[Study on expression of nm23-H1 gene in laryngeal cancer tissues]

The nm23 gene is a metastasis suppressor gene. There are now two known isotypes of human nm23, namely nm23-H1 and nm23-H2. Several investigators have reported that reduced expression of nm23-H1 is associated with metastasis or disease progression in some of the tumor cases. In this study, the expression of nm23-H1 mRNA in the human laryngeal squamous cell carcinoma was investigated by Northern blot analysis. The levels of nm23-H1 mRNA were higher in cancers (n = 31) than in the adjacent normal tissues (n = 7), but the difference was not significant (P > 0.05). There was a significant decrease of nm23-H1 mRNA levels in tumors with lymph node metastasis (n = 11) as compared with those without (n = 20) (P < 0.01). Cancer tissues in clinical stages III-IV. (n = 23) also exhibited lower levels of nm23-H1 mRNA expression than those in stages I-II (n = 8) (P < 0.05). These results suggest that the nm23-H1 gene may play a role in the suppression of lymph node metastasis or disease progression in laryngeal cancer.