Association of miR-1266 with Recurrence/Metastasis Potential in Estrogen Receptor Positive Breast Cancer Patients

The Homeobox B13 (HOXB13):Interleukin 17 Receptor B (IL17BR) index of estrogen receptor (ER)-positivebreast cancer (ER (+) BC) patients may be a potential biomarker of recurrence/ metastasis. However, effects ofmicroRNA (miRNA) binding to the 3’ untranslated region (3´UTR) of HOXB13 and IL17BR and its function onrecurrence/metastasis in ER (+) BC remains elusive. The aims of this study were to determine the expressionof miRNAs that bind to 3´UTR of HOXB13 and IL17BR in ER (+) BC patients and asess the effects of thesemiRNAs on recurrence/metastasis. The expression profiles of HOXB13 and IL17BR were evaluated using RTPCRin tumors and normal tissue samples from 40 ER (+) BC patients. The expression level of 4 miRNAs, whichwere predicted to bind the 3´UTR of HOXB13 and IL17BR using TargetScan, microRNA.org and miRDB onlinedatabases, were further evaluated with RT-PCR. Our findings demonstrated that high miR-1266 levels might besignificant prognostic factor for recurrence/metastasis occurrence (3.05 fold p=0.004) and tamoxifen response(3.90 fold; p=0.2514) in ER (+) BC cases. Although we suggest that modulation of miR-1266 expression may bean important mechanism underlying the chemoresistance of ER (+) BC, advanced studies and validation arerequired.