Abstract:

Objective： To discuss the effect of human ceramide 1-phosphate transfer protein （CPTP） on the biological behavior of oral squamous cell carcinoma HSC-3 cells，and to clarify its related mechanism. Methods The HSC-3 cells were cultured in vitro and divided into control group and experiment group，and the cells in two groups were transfected with pFlag-CMV4 and pFlag-CPTP plasmids，respectively；the cells stably transfected with CPTP were constructed by using resistance screening method. Western blotting and immunofluorescence methods were used to detect the expression levels of CPTP protein in cells in two groups； clone formation experiment and CCK-8 assay were used to detect the numbers of clone formation and proliferation activities of cells in two groups； cell scratch experiment was used to detect the scratch healing rates of cells in two groups； Transwell chamber experiment was used to detect the numbers of invasion cells in two groups. The mice were randomly divided into control group and experiment group， and the mice were injected with the HSC-3 cells stably transfected with pFlag-CMV4 and the HSC-3 cells stably transfected with pFlag-CPTP respectively to construct the subcutaneous transplanted tumor models in the mice.The volumes and weights of transplant tumors of the mice in two groups were detected. The enrichment analysis on CPTP differentially expressed genes in head and neck squamous cell carcinoma （HNSCC） cells was analyzed by using bioinformatics method；real-time fluorescence quantitative PCR （RT-qPCR） method was used to detect the expression levels of p53， thrombospondin-1 （THBS1）， and cyclin G2 （CCNG2） mRNA in cells in two groups. Results Compared with control group， the expression amount of CPTP protein in the cells in experiment group was increased.Compared with control group， the number of clone formation in the cells in experiment group was significantly increased （P<0.01）， the proliferation activity and scratch healing rate of the cells were significantly increased （P<0.05 or P<0.01）， and the number of invasion cells was increased （P<0.01）. After injecting tumor cells for 2，3，and 4 weeks， compared with control group， the volumes of the transplanted tumor of the mice in experiment group were increased （P<0.05 or P<0.01）；after injecting tumor cells for 4 weeks，compared with control group，the weight of transplanted tumor of the mice in experiment group was increased（P<0.05）. The bioinformatics analysis results showed that the role of CPTP in the HNSCC tissue may be mediated through the signaling pathways such as p53. Compared with control group， the expression levels of p53， THBS1， and CCNG2 mRNA in the cells in experiment group were significantly decreased （P<0.01）. Conclusion Over-expression of CPTP can promote the proliferation， migration， invasion， and tumorigenesis of the HSC-3 cells. CPTP promotes the growth of the oral squamous cell carcinoma HSC-3 cells by inhibiting the p53 signaling pathway.

Key words: Oral squamous cell carcinoma, Ceramide-1-phosphate transfer protein, Cell invasion, Signaling pathway