[Inhibitory effect of full-length spleen tyrosine kinase on invasion and metastasis of human laryngeal squamous cells].

Objective: To study the effect of gene transfection of full length spleen tyrosine kinase (Syk (L)) on the biological behavior of malignant cancer cells.

Methods: Eukaryotic expression vector pIRES2-EGFP-Syk (L) was constrauted and sequenc. Laryngeal carcinoma cell line Hep-2 were transfected with pIRES2-EGFP-Syk (L) vectors or blank vectors. The expressions of mRNA and protein were examined by real time fluorescence quantitative polymerase chain reaction (Q-RT-PCR) and Western blot analysis. CCK-8 method was used for evaluating cell proliferation, Transwell for cell invasion capacity in vitro, and tumor formation in nude mice for in vivo tumorigenicity.

Results: pIRES2-EGFP-Syk (L) vectors were successfully construct and transfected to Hep-2 cells. Q-PCR showed that mRNA expression level in Hep-2 cells transfected with Sky (L) (28.395 ± 0.067) was higher than those in Hep-2-neo cells transfected with blank vectors (3.891 ± 0.021) and Hep-2 cells with no transfection (1.005 ± 0.012), with statistically significant difference (F = 104.02, P < 0.01). Western blot showed that protein expression level of transfected-Sky (L) cells (0.821 ± 0.047) was significantly higher than those of Hep-2-neo cells (0.558 ± 0.031) and Hep-2 cells (0.468 ± 0.031), and the difference was statistically significant (F = 112.32, P < 0.01) ; CCK-8 assay showed OD value (1.390 ± 0.067) of transfected-Sky (L) cells was lower than those of Hep-2-neo cells (1.830 ± 0.067) and Hep-2 cells (1.920 ± 0.040), and the difference was statistically significant (F = 107.64, P < 0.01). Transwell assay showed average cell number per field of transfected-Sky (L) cells (176.04 ± 22.32) was higher than those of Hep-2-neo cells (301.02 ± 21.45) and Hep-2 cells (336.04 ± 26.01) with statistically significant difference (F = 123.46, P < 0.01). The volume (250.77 ± 34.83) mm(3) tumor formed from transfected-Sky (L) cells in nude mice, was less than those from Hep-2-neo cells (750.77 ± 40.83) mm(3) and Hep-2 cells (770.77 ± 30.83) mm(3), with statistically significant difference (F = 165.78, P < 0.01).

Conclusion: Down-regulation of Syk in Hep-2 cells is associated with the malignant biological behaviors of the cells. Syk (L) may be a potential target in gene therapy for laryngeal squamous cell carcinoma.