Assessment of TNF-a and collagen type I and III expression in the gastric carcinoma tissue
Abstract
Introduction: Neoplasms are the second most frequent cause of death in Poland after vascular diseases. Recently, gastric cancer morbidity has decreased, but mortality is steel at a high level.
Material and methods: Tissues from 24 patients with a histopathologically diagnosed mucosal and adenomucosal gastric cancer have been tested. Patients were divided in two equal groups: patients without metastases (G1) and patients with metastases in the liver (G2). RNA was isolated from homogenates after preliminary powdering of tissues in liquid nitrogen. RNA concentration was determined using spectrophotometer with RNA/DNA calculator ’Gene Quant’ (LKB Pharmacia Biotech). The tissue expression of the TNF-a, collagen type I and collagen type II encoding genes were assessed.
Results: Higher TNF-a RNA expression was observed only for 2 patients from group G1, while in G2 group higher expression was observed in 5 from 12 patients in comparison to mean expression in margin. Higher expression of collagen I was found in 6 of 12 patients from the G1 group in comparison to margin. In the tissues with metastases (G2) higher expression of collagen type I was found in 5 tested tissues in comparison to margin. Higher expression of collagen III gene in comparison to margin was found in 8 from 12 tested tissues from G1 group. Higher expression in group 2 was also observed in 8 out of 12 tissues, in comparison to margin value in group I. Correlation analysis showed correlation between collagen I and TNF-a only in the healthy tissue (r = –0.603; p < 0.05).
Conclusions. A statistically non-significant increase in expression of the TNF-a coding genes, type I and III collagen and lack of their mutual correlation weighs in favor of the fact that they are independent parameters. A statistically non-significant increase in expression of the TNF-a and collagen type I coding genes and a negative correlation between them indicates that TNF can’t affect the synthesis of collagen I.
Keywords: TNF-acollagen Icollagen IIIgastric cancer