Radiation protective effect of hypoxia-inducible factor-1α (HIF-1α) on human oral squamous cell carcinoma cell lines

Radiat Prot Dosimetry. 2012 Nov;152(1-3):159-63. doi: 10.1093/rpd/ncs215. Epub 2012 Aug 26.

Abstract

We examined the effects of 5-Gy radiation on the expression of hypoxia-inducible factor-1α (HIF-1α) and the radiosensitivity of five human oral squamous cell carcinoma (OSCC) cell lines (SAS, Ca9-22, TT, BSC-OF and IS-FOM). In all of the cell lines, HIF-1α was expressed in mRNA, and radiation had no influence on gene transcription. The number of apoptotic cells increased 72 h after irradiation in cell lines SAS, Ca9-22 and TT cells, indicating low transcriptional levels of HIF-1α, and the levels of non-cleaved caspase-3, an executioner of apoptosis, and non-cleaved poly (adenosine diphosphate-ribose) polymerase (PARP), a marker of DNA damage early in apoptosis, decreased simultaneously. Conversely, radiation failed to induce apoptosis or to decrease expression of non-cleaved caspase-3 and PARP in cell lines BSC-OF and IS-FOM cells that expressed high levels of HIF-1α. BSC-OF and IS-FOM cells exhibited high migratory capacity. When CoCl(2) was present in the medium, HIF-1α expression increased along with the survival of Ca9-22 cells after radiation exposure. These results suggest that OSCC cells expressing high levels of HIF-1α are resistant to radiation. HIF-1α can be used to control the short-term radiosensitivity of cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis
  • Carcinoma, Squamous Cell / radiotherapy*
  • Cell Line
  • Cell Line, Tumor
  • Cell Movement
  • Cell Survival
  • Culture Media, Conditioned / pharmacology
  • Densitometry / methods
  • Humans
  • Hypoxia-Inducible Factor 1, alpha Subunit / metabolism*
  • Mouth Neoplasms / radiotherapy*
  • Radiation-Protective Agents
  • Reverse Transcriptase Polymerase Chain Reaction / methods
  • Time Factors
  • Transcription, Genetic
  • X-Rays

Substances

  • Culture Media, Conditioned
  • Hypoxia-Inducible Factor 1, alpha Subunit
  • Radiation-Protective Agents