Tuberous sclerosis complex (TSC) is a genetically heterogeneous disease caused by mutations of TSC1 or TSC2 genes. It involves multiple organ systems resulting in mild to lethal hamartoma formation due to gene mutation in the germ line and loss of heterozygosity (LOH) in somatic cells. Hamartin (TSC1) and tuberin (TSC2) are expressed broadly. However, little is known about tissue susceptibility to hamartomas when equal or similar amounts of TSC gene expression are present. In this study, we present a 19-week gestational age fetus with pathological features of TSC, which was confirmed by finding LOH of TSC2 in a cardiac rhabdomyoma. Developmental expression of hamartin and tuberin in the TSC fetus, an age-matched non-TSC fetus, and a 26-week gestational age non-TSC fetus were analyzed by immunohistochemistry. We found that in addition to the differential expression of the TSC genes in some normal tissues compared with that in the TSC-affected fetus, the cellular localization and distribution of hamartin and tuberin were dramatically different in different tissues. In general, hamartin and tuberin are mainly expressed in epithelial cells, myocytes, and neural tissues. By comparing the incidence of the hamartomas in early childhood and gene expression in tissues, it appears that tissues with co-expression of hamartin and tuberin are prone to a higher incidence of hamartomas than those expressing only one protein, or two proteins but in different patterns of cellular localization.
HymanMH, WhittemoreVH. National Institutes of Health Consensus Conference: tuberous sclerosis complex. Arch Neurol2000;157:662–665.
2.
Al-SaleemT, WessnerLL, ScheithauerBW, Malignant tumors of the kidney, brain, and soft tissues in children and young adults with the tuberous sclerosis complex. Cancer1998;83:2208–2216.
3.
VerhoefS, van Diemen-SteenvoordeR, AkkersdijkWL, Malignant pancreatic tumor within the spectrum of tuberous sclerosis complex in childhood. Eur J Pediatr1999;158:284–287.
4.
FukudaT, KobayashiT, MomoseS, YasuiH, HinoO.Distribution of TSC1 protein detected by immunohistochemistry in various normal rat tissues and the renal carcinomas of Eker rat: detection of limited colocalization with TSC1 and TSC2 gene products in vivo. Lab Invest2000;80:1347–1359.
5.
Van SlegtenhorstM, de HoogtR, HermansC, Identification of the tuberous sclerosis gene TSC1 on chromosome 9q34. Science1997;277:805–808.
6.
The European Chromosome 16 Tuberous Sclerosis Consortium. Identification and characterization of the tuberous sclerosis gene on chromosome 16. Cell1993;75:1305–1315.
7.
JonesAC, ShyamsundarMM, ThomasMW, Comprehensive mutation analysis of TSC1 and TSC2 and phenotypic correlations in 150 families with tuberous sclerosis. Am J Hum Genet1999;64:1305–1315.
8.
DaboraSL, JozwiakS, FranzDN, Mutational analysis in a cohort of 224 tuberous sclerosis patients indicates increased severity of TSC2, compared with TSC1, disease in multiple organs. Am J Hum Genet2001;68:64–80.
9.
GreenAJ, JohnsonPH, YatesJR. The tuberous sclerosis gene on chromosome 9q34 acts as a growth suppressor. Hum Mol Genet1994;3:1833–1834.
10.
SeppT, YatesJR, GreenAJ. Loss of heterozygosity in tuberous sclerosis hamartomas. J Med Genet1996;33:962–964.
11.
CarbonaraC, LongaL, GrossoE, Apparent preferential loss of heterozygosity at TSC2 over TSC1 chromosomal region in tuberous sclerosis hamartomas. Genes Chromosomes Cancer1996;15:18–25.
12.
HenskeEP, WessnerLL, GoldenJ, Loss of tuberin in both subependymal giant cell astrocytomas and angiomyolipomas supports a two-hit model for the pathogenesis of tuberous sclerosis tumors. Am J Pathol1997;151:1639–1647.
13.
AuKS, HebertAA, RoachES, NorthrupH.Complete in-activation of the TSC2 gene leads to formation of hamartomas. Am J Hum Genet1999;65:1790–1795.
14.
PasumarthiKB, NakajimaH, NakajimaHO, JingS, FieldLJ. Enhanced cardiomyocyte DNA synthesis during myocardial hypertrophy in mice expressing a modified TSC2 transgene. Circ Res2000;86:1069–1077.
15.
CarsilloT, AstrinidisA, HenskeEP. Mutations in the tuberous sclerosis complex gene TSC2 are a cause of sporadic pulmonary lymphangioleiomyomatosis. Proc Natl Acad Sci USA2000;97:6085–6090.
16.
WieneckeR, MaizeJCJr., ReedJA, de GunzburgJ, YeungRS, DeClueJE. Expression of the TSC2 product tuberin and its target Rap1 in normal human tissues. Am J Pathol1997;150:43–50.
17.
XiaoGH, ShoarinejadF, JinF, GolemisEA, YeungRS. The tuberous sclerosis 2 gene product functions as a rab5a GTPase activating protein (GAP) in modulating endocytosis. J Biol Chem1997;272:6097–6100.
18.
AltschulerDL, RibeiroNeto F.Mitogenic and oncogenic properties of the small G protein Rap1b. Proc Natl Acad Sci USA1998;95:7475–7479.
GorvelJP, CharvrierP, ZerialM, GruenbergJ.Rab5 controls early endosome fusion in vitro. Cell1991;64:915–925.
21.
SoucekT, HolzlG, BernaschekG, HengstschlagerM.A role of the tuberous sclerosis gene-2 product during neuronal differentiation. Oncogene1998;16:2197–2204.
22.
CrinoPB, HenskeEP. New developments in the neurobiology of the tuberous sclerosis complex. Neurology1999;53:1384–1390.
23.
RennebeckG, KleymenovaEV, AndersonR, YeungRS, ArtztK, WalkerCL. Loss of function of the tuberous sclerosis 2 tumor suppressor gene results in embryonic lethality characterized by disrupted neuroepithelial growth and development. Proc Natl Acad Sci USA1998;95:15629–15634.
24.
LambRF, RoyC, DiefenbachTJ, The TSC1 tumour suppressor hamartin regulates cell adhesion through ERM proteins and the GTPase Rho. Nat Cell Biol2000;2:281–287.
25.
ParkS-H, PepkowitzSH, KerfootC, Tuberous sclerosis in a 20-week gestation fetus: immunohistochemical study. Acta Neuropathol1997;94:180–186.
26.
BrackleyKJ, FarndonPA, WeaverJB, DowDJ, ChapmanS, KilbyMD. Prenatal diagnosis of tuberous sclerosis with intracerebral signs at 14 weeks' gestation. Prenat Diagn1999;19:575–579.
27.
BordarierC, Lellouch-TubianaA, RobainO.Cardiac rhabdomyoma and tuberous sclerosis in three fetuses: a neuropathological study. Acta Neuropathol1994;16:467–471.
28.
MenchineM, EmelinJK, MischelPS, Tissue and cell-type specific expression of the tuberous sclerosis gene, TSC2, in human tissues. Mod Pathol1996;9:1071–1080.
29.
KerfootC, WieneckeR, MenchineM, Localization of tuberous sclerosis 2 mRNA and its protein product tuberin in normal human brain and in cerebral lesions of patients with tuberous sclerosis. Brain Pathol1996;6:367–375.
30.
MizuguchiM, KatoM, YamanouchiH, IkedaK, TakashimaS.Tuberin immunohistochemistry in brain, kidneys and heart with or without tuberous sclerosis. Acta Neuropathol1997;94:525–531.
31.
PlankTL, LogginidouH, Klein-SzantoA, HenskeEP. The expression of hamartin, the product of the TSC1 gene, in normal human tissues and in TSC1- and TSC2-linked angiomyolipomas. Mod Pathol1999;12:539–545.
32.
GutmannDH, ZhangY, HasbaniMJ, Expression of the tuberous sclerosis complex gene products, hamartin and tuberin, in central nervous system tissues. Acta Neuropathol2000;99:223–230.
33.
JohnsonMW, KerfootC, BushnellT, LiM, VintersHV. Hamartin and tuberin expression in human tissues. Mod Pathol2001;14:202–210.
34.
MizuguchiM, IkedaK, TakashimaS.Simultaneous loss of hamartin and tuberin from the cerebrum, kidney and heart with tuberous sclerosis. Acta Neuropathol2000;99:503–510.
35.
MizuguchiM, KatoM, YamanouchiH, IkedaK, TakashimaS.Loss of tuberin from cerebral tissues with tuberous sclerosis and astrocytoma. Ann Neurol1996;40:941–944.
36.
ParryL, MaynardJH, PatelA, Molecular analysis of the TSC1 and TSC2 tumor suppressor genes in sporadic glial and glioneuronal tumors. Hum Genet2000;107:350–356.
37.
SoongR, IacopettaBJ. A rapid and nonisotopic method for the screening and sequencing of p53 gene mutations in formalin-fixed, paraffin-embedded tumors. Mod Pathol1997;10:252–258.
38.
WeiJ, HodesME, WangY, FengY, GhettiB, DlouhySR. Direct cDNA selection with DNA microdissected from mouse chromosome 16: isolation of novel clones and construction of a partial transcription map of the C3–C4 region. Genome Res1996;6:678–687.
39.
NellistM, Van SlegtenhorstMA, GoedbloedM, van den OuwelandAM, HalleyDJ, van der SluijsP.Characterization of the cytosolic tuberin-hamartin complex. Tuberin is a cytosolic chaperone for hamartin. J Biol Chem1999;274:35647–35652.
40.
MurthyV, HaddadLA, SmithN, Similarities and differences in the subcellular localization of hamartin and tuberin in the kidney. Am J Physiol Renal Physiol2000;278:F737–F746.
41.
FukudaT, KobayashiT, YasuiH, TsutsumiM, KonishiY, HinoO.Distribution of Tsc2 protein in various normal rat tissues and renal tumors of Tsc2 mutant (Eker) rat detected by immunohistochemistry. Virchows Arch1999;434:341–350.
42.
JozwiakS, SchwartzRA, JannigerCK, Bielicka-CymermanJ.Usefulness of diagnostic criteria of tuberous sclerosis complex in pediatric patients. J Child Neurol2000;15:652–659.
43.
PotterCJ, HuangH, XuT.Drosophila Tsc1 functions with Tsc2 to antagonize insulin signaling in regulating cell growth, cell proliferation, and organ size. Cell2001;105:357–368.
44.
TaponN, ItoN, DicksonBJ, TreismanJE, HariharanIK. The Drosophila tuberous sclerosis complex gene homologs restrict cell growth and cell proliferation. Cell2001;105:345–355.
45.
AstrinidisA, KhareL, CarsilloT, Mutational analysis of the tuberous sclerosis gene TSC2 in patients with pulmonary lymphangioleiomyomatosis. J Med Genet2000;37:55–57.
46.
SmolarekTA, WessnerLL, McCormackFX, MyletJC, MenonAG, HenskeEP. Evidence that lymphangiomyomatosis is caused by TSC2 mutations: chromosome 16p13 loss of heterozygosity in angiomyolipomas and lymph nodes from women with lymphangiomyomatosis. Am J Hum Genet1998;62:810–815.
47.
PlankTL, YeungRS, HenskeEP. Hamartin, the product of the tuberous sclerosis 1 (TSC1) gene, interacts with tuberin and appears to be localized to cytoplasmic vesicles. Cancer Res1998;58:4766–4770.
48.
TsuchiyaH, OrimotoK, KobayashiK, HinoO.Presence of potent transcriptional activation domains in the predisposing tuberous sclerosis (Tsc2) gene product of the Eker rat model. Cancer Res1996;56:429–433.
WolfDC, GoldsworthyTL, DonnerEM, HardenR, FitzpatrickB, EverittJI. Estrogen treatment enhances hereditary renal tumor development in Eker rats. Carcinogenesis1998;19:2043–2047.
51.
MelchiorF, PaschalB, EvansJ, GeraceL.Inhibition of nuclear protein import by nonhydrolyzable analogues of GTP and identification of the small GTPase Ran/TC4 as an essential transport factor. J Cell Biol1993;123:1649–1659.
52.
ZhangB, BergerJ, ZhouG, Insulin- and mitogen-activated protein kinase-mediated phosphorylation and activation of peroxisome proliferator-activated receptor. J Biol Chem1996;271:31771–31774.
53.
SoucekT, YeungRS, HengstschlagerM.Inactivation of the cyclin-dependent kinase inhibitor p27 upon loss of the tuberous sclerosis complex gene-2. Proc Natl Acad Sci USA1998;95:15653–15658.
