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DNA biomarkers antecede semiquantitative anthracycline cardiomyopathy
Sae Hahm1, Harley S Dresner, David Podwall
1Unified Tumor Marker Laboratory, Department of Pathology and Radiation Oncology, Montefiore Medical Center, 111 East 210th Street, Central 312, Bronx, NY 10467, USA.
Abstract:
Adriamycin (ADM, or doxorubicin hydrochloride) is an effective antineoplastic agent whose use is restricted by its well-described, dose-dependent cardiotoxicity. This study measures ADM DNA adduct formation by 32P-radiolabeling DNA, enzymatically digesting radiolabeled DNA, separating the formed adducts on two-dimensional thinlayer chromatography (2D-TLC), and quantitating the adducts with autoradiography and densitometry. Thirty-six male Sprague-Dawley rats are randomized to receive ADM at varying intraperitoneal (i.p.) injection concentrations: 0.9% saline i.p. controls, 4 mg/kg ADM i.p., and 6 mg/kg ADM i.p. Myocardial and pulmonary tissues are harvested 48 hours after i.p. injection for autoradiographic and histopathologic analyses. The results indicate differences in the amount and type of adduct formation as a function of ADM concentration. Increased partial depurination of dGMP and dAMP occurs with increasing ADM concentration at equal incubation times. This depurination correlates with the emergence of new adducts HM-dUMP, 8-OH-dGMP, HM-dCMP, and Me-dCMP. The quantification of these adducts can potentially represent an early marker of ADM cardiotoxicity and thereby optimize the efficacy of individual chemotherapy regimens while minimizing adverse effects.
Insights
Adriamycin (doxorubicin hydrochloride) DNA adducts in rat heart and lung tissues were quantified. Increased Adriamycin concentration correlated with specific DNA adducts, potentially serving as early cardiotoxicity markers.
Area of Science:
- Molecular toxicology
- Pharmacology
- Cardiology
Background:
- Adriamycin (doxorubicin hydrochloride) is a potent antineoplastic drug.
- Its clinical utility is limited by dose-dependent cardiotoxicity.
- Understanding Adriamycin-induced DNA damage is crucial for mitigating toxicity.
Purpose of the Study:
- To measure Adriamycin DNA adduct formation in vivo.
- To investigate the relationship between Adriamycin concentration and adduct profiles.
- To explore the potential of adducts as early biomarkers of cardiotoxicity.
Main Methods:
- Male Sprague-Dawley rats received intraperitoneal injections of Adriamycin (4 or 6 mg/kg) or saline control.
- Myocardial and pulmonary tissues were analyzed 48 hours post-injection.
- DNA was radiolabeled, enzymatically digested, and adducts were separated by 2D-TLC, quantified via autoradiography and densitometry.
Main Results:
- Differences in the amount and type of Adriamycin DNA adducts were observed based on drug concentration.
- Increased Adriamycin dosage led to greater partial depurination of dGMP and dAMP.
- New adducts (HM-dUMP, 8-OH-dGMP, HM-dCMP, Me-dCMP) emerged with higher Adriamycin concentrations.
Conclusions:
- Quantification of specific Adriamycin DNA adducts can serve as an early indicator of cardiotoxicity.
- This approach may enable optimization of chemotherapy regimens to minimize adverse effects.
- Further research can refine the use of these adducts for personalized cancer treatment.