Establishment of Fischer 344 rat model of ovarian cancer with lymphatic metastasis.

Abstract

PURPOSE: To establish a model of ovarian cancer with highly lymphatic metastasis in immunocompetent rats. METHODS: Thirty-two female Fischer 344 rats were divided randomly and equally into two groups: footpad group and intraperitoneal (i.p.) group. At 8 weeks after injection with NuTu-19 ovarian cancer cells, lymphatic metastasis were analyzed by pathohistology; body weight was monitored per week, Survival curves were determined by Kaplan-Meier analysis. RESULTS: Footpad injection could efficiently generate the lymphatic metastasis; specifically, the incidences of metastasis in the ipsilateral popliteal, inguinal and para-iliac lymph nodes were 100% (8/8), 75% (6/8), and 37.5% (3/8), respectively. The mean volume and weight of the ipsilateral popliteal lymph nodes were 0.405 ± 0.096 cm(3) and 0.418 ± 0.118 g in footpad group. However, no lymphatic metastasis lesions were found in i.p. group. Moreover, Kaplan-Meier analysis showed that the average survival time of the footpad group was significantly longer than that of the i.p. group (18.429 ± 1.112 vs. 10.286 ± 0.505 weeks). CONCLUSIONS: Our experiments suggest that footpad injection is a very efficient method to generate ovarian cancer with lymphatic metastasis in an immune-competent animal, and we believe that this model will be very helpful for shedding light on the mechanism of lymphogenous metastasis and developing novel therapeutic targets for ovarian cancer patients.