# TUMOR PROMOTERS EFFECTING BASE MODIFICATION IN DNA

> **NIH NIH R01** · NEW YORK UNIVERSITY · 1987 · $137,977

## Abstract

The primary objective of this proposal is to determine whether the
oxidative burst induced in polymorphonuclear leukocytes (PMNs) by tumor
promoting agents causes modification of the thymine moiety in DNA through
hydroxyl radical (.OH) attack.  PMNs will be isolated from the blood of
healthy, informed volunteers by venipuncture into tubes containing
anticoagulant.  The production of superoxide anion radical, H2O2 and .OH
resulting from the response of the PMNs to stimulation by tumor promoters
will be measured in the presence or absence of human plasma.  Tumor
promoters will include 12-0-tetradecanoylphorbol-13-acetate (TPA), a
complete promoter, and mezerein, a second stage promoter.  To determine
whether the extent of thymine modification in DNA exposed to activated PMNs
is proportional to .OH formation, DNA will be analyzed for the presence of
5-hydroxymethyl-2'-deoxyuridine (HMdU) and thymidine glycol (dTG), products
known to be formed through the .OH-mediated action of ionizing radiation.
Initial experiments will be carried out with E. coli (3H)thymidine-labeled
DNA co-incubated with activated PMNs.  This will be followed by
co-incubating (3H)thymidine-labeled HeLa cells with activated PMNs to
determine whether the oxygen radical species formed can effect modification
of cellular DNA.  When the extent and nature of PMN-mediated thymine
modification has been determined in these systems, then non-radioactive
HeLa cells will be incubated with activated PMNs and thymine modification
detected by post-labeling with 32P.  A second objective is to characterize
the DNA-protein crosslink which we have identified in DNA incubated with
activated PMNs.  First, E. coli (3H)thymidine-labeled DNA and then HeLa
cells whose DNA will be prelabeled with (3H)thymidine will be incubated
with TPA-activated PMNs in the presence of autologous human plasma.  After
digestion of proteins with Proteinase K, the DNA will be enzymatically
hydrolyzed and analyzed by HPLC for the presence of HMdU-amino acid adducts
using 14C-containing marker compounds which will be synthesized in this
laboratory.

## Key facts

- **NIH application ID:** 3175731
- **Project number:** 5R01CA037858-03
- **Recipient organization:** NEW YORK UNIVERSITY
- **SAM.gov UEI:** NX9PXMKW5KW8
- **Principal Investigator:** Krystyna Frenkel
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1987
- **Award amount:** $137,977
- **Award type:** 5
- **Project period:** 1985-04-01 → 1988-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3175731

## Citation

> US National Institutes of Health, RePORTER application 3175731, TUMOR PROMOTERS EFFECTING BASE MODIFICATION IN DNA (5R01CA037858-03). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3175731. Licensed CC0.

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