miR-485-5p/HSP90 axis blocks Akt1 phosphorylation to suppress osteosarcoma cell proliferation and migration via

Qing Liu1,2, Zhenting Wang1,3, Xiaohua Zhou2

  • 1Department of Spine Surgery, The Third Xiangya Hospital of Central South University, No. 138, Tongzipo Road, Changsha, Hunan, People's Republic of China.

Insights

Heat shock protein 90 (HSP90) and AKT1 are upregulated in osteosarcoma. Inhibiting HSP90 or increasing miR-485-5p suppresses tumor growth by affecting the PI3K/AKT pathway.

Area of Science:

  • Molecular Biology
  • Oncology
  • Biochemistry

Background:

  • Osteosarcoma (OS) is a primary bone cancer characterized by dysregulated intracellular signaling pathways.
  • The PI3K/Akt signaling pathway is frequently implicated in OS pathogenesis.
  • Heat shock protein 90 (HSP90) is known to stabilize phospho-Akt, and both AKT1 and HSP90 are upregulated in OS.

Purpose of the Study:

  • To investigate the roles of AKT1, HSP90, and miR-485-5p in osteosarcoma.
  • To elucidate the molecular mechanisms underlying their involvement in OS progression.
  • To explore potential therapeutic targets for osteosarcoma treatment.

Main Methods:

  • Quantitative analysis of AKT1 and HSP90 mRNA and protein expression in OS tissues and cells.
  • Gene knockdown experiments (siRNA) for AKT1 and HSP90.
  • Gene overexpression experiments for AKT1.
  • Analysis of protein levels (ki-67, Vimentin, p21, E-cadherin) using Western blotting.
  • Cell viability, proliferation, and migration assays.
  • Luciferase reporter assays to confirm miR-485-5p targeting of AKT1 and HSP90 3'-UTRs.
  • Overexpression of miR-485-5p.

Main Results:

  • AKT1 and HSP90 expression were significantly upregulated in osteosarcoma.
  • AKT1 knockdown inhibited OS cell viability.
  • HSP90 knockdown suppressed AKT1 phosphorylation, decreased ki-67 and Vimentin, increased p21 and E-cadherin, and inhibited OS cell proliferation and migration.
  • AKT1 overexpression reversed the effects of HSP90 knockdown.
  • miR-485-5p directly targeted the 3'-UTRs of AKT1 and HSP90, inhibiting their expression.
  • miR-485-5p overexpression reduced AKT1, HSP90, and ki-67, increased E-cadherin, and inhibited OS cell proliferation and migration.

Conclusions:

  • HSP90 knockdown inhibits osteosarcoma progression by blocking AKT1 phosphorylation via the PI3K/AKT pathway.
  • miR-485-5p acts as a tumor suppressor in osteosarcoma by targeting and inhibiting both HSP90 and AKT1 expression.
  • Targeting HSP90 and modulating miR-485-5p levels represent potential therapeutic strategies for osteosarcoma.

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