Abstract:

Objective To discuss the effect of long non-coding RNA （lncRNA） gastric cancer related transcript 2（GACAT2） gene on the proliferation and stemness of the lung cancer A549 and H1299 cells， and to clarify the effect of lncRNA GACAT2 gene on the occurrence and development of lung cancer. Methods The full-length sequence of lncRNA GACAT2 gene was amplified by real-time fluorescence quantitative PCR （RT-qPCR） method， and was cloned into the pc3.1 （+） eukaryotic expression vector. The construction of GACAT2 over-expression vector was confirmed by bacterial liquid PCR method and gene sequencing. The pc3.1-GACAT2 over-expression plasmid and control plasmid pc3.1 were separately transfected into the human lung cancer A549 and H1299 cells. The A549 and H1299 cells with stable over-expression of GACAT2 were established by G418 screening， and the cells were divided into blank vector group （transfected with pc3.1 empty vector） and pc3.1-GACAT2 group （transfected with pc3.1-GACAT2 recombinant plasmid）. RT-qPCR method was used to detect the expression levels of GACAT2 mRNA in the A549 and H1299 cells in two groups；CCK-8 assay was used to detect the proliferation activities of the cells in two groups； cell clone formation assay was used to detect the clone formation numbers of the cells in two groups； stem cell sphere formation experiment was used to detect the sphere formation numbers of the A549 and H1299 cells in two groups. Results The eukaryotic over-expression vector of GACAT2 was successfully constructed. Compared with blank vector group， the expression levels of GACAT2 mRNA in the A549 and H1299 cells in pc3.1-GACAT2 group were increased （P<0.05 or P<0.01）， the cell proliferation activities were decreased （P<0.05 or P<0.01），the clone formation numbers were decreased （P<0.05 or P<0.01）， and the sphere formation numbers were decreased （P<0.05 or P<0.01）. Conclusion Over-expression of human lncRNA GACAT2 gene can inhibit the proliferation and stemness of the lung cancer A549 and H1299 cells.

Key words: Lung neoplasm, Long non-coding RNA, Gastric cancer related transcript 2, Cell proliferation, Cell stemness