At last, we explored the methylation status of miR-106a promoter in 28 paired GC tissues through methylation-specific PCR (MSP), the result showed that the methylation rate was 53.6% in cancer tissues and 85.7% in adjacent tissues.
Based on the quantitative droplet digital PCR (ddPCR), four miRNAs (miR-21, miR-93, miR-106a and miR-106b) related to the presence of GC were identified in plasma from a training cohort of 147 participants and a validation cohort of 28 participants.
By employing Au nanoparticles- and CdSe@CdS quantum dots-contained magnetic nanocomposites as electrochemical labels along with the polythiophene/reduced graphene oxide-modified carbon electrodes, this dual signal nanobiosensor showed a considerable performance in quantifying miR-106a (a GC oncogenic miRNA) and let-7a (a GC tumor suppressor miRNA).
Furthermore, based on the model developed from the data, a signature composed of the 2 miRNAs (miR-19b-3p and miR-106a-5p) correctly discriminated 19 out of 20 GC serum samples (95% sensitivity) and 18 out of 20 normal samples (90% specificity) in the blinded phase.
Furthermore, several of these miRNAs passed the gene-based permutation test when analyzed according to GC subtypes: three tagSNPs of the miR-29a/miR-29b-1 cluster were associated with diffuse subtype (minimum p-value = 1.7 × 10(-4) ; odds ratio, OR = 1.72; 95% confidence interval, CI = 1.30-2.28), two tagSNPs of the miR-25/miR-93/miR-106b cluster were associated with cardia GC (minimum p-value = 5.38 × 10(-3) ; OR = 0.56, 95% CI = 0.37-0.86) and one tagSNP of the miR-363/miR-92a-2/miR-19b-2/miR-20b/miR-18b/miR-106a cluster was associated with noncardia GC (minimum p-value = 5.40 × 10(-3) ; OR = 1.41, 95% CI = 1.12-1.78).
In the present study, we found that miR-106a is elevated in MDR cell lines. miR-106a promotes chemo-resistance of GC cells, accelerates ADR efflux, and suppresses drug-induced apoptosis.
LINC01133 inhibits GC progression and metastasis by acting as a ceRNA for miR-106a-3p to regulate APC expression and the Wnt/β-catenin pathway, suggesting that LINC01133 may serve as a potential prognostic biomarker and anti-metastatic therapeutic target for GC.
Our comprehensive and integrative analysis revealed that miR-106 may be suitable as a diagnostic biomarker for GC while microRNA combination biomarkers may provide a new alternative for clinical application.
Our research, according to these results, indicated that FFPE samples can serve as an important research tool for miRNA field, and the early changes of miR-106a detected in such samples may have clinical application as a potential biomarker for the discovery and diagnosis of gastric cancer.