# DETECTION OF DRUG-RESISTANT CELLS IN ACUTE LEUKEMIA

> **NIH NIH R01** · UNIVERSITY OF MARYLAND BALTIMORE · 1993 · $33,271

## Abstract

This study is designed to fill crucial gaps in knowledge concerning
cytosine arabinoside (ara-C) mechanism of action and cytotoxicity.  Our
specific aims focus on (1.) utilization of pH-step alkaline elution in
conjunction with a cell-free human DNA synthetic system to define more
precisely how ara-C interferes with the DNA replicative process in intact
human cells, and (2.) determining the biological consequences of ara-C
incorporated into DNA in terms of its effects on the recognition of a
replication origin in DNA by a known DNA synthesis initiator protein, and
on the transcription of messenger RNA.  To accomplish the first aim, we
will utilize a human multi-protein complex that contains the enzymatic
components necessary for DNA replication.  This complex has a
sedimentation coefficient of 21S, and is fully competent to carry out the
cell-free replication of the Simian virus 40 (SV40) genome, provided that
the SV40-specific initiator protein, large T-antigen (T-Ag) is present.
We will strive to develop this 21S multi-protein complex system into a
cell-free model that emulates the DNA synthetic apparatus in the intact
cell, thereby facilitating the study of the effects of ara-C on the
intricate process of human DNA replication.  The validity of the 21S
replication complex model to mimic cellular events will be monitored by
studies of ara-C effects on DNA synthesis in intact cells, using the pH-
step alkaline elution technique.  For the second aim, we will use
recombinant DNA methods to insert ara-C into selected sites in a defined
DNA template.  We have selected for this template the well characterized
SV40 viral genome, or plasmids containing the SV40 origin of replication,
ori.  These sites for ara-C insertion include a specific gene (T-Ag), and
the replication origin, ori.  We will then test the effects of the
incorporated ara-C on initiator protein (T-Ag) recognition of ori, on RNA
transcription of the T-Ag gene, and on the properties and biologic
function of any transcript of T-Ag that may be made from an ara-C
containing template.  Although these studies utilize a viral gene and DNA
template, any effects of ara-C incorporation observed should directly
reflect the same consequences of ara-C on biological function in human
cancer cells.  No one has ever studied the effects of ara-C on these
processes in such a direct manner.  the information obtained from these
studies may contribute substantially to improving ara-C therapy, and in
devising new and improved methods for the detection of ara-C resistance
in acute leukemia patients.

## Key facts

- **NIH application ID:** 3179815
- **Project number:** 2R01CA040188-07A2
- **Recipient organization:** UNIVERSITY OF MARYLAND BALTIMORE
- **SAM.gov UEI:** Z9CRZKD42ZT1
- **Principal Investigator:** DOUGLAS DONALD ROSS
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1993
- **Award amount:** $33,271
- **Award type:** 2
- **Project period:** 1985-07-01 → 1995-11-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3179815

## Citation

> US National Institutes of Health, RePORTER application 3179815, DETECTION OF DRUG-RESISTANT CELLS IN ACUTE LEUKEMIA (2R01CA040188-07A2). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3179815. Licensed CC0.

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