MiR-4728-3p could act as a marker of HER2 status

BACKGROUND: MiR-4728 was recently identified to be related with HER2 in several cell lines and limited tissue samples. OBJECTIVE: To investigate whether miR-4728 could predict HER2 status in a larger cohort. METHODS: The expression of miR-4728-3p and miR-4728-5p was identified in breast cancer (BC) and gastric cancer (GC) tissues with different HER2 status using quantitative reverse transcription polymerase chain reaction (qRT-PCR) and fluorescence in situ hybridization (FISH). An additional 22 plasma samples was investigated to explore the potential application of miR-4728 as a non-invasive biomarker in predicting HER2 status. RESULTS: MiR-4728-3p and miR-4728-5p were significantly up-regulated in HER2-positive patients compared with HER2-negative patients. Compared with the expression in adjacent normal tissues, miR-4728-3p and miR-4728-5p were both elevated in HER2-negative and HER2-positive GC tissues but only miR-4728-3p in HER2-positive BC tissues. Further analyses revealed that miR-4728-3p had greater ability than miR-4728-5p in discriminating subgroups with different intensity of HER2 staining in both BC and GC patients. In addition, miR-4728-3p but not miR-4728-5p was significantly up-regulated in plasma of BC patients with positive HER2. CONCLUSIONS: MiR-4728-3p had better ability in distinguishing patients with different status of HER2 than miR-4728-5p. And plasma miR-4728-3p might act as a non-invasive biomarker in predicting HER2 status.