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Published on: February 6, 2015
Adaptive response towards adriamycin in vitro: circumvention with verapamil
E L Anuszewska1, J H Koziorowska
1Drug Institute, Warsaw, Poland.
Abstract:
In an attempt to identify mechanisms of adaptive response to adriamycin (ADR), we have earlier isolated ADR-resistant cell lines CHO/R and ME18/R by short-term pulse exposures of parent cell lines to this drug, followed by single-cell cloning. The results presented in this study have shown that the development of resistance to ADR was accompanied by cross-resistance to vinblastine and methotrexate. The resistance of tested cell lines towards ADR was substantially reversed by verapamil (VPL) at non-toxic concentrations. VPL abolished also the capability of these cell lines to express adaptive response after treatment of the cells with a conditioning dose of ADR. From the results of our study, we conclude that similar characteristics play a role in the mechanism of the phenomenon of adaptive response as in the mechanism of pleiotropic multidrug resistance.
Insights
This study reveals that adaptive resistance to adriamycin (ADR) in cancer cells involves mechanisms similar to pleiotropic multidrug resistance. Verapamil (VPL) reversed ADR resistance and blocked adaptive responses, suggesting a common pathway.
Area of Science:
- Cell Biology
- Pharmacology
- Cancer Research
Background:
- Adriamycin (ADR) is a chemotherapy drug with significant side effects.
- Understanding adaptive resistance mechanisms is crucial for improving cancer therapy.
- Previous work isolated ADR-resistant cell lines (CHO/R, ME18/R) using pulse exposures.
Purpose of the Study:
- To investigate the mechanisms of adaptive response to adriamycin (ADR).
- To explore the relationship between ADR resistance and pleiotropic multidrug resistance.
- To assess the effect of verapamil (VPL) on ADR resistance and adaptive response.
Main Methods:
- Isolation of ADR-resistant cell lines (CHO/R, ME18/R) via single-cell cloning after pulse ADR exposure.
- Assessment of cross-resistance to vinblastine and methotrexate.
- Evaluation of verapamil (VPL) effects on ADR resistance and adaptive response induction.
Main Results:
- ADR-resistant cell lines exhibited cross-resistance to vinblastine and methotrexate.
- Verapamil (VPL) significantly reversed ADR resistance at non-toxic concentrations.
- VPL also inhibited the adaptive response to a conditioning ADR dose.
Conclusions:
- The mechanisms underlying adaptive response to ADR share similarities with pleiotropic multidrug resistance.
- Verapamil (VPL) may be a potential agent to overcome or modulate ADR resistance.
- These findings contribute to understanding drug resistance in cancer treatment.
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