Malignant phenotypic changes in gastric cancer cells that survived hypoosmotic stress

<p>The prognosis for the recurrence of peritoneal metastases of gastric cancer is poor possibly due to the presence of free cancer cells in the abdominal cavity and digestive tract lumen. Washing the abdominal cavity and digestive tract lumen with hypotonic solution is a promising preventive measure.<br>However, cancer cells that survive after washing with hypotonic solution might become highly malignant. Therefore, in this study, we exposed gastric cancer cell lines MKN7 (well-differentiated tubular adenocarcinoma ; tub1) and MKN74 (moderately differentiated tubular adenocarcinoma ; tub2) to distilled water for 10 min and MKN45 (poorly differentiated tubular adenocarcinoma ; por) for 5 min. The surviving cell lines were recultured and examined for growth capacity, invasive ability, and drug sensitivity. The results showed that growth capacity of MKN7 and MKN45 did not have a significant difference, but that of MKN74 significantly increased at 48 h and did not significantly change at 72 h. The invasive ability was significantly decreased in MKN74 and MKN45, but it could be increased in MKN7. There were no significant changes in drug sensitivity in all cells. In the present study, MKN7 and MKN74, well-differentiated and moderately differentiated tubular adenocarcinoma, respectively, could become more aggressive after exposure to distilled water. <br>However, MKN45, a poorly differentiated adenocarcinoma, showed no change in growth capacity, invasive ability, and drug sensitivity, indicating a positive outcome.</p>