Abnormal expression of miR-22-5p in breast cancer patients and its correlation with 18 F-FDG PET/CT features and serum-related tumor markers

To explore the abnormal expression of miR-22-5p in the serum of breast cancer (BC) patients and its clinical significance, and to clarify the potential mechanism of action. A total of 130 female breast cancer patients diagnosed by 18 F-FDG PET-CT and surgical pathology, along with 130 healthy female controls, were enrolled. Real-time quantitative polymerase chain reaction was used to detect serum miR-22-5p expression. Receiver Operating Characteristic curve analysis was applied to evaluate the diagnostic potential of miR-22-5p in BC. A dual-luciferase reporter gene assay was performed to validate the targeting of the MAS1 gene by miR-22-5p. Serum miR-22-5p expression was significantly higher in BC patients than in healthy controls, and positively correlated with clinical stages (III/IV vs. I/II, p < 0.001). ROC curve analysis showed an AUC of 0.887 for diagnostic efficacy. miR-22-5p expression exhibited positive correlations with PET/CT metabolic parameters and serum tumor markers. Cell-based experiments confirmed that miR-22-5p directly targeted the 3’-UTR of the MAS1 gene, suppressing MAS1 mRNA expression. Knockdown of miR-22-5p inhibited the proliferation, migration, and invasion of BC cells, whereas concurrent suppression of MAS1 reversed these inhibitory effects. Serum miR-22-5p emerges as a potential biomarker for BC diagnosis, participating in tumor metabolism and progression by regulating the MAS1 gene. This finding provides a novel therapeutic direction for BC targeted therapy.