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424

Induction by rapamycin and proliferation‑promoting activity of Hspb1 in a

Takayuki Kitano1,2, Keiko Nishikawa1,2, Tetsuya Takagaki2

  • 1Department of Molecular Pathogenesis, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan.

Experimental and Therapeutic Medicine
|June 5, 2023
PubMed

Insights

Rapamycin treatment for Tuberous Sclerosis Complex (TSC) increases heat shock protein B1 (Hspb1) expression and phosphorylation. Hspb1 promotes tumor cell proliferation, suggesting it as a potential therapeutic target for TSC.

Area of Science:

  • Oncology
  • Genetics
  • Molecular Biology

Background:

  • Tuberous Sclerosis Complex (TSC) is an inherited disorder caused by mutations in TSC1 or TSC2 tumor suppressor genes.
  • Rapamycin shows promise in TSC treatment but often results in tumor regrowth after cessation.
  • Novel therapeutic targets are needed to overcome residual tumors in TSC.

Purpose of the Study:

  • Investigate rapamycin-responsive signaling pathways in Tsc2-deficient tumor cells.
  • Focus on heat shock protein-related pathways to identify new therapeutic targets for TSC.

Main Methods:

  • Analyzed rapamycin's effect on heat shock protein family B (small) member 1 (Hspb1) expression and phosphorylation in Tsc2-deficient cells.
  • Utilized Hspb1 knockdown and overexpression to assess its role in cell proliferation.

Main Results:

  • Rapamycin treatment increased Hspb1 expression and phosphorylation.
  • Hspb1 knockdown suppressed cell proliferation without rapamycin.
  • Hspb1 overexpression enhanced cell proliferation, with or without rapamycin.

Conclusions:

  • Hspb1 plays a significant role in TSC tumor cell proliferation.
  • Hspb1-associated pathways represent potential therapeutic targets for Tuberous Sclerosis Complex.
Keywords:
TSC complex subunit 2heat shock protein family B (small) member 1mTORC1rapamycintuberous sclerosis complex

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