[The expression of DNMT1 in laryngeal squamous cell carcinoma and its clinical significance].

To investigate the expression of DNMT1 in laryngeal squamous cell carcinoma (LSCC) and its relationship with clinicopathological factors. Ninety-six cases of LSCC samples were detected by immunohistochemical staining to analyze the expression of DNMT1 protein, while 66 cases of them were detected by real-time PCR. And the relationship between the expression of DNMT1 mRNA and clinicopathologic factors was then analyzed. The expression of DNMT1 mRNA in LSCC were up-regulated (P < 0.05). The positive rate of DNMT1 protein expression in LSCC and in peri-cancer tissue were 100% (96/96) and 36% (8/22) respectively, which showed a significant difference (P < 0.05). DNMT1 mRNA expression wasn't correlated with patients' age, gender, T stage and lympha node metastasis, but was associated with smoking habit (P < 0.05, respectively). DNMT1 may initiate the oncogenesis of LSCC by increasing expression, and smoking habit may induce the expression of DNMT1 gene.