Epithelial cell turnover, p53 and bcl-2 protein expression during oncogenesis of early and advanced gastric cancer in a Western population.
OBJECTIVE
To investigate epithelial cell turnover alterations, and p53, bcl-2 protein expression during development of early and advanced gastric cancer in a Western population.


METHODS
We investigated cell apoptosis and proliferation rates, p53 and bcl-2 protein expression in 17 early and 34 advanced gastric carcinomas and in the adjacent non-dysplastic mucosa. Cell proliferation, p53 and bcl-2 expression were detected immunohistochemically using MIB-1, anti-p53 and anti-bcl-2 monoclonal antibodies. Apoptosis was measured by TUNEL. The rate of the positive stained cells (labelling index) was count using image analysis technique.


RESULTS
No difference was observed of either apoptotic (10 vs. 11) or proliferation (35 vs. 25) index between early and advanced cancers. However, the apoptotic index was significantly higher in intestinal type advanced tumors. While both apoptotic and proliferation indices were significantly higher in tumors than in the adjacent mucosa, no difference was observed of either apoptotic (2 vs. 2) or proliferation (8 vs. 13) index between the tissues adjacent to early and advanced tumors. p53 protein expression was significantly higher in advanced cancers (7 vs. 5, p=0.001) and in the non-dysplastic tissue adjacent to advanced tumors (3.5 vs. 2, p=0.001). bcl-2 labelling index was significantly higher in the mucosa adjacent to advanced carcinomas (15 vs. 5, p=0.016) but this difference did not reach significance in the tumors (20 vs. 15, p=0.37).


CONCLUSIONS
Our data indicate similar cell turnover during tumorigenesis of early and advanced cancer. p53 and bcl-2 protein accumulation is more intense in gastric mucosa adjacent to advanced tumors and p53 immunoreactivity peaks in advanced carcinomas.
Hepatogastroenterology Unit, 2nd Department of Internal Medicine, Attikon University General Hospital, Medical School, Athens University, 1 Rimini Street, 12462 Haidari, Athens, Greece. ktriant@med.uoa.gr
K
K
Triantafyllou
P
P
Kitsanta
D G
DG
Karamanolis
C
C
Kittas
S D
SD
Ladas
D017209:Apoptosis / Q000502:physiology*; D014408:Biomarkers, Tumor / Q000096:biosynthesis; D002277:Carcinoma / Q000453:epidemiology / Q000235:genetics / Q000473:pathology*; D049109:Cell Proliferation; D004847:Epithelial Cells / Q000378:metabolism* / Q000473:pathology; D006115:Greece / Q000453:epidemiology; D006801:Humans; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D009017:Morbidity; D009367:Neoplasm Staging; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis*; D013274:Stomach Neoplasms / Q000453:epidemiology / Q000235:genetics / Q000473:pathology*; D016159:Tumor Suppressor Protein p53 / Q000096:biosynthesis*
D014408:Biomarkers, Tumor; D019253:Proto-Oncogene Proteins c-bcl-2; D016159:Tumor Suppressor Protein p53