OBJECTIVE: To assess the association of genomic instability of epithelial cadherin 1 (CDH1) gene and clinicopathological characteristics of gastric cancer. METHODS: In total 120 paraffin-embedded gastric cancer tissue specimen were prepared, and genomic DNA was extracted. The genomic instability of the CDH1 gene was analyzed by immunohistochemistry and silver staining PCR-single-strand conformation polymorphism. RESULTS: The number of information individuals (heterozygotes) was 98 for the D16S752 locus. The detection rates for microsatellite instability (MSI) and loss of heterozygosity (LOH) at the D16S752 locus and the positive rate of CDH1 protein were 19.39%, 16.33% and 51.02%, respectively. The detection rate of MSI in TNM stages I or II was significantly higher than that in stages III or IV (P<0.05) while the detection rate of LOH was significantly lower than that in stages III or IV (P<0.05). The positive rate of CDH1 protein in TNM stages III or IV was significantly lower than that in stages I or II (P<0.05). The detection rate of MSI of cases with lymph node metastasis was significantly lower than that of without lymph node metastasis (P<0.05) while the detection rate of LOH was significantly higher than that without lymph node metastasis (P<0.05). The positive rate of CDH1 protein in patients with lymph node metastasis was significantly lower than that in patients without lymph node metastasis (P<0.05). The positive rate of CDH1 protein in MSI-positive group was significantly higher than that in MSI-negative group (P<0.05), and the positive rate of CDH1 protein in the LOH-positive group was significantly lower than that the LOH-negative group (P<0.05). CONCLUSION The genomic instability of the CDH1 gene is associated with the progression of gastric cancer. MSI at the D16S752 locus may be used as a molecular marker for early gastric cancer, while LOH at this locus mostly occurs in advanced gastric cancer and can be regarded as an effective indicators for malignancy evaluation and prognosis.
Humans ; Stomach Neoplasms/pathology* ; Lymphatic Metastasis ; Cdh1 Proteins/genetics* ; Microsatellite Instability ; Loss of Heterozygosity ; Genomic Instability ; Microsatellite Repeats ; Antigens, CD/genetics* ; Cadherins/genetics*