# QUANTITATION OF HYPOXIC TUMOR CELLS

> **NIH NIH R01** · BRITISH COLUMBIA CANCER AGENCY · 1993 · $96,094

## Abstract

Hypoxic cells in solid tumors are known to resist damage by ionizing
radiation and some chemotherapeutic agents, yet hypoxic fraction is not
routinely monitored in human tumors largely because methods are still
inadequate or impractical.  The overall aim of this proposal continues
to be the development of methods to identify and quantify hypoxic cells
in solid tumors.  During the current funding period, a method developed
in this laboratory for detection of hypoxic cells in solid tumors will
be evaluated in murine and human tumors.  Based on single cell
microelectrophoresis, the 'comet' assay is used to quantify DNA strand
breaks in individual cells.  Radiobiologically hypoxic cells are about
three times more resistant to DNA damage than aerobic cells, thus
providing the basis for measuring hypoxic fraction in single cell
suspensions prepared from solid tumors.  There are several advantages to
this approach which has been shown to quantify hypoxic fraction in SCCVII
murine tumors.  It is now necessary to determine the general
applicability of the assay.  The first Specific Aim is therefore to apply
the comet assay to a panel of murine tumors chosen to exhibit a range of
hypoxic fractions as well as different types of hypoxia (i.e., acute
versus chronic hypoxia).  Hypoxic fraction will be measured in Lewis
lung, WiDr, SiHa, KHT and RIF-1 tumors growing in mice, and results
compared with a standard method for determining hypoxic fraction, paired-
survival curve analysis.  Using the SCCVII tumor, hypoxic fraction will
be measured in tumor cells versus macrophages, in cells close to versus
distant from the blood supply, after high (5-15 Gy) and low (2 Gy) doses
of radiation, and in proliferating versus non-proliferating tumor cells.
In a second Specific Aim, hypoxic fraction in 10-20 accessible human
tumors will be measured in tumor cells recovered from fine needle
aspirates.  Since reoxygenation rate may be more critical for successful
radiotherapy than pre-treatment hypoxic fraction, a third Specific Aim
is directed towards the development and application of a fluorescence
image analysis method for quantifying changes in tumor perfusion at
different times following exposure of SCCVII tumors to ionizing
radiation.  Results will be compared with oxygen consumption by tumor
cubes, cell recovery, and hypoxic fraction measured using the comet
assay.  The comet assay will hopefully provide a practical method to
assess both pre- and post-treatment hypoxic fractions in solid human
tumors, and together with ongoing studies of tumor perfusion, tumor
oxygen consumption and vascular density, will help to determine the role
of hypoxia in the response of tumors to ionizing radiation.

## Key facts

- **NIH application ID:** 3175774
- **Project number:** 2R01CA037879-10
- **Recipient organization:** BRITISH COLUMBIA CANCER AGENCY
- **SAM.gov UEI:** LKF9B2BABMM6
- **Principal Investigator:** PEGGY L OLIVE
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1993
- **Award amount:** $96,094
- **Award type:** 2
- **Project period:** 1984-03-01 → 1996-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3175774

## Citation

> US National Institutes of Health, RePORTER application 3175774, QUANTITATION OF HYPOXIC TUMOR CELLS (2R01CA037879-10). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3175774. Licensed CC0.

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