FIGURE 5.

Antitumor activity of cisplatin in A2780, A2780cisR, SKOV3, and SKOV3cisR xenograft mouse models. Antitumor efficacy of cisplatin was investigated in the A2780, A2780cisR, SKOV3, and SKOV3cisR xenograft mouse models. Tumor‐bearing mice were administered PBS or cisplatin (3 mg/kg) twice weekly (days 0, 4, 8, and 12) four times. Dots represent observed values and bars represent SEM. NS, not significant, *P < .05, **P < .01; Mann‐Whitney U test was used to compare the groups). A and B, A2780 xenografted mice treated with PBS were sacrificed on day 16 after drug administration because of the tumor size. In the A2780 xenograft model, tumor size in the cisplatin treatment group was significantly more suppressed than that in the PBS group on day 16 after drug administration (841.9 vs 1991.5 mm³, P < .05). Similarly, tumor size in the cisplatin treatment group was more inhibited than that in the PBS group (254.4 vs 706.4 mm³, P < .01) in the SKOV3 xenograft model on day 28. C and D, In A2780cisR and SKOV3cisR xenograft models, tumor growth in the cisplatin group was similar to that in the PBS group (A2780cisR: 1548.4 vs 1829.8 mm³, P = .10 and SKOV3cisR: 605.0 vs 733.4 mm³, P = .45). Platinum resistance was confirmed in A2780cisR and SKOV3cisR xenograft models. Mice in the PBS group were the same as those used to determine the effect of the cluster of differentiation 70‐antibody drug conjugate. E, In A2780 xenograft mice treated with PBS, the mice were euthanized on day 16 due to the excessive tumor size. In the SKOV3 xenograft mice, the tumor weight was significantly lower in the cisplatin group than in the PBS group (263.3 vs 503.3 mg, P < .05). In A2780cisR and SKOV3cisR xenograft mice, the tumor weight on day 28 post‐administration (A2780cisR: 1260 vs 1340 mg, P = .75, SKVO3cisR: 531.7 vs 561.7 mg, P = .52) were similar in the cisplatin and PBS‐treated groups. The bar graph shows the average tumor weight with SEM. Abbreviations: PBS, phosphate‐buffered saline; CDDP, cisplatin; NA, not applicable; NS, not significant