The Expression Of MiR-17-92 Cluster In Hepatocellular Carcinoma And Gastric Carcinoma Cell Lines Detected By Real-time RT-PCR

ObjectiveThe miR-17-92 cluster is a polycistronic gene located in human chromosome 13 ORF 25 (C13orf25). The cluster is composed of 7 mature miRNAs, named miR-17-5p, miR-17-3p, miR-18a, miR-19a, miR-20a, miR-19b, and miR-92-1. The nucleotide sequences and organization of this cluster is highly conserved in vertebrates. The miR-17-92 cluster involve in mammalian organ development and have relationship with many tumors. So far, the research of miR-17-92 was focused on lung cancer, especially in small cell lung cancer and malignant lymphoma. There are rarely researches in gastrointestinal tumors such as hepatocellular and gastric carcinoma. we collected two hepatocellular and seven gastric carcinoma cell lines in the experiment, compared with L-02 normal hepatic cell line and GES-1 gastric mucosa cell line, used the TaqMan probe Real-time quantitative PCR technology, to detect the expression of miR-17-92 in the above-mentioned cell lines, and initially investigate the relationship and function between the abnormal expression of miR-17-92 and the hepatocellular and gastric carcinoma.MethodsWe cultured L-02 normal hepatic cell line, Bel7402, Hep G2 hepatoma cell lines, GES-1 normal gastric mucosa cell line, AGS, MKN-1, MKN-28, SGC-7901, MKN-45, MGC-803, BGC-823 7 gastric carcinoma cell lines. In these gastric carcinoma cell lines, AGS, MKN-1, MKN-28 is well-differentiated adenocarcinoma, SGC-7901, MKN-45, MGC-803, BGC-823 is poorly differentiated adenocarcinoma. When the cells enter logarithmic phase, we collected about 1x105 cells, extracted total RNA by TRIzol method, then after reverse transcription, used the TaqMan probe Real-time quantitative RT-PCR to detect the expression of miR-17-92 in the above-mentioned cell lines, blank control was DEPC water, negative control was the L-02 total RNA, HL-60 leukemia cell line was the positive control, used the 2-△△Ct method to calculate the expression of miR-17-92, then clear whether the gene the hepatocellular and gastric carcinoma cell lines expressed was up-regulation by comparing with normal cell lines.ResultsIn the L-02 normal hepatic cell lines and the two hepatoma cell lines, L-02 normal hepatic cell lines do not express miR-17-92 gene, the Hep G2 cell line was higher 3.86 times than the Bel7402 cell line in the gene expression. While the Hep G2 cell line is poorly differentiated and the Bel7402 is well differentiated. The miR-17-92 in seven gastric cancer cell lines expressed differently, but all of them was up-regulated compared with the GES-1 normal gastric mucosa cell line. The highest expression was the poorly differentiated BGC-823,6.23 times higher. Poorly differentiated gastric cancer cell lines of miR-17-92 gene (4.29±1.36) expression was significantly higher than well-differentiated gastric cancer cell lines (1.53±0.28), (p=0.02＜0.05).Conclusion1. The miR-17-92 cluster have different level of up-regulation in hepatocellular and gastric carcinoma cell lines, they may be involved in the occurrence and development of these two carcinomas.2. The abnormal expression of the miR-17-92 cluster may be related to cell differentiation of gastric carcinoma.