Fibrous papule of the face, similar to tuberous sclerosis complex-associated angiofibroma, shows activation of the mammalian target of rapamycin pathway: Evidence for a novel therapeutic strategy?

Jung Yi Lisa Chan, Kuo Hsien Wang, Chia Lang Fang, Wei Yu Chen

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5 Citations (Scopus)


Fibrous papules of the face are hamartomas characterized by stellate-shaped stromal cells, multinucleated giant cells, and proliferative blood vessels in the dermis. The pathogenesis of fibrous papules remains unclear. There is a striking microscopic resemblance between fibrous papules and tuberous sclerosis complex (TSC)-associated angiofibromas. A germline mutation of the TSC1 or TSC2 gene, leading to activation of the mammalian target of rapamycin (mTOR) pathway, accounts for the pathogenesis of TSC-associated angiofibromas. Activated mTOR subsequently activates p70 ribosomal protein S6 kinase (p70S6K) and ribosomal protein S6 (S6) by phosphorylation. Rapamycin, a mTOR inhibitor, is effective in treating TSC-associated angiofibromas. The aim of this study was to understand whether the mTOR pathway is activated in fibrous papules. We studied immunoexpressions of phosphorylated (p-) mTOR effectors in fibrous papules, TSC-associated angiofibromas, and normal skin controls. P-mTOR, p-p70S6K and p-S6 were highly expressed in dermal stromal cells and epidermal keratinocytes in fibrous papules and TSC-associated angiofibromas but not in fibroblasts and epidermal keratinocytes of normal skin controls (p

Original languageEnglish
Article numbere89467
JournalPLoS One
Issue number2
Publication statusPublished - Feb 18 2014


ASJC Scopus subject areas

  • Agricultural and Biological Sciences(all)
  • Biochemistry, Genetics and Molecular Biology(all)
  • Medicine(all)

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