Expression Of Polo Like Kinase 1 In Laryngeal Squamous Cell Carcinoma

Objective:To study the expression of polo-like kinasel(PLK1) in laryngeal squamous cell carcinoma(LSCC) and its correlation with clinical factors of LSCC.Methods:Immunohistochemistry and Western blot were used to detect PLK1 protein in LSCC and adjacent tissues.70 samples of LSCC and 21 samples of adjacent tissues were detected with Immunohistochemistry,23 fesh samples of LSCC and 23 fresh samples of their adjacent tissues were detected with Western blot.70 patients of LSCC were followed up to study the relationship of the expression of PLK1 and the prognosis LSCC. Statistical methods were used for the analysis of the data.Results:1. Immunohistochemistry showed that expression of PLK1 protein was heterogeneous expression both in cytoplasm and nucleus, pellets can be see in cytoplasm and can be see in the nucleus of some cells.The total positive rate of LSCC tissues and adjacent tissues were 68.6% and 28.6%, respectively. The former was higher than the latter, the difference was statistically significant (P<0.05).2. Western blot results showed that in 23 pairs of fresh samples of LSCC and its adjacent tissues,4 pairs showed PLK1 positive expression; there were 12 cases positive expression corresponding adjacent tissues were negative; only 1 case was positive expression in adjacent tissue, but LSCC was negative; the rest of 6 pairs were negtive expression.There are 16 cases with positive expression of PLK1 protein in LSCC samples, the positive rate was 69.6%; the positive expression in LSCC adjacent tissues was only 5 cases, the positive rate was 21.7%, far lower than the former, the difference was statistically significant (P<0.05).3. Statistical results of Immunohistochemistry and Western blot showed, PLK1 over-expression in LSCC was positively associated with clinicopathologic variables and lymph node metastasis. The expression of PLK1 in T3-T4 tumors was higher than that of T1-T2 period, clinical stage III-IV was higher than clinical stagel-â…¡, the tumors with lymph node metastasis was higher than that without lymph nobe metasis. There were statistically significant(P<0.05).And there were no significant correlation in PLK1 expression with sex, LSCC's site and the degree of differentiation (P>0.05)4.70 cases were followed up for at least 5 years after operation(cut-off time of death or study end date). PLK1-positive patients in the 5-year overall survival rate was 37.8%, and the negative was 71.4%, the difference was statistically significant(P <0.05).Conclusion:1. PLK1 protein overexpression in LSCC is a common phenomenon.2. The higher PLK1 process may play a key role in malignant of LSCC. There were no significant correlation in PLK1 expression with sex, LSCC's site and the degree of differentiation.3. PLK1 protein may contribute to the development, progression and metastasis of LSCC, and it would be a novel prognosis indictor and therapeutic target for LSCC.