Protein and mRNA expression of KAI1 metastasis suppressor gene and its clinical significance in cervical carcinoma

AIM:To study the mRNA and protein expression of Kang ai1 (KAI1) tumor suppressor gene and to determine the relationship between KAI1 and invasiveness and metastasis of cervical cancer. METHODS:The expression of KAI1 metastasis suppressor was detected by immunohistochemistry in paraffin slides and by real-time quantitative polymerase chain reaction (RT-PCR) in fresh tissue. The samples included 20 cases of normal cervical tissues,20 cases of cervical intraepithelial neoplasia (CIN) and 40 cases of cervical carcinoma. The results of the gene expression combined with the pathological and clinical data were also analyzed. RESULTS:The expression of KAI1 protein and mRNA was related to the tissue differentiation of cervix. The positive rates of KAI1 expression were the highest in the normal cervical tissue,the middle in CIN and the lowest in cervical carcinoma with significant difference among three groups (P0.01). The expression of KAI1 protein was not related with the grade of CIN (P0.05). However,both mRNA and protein expression of KAI1 were related to the differentiation and the clinical stages of cervical cancer (P0.01) and also related to the metastasis of the cancer. The positive rates between the non-lymphatic metastasis and lymphatic metastasis (P0.05) were significant different. Cox regression and logistic regression showed that the tissue differentiation,clinical stages,lymphatic metastasis and expression of KAI1 were all related factors with recurrence and prognosis of cervical cancer. CONCLUSION:The down-regulation of KAI1 tumor suppressor gene at both mRNA and protein levels is related to the differentiation,clinical stages and metastasis of cervical cancer,indicating that the expression of KAI1 is a prognostic factor for cervical cancer.