# EFFECT OF CALMODULIN INHIBITORS ON ADRIAMYCIN RESISTANCE

> **NIH NIH R01** · CLEVELAND CLINIC FOUNDATION · 1993 · $153,170

## Abstract

The basic theme of this proposal is to study the effect of calmodulin
inhibitors on cellular targets governing a cytotoxic response to adriamycin
and cross-resistant drugs in progressively adriamycin-resistant tumor
models.  The tumor models to be characterized will include the
parent-sensitive and progressively adriamycin-resistant variants of L1210
mouse leukemia, B16-BL6 mouse melanoma and HL-60 human promyelocytic
leukemia.  The calmodulin inhibitors to be evaluated are trifluoperazine,
and 1,3-dihydro-1-[1-[(4-methyl-4H, 6H-pyrrolo[1,2-a][4,1]-benzoxazepin-4-
yl)methyl]-4-piperidinyl]-2H-benzimidazol-2-one(l:l)maleate (CGS9343B) a
selective calmodulin inhibitor which does not inhibit protein kinase
activity.  The sensitive and progressively adriamycin-resistant tumors will
be characterized to determine: (a) the cellular accumulation/retention and
subcellular distribution of calmodulin inhibitors in the absence or
presence of adriamycin, etoposide and vincristine using radiolabelled drugs
and/or high performance liquid chromatography (HPLC); and (b) the role of
extranuclear factors in governing adriamycin or etoposide induced DNA
damage and repair/rejoining of these lesions in the absence or presence of
calmodulin Inhibitors using isolated nuclei alone or nuclei reconstituted
with membrane and/or cytosol fractions, by the technique of alkaline
elution.  Further, adriamycin or etoposide induced DNA damage based on
Interaction with the 170 kDa and 180 kDa isoforms of topoisomerase II will
be determined by band depletion-immunoblotting technique.  Alterations in
phosphorylation of P-glycoprotein and topoisomerase II and its modulation
by calmodulin inhibitors will be determined by sodium dodecyl
sulfate-polyacrylamide gel electrophoresis of immunoprecipitates.  The
phosphorylated immunoprecipitates of P-glycoprotein and topoisomerase II
will be further characterized to determine phosphorylated amino acids by
thin layer electrophoresis and phosphopeptides following digestion with
Staphylococcus aureus V8 protease.  Purified topoisomerase II will be
isolated from sensitive and adriamycin-resistant cells by fast protein
liquid chromatography and characterized for catalytic activity based on P4
unknotting, drug induced DNA protein cross linking using uniquely 3' end
labelled SV-40 DNA and phosphorylation by calcium/calmodulin dependent
protein kinase 11.  The role of calmodulin inhibitors in modulation of
resistance and emergence of a resistant phenotype will be characterized in
tumor cells selected for resistance to a combination of adriamycin plus,
trifluoperazine, by evaluating cytotoxic response, induction of DNA damage
and phosphorylation of putative targets viz.  P-glycoprotein and
topoisomerase II, in the absence or presence of calmodulin inhibitors.  The
proposed studies from a pharmacological and biochemical standpoint should
in the long term help us understand the targets involved in the acquisition
and expression of resistance to adriamyc...

## Key facts

- **NIH application ID:** 3173098
- **Project number:** 5R01CA035531-09
- **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:** 1993
- **Award amount:** $153,170
- **Award type:** 5
- **Project period:** 1984-05-01 → 1996-12-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3173098

## Citation

> US National Institutes of Health, RePORTER application 3173098, EFFECT OF CALMODULIN INHIBITORS ON ADRIAMYCIN RESISTANCE (5R01CA035531-09). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3173098. Licensed CC0.

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