Objective: The purpose of this study was to investigate the markers which can be used in auxiliary diagnosis of gastric adenocarcinoma (GAC), and their correlation with their clinicopathological features.
Methods: 122 surgical specimens including 99 gastric adenocarcinoma (GAC), 18 adjacent mucosa and 5 distal normal mucosa were collected, and analyzed by in situ hybridization (FISH). The centromere probe cen17, specific for chromosome 17, which was reported to be frequently amplified in GAC, was selected for the FISH analysis. The clinicopathological features of the 99 GAC cases were reviewed, and the level of TP53 and TOPIIalpha gene expression, located in chromosome 17, was detected using tissue micro-array (TMA), compared with that of corresponding adjacent normal mucosa. Data were analyzed with SPSS 11.5 for Windows.
Results: The statistical results of FISH and TMA showed that 58.6% of cen17 in tumor tissues were aneuploid, and 45.5% of TP53 and 84.7% of TOPIIalpha were over-expressed in GAC samples, significantly higher than those in non-tumor gastric mucosa (0, 12.1% and 14.1%, respectively) (P = 0.000). 58 GAC tissues were aneuploid of cen17, including 26 cases TP53-positive and 49 cases TOPIIalpha-positive. The expression of TP53 in non-tumor gastric mucosa with dysplasia was significantly higher than that in the mucosa without dysplasia (P = 0.009). Aneuploidy of cen17 was more frequent in grade 1 or 2 than in grade 3 GAC (P < 0.05). Higher frequency of aneuploidy of cen17 was also observed in the gastric cardia than in pylorus (P < 0.05), while no correlation was found between aneuploidy of cen17 and age, sex of patients, lymph node metastasis, and clinical stage of tumors. Over-expression of TP53 protein was associated with the size of tumors (P < 0.05). In addition, a negative correlation was observed between over-expression of TOPIIalpha and lymph node metastasis (LNM) as well as TNM classification (P < 0.05).
Conclusion: Detection of aneuploidy of cen17 as well as over-expression of TP53 and TOPIIalpha may be helpful in the diagnosis and prognostic prediction of gastric adenocarcinoma.