# EFFECT OF CALMODULIN INHIBITORS ON ADRIAMYCIN RESISTANCE

> **NIH NIH R01** · CLEVELAND CLINIC FOUNDATION · 1990 · $119,564

## Abstract

The basic theme of this proposal is to study the effect of
calmodulin inhibitors in vitro and in vivo in modulating the
cytotoxic response to adriamycin and cross-resistant drugs in
progressively adriamycin-resistant tumor models.  The tumor models
to be studied will include the parent-sensitive and progressively
adriamycin-resistant variants of the P388 and L1210 mouse leukemia
and B16-BL6 mouse melanoma.  The calmodulin inhibitors to be
evaluated are trifluoperazine, and N-(4-aminobutyl)-5-chloro-2-
naphthalenesulfonamide (W-13) a significantly less lipophilic and
"more specific" inhibitor of calmodulin.  The sensitive and
progressively resistant tumors will be characterized to determine
the effect of calmodulin inhibitors on: (a) distribution of
adriamycin in sub-cellular fractions obtained from cell homogenates
by differential centrifugation and quantification of adriamycin
levels by high performance liquid chromatography (HPLC); and (b)
adriamycin induced DNA protein cross links, DNA single and double
strand breaks, and the repair/rejoining of these lesions using the
technique of alkaline and neutral elution.  The effects of caffeine
on adriamycin cytotoxicity in the absence and presence of
calmodulin inhibitors will be focused on determining alterations
in adriamycin accumulation, changes in cellular free calcium
concentrations, damage to DNA and cytotoxicity.  Cellular
adrlamycin levels wlll be measured by HPLC and also by laser flow
cytometry.  Cellular free calcium levels will be determined with
the fluorescent calcium indicator Quin-2, and cytotoxicity by soft-
agar colony assay.  The relationship between progressive adriamycin
resistance, cross resistance characteristics, and the modulating
effect of calmodulin inhibitors with antltumor agents such as vinca
alkaloids, epipodophyllotoxins, anthracycline and non-anthracycline
agents with variable affinity to bind to DNA will be evaluated in
vivo.  Antitumor effects in vivo will be determined bv measuring
changes in prolongation of life span with P388 and L1210 leukemia,
and changes in tumor volume and/or reduction of pulmonary
metastases with B16-BL6 melanoma.  Acquisition of resistance to
adrlamycin in vivo will be evaluated with the B16-BL6 melanoma.
Metastatic characteristics of resistant cells will be based on
formation of experimental and spontaneous metastases, and the
response to antltumor effects of adriamycin in vltro and in vivo
will be determined by soft-agar colony assay and reductlon in tumor
burden respectively.  The proposed studies should in the long term
help us understand the molecular basis for the acquisition and
expression of resistance to adriamycin and the potential role of
calmodulin inhibitors in modulating adriamycin cytotoxicity.

## Key facts

- **NIH application ID:** 3173096
- **Project number:** 5R01CA035531-06
- **Recipient organization:** CLEVELAND CLINIC FOUNDATION
- **SAM.gov UEI:** TDGUJ1WA4UJ9
- **Principal Investigator:** RAM N. GANAPATHI
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1990
- **Award amount:** $119,564
- **Award type:** 5
- **Project period:** 1984-05-01 → 1991-12-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3173096

## Citation

> US National Institutes of Health, RePORTER application 3173096, EFFECT OF CALMODULIN INHIBITORS ON ADRIAMYCIN RESISTANCE (5R01CA035531-06). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3173096. Licensed CC0.

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