Analysis of NM23-H1 expression in clinical specimens revealed high expression in premalignant lesions (liver cirrhosis and colon adenoma) and the central body of primary liver or colon tumors, but downregulation at the invasive front of tumors.
We used ribonuclease protection assays to analyze human colon tumors for the level of nm23-H1 (43 samples) and nm23-H2 (41 samples) transcript (mRNA) expression and the presence of mutations that could inactivate potential suppressor function.
In addition, nm23 expression was maintained in culture in each of 12 cell lines initiated from human colon neoplasms and did not differ between lines established from neoplasms of high or low metastatic capability.