RT-PCR and Western blot were used to detect the LATS2 mRNA and protein level in 57 cases of oral squamous cell carcinoma (OSCC)specimens and 12 normal oral mucosa tissues.LATS2 mRNA and protein were expressed in all the normal oral mucosa samples (100%),but only 47.4% (27 /57)and 42.1% (24 /57)in OSCC samples respectively with positive correlation of both(P <0.01),and were respectively correlated with the tumor differentiation degree and lymph node metastasis(P <0.05).

Objective: To investigate the expression of large tumor suppressor homolog 2 (LATS2) gene and its promotor methylation in oral squamous cell carcinoma (OSCC). Methods: Reverse transcription-PCR (RT-PCR) and pyrosequencing were used to detect the mRNA and promotor methylation of LATS2 gene in 72 OSCC specimens and normal oral mucosa tissues. Western blotting was used to detect the LATS2 protein in six OSCC specimens and normal oral mucosa tissues. Results: All cases had expression of LATS2 mRNA in normal oral mucosa tissues, but the expression was down-regulated significantly, only 47% (34/72) in 72 cases of OSCC showed LATS2 mRNA expression. The expression was correlated with the degree of tumor differentiation and lymph node metastasis (P<0.05). The results of pyrosequencing show that 68% of promotor methylation (49/72) in 72 cases of OSCC. Furthermore, there was significant correlation between the mRNA and promotor methylation of LATS2 gene (χ²=16.980, P<0.01). All the six specimens had the low LATS2 protein expression. Conclusions The promotor methylation of LATS2 gene may play an important role in the occurrence of OSCC.