OBJECTIVES: MicroRNAs (miRNAs) are endogenous small RNAs of 21-25 nucleotides that can pair with sites in 3' untranslated regions in mRNAs of protein-coding genes to downregulate their expression. Recently, miR-499 and other miRNAs released in circulating blood have been reported as promising biomarkers for acute myocardial infarction (AMI). In the present study, we developed a novel reverse-transcription real-time PCR assay for human miR-499 quantification. DESIGN AND METHODS: miR-499 was reverse-transcribed with a 3' portion-specific primer into cDNAs. The cDNAs were further extended with overlap PCR. The extended cDNAs were determined by quantitative, real-time PCR. Synthetic miR-499 was put into the RT reaction over an optimal range to generate standard curves for absolute quantification of miR-499. RESULTS: In the presence of 0.0001 amol/μL to 1.0×10⁶ amol/μL of synthetic miR-499, we observed a linear correlation (R²=0.999) between the logarithm of the amount of input RNA and the CT value. The miR-499 was reliably measured at a detection limit of 0.0001 amol/μL. The miR-499 measurements in spiked plasma samples indicated excellent correlation between the novel qRT PCR and classic stem loop qRT PCR. The qRT PCR analysis demonstrated that miR-499 was detected with higher levels in plasma from the patient with AMI in acute phase (AMI) compared with those from the control groups (P<0.001). CONCLUSIONS: We developed a novel reverse-transcription real-time PCR assay for human miR-499 quantification. The good reproducibility and wide linearity range may permit more use of it in the quantification of other human miRNAs in future.
OBJECTIVES: MicroRNAs (miRNAs) are endogenous small RNAs of 21-25 nucleotides that can pair with sites in 3' untranslated regions in mRNAs of protein-coding genes to downregulate their expression. Recently, miR-499 and other miRNAs released in circulating blood have been reported as promising biomarkers for acute myocardial infarction (AMI). In the present study, we developed a novel reverse-transcription real-time PCR assay for humanmiR-499 quantification. DESIGN AND METHODS: miR-499 was reverse-transcribed with a 3' portion-specific primer into cDNAs. The cDNAs were further extended with overlap PCR. The extended cDNAs were determined by quantitative, real-time PCR. Synthetic miR-499 was put into the RT reaction over an optimal range to generate standard curves for absolute quantification of miR-499. RESULTS: In the presence of 0.0001 amol/μL to 1.0×10⁶ amol/μL of synthetic miR-499, we observed a linear correlation (R²=0.999) between the logarithm of the amount of input RNA and the CT value. The miR-499 was reliably measured at a detection limit of 0.0001 amol/μL. The miR-499 measurements in spiked plasma samples indicated excellent correlation between the novel qRT PCR and classic stem loop qRT PCR. The qRT PCR analysis demonstrated that miR-499 was detected with higher levels in plasma from the patient with AMI in acute phase (AMI) compared with those from the control groups (P<0.001). CONCLUSIONS: We developed a novel reverse-transcription real-time PCR assay for humanmiR-499 quantification. The good reproducibility and wide linearity range may permit more use of it in the quantification of other human miRNAs in future.
Authors: Jonathan Rice; Henry Roberts; James Burton; Jianmin Pan; Vanessa States; Shesh N Rai; Susan Galandiuk Journal: PLoS One Date: 2015-04-08 Impact factor: 3.240