth ASMs. Their proliferation required epidermal growth factor in the medium as previously described for TSC2-/- ASMs. Blockade of epidermal growth factor with monoclonal antibodies caused the death of TSC2 -/meth ASMs. In addition, rapamycin effectively blocked the proliferation of these cells. Our data show for the first time that methylation of the TSC2 promoter might cause a complete loss of tuberin in TSC2 cells , and that the pathogenesis of angiomyolipomas might also originate from epigenetic defects in smooth muscle cells. Additionally, the effect of chromatin-remodeling agents in these cells suggests a further avenue for the treatment of TSC as well as lymphangioleiomyomatosis.
AB - Tuberous sclerosis complex (TSC) is an autosomal-dominant disease that is caused by mutations in either the TSC1 or TSC2 gene. Smooth muscle-like cells (ASMs) were isolated from an angiomyolipoma of a patient with TSC. These cells lacked tuberin, were labeled by both HMB45 and CD44v6 antibodies, and had constitutive S6 phosphorylation. The cells bear a germline TSC2 intron 8-exon 9 junction mutation, but DNA analysis and polymerase chain reaction amplification failed to demonstrate loss of heterozygosity. Testing for an epigenetic alteration, we detected methylation of the TSC2 promoter. Its biological relevance was confirmed by tuberin expression and a reduction in HMB45 labeling and S6 constitutive phosphorylation after exposure to the chromatin-remodeling agents, trichostatin A and 5-azacytidine. These cells were named TSC2 -/meth ASMs. Their proliferation required epidermal growth factor in the medium as previously described for TSC2-/- ASMs. Blockade of epidermal growth factor with monoclonal antibodies caused the death of TSC2 -/meth ASMs. In addition, rapamycin effectively blocked the proliferation of these cells. Our data show for the first time that methylation of the TSC2 promoter might cause a complete loss of tuberin in TSC2 cells , and that the pathogenesis of angiomyolipomas might also originate from epigenetic defects in smooth muscle cells. Additionally, the effect of chromatin-remodeling agents in these cells suggests a further avenue for the treatment of TSC as well as lymphangioleiomyomatosis.
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U2 - 10.2353/ajpath.2009.080799
DO - 10.2353/ajpath.2009.080799
M3 - Article
VL - 174
SP - 2150
EP - 2159
JO - American Journal of Pathology
JF - American Journal of Pathology
SN - 0002-9440
IS - 6
ER -