NK4 Regulates Laryngeal Squamous Cell Carcinoma Cell Properties and Inhibits Tumorigenicity by Modulating the DKK1/Wnt/β-Catenin Axis

OBJECTIVE: To investigate the effects of NK4 gene on the properties and tumorigenicity in laryngeal squamous cell carcinoma cell. METHODS: Here, we used the attenuated Salmonella carrying the NK4 gene to transfect the AMC-HN-8 cells and detected the expression of NK4 by the real-time quantitative polymerase chain reaction (q RT-PCR). The properties of NK4 gene was determined by MTT method, cell scratch test, and flow cytometry. A nude mouse tumorigenesis model was used to evaluate the effect of NK4 gene on the growth of AMC-HN-8 cells in vivo. While a western blot assay was used to assess the expression of DKK1, Wnt1 and β-Catenin in nude mouse tumors. RESULTS: qRT-PCR showed that the expression of NK4 in the transfection group was significantly higher than that in the control group (P<0.01), and the expression increased with the time of transfection. MTT results showed NK4 overexpression inhibited the proliferation of AMC-HN-8 cells, and the inhibitory activity no longer increased with increasing dose when 30% expression supernatant was added (P<0.01). Scratch experiment showed that NK4 overexpression decreased the cell migration ability (P<0.01). Annexin V/PI double staining experiment showed that NK4 gene induced AMC-HN-8 cell apoptosis (P<0.01), and cell cycle arrest in S phase (P<0.01). NK4 overexpression inhibited tumor formation ability of AMC-HN-8 cells in vivo (P <0.05). WB detection showed that the expression of DKK1 increased, Wnt1 and β-Catenin protein decreased after the high expression of NK4. CONCLUSIONS: NK4 gene inhibit cell proliferation and migration, while promote cell apoptosis, and induce cell cycle arrest in S phase of laryngeal carcinoma AMC-HN-8 cells. NK4 overexpression inhibit the tumorigenesis ability of AMC-HN-8 cells, which may be related to the regulation of DKK1/Wnt1/β-Catenin signal axis.