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Phenotypic reversion induced by anthracyclines in ras oncogene-expressed cells; structure-activity relationships
T Kanbe1, K S Tsuchiya, M Hori
1Showa College of Pharmaceutical Sciences, Tokyo, Japan.
Abstract:
Several antitumor anthracyclines, including those in preclinical stages, were examined for their action in reversing tumorous phenotypes of H- or K-ras 3T3 cells (NIH3T3 cells transformed by human H- or K-ras oncogene) into normal phenotypes, such as flattened cell morphology, anchorage dependent cell growth, etc. (referred to as anti-ras activity). The study elucidated relationships between the chemical structure of anthracyclines and the anti-ras activity. The human tumor cell line T24, which has a mutated H-ras gene, responded to the anthracyclines, as did K- or H-ras 3T3 cells, in respect to the phenotypic alterations. Pirarubicin was more than 4 times as active as aclarubicin in inhibiting the growth of solid tumors of K-ras 3T3 cells in nude mice, possibly reflecting a difference in anti-ras activity between the two antibiotics.
Insights
Anthracyclines can reverse tumor cell characteristics. Pirarubicin showed greater anti-ras activity than aclarubicin in preclinical models, suggesting structural differences influence efficacy.
Area of Science:
- Oncology
- Molecular Biology
- Pharmacology
Background:
- Ras oncogenes drive tumor development by altering cell phenotypes.
- Anthracyclines are a class of antitumor antibiotics with diverse mechanisms.
- Understanding structure-activity relationships is crucial for drug development.
Purpose of the Study:
- To investigate the anti-ras activity of various anthracyclines.
- To correlate anthracycline chemical structure with phenotypic reversion of ras-transformed cells.
- To evaluate anthracycline efficacy in preclinical tumor models.
Main Methods:
- Utilized H- or K-ras transformed NIH3T3 cells to assess phenotypic reversion.
- Tested anthracyclines for their ability to restore normal cell morphology and growth dependence.
- Employed a nude mouse xenograft model with K-ras 3T3 solid tumors to compare pirarubicin and aclarubicin efficacy.
Main Results:
- Several anthracyclines demonstrated the ability to reverse tumorous phenotypes in ras-transformed cells.
- A correlation between anthracycline chemical structure and anti-ras activity was identified.
- Pirarubicin exhibited over fourfold greater efficacy than aclarubicin in inhibiting K-ras 3T3 solid tumor growth in vivo.
Conclusions:
- Anthracyclines possess anti-ras activity, capable of reverting oncogenic phenotypes.
- Chemical structure significantly influences the anti-ras efficacy of anthracyclines.
- Pirarubicin represents a promising candidate for further investigation due to its superior preclinical anti-ras activity.