The loss of heterozygosity and mutation for nm23-H1 gene in colorectal carcinomas were studied by Southern blot and RT-PCR-SSCP/silver staining sequencing. The rate of loss of heterozygosity for nm23-H1 was 29.63%. The cases of Duke’s stage D and distant metastatsis had higher frequency of the loss of heterozygosity. No mutation for nm23-H1 was found in colorectal carcinomas. These reaults indicate that the loss of heterozygosity for nm23-H1 may play a significant role in the malignant progression and distant metastasis in colorectal carcinomas.
For an advanced elucidation of mechanisms of nm23-H1 suppressive effects on metastasis of primary hepatocellular carcinoma (HCC), it is necessary to investigate the correlation between nm23-H1 expression and relative factors involved in the HCC invasion. In present report, full-length cDNA of nm23-H1 was subcloned into pBKCMV vector and transfected into HCC cell line to observe its effects on invasion, cytosolic free Ca2+ and Nras mRNA expression. The results showed that lower expression of N-ras and higher cytosolic free Ca2+ in transfected cell line were detected, while the potential of invasion was depressed. It suggests that the suppressive effects on HCC metastasis might interact with intracellular signal transduction which is essential for stimulating cell invasion.
To investigate the mRNA expression of nm23-H1 gene in human liver tumor. In tumor and corresponding nontumoral liver specimens from 20 patients, nm23-H1 mRNA were examined by reverse transcriptionpolymerase chain reaction (RT-PCR) method with specific primers. Results: The primers designed in this study could amplified nearly entire coding sequence of nm23-H1 gene. All the samples showed positive expression of nm23-H1 mRNA, indicating there was no expression loss or obvious alteration. Conclusions: The achievement of RT-PCR method lays foundation for quantitative gaugement of nm23-H1 mRNA in liver tumor.