[Role of tumor metastasis suppressor gene KAI1 in development of colorectal cancer].

The study of tumor metastasis suppressor gene KAI1 in colorectal cancer (CRC) is limited nowadays. There are some controversies about the expression of KAI1 and its relationship with pathologic classification of CRC, and up today, the reports of the correlation between KAI1 and the prognosis of CRC still be few. This study was designed to investigate the role of KAI1 in development of CRC and its value in predicting the prognosis of CRC. The expression of KAI1 in 91 cases of primary CRC and 25 cases of lymph node metastases were determined using immunohistochemistry. The positive cases of KAI1 in primary CRC were 54 (59.3%), the weak positive cases were 22 (24.2%), the negative cases were 15 (16.5%). KAI1 expression reduced significantly in the cases with low differentiation, lymph node metastasis and distant metastatic tumor (P< 0.01). The positive expression rate of KAI1 in the patients who survived more than 5 years (67.14%) was higher than that in the patients who survived less than 5 years (33.33%) (P< 0.05). The 5-year survival rates of the patients with positive, weak positive, and negative expression of KAI1 decreased in turn (87.04%, 63.34%, 60.00%; P< 0.05). KAI1 expression in lymph node metastases was lower than that in primary locus (P< 0.05). The abnormal expression of KAI1 participates in malignant progression of CRC. Detecting the expression of KAI1 probably possesses clinical significance in evaluating the differentiation, lymph node metastasis,and distant metastasis of CRC, and predicting the prognosis of CRC.