The overall goal of our ongoing research is to delineate the mechanisms of cell killing and radiosensitization by hyperthermia, in both acute 43 degree C - 45 degreeC, and moderate, 41 degree C - 42 degree C, temperature ranges. We propose to test one hypothesis on heat-induced cell killing and one on radiosensitization. The first hypothesis addresses the mechanism of S-phase cell killing because S-phase cells are the most sensitive to acute hyperthermia and appear to be the only cells that are killed at moderate temperatures. Hypothesis 1: heat-induced aggregation of proteins to DNA replication factories and/or the altered binding of proteins normally associated with these structures is a key step in S-phase cell killing. For the purposes of this proposal, we will use """"""""protein aggregation"""""""" to refer to a process where proteins not normally targeted to a subnuclear structure become bound to that structure due to heat shock. Similarly, """"""""altered binding of proteins"""""""" refers to proteins that are functionally part of a subnuclear structure and are solubilized under normal isolation conditions, but coisolate with that structure and/or the nuclear matrix (NM) after heat shock. Hypothesis 2: proteins thermally aggregated or bound to the NM contribute to radiosensitization at 41 degree C by inhibiting or altering DNA repair in a manner analogous to that at 43 degree C - 45 degree C.
The specific aims are: 1. Determine if protein targeting sequences specific for DNA- replication-factories affect heat-induced aggregation and/or protein binding to DNA replication factories in vivo. 2. Determine if the association of heat-labile proteins with DNA replication factories sensitizes cells to (or mimics) heat- induced cell killing. 3. Determine if DNA replication factories are a target for heat-induced cell killing at 45 degree C. 4. Determine if DNA replication factories are a target for heat- induced cell killing at 41.1 degree C. 5. Determine if heat- induced alterations in protein binding and/or aggregation to the NM and/or DNA repair complexes inhibit or alter DNA repair and thereby contribute to radiosensitization by 41.1 degree C hyperthermia in a manner analogous to that at 43 degree C - 45 degree C.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA043198-17
Application #
6604670
Study Section
Radiation Study Section (RAD)
Program Officer
Stone, Helen B
Project Start
1986-08-01
Project End
2005-06-30
Budget Start
2003-07-01
Budget End
2004-06-30
Support Year
17
Fiscal Year
2003
Total Cost
$277,200
Indirect Cost
Name
Washington University
Department
Radiation-Diagnostic/Oncology
Type
Schools of Medicine
DUNS #
068552207
City
Saint Louis
State
MO
Country
United States
Zip Code
63130
Myerson, R J; Roti Roti, J L; Moros, E G et al. (2004) Modelling heat-induced radiosensitization: clinical implications. Int J Hyperthermia 20:201-12
Vanderwaal, R P; Roti Roti, J L (2004) Heat induced 'masking' of redox sensitive component(s) of the DNA-nuclear matrix anchoring complex. Int J Hyperthermia 20:234-9
Roti Roti, Joseph L (2003) Radiation-induced versus endogenous DNA damage and assays that measure parameters reflecting DNA damage on cell by cell basis: comments on the article by Pollycove and Feinendegen. Hum Exp Toxicol 22:309-13; discussion 321-3
Bisht, K S; Bradbury, C M; Zoberi, I et al. (2003) Inhibition of cyclooxygenase-2 with NS-398 and the prevention of radiation-induced transformation, micronuclei formation and clonogenic cell death in C3H 10T1/2 cells. Int J Radiat Biol 79:879-88
Zoberi, Imran; Bradbury, C Matthew; Curry, Heather A et al. (2002) Radiosensitizing and anti-proliferative effects of resveratrol in two human cervical tumor cell lines. Cancer Lett 175:165-73
Xu, M; Myerson, R J; Straube, W L et al. (2002) Radiosensitization of heat resistant human tumour cells by 1 hour at 41.1 degrees C and its effect on DNA repair. Int J Hyperthermia 18:385-403
Locke, J E; Bradbury, C M; Wei, S J et al. (2002) Indomethacin lowers the threshold thermal exposure for hyperthermic radiosensitization and heat-shock inhibition of ionizing radiation-induced activation of NF-kappaB. Int J Radiat Biol 78:493-502
VanderWaal, R P; Wright, W D; Roti Roti, J L (1999) The effects of heat-shock on nuclear matrix-associated DNA-replication complexes. Crit Rev Eukaryot Gene Expr 9:363-71
Chen, M S; Roti, J R; Laszlo, A (1999) Hsc40, a new member of the hsp40 family, exhibits similar expression profile to that of hsc70 in mammalian cells. Gene 238:333-41
Xu, M; Wright, W D; Higashikubo, R et al. (1999) Thermal radiosensitization of human tumour cell lines with different sensitivities to 41.1 degrees C. Int J Hyperthermia 15:279-90

Showing the most recent 10 out of 28 publications