Exosomal miR-1470 is a diagnostic biomarker and promotes cell proliferation and metastasis in colorectal cancer

Background: In recent years,the lack of specific markers for the diagnosis of colorectal cancer has led to an upward trend in both morbidity and mortality from this condition. There is an urgent need to identify molecular biomarkers that contribute to early cancer detection. This study aimed to identify specific exosomal microRNAs that hold potential as diagnostic biomarkers for CRC.

Methods: We screened for differentially expressed miRNAs using the CRC exosome dataset GSE39833. To validate the results in the public database, we collected serum from 168 CRC patients and 168 healthy volunteers. The expression levels of exosomal miR-1470 in healthy volunteers and CRC patients were analyzed using qRT-PCR. To evaluate the diagnostic potential of the selected miR-1470 in distinguishing CRC patients from healthy controls, we analyzed its receiver operating characteristic curve. To explore the biological functions of miR-1470 in CRC cell lines, we detected the miR-1470's ability to regulate the growth and metastasis of CRC cells by CCK8, transwell and other assays after transfection of miR-1470 in SW480, HCT-116 cells.

Results: Exosomal miR-1470 exhibited significant up-regulation in CRC patients compared to healthy volunteers. The ROC curve analysis revealed an area under the curve (AUC) of 0.74 (95% confidence interval: 0.6876-0.7920) for exosomal miR-1470, indicating its potential as a diagnostic biomarker. Furthermore, the expression level of miR-1470 in CRC patients showed correlations with age, metastasis, and HDL content. We overexpressed miR-1470 in CRC cell lines. CCK8 proliferation assay showed that miR-1470 promoted the proliferation ability of SW480 and HCT-116 cells. Transwell assay showed that miR-1470 promoted the migration and invasion ability of SW480 and HCT-116 cells.

Conclusion: This suggested that non-invasive diagnosis of CRC is possible by detecting the level of miR-1470 in exosomes, which has important implications for early detection and treatment of this disease.