Heat-induced intranuclear protein aggregation and thermal radiosensitization

Area of Science:

• Cell Biology
• Radiation Oncology
• Molecular Biology

Background:

• Thermal radiosensitization, the enhanced sensitivity of cells to radiation after heat treatment, is a complex phenomenon.
• The role of heat-induced nuclear protein aggregation in this process requires further investigation.

Purpose of the Study:

• To investigate the hypothesis that thermal radiosensitization is indirectly caused by heat-induced denaturation and aggregation of nuclear proteins.
• To explore the influence of heat shock proteins (hsps) on nuclear protein aggregation and thermal radiosensitization.

Main Methods:

• Comparing protein aggregation in thermotolerant and non-tolerant rodent cells post-heat treatment.
• Assessing radiosensitization after heat treatment with varying time intervals.
• Analyzing the effects of transfecting cells with heat shock protein genes (hsp72 and hsp27).

Main Results:

• Thermotolerant cells exhibited reduced nuclear protein aggregation and radiosensitization compared to non-tolerant cells.
• Separating heat and radiation treatments led to faster protein disaggregation and radiosensitization decline in thermotolerant cells.
• hsp72 transfection protected against aggregation and reduced radiosensitization, while hsp27 accelerated disaggregation and radiosensitization decline.

Conclusions:

• The study supports the hypothesis that radiosensitization is primarily caused by heat-induced inhibition of DNA repair due to nuclear protein aggregation.
• Heat shock proteins modulate thermal radiosensitization by influencing nuclear protein aggregation.