Synchronization Of LOVO Cell Cycle By CO₂ Pneumoperitoneum And Its Significance In Early Chemotherapy With 5-Fu

In recent years, considerable attention has been focused on early postoperative chemotherapy (EPC), but it is unclear whether carbon dioxide (CO₂) pneumoperitoneum results in the difference of between EPC after laparoscopic operations and its open counterparts. In this study,employing human colon carcinoma cell line (LOVO) and an in vitro pneumoperitoneum model, we found there was S phase arrest on days 3,4 after 15mmHg CO₂ pneumoperitoneum for 3h or 4h. Furthermore, on days 3,4 after 15mmHg CO₂ pneumoperitoneum for 3h or 4h ,the growth inhibitory and apoptotic effects of 5-fluorouracil(5-Fu) increased significantly as evident from ( i ) DNA fragmentation, (ii) Annexin V- FITC assay, and (iii) MTT proliferation assay. These results suggest CO₂ pneumoperitoneum improves 5-Fu chemotherapy through cell cycle-mediated apoptosis. Also, these results provide clues for further explore the significations and optimum timing of EPC after laparoscopic resection of colorectal cancer.