[Expression of p-STAT3 in laryngeal squamous carcinoma and its correlation with PTEN]

To study the expression of p-STAT3 and PTEN in human laryngeal squamous carcinoma, to explore their relations and clinical significance.

Formalin-fixed and paraffin-embedded tissues from 67 cases of laryngeal squamous carcinoma, 25 cases of normal mucosa over 2.0 cm away from tumor margin in 25 patients with total or subtotal laryngectomy were evaluated for the expression of p-STAT3, PTEN by SP immunohistochemistry, the levels of these proteins in tissues and their correlation with clinicopathological parameters of laryngeal squamous carcinoma were analyzed. The prognostic analysis was performed by Kaplan-Merier.

The expression rates of p-STAT3 protein in laryngeal squamous carcinoma and normal control laryngeal mucous tissues were 71.64%, 16% respectively. There was significant difference between them (Zc = 4.7052, P < 0.01); The expression rates of PTEN protein in laryngeal squamous carcinoma and normal control laryngeal mucous tissues were 41.79%, 96% respectively. There was significant difference between them (Zc = 5.7037, P < 0.01); The expressions of p-STAT3 and PTEN in laryngeal squamous carcinoma were associated with clinical stage, differentiation grade, lymph nodal metastases and prognosis (P < 0.01). There was a negative correlation between the expression of p-STAT3 and PTEN,and their correlation coefficient was r = -0.5148 (P < 0.01). p-STAT3 positive expression rate in patients survived over a 5 years follow up was 56.25% (18/32), which was obviously lower than the rate 82.35% (14/17) in those dead.

The expression of p-STAT3 and PTEN may take important roles in the tumorigenesis, aggressiveness, metastases and prognosis of laryngeal squamous carcinoma. The high expression of p-STAT3 was negatively correlated with the lower PTEN in laryngeal squamous carcinoma, which suggested that PTEN may be a downstream target gene of p-STAT3.