Isolation and growth of smooth muscle-like cells derived from tuberous sclerosis complex-2 human renal angiomyolipoma: epidermal growth factor is the required growth factor

Am J Pathol. 2005 Oct;167(4):1093-103. doi: 10.1016/S0002-9440(10)61198-4.


Tuberous sclerosis complex (TSC) is a tumor suppressor gene disorder characterized by mutations in the TSC1 or TSC2 genes. These mutations lead to the development of benign tumors involving smooth muscle cells, causing life-threatening lymphangioleiomyomatosis. We isolated and characterized two types of cells bearing a mutation in TSC2 exon 18 from a renal angiomyolipoma of a TSC patient: one population of alpha-actin-positive smooth muscle-like cells with loss of heterozygosity for the TSC2 gene (A(+) cells) and another of nonloss of heterozygosity keratin 8/18-positive epithelial-like cells (R(+) cells). Unlike control aortic vascular smooth muscle cells, A(+) cells required epidermal growth factor (EGF) to grow and substituting EGF with insulin-like growth factor (IGF)-1 failed to increase the cell number; however, omission of EGF did not cause cell loss. The A(+) cells constantly released IGF-1 into the culture medium and constitutively showed a high degree of S6K phosphorylation even when grown in serum-free medium. Exposure to antibodies against EGF and IGF-1 receptors caused a rapid loss of A(+) cells: 50% by 5 days and 100% by 12 days. Signal transduction mediated by EGF and IGF-I receptors is therefore involved in A(+) cell survival. These results may offer a novel therapeutic perspective for the treatment of TSC complications and lymphangioleiomyomatosis.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / metabolism
  • Adult
  • Angiomyolipoma / genetics
  • Angiomyolipoma / pathology*
  • Aorta / cytology
  • Cell Culture Techniques
  • Cell Proliferation
  • Cell Survival / drug effects
  • DNA Mutational Analysis
  • Epidermal Growth Factor / pharmacology
  • Epidermal Growth Factor / physiology*
  • Exons
  • Female
  • Fluorescein-5-isothiocyanate
  • Fluorescent Antibody Technique, Indirect
  • Fluorescent Dyes
  • Genes, Tumor Suppressor
  • Genetic Markers
  • Humans
  • Immunohistochemistry
  • Insulin-Like Growth Factor I / metabolism
  • Insulin-Like Growth Factor I / pharmacology
  • Keratins / metabolism
  • Loss of Heterozygosity
  • Microsatellite Repeats
  • Muscle, Smooth / chemistry
  • Muscle, Smooth / cytology
  • Muscle, Smooth / growth & development*
  • Muscle, Smooth / metabolism
  • Muscle, Smooth, Vascular / chemistry
  • Muscle, Smooth, Vascular / cytology
  • Muscle, Smooth, Vascular / growth & development
  • Muscle, Smooth, Vascular / metabolism
  • Mutation
  • Phosphorylation
  • Rhodamines
  • Ribosomal Protein S6 Kinases, 70-kDa / metabolism
  • Tuberous Sclerosis / genetics
  • Tuberous Sclerosis / pathology*
  • Tuberous Sclerosis Complex 1 Protein
  • Tuberous Sclerosis Complex 2 Protein
  • Tumor Suppressor Proteins / genetics
  • Tumor Suppressor Proteins / metabolism*


  • Actins
  • Fluorescent Dyes
  • Genetic Markers
  • Rhodamines
  • TSC1 protein, human
  • TSC2 protein, human
  • Tuberous Sclerosis Complex 1 Protein
  • Tuberous Sclerosis Complex 2 Protein
  • Tumor Suppressor Proteins
  • Epidermal Growth Factor
  • Insulin-Like Growth Factor I
  • Keratins
  • Ribosomal Protein S6 Kinases, 70-kDa
  • ribosomal protein S6 kinase, 70kD, polypeptide 2
  • Fluorescein-5-isothiocyanate