DLC-1, a candidate tumor suppressor gene, inhibits the proliferation, migration and tumorigenicity of human nasopharyngeal carcinoma cells

Abstract

In our previous study we demonstrated the downregulation or loss of deleted in liver cancer‑1 (DLC-1) gene expression in nasopharyngeal carcinoma (NPC). In this study, we report the effects of the DLC-1 gene on NPC cells and its mechanisms of action. DLC-1 expression was restored in the 5-8F NPC cell line, which lacks DLC-1 expression, and the biological characteristics of 5-8F-DLC‑1 cells were analyzed by MTT assay, colony formation assay, flow cytometry (FCM), tumorigenesis analysis in nude mice, as well as invasion and migration assay. Differentially expressed genes in response to DLC-1 expression were screened using microarray analysis and identified by RT-PCR. The re-expression of DLC-1 in the NPC cells attenuated the proliferation and colony formation ability of the cells in vitro, blocked NPC cells at the G0/G1 phase, reduced tumorigenicity potential in vivo, inhibited the invasion and migration ability of NPC cells and resulted in the reorganization of the actin cytoskeleton. DLC-1 altered the gene expression profile in 5-8F cells. Some tumor suppressor genes (TSGs) were upregulated and some oncogenes were downregulated. These results demonstrate that DLC-1 gene can partially reverse the malignant phenotype of NPC cells by changing the tumor-related gene expression profile, and may be a candidate tumor suppressor gene and a promising diagnostic and therapeutic target in NPC.