Study on the expression and significance of nm23 mRNA, CD44s and CD44v6 in human colorectal adenocarcinoma by tissue microarray

AIM To study the relationship between the expression level of nm23 mRNA, CD44s and CD44v6 and the biological behavior of human colorectal adenocarcinoma. METHODS Using tissue microarray technique, specimens of 40 colorectal adenocarcinoma and 22 normal colorectal mucosa were examined for CD44s, CD44v6 and nm23 mRNA expression by immunohistochemical (IHC) staining and in situ hybridization (ISH). RESULTS Expression of nm23 mRNA in the tissues of colorectal adenocarcinoma differed little from that in normal colorectal mucosa (P0.05), nor did it correlate with pathological grade of the colorectal adenocarcinoma (P0.05). But it was negatively related to the invasion of tumor and lymph node metastasis (r=-0.49, P0.01). The expression of CD44s in the tissues of colorectal adenocarcinoma and normal colorectal mucosa was 42% (17/40) and 18.1% (4/22) respectively and they had statistical difference (P0.05). But the positive staining of CD44v6 was only seen in the tissues of colorectal adenocarcinoma (55.8%, 22/40) and they were positively related to lymph node metastasis and invasion (r=0.47, P0.01). The expression of CD44v6 in the high and middle differentiated colorectal cancer were 45.8% (11/24) and 68.7% (11/16) respectively, which had significant difference (P0.05), but which had no striking difference from the expression in human colorectal adenocarcinoma (P0.05). CONCLUSION Patients who had overexpression of CD44s and CD44v6 and low expression of nm23 mRNA have a higher invasion of tumor and lymph node metastatic rate. Combined detection of three genes is a reliable index to evaluate the invasion and metastasis of colorectal adenocarcinoma. In addition, overexpression of CD44v6 correlates with the pathological grade of colorectal adenocarcinoma.