Expression Of Kai1 In Papillary Thyroid Carcinoma And Its Clinical Significance

Objective: To explore the clinicopathological significance of total expression of tumor metastasis suppressor KAI1 protein in papillary thyroid cancer (PTC); and to explore the expression of KAI1 in membrane and cytoplasm of PTC cell. Methods: Western blot was used to investigate: the positive expression of KAI1 protein in different pathological thyroid tissue (PTC, adjacent normal tissue, lymph node metastases and benign thyroid disease tissue); expression of total KAI1 protein in 30 PTC cases with different clinicopathological features; the KAI1 protein expression in membrane and cytoplasm in different pathological thyroid tissue. Results: In different pathological nature tissues, the rate of KAI1 protein expression differs: the highest one was in benign thyroid disease tissue, while in lymph node metastasis the rate was the lowest. The rate of KAI1 protein expression was correlated with the absence of lymph node metastases(33.3% vs 77.8%,P<0.05) and the low stage of TNM(70.6% vs 23.1%, P<0.05); there were no significant correlation between KAI1 expression and primary tumor size or patient age(P > 0.05,respectively). The expression of KAI1 protein in membrane was significant lower than that in cytoplasm of primary PTC(43.3% vs 10.0%,P<0.01); while the expression were unchanged in membranes and cytoplasm of tissues adjacent normal tissue(46.2% vs 30.8%,P>0.05), lymph node metastases(28.6% vs 71.4%,P>0.05) and benign cases(30.8% vs 53.8%,P>0.05).The rate of KAI1 protein expression was higher in tumor cell membranes of PTC without lymph node metastasis than that with metastasis(0/21 vs 3/9, P<0.05). Conclusion: Loss of location in cell membrane may be the cause of KAI1 losing its ability to suppress the tumor progression and metastases. The low expression of KAI1 protein was significantly correlated with the clinical progression and lymph node metastases of PTC and it may be used to anticipate the progression and metastases, and may be the potential target of PTC for therapy.