# DETERMINATION OF CELL SURVIVAL FROM DNA PARAMETERS

> **NIH NIH R01** · SUNY DOWNSTATE MEDICAL CENTER · 1990 · $153,745

## Abstract

This program will use the recently developed method of viscoelastometry
(VE) to measure the size, conformation, and concentration (number) of
mammalian chromosomal DNA molecules.  By comparing changes in molecular
size (Gamma), conformation (relative Tau and Gamma), and size concentration
(ri) distribution, as functions of radiation dose and postirradiation
treatment and/or repair, the rates of induction and repair of double-stand
breaks (DSBs) will be determined.  Cellular loss of reproductive integrity
will be correlated with unrepaired DSBs per cell in order to determine if
the unrepaired DSB is the major lethal lesion.  Should such a correlation
prove significant, the basis for a DNA based assay for cellular
radiosensitivity will have been established.  Since VE can detect the
effects of clinically (and biologically) relevant doses (0.50 - 20 Gy), the
above relationship will then provide a useful clinical assay.  This assay
will be tested in a competing renewal of this proposal.

In addition, several biologically important points will be established by
the data we propose to collect.  The first of these is a determination as
to whether mammalian chromosomal DNA consists of linear or circular
molecules.  At present nok data exist which directly demonstrate the DNA
conformation.  The data we propose to collect will demonstrate either the
linear or the circular nature of relaxed chromosomal DNA in mammalian
cells.  This has far reaching consequences for our understanding of
chromosome structure.  The second point will be the determination of a
general method for the determination of the D37, DSB and molecular
conformation by the use of VE.  The third point will be a test of the
hypothesis that the shapes of the cell survival curves can be explained
solely in terms of potentially lethal lesions (PLL) and their repair.  We
will examine the effects of postirradiation repair time followed by
hypertonicity treatment to see if cell survival curves consistent with this
interpretation are obtained.  This has been done in one cell line but it is
not clear if this is a general finding.  The fourth point will be the
determination of the number of unrepaired DSBs after each of the treatment
used to assess PLL, and a test as to whether the PLL can be correlated with
the DSB.

## Key facts

- **NIH application ID:** 3177728
- **Project number:** 2R01CA039045-04A3
- **Recipient organization:** SUNY DOWNSTATE MEDICAL CENTER
- **SAM.gov UEI:** NJ14V2NZYM68
- **Principal Investigator:** CHRISTOPHER S. LANGE
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1990
- **Award amount:** $153,745
- **Award type:** 2
- **Project period:** 1984-12-01 → 1993-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3177728

## Citation

> US National Institutes of Health, RePORTER application 3177728, DETERMINATION OF CELL SURVIVAL FROM DNA PARAMETERS (2R01CA039045-04A3). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3177728. Licensed CC0.

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