[Effects of hyperthermic chemotherapy on gastrointestinal cancer cells in vitro]

Little evidence is known from experimental research for intraoperative hyperthermic intraperitoneal chemotherapy. This study was to investigate the effect of hyperthermic chemotherapy on gastrointestinal cancer cells in vitro and explore the possible factors which may affect this method.

Gastric cancer cell line MGC-803 and intestinal cancer cell line HCT-116 were chosen. Cells were treated with different drugs, temperatures and duration. Cell viability and growth were measured by MTS-PMS assay. The morphology of the cells was observed under a microscope.

Significant synergistic effect was observed when the two cancer cell lines were treated with 5-FU, MMC, DDP and THP in combination with elevated hyperthermia from 41 degrees C to 45 degrees C compared with control group (P<0.01). The strongest effect was achieved at 45 degrees C, which the inhibitory effects of these four drugs were 61.7%, 79.2%, 88.7%, 94.7% on MGC-803 and 76.4%, 78.7%, 77.8%, 91.7 on HCT-1116, respectively. The inhibitory effect demonstrated a time and dose-dependent manner in HCT-116 cells within a certain period of time. The effect revealed a flat curve after 90 min when HCT-116 was treated with 43 centigrade. THP had the strongest effect at any conditions among all tested drugs (P<0.01). Either simple thermotherapy or chemohyperthermia displayed considerable killing effects on cancer cells which were confirmed by microscope observation. And a great deal of dead cells were observed when treated with chemohyperthermia.

DDP or MMC reveals relatively satisfactory antitumor effects with the optimal temperature of 43-45 degrees C. Taken practical application into consideration, 60 min may be selected in clinical use. Synergistic antitumor effects of THP in combination with hyperthermia were prior to 5-FU, DDP or MMC, which deserve further clinical research.