Dysregulated miR1254 and miR579 for cardiotoxicity in patients treated with bevacizumab in colorectal cancer.

Methods for detecting circulating microRNAs (miRNAs), small RNAs that control gene expression, at high sensitivity and specificity in the blood have been reported in recent studies. The goal of this study was to determine if detectable levels of specific miRNAs are released into the circulation for bevacizumab-induced cardiotoxicity. A miRNA array analysis was performed using RNA isolated from 10 control patients in bevacizumab treatment, and n=10 patients have been confirmed to have bevacizumab-induced cardiotoxicity. From the array, we selected 19 candidate miRNA for a second validation study in 90 controls and 88 patients with bevacizumab-induced cardiotoxicity. Consistent with the data obtained from the microRNA array, circulating levels of five miRNAs were significantly increased in patients with bevacizumab-induced cardiotoxicity compared with controls. To confirm these data, we compared selected miRNAs in the plasma of patients with bevacizumab-induced cardiotoxicity with those of 66 patients with acute myocardial infarction (AMI). Moreover, we went on to analyze what factors may influence the levels of potential biomarker miRNAs. Consistent with the data obtained from the microRNA array, circulating levels of five miRNAs were significantly increased in patients with bevacizumab-induced cardiotoxicity compared with those of healthy bevacizumab treatment controls. However, only miRNA1254 and miRNA579 showed high specificity in the validation experiments. Moreover, we went on to analyze what factors may influence the levels of potential biomarker miRNAs. We identify two miRNAs that are specifically elevated in patients with bevacizumab-induced cardiotoxicity, miR1254 and miRNA579, and miRNA1254 shows the strongest correlation to the clinical diagnosis of bevacizumab-induced cardiotoxicity.