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Acute extracellular acidification increases nuclear associated protein levels in human melanoma cells during 42°C hyperthermia and enhances cell killing
- Source :
- International Journal of Hyperthermia. 18:404-415
- Publication Year :
- 2002
- Publisher :
- Informa UK Limited, 2002.
-
Abstract
- Acute acidification is being investigated as a strategy to sensitize human melanoma to 42 degrees C hyperthermia. The present study was conducted to determine the effect of hyperthermia and acute extracellular acidification on the nuclear associated protein (NAP) levels, heat shock protein (hsp) 70 and hsp27 content, and cell survival of human melanoma cells cultured at pH 7.3 or pH 6.7. It was observed that NAP levels increased slightly in both populations after 2 h of heating and then decreased to control levels with increasing time of heating at the growth pH. However, the NAP levels continued to increase in cells acutely acidified to pH 6.3 prior to and during heating. Hsp70 was induced to comparable levels in cells heated at their growth pH; however, the hsp27 levels were greater in cells cultured and heated at pH 6.7 than in cells cultured and heated at pH 7.3. Acute acidification to pH 6.3 prior to and during heating suppressed the 42 degrees C induction of hsp70 and hsp27 in both cell populations. The melanoma cells cultured and heated at pH 6.7 were more resistant to cell killing than cells cultured and heated at pH 7.3. Both populations were sensitized to cell killing by acute acidification to pH 6.3. The results suggest that hsps induced during 42 degrees C treatment associate with aggregating NAPs, enhancing their detergent solubility, and that abrogation of induced expression of hsps during heating at pH 6.3 contributes to increased levels of insoluble NAPS. In conclusion, acute extracellular acidification inhibits 42 degrees C induction of hsps, increases NAP levels, and decreases cell survival in DB-1 human melanoma cells.
- Subjects :
- Hyperthermia
Cancer Research
medicine.medical_specialty
Hot Temperature
Time Factors
Cell Survival
Physiology
Blotting, Western
HSP27 Heat-Shock Proteins
Hsp27
Physiology (medical)
Internal medicine
Heat shock protein
Tumor Cells, Cultured
medicine
Extracellular
Humans
HSP70 Heat-Shock Proteins
Heat-Shock Proteins
Cell Nucleus
biology
Temperature
Nuclear Proteins
Hyperthermia, Induced
Hydrogen-Ion Concentration
Flow Cytometry
medicine.disease
Molecular biology
Neoplasm Proteins
Hsp70
Nap
Cell killing
Endocrinology
Cell culture
biology.protein
Electrophoresis, Polyacrylamide Gel
Molecular Chaperones
Subjects
Details
- ISSN :
- 14645157 and 02656736
- Volume :
- 18
- Database :
- OpenAIRE
- Journal :
- International Journal of Hyperthermia
- Accession number :
- edsair.doi.dedup.....72c329365aa5265bc7c098d542820e55