Detection of miR-122 expression in serum by Taqman probe real-time fluorescence quantitative PCR and its clinical significance

AIM: To detect the serum level of miR-122 expression by the technique of Taqman probe real-time fluorescence quantitative PCR for identifying its clinical significance. METHODS: The stem-loop RT primer, PCR primer and Taqman probe of miR-122 and U6 snRNA were designed. The expression of miR-122 in the serum samples of 27 cases of preoperative hepatocellular carcinoma (HCC), 15 cases of hepatitis B, 15 cases of hepatitis C, 15 cases of healthy control (HC), 11 cases of postoperative hepatocellular carcinoma (PHCC) and 10 cases of recurrence after postoperative hepatocellular carcinoma was detected by Taqman probe real-time fluorescence quantitative PCR. U6 snRNA was used as the internal control. RESULTS: The results showed that the method of Taqman probe real-time fluorescence quantitative PCR could detect the amplification signal of serum miR-122. The expression level of serum miR-122 in the patients with HCC, hepatitis B, hepatitis C and recurrence was higher than that in HC and the patients with PHCC. Meanwhile, the serum level of miR-122 in the patients with hepatitis C was higher than that in the patients with HCC, hepatitis B and recurrence. However, no difference of miR-122 expression level among HCC, hepatitis B and recurrent patients was observed. The miR-122 level was lower in PHCC patients than that in HCC and recurrent patients. In hepatitis B virus surface antigen (HBsAg) and/or hepatitis B virus e antigen (HBeAg) positive patients, the miR-122 level was higher than that in the negative ones. The miR-122 level in hepatitis C antibody (HCV-Ab) positive patients was raised compared with the negative ones. The serum level of alanine aminotransferase (ALT) was positively correlated with the serum level of miR-122 (r=0.34, P<0.05). The miR-122 expression level in the patients with serum AFP≥400 μg/L was higher than that in the patients with serum AFP<400 μg/L. CONCLUSION: The method of Taqman probe real-time fluorescence quantitative PCR can detect the serum level of miR-122 expression. Serum miR-122 might be used as a new biomarker of liver diseases, especially in the early diagnosis of primary hepatocellular carcinoma, the curative effect of surgical operation and the prognosis.