Hyperthermic carbon dioxide pneumoperitoneum reinforces the inhibition of 5-FU on the proliferation and invasion of colon cancer

The effect of hyperthermic carbon dioxide (CO2) pneumoperitoneum in combination with 5-fluorouracil (5-FU) on the proliferation and invasion of colon cancer was explored. Colon cancer cell line SW-480 was sealed into the urine collection bag to simulate pneumoperitoneum with 100% CO2 under a pressure of 12 mmHg. The cells were divided into group A, CO2 at 37°C; group B, CO2 at 43°C; group C, 5-FU; group D, CO2 at 37°C+5-FU; group E, CO2 at 43°C+5-FU; and control groups under normal culture conditions. The cell proliferation was assessed by CCK-8 test; the cell apoptosis was tested by FACS analysis; the cell invasion was examined by Transwell assay; the expression of HSP-70, caspase-3, HIF-1α and MMP-9 proteins and genes were detected by western blot analysis and RT-PCR. The SW-480 cells were injected into nude mouse cecum subserosal to establish a colon cancer model. We applied 43°C CO2 pneumoperitoneum or 5-FU intraperitoneal chemotherapy to intervene, detected the transplantation tumor growth and metastasis. The cell proliferation was inhibited in groups B, C, D and E, apoptosis was induced in groups B, C, D and E, the Transwell cell number decreased in groups B, C, D and E, the transplantation tumor weight and metastasis rate were inhibited in groups B, C, D and E, but all not in group A. The most significant change was observed in group E. Hyperthermic CO2 pneumoperitoneum was able to reinforce the inhibition of 5-FU on proliferation and invasion of colon cancer.