Anthracycline-mediated cardiomyopathy: Basic molecular knowledge for the cardiologist / Miocardiopatía inducida por antraciclinas: conocimientos moleculares básicos para el cardiólogo

Anthracyclines are cytostatic antibiotics discovered almost half a century ago exerting their action through inhibition of topoisomerase II. The two most representative drugs are doxorubicin and daunorubicin and they have been proven as useful antineoplastics and are widely prescribed in daily oncology practice; unfortunately, cardiotoxicity has been a limiting factor when it comes to their use. Diverse mechanisms have been involved in anthracycline cardiotoxicity, none of which are capable of causing the whole clinical picture by itself. Traditionally, reactive oxygen species (ROS) have received more attention, although recently basic research has proven other factors to be as important as ROS. These factors mainly involve sarcomeric structure disruption, toxic accumulation of metabolites, iron metabolism, energetic alterations and inflammation. The role of genetics has been studied by some groups, although a clear genotype-response relationship is yet to be elucidated. With the improved survival from different oncologic diseases we are witnessing more cases of chemotherapy-induced cardiotoxicity and the advent of new anticancer drugs poses several challenges for the cardiologist, highlighting the importance of a deep knowledge of the main mechanisms inducing this toxicity.

Hace casi medio siglo se descubrieron las antraciclinas; estas son antibióticos citostáticos inhibidores de la topoisomerasa II. Los 2 fármacos más representativos de este grupo son la doxorrubicina y la daunorrubicina. Estos fármacos han demostrado ser eficaces antineoplásicos y han sido ampliamente utilizados en la práctica oncológica. Desafortunadamente, la cardiotoxicidad sigue siendo un elemento limitante para su uso. Los mecanismos mediante los cuales estos fármacos ocasionan cardiotoxicidad son múltiples pero ninguno de ellos de forma individual es capaz de explicar el cuadro clínico por completo. Casi siempre se ha considerado que la formación de especies reactivas de oxígeno era responsable de gran parte de la toxicidad, sin embargo la experimentación básica reciente ha demostrado que hay otros factores, entre los que destacan las alteraciones en la estructura sarcomérica, la acumulación de metabolitos tóxicos, las alteraciones del metabolismo del hierro o de los mecanismos energéticos, y la liberación de mediadores de inflamación. Por otra parte, diversos grupos han investigado la intervención que la genética podría tener en el desarrollo de esta enfermedad, si bien no se puede definir aún una clara correlación genotipo-respuesta. Con el aumento de la supervivencia por el tratamiento de diversas enfermedades oncológicas, se están detectando más casos de cardiotoxicidad mediada por quimioterapia; y con la aparición de nuevos fármacos quimioterápicos se añaden nuevos retos, con lo que se demuestra la importancia del estudio profundo de los mecanismos causales.

Anthracycline-mediated cardiomyopathy: basic molecular knowledge for the cardiologist.

Anthracyclines are cytostatic antibiotics discovered almost half a century ago exerting their action through inhibition of topoisomerase II. The two most representative drugs are doxorubicin and daunorubicin and they have been proven as useful antineoplastics and are widely prescribed in daily oncology practice; unfortunately, cardiotoxicity has been a limiting factor when it comes to their use. Diverse mechanisms have been involved in anthracycline cardiotoxicity, none of which are capable of causing the whole clinical picture by itself. Traditionally, reactive oxygen species (ROS) have received more attention, although recently basic research has proven other factors to be as important as ROS. These factors mainly involve sarcomeric structure disruption, toxic accumulation of metabolites, iron metabolism, energetic alterations and inflammation. The role of genetics has been studied by some groups, although a clear genotype-response relationship is yet to be elucidated. With the improved survival from different oncologic diseases we are witnessing more cases of chemotherapy-induced cardiotoxicity and the advent of new anticancer drugs poses several challenges for the cardiologist, highlighting the importance of a deep knowledge of the main mechanisms inducing this toxicity.