Functional evaluation of the interaction of FAK with BCLAF1 during genotoxic stress induced by doxorubicin in H9c2 myocytes

Abstract

Cardiovascular complications of antineoplastic therapies are considered an emerging public health problem, given the growing population of cancer survivors. Cardiotoxicity induced by chemotherapy agents, such as doxorubicin (doxo), is a serious condition that can progress to chronic cardiomyopathy, congestive heart failure, and patient death. Studies focusing on signaling activated by antineoplastic therapies have demonstrated the importance of Focal adhesion kinase (FAK) for cell survival and resistance to this treatment, however, this signaling remains poorly understood. The present proposal aims to identify and characterize the molecular mechanisms of action of FAK during genotoxic stress induced by doxorubicin in H9c2 myocytes. Recently, we demonstrated that FAK interacts with BCLAF1 (BCL-2 Associated Transcription Factor 1), a nuclear protein that participates in the DNA damage response (DDR) and in the control of cell death. Data obtained from super-resolution microscopy revealed that BCLAF1 displays a spot-like shape with an area of approximately 150 nm² in the nucleus of myocytes under genotoxic stress and that FAK is concentrated in these nuclear clusters. However, it is not clear how this interaction and co-localization affect cell survival. Our hypothesis is that the interaction of FAK with BCLAF1 is involved in the control of cell death of myocytes with irreparable DNA damage. Therefore, BCLAF1 gene silencing will be performed and parameters such as the interaction of FAK with p53, p53 expression levels, and cell death rate will be investigated in H9c2 myocytes treated with doxo. The impact of BCLAF1 silencing on the subcellular distribution of FAK and p53 by super-resolution microscopy and advanced image analysis will also be investigated. The data generated by this study may contribute to the understanding of signaling activated by antineoplastic agents and also with future applications in the field of human health. (AU)