Effect of ARHI on lung cancer cell proliferation, apoptosis and invasion in vitro.

The purposes of this study were to elucidate the effects of ARHI (aplysia ras homolog I) on several biological features of lung cancer cells, including growth, proliferation and invasion, to collect experimental evidence for the future biological treatment of human lung cancer. The eukaryotic expression vector, pcDNA3.1-ARHI, was constructed and transfected into the human lung cancer cell line SK-MES-1. The biological properties of the resulting ARHI-expressing lung cancer cell line were evaluated using methyl thiazolyl tetrazolium assay, flow cytometry, and a Transwell invasion assay. Additionally, the influence of ARHI on the gene expression levels of cyclin D1, p27(KIP1), death-associated protein kinase 1 (DAPK1), and matrix metalloproteinases1/2 (MMP-1/2) was determined. Compared to the non-transfected SK-MES-1 cells and the cells transfected with the empty pcDNA3.1 plasmid, the ARHI-transfected cells displayed significantly reduced growth rates and decreased viability (P < 0.05). The ARHI-transfected cells also displayed a significantly higher percentage of cells in G1 phase (P < 0.05) and a lower percentage of cells in S phase (P < 0.05); a higher percentage of apoptosis (P < 0.05); and finally, a notable reduction in the basement membrane-penetration rate in the Transwell invasion assay (P < 0.05). Furthermore, it was determined that ARHI is capable of inhibiting the expression of cyclin D1, MMP-1, and MMP-2; however, ARHI promotes the expression of both p27(KIP1) and DAPK1 in SK-MES-1 cells. In conclusion, overexpression of ARHI gene might be associated with the inhibition of lung cancer cell growth, proliferation and invasion, and the promotion of apoptosis.