Fig 1: In vivo evaluation of T4H11-DM4 on tumor growth. (A–C) Antitumor efficacy of T4H11-DM4 in HT-29, HCT116 and HCT15 xenograft models. The tumor-bearing mice were given PBS (control), T4H11 (10 mg·kg-1) or T4H11-DM4 (2.5, 5 or 10 mg·kg-1) intravenously on days 1, 4 and 7. Each treatment group included six mice. Each point on the graph represents the average tumor volume. Changes in bodyweight are also represented. Error bars represent standard error of the mean. (D) Mechanisms of the action of T4H11-DM4 in HT-29 xenograft. After three times injections of T4H11-DM4 treatment, on day 21 the tumors were harvested and stained with Ki67 antibody (1 : 100 dilution, CST #9027), a marker for proliferative reaction. The number of Ki67-positive cells significant decreases in T4H11-DM4-treated tumors, indicating an inhibition of tumor proliferation (left). For cell mitosis evaluation, animals bearing HT-29 tumor xenografts were given a single dose of PBS, T4H11 (10 mg·kg-1) or T4H11-DM4 (10 mg·kg-1). After 24 h, the tumors were harvested and stained with anti-phospho-histone H3 (Ser10) antibody (1 : 100 dilution, CST #9701) to detect mitotic cells (right). The pHH3-positive tumor cells increased in T4H11-DM4 treatment compared with control and T4H11 group, evidence that DM4 induced cell arrest in mitosis. Black scale bar: 500 µm.