Folate depletion increases sensitivity of solid tumor cell lines to 5-fluorouracil and antifolates

Efficacy of intraperitoneal versus intravenous pemetrexed administration in management of malignant ascites in mice bearing ascitic hepatoma-22

AIM: To compare the effectiveness of intraperitonea and intravenous administration of pemetrexed (PEM) in the management of malignant ascites in mice bearing hepatoma-22 (H22).

METHODS: A mouse model of ascites was established by intraperitoneal injection of 0.2 mL of H22 cell suspension (at a density of 1 × 10⁷/mL cells). The mice were randomly divided into three groups at random on day 5 after induction of ascites (n = 18 per group): normal control group (normal saline), intraperitoneal pemetrexed group (PEM 300 mg/kg), and intravenous pemetrexed group (PEM 300 mg/kg). Pemetrexed was injected intraperitoneally or intravenously on days 5 and 8. The body weight, abdomen circumference and behavior of the mice were measured daily. Eight mice of each group were sacrificed on day 11 to measure the volume of ascites. The survival time of rest mice were recorded.

RESULTS: The mean volumes of ascites in the normal control group, intraperitoneal pemetrexed group and intravenous pemetrexed group were 15.74 mL ± 1.71 mL, 13.31 mL ± 2.45 mL and 8.58 mL ± 1.89 mL, respectively. In comparison to the normal control group, the two pemetrexed treatment group had significantly less production of ascites in (both P < 0.05). The mean volume of ascites in the intraperitoneal pemetrexed group was significantly lower than that in the intravenous administration group (P < 0.01). The mean survival times of mice in the intraperitoneal pemetrexed group, intravenous pemetrexed group, and normal control group were 15.10 d ± 0.46 d, 17.90 d ±0.71 d, and 14.20 d ± 0.44 d, respectively. The survival time was prolonged by 6.34% and 26.06% in the intraperitoneal pemetrexed group and intravenous pemetrexed group compared to the normal control group. There was no significant difference in the survival time between the intraperitoneal pemetrexed group and normal control group (P > 0.05), but the mean survival time was significantly longer in the intravenous pemetrexed group than in the normal control group and intraperitoneal pemetrexed group (both P < 0.01).

CONCLUSION: Intraperitoneal administration of pemetrexed is not superior to traditional intravenous administration in the management of malignant ascites in mice bearing ascitic hepatoma-22.