# BIOCHEMISTRY OF HYPERTHERMIC CELLULAR INACTIVATION

> **NIH NIH R01** · VANDERBILT UNIVERSITY · 1992 · $236,660

## Abstract

The long term objective of this grant proposal is to provide a basic
understanding of hyperthermia in order to increase its therapeutic
effectiveness.  The mechanisms which regulate thermal sensitivity and
hyperthermic enhancement of radiation sensitivity are not well understood.
Both, however, can be regulated by the intracellular glutathione
concentration and redox ratio.  Specific aim 1 tests the hypothesis that
glutathione acts in an antioxidant capacity during hyperthermic treatment.
The intracellular hydrogen peroxide concentration will be measured in
control and glutathione depleted cells incubated at temperatures ranging
from 37o to 46oC.  The role of iron redox cycling in thermal sensitivity
will also be investigated.  Compounds which mimic superoxide dismutase and
human embryonic kidney cells transfected with superoxide dismutase will be
used to investigate the relationship between glutathione concentrations and
superoxide dismutase activity during hyperthermia.  Specific aim 2 tests
the hypothesis that enhanced synthesis of heat shock proteins and the
development of thermotolerance protects cells from oxidative damage.  This
hypothesis will be tested using the glucocorticoid receptor as a model.
The results obtained will be compared to those obtained when the receptor
is inactivated by heat shock.  Aim 3 seeks to determine if thiol oxidation
triggers the synthesis of heat shock proteins and/or the development of
thermotolerance.  Experiments have been designed to determine if there is
a correlation between the rate of GSSG formation measured during oxidant
challenge and enhanced synthesis of the 110, 90, 73/72, and 27 kDa heat
shock proteins.  Northern analysis of mRNA, nuclear run-offs, and in vitro
translation will be used to determine if enhanced synthesis is due to
increased transcription of heat shock genes.  If transcription is
increased, then a gel mobility-shift assay will be used to determine if
thiol oxidation can induce binding activity specific to a region of the
element of the heat shock 70 promoter.  Aim 4 is designed to investigate
the regulation of the intracellular glutathione concentration.  Cells will
be exposed to xenobiotics such as BSO or adriamycin and the rate of GSH
synthesis, the activity and mRNA levels of gamma-glutamyl transpeptidase
and gamma-glutamyl cysteine synthetase, the activity of GSH reductase, rate
of GSH turnover and efflux will be quantified.  Aim 5 will test the
hypothesis that glutathione metabolism is involved in the enzymatic repair
of aerobic radiation damage.  The role of iron and Se-dependent and
independent peroxidase activity in the expression of radiation damage, as
measured by cell survival and the formation and repair of DNA double strand
breaks, will be determined.  The purpose of this aim is to obtain
information which can be applied toward understanding how glutathione
depletion can increase thermal radiosensitivity.

## Key facts

- **NIH application ID:** 3176101
- **Project number:** 2R01CA038079-08A1
- **Recipient organization:** VANDERBILT UNIVERSITY
- **SAM.gov UEI:** GTNBNWXJ12D5
- **Principal Investigator:** MICHAEL L. FREEMAN
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1992
- **Award amount:** $236,660
- **Award type:** 2
- **Project period:** 1984-07-01 → 1995-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3176101

## Citation

> US National Institutes of Health, RePORTER application 3176101, BIOCHEMISTRY OF HYPERTHERMIC CELLULAR INACTIVATION (2R01CA038079-08A1). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3176101. Licensed CC0.

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