(PR056) A Pilot Study on miRNA Quality Control from ECR samples for RNArray

Objective: miRNA are crucial noncoding RNAs that influence cell signaling pathways, and can be studied by RNArray. Due to the fragility of ECR samples, it is questionable whether RNArray is practical with miRNA from ECR (external cervical resorption) samples. As QC (quality control) test is critical for miRNA RNArray, this study evaluated the QC by RIN (RNA integrity number) value, exploring the potential to carry out RNArray on ECR miRNA.

Methods: Sample tissue of ECR, PARL (periapical radiolucency) and PDL tissues were collected at a university clinic. The IRB was approved by Office of the Institutional Review Board. The tissue was collected from apical surgeries as well as extractions, and then stored in RNA later. Total RNA was isolated using QIA shredder , miRNA easy minikit, and RNase-Free DNase set. Sample integrity was verified using the High Sensitivity RNA 6000 Pico Assay RNA run on an Agilent 2100 Bioanalyzer.

Results: 129 teeth from 62 patients were recruited for the study. 18 PARL, 5 PDL, and 8 ECR samples were verified for the integrity. 4 PARL and 1 ECR yielded a RIN of >5. 4 PARL, 3 PDL, and 3 ECR yielded a RIN of 3-5.

Conclusion: Only 1 sample out of 8 revealed an ideal RIN. miRNArray from tissue sample is challenging, but possible thus far. Better miRNA isolation method is critical for future study.