Objective: To investigate the expressions of high mobility group box B1 protein (HMGB1), matrix metalloproteinases-2(MMP-2) and matrix metalloproteinases-9 (MMP-9) in human laryngeal carcinoma and study their relationships with clinicopathological characteristics and prognosis.
Method: The expressions of HMGB1, MMP-2 and MMP-9 proteins were examined with the EnVision immunohistochemical method in 61 cases of laryngeal carcinoma. The expressions of HMGB1, MMP-2 and MMP-9 mRNA were detected by real-time quantitative RT-PCR method in 30 cases of laryngeal carcinoma.
Result: The positive expression rates of HMGB1, MMP-2 and MMP-9 proteins were significantly higher in laryngeal carcinoma than those in adjacent tissue (chi2=44.934, 49.923 and 36.054, P<0.01). The relative expression levels of HMGB1, MMP-2 and MMP-9 mRNA in laryngeal carcinoma were significantly higher than those in adjacent tissue (t=5.940, 7.005 and 7.664, P<0.01). The high level expression of HMGB1, MMP-2, MMP-9 proteins was closely associated with T stage, clinical stage and the status of lymph node metastasis (P<0.05 or P<0.01). There was a positive correlation between the expression of HMGB1 and MMP-9 protein (r=0.381, P<0.01). Univariate analysis indicated that the overall survival rate was lower in patients with a positive expression of HMGB1 and MMP-9 than those with negative expression (chi2= 4.974, 6.418, P<0.05). Multivariate analysis showed that HMGB1 was a risk predictor. A higher expression of HMGB1 was associated with a shorter survival time.
Conclusion: HMGB1, MMP-2 and MMP-9 play a role in invasion and metastasis of laryngeal carcinoma; Also there is a synergistic effect between HMGB1 and MMP-9; Moreover HMGB1 may be a independent prognostic factor.