A Germ-Line Tsc1 Mutation Causes Tumor Development and Embryonic Lethality That are Similar, but not Identical to, Those Caused by Tsc2 Mutation in Mice

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 98; no. 15; pp. 8762 - 8767
• Main Authors: Kobayashi, T, Minowa, O, Sugitani, Y, Takai, S, Mitani, H, Kobayashi, E, Noda, T, Hino, O
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences 17.07.2001; National Acad Sciences; The National Academy of Sciences
• Subjects: Alleles; Animals; Base Sequence; Biological Sciences; Cloning, Molecular; Cystadenoma - genetics; Cystadenoma - metabolism; DNA, Complementary; Embryos; Exons; Gene Targeting; Genes, Tumor Suppressor; Genetic mutation; Germ-Line Mutation; Hemangioma; Histology; Humans; Kidney Neoplasms - genetics; Kidney Neoplasms - metabolism; Kidneys; Male; Medical research; Mice; Mice, Inbred C57BL; Mice, Knockout; Mice, Mutant Strains; Molecular Sequence Data; Mutation; Proteins - genetics; Proteins - physiology; Rats; Repressor Proteins - genetics; Repressor Proteins - physiology; Rodents; Tsc1 gene; TSC2 gene; tuberous sclerosis; Tumor Suppressor Proteins; Tumors
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.151033798

Tuberous sclerosis (TS) is characterized by the development of hamartomas in various organs and is caused by a germ-line mutation in either TSC1 or TSC2 tumor suppressor genes. From the symptomatic resemblance among TS patients, involvement of TSC1 and TSC2 products in a common pathway has been suggested. Here, to analyze the function of the Tsc1 product, we established a line of Tsc1 (TSC1 homologue) knockout mouse by gene targeting. Heterozygous Tsc1 mutant Tsc1+/-mice developed renal and extra-renal tumors such as hepatic hemangiomas. In these tumors, loss of wild-type Tsc1 allele was observed. Homozygous Tsc1 mutants died around embryonic days 10.5-11.5, frequently associated with neural tube unclosure. As a whole, phenotypes of Tsc1 knockout mice resembled those of Tsc2 knockout mice previously reported, suggesting that the presumptive common pathway for Tsc1 and Tsc2 products may also exist in mice. Notably, however, development of renal tumors in Tsc1+/-mice was apparently slower than that in Tsc1+/-mice. The Tsc1 knockout mouse described here will be a useful model to elucidate the function of Tsc1 and Tsc2 products as well as pathogenesis of TS.