Objective: To understanding the molecular mechanisms in invasion and metastasis of the ovarian carcinoma, we investigate a novel candidate metastasis-associated gene (MTA1) and nm23H1 mRNA expression and mutation in ovarian carcinoma.
Methods: Twenty primary ovarian carcinoma specimens, 20 corresponding lymph nodes and 8 normal ovarian was examined for mRNA expression and mutation of MTA1 and nm23H1 genes by reverse-transcription polymerase chain reaction (RT-PCR) and RT-PCR-SSCP analysis. The level of the expression was determined by the relative optic density (ROD) of the PCR products.
Results: The frequency of MAT1 overexpression was 100% (7/7) in primary ovarian carcinoma with metastasis but only 38.5% (5/13) in those without metastasis (P=0.0103). Overexpression of MAT1 was observed in 87.5% (6/7) of lymph nodes with metastasis but only 23% (3/13) of lymph nodes without metastasis (P=0.0118). In contrast with MAT1, low expression of nm23H1 mRNA was seen in 7 of 7 ovarian carcinoma with metastasis but only in 4 of 13 (30%) of those without metastasis (P=0.0043). Low nm23H1 expression was also seen in 7 of 7 lymph nodes with metastasis but only in 5 of 13 (38.5%) nonmetastatic lymph nodes (P=0.0102). The ROD ratio of MAT1 to nm23H1 increased with the development of metastasis. No mutation of MAT1 and nm23H1 genes was found by SSCP analysis.
Conclusion: The mRNA expression of MTA1 and nm23H1 is positively and negatively correlated with lymph node metastasis, respectively. Expression abnormalities but not mutation of the two genes are frequent events related to lymph node metastasis of ovarian cancer.