Millimeter wave treatment promotes chondrocyte proliferation by upregulating the expression of cyclin-dependent kinase 2 and cyclin A

Int J Mol Med. 2010 Jul;26(1):77-84. doi: 10.3892/ijmm_00000437.

Abstract

We investigated the effects of millimeter wave treatment on the expression of the cell cycle regulating proteins cyclin-dependent kinase 2 (CDK2) and cyclin A in chondrocytes. Knee articular cartilage from SD rats was used to establish cultured primary chondrocytes. After identification using toluidine blue staining, passage 2 chondrocytes were randomly divided into different groups and treated with nocodazole or millimeter wave. The RNA expression of CDK2 and cyclin A was measured using RT-PCR, and their protein levels were detected by Western blotting. Cell cycle analysis showed that nocodazole treatment significantly increased the number of G0/G1 and G2/M stage chondrocytes and decreased the amount of S phase cells. In contrast, millimeter wave treatment significantly decreased the number of G0/G1 and G2/M chondrocytes and increased the number of S phase cells. The mRNA and protein levels of CDK2 and cyclin A consistently demonstrated a reverse trend, with the lowest levels in the chondrocytes treated with nocodazole. The expression of CDK2 and cyclin A was higher in chondrocytes receiving millimeter wave treatment than in untreated cells. In conclusion, millimeter wave treatment induces CDK2 and cyclin A expression, accelerates S-phase entry and G2/M transition and promotes chondrocyte cell cycle progression.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blotting, Western
  • Cell Cycle / drug effects
  • Cell Cycle / radiation effects
  • Cell Proliferation / drug effects
  • Cell Proliferation / radiation effects*
  • Cell Survival / drug effects
  • Cell Survival / radiation effects
  • Cells, Cultured
  • Chondrocytes / cytology
  • Chondrocytes / metabolism*
  • Chondrocytes / ultrastructure
  • Cyclin A / genetics
  • Cyclin A / metabolism*
  • Cyclin-Dependent Kinase 2 / genetics
  • Cyclin-Dependent Kinase 2 / metabolism*
  • Flow Cytometry
  • Male
  • Microscopy, Electron, Transmission
  • Nocodazole / pharmacology
  • Radiation
  • Rats
  • Rats, Sprague-Dawley
  • Reverse Transcriptase Polymerase Chain Reaction
  • Tubulin Modulators / pharmacology
  • Up-Regulation / drug effects
  • Up-Regulation / radiation effects

Substances

  • Cyclin A
  • Tubulin Modulators
  • Cyclin-Dependent Kinase 2
  • Nocodazole