# ONCOGENESIS FROM LOW-DOES-RATE X-IRRADIATION

> **NIH NIH R01** · UNIVERSITY OF MARYLAND BALTIMORE · 1987 · $95,402

## Abstract

Our aim is to obtain information on the frequency of oncogenic
transformation as an explicit function of exposure time for a variety of
dose rates on latent transformation damage remaining after protracted
X-irradiation.  This latent damage and its expression by the promoter
12-0-tetradecanoyl-phorbol-13-acetate will be investigated by chronic
TPA-treatment of cells initiated with X-rays delivered at high dose rate or
protracted over times up to 8 h.

We will continue to use the C3H/10T1/2 cell line derived from mouse cells
in which transformation is quantitated by scoring piled-up foci on top of a
confluent monolayer.  Experiments will be performed at 37 degrees C with
actively growing cultures.  We will continue to use a constant exposure
time technique for cellular irradiation at reduced dose rates.  At
cumulative or acute doses of .25 to 4 Gy, we will assay the population of
X-ray initiated cells by TPA-treatments at 0.1 Mug/ml beginning immediately
after irratiation.  The control groups (without TPA but with TAP-solvent)
will follow the same procedure.  Relative factors will be estimated from
the ratio of the transformation frequencies from protracted exposures over
time T to frequency from an acute exposure (4 Gy/min) to the same dose,
with or without TPA versus (a) the dose to obtain information on the
efficacy of rapair processes, or (b) the total exposure time to obtain
information on the kinetics of repair processes.

## Key facts

- **NIH application ID:** 3170598
- **Project number:** 5R01CA032729-05
- **Recipient organization:** UNIVERSITY OF MARYLAND BALTIMORE
- **SAM.gov UEI:** Z9CRZKD42ZT1
- **Principal Investigator:** ELIZABETH K BALCER-KUBICZEK
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1987
- **Award amount:** $95,402
- **Award type:** 5
- **Project period:** 1983-05-01 → 1989-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3170598

## Citation

> US National Institutes of Health, RePORTER application 3170598, ONCOGENESIS FROM LOW-DOES-RATE X-IRRADIATION (5R01CA032729-05). Retrieved via MORVS 2026-10-24 from https://api.morvs.ai/grant/nih/3170598. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*