Fig 1: In vivo antitumor effect of Sgc8c-M in TNBC. a IHC characterization of PTK7 expression on tumor tissues of SUM159, MDA-MB-468, and TNBC PDX models. Scale bars, 20 μm. b Tumor volume and body weight of SUM159 tumor-bearing mice from a dose screening trial of Sgc8c-M (n = 4, one-way ANOVA). c, d, f Tumor growth curves for SUM159 (n = 4), MDA-MB-468 (n = 4, unpaired t test), and TNBC PDX (n = 5, unpaired t test) tumor-bearing mice after multiple dosing of 7 mg/kg Sgc8c-M (intravenous injection, i.v.), 10 mg/kg paclitaxel (intraperitoneal injection, i.p.), or 0.359 mg/kg MMAE (i.v.). e, g Tumor-killing effect study of Sgc8c-M in MDA-MB-468 (n = 3, unpaired t test) and TNBC PDX (n = 3, unpaired t test). Mice were given 7 mg/kg Sgc8c-M intravenously from day 0, and immunohistochemical characterization of CK19, Ki67, and pHH3 was performed at 48–96 h (48 h for MDA-MB-468, 96 h for TNBC PDX) at the end of administration. Scale bars, 20 μm. Data are presented as mean ± SEM. *P < 0.05, **P < 0.01
Fig 2: Characterization of Sgc8c-M in synthesis, targeting, internalization, and cytotoxicity in vitro. a Chemical structure, HPLC, and mass spectrum of Sgc8c-M. b Surface plasmon resonance (SPR) analysis of Sgc8c-M for binding to recombinant PTK7 proteins from humans, mice, rats, and cynomolgus monkeys at 400 nM. c Flow cytometry analysis of Cy5-labeled Ctrl, Sgc8c, Ctrl-M, and Sgc8c-M (250 nM) for binding to PTK7-positive SUM159 and MDA-MB-468 cells, as well as PTK7-negative Ramos cells. d Flow cytometry analysis of the internalization and endocytic pathway of Cy5-Sgc8c-M in SUM159 cells. The endocytic pathway was determined by measuring the uptake upon the application of various inhibitors. M-β-CD (0.2 mM), CPZ (25 μM), and AMI (100 μM) were preincubated with cells for 30 min at 37 °C; then 400 nM Cy5-Sgc8c-M were added and incubation continued for another 2 h (n = 3). Unpaired t test was used in comparison to control, **P < 0.01, ***P < 0.001, ns, not significant. e Confocal microscopy analysis of Cy5-Sgc8c-M (400 nM) for internalization in SUM159 cells at 0.5 h and 2 h. Scale bars, 10 μm. f Cytotoxicity of VcMMAE and Sgc8c-M in SUM159 and MDA-MB-468 cells after a 72-h incubation (n = 3). Data are presented as mean ± SEM
Fig 3: Antitumor activity of Sgc8c-M in HT-29, NCI-H1975, and OVCAR3 xenograft models. In vivo therapeutic efficacy of Sgc8c-M in HT-29 (n = 4, one-way ANOVA) (a), NCI-H1975 (n = 3) (b), and OVCAR3 (n = 3, one-way ANOVA) (c) xenografts. Tumor-bearing mice were dosed with 7 mg/kg Sgc8c-M (i.v.) or 10 mg/kg paclitaxel (i.p.) when the tumor size reached an average of 100–200 mm3. Histology and PTK7 expression in these models were shown as HE staining and IHC staining on tumor tissues of untreated mice, respectively. d The antitumor effects of Sgc8c-M (3.5 mg/kg) and PTK7-targeted ADC h6M24-VcMMAE (DAR4, 5 mg/kg) in the OVCAR3 model (n = 5, unpaired t test). Scale bars, 20 μm. Data are presented as mean ± SEM. *P < 0.05, **P < 0.01
Fig 4: Antitumor effect of Sgc8c-M in pancreatic cancer. a Cytotoxicity of VcMMAE, Sgc8c-M, and MMAE in MIA PaCa-2 cells after a 72-h incubation (n = 3). b, e, f Antitumor effects of Sgc8c-M for MIA PaCa-2, PDX F4, and PDX F5 in vivo (n = 5, unpaired t test). Tumor-bearing mice were dosed by i.v. every four days for 5–6 cycles with 7 mg/kg Sgc8c-M or 0.359 mg/kg MMAE. PTK7 IHC characterization and hematoxylin-eosin (HE) staining on these tumors showed the differences in PTK7 expression and tissue structure. Scale bars, 20 μm. c MMAE concentration in MIA PaCa-2 tumors at 2 h after a single dose of 7 mg/kg Sgc8c-M or 0.359 mg/kg MMAE (n = 3, unpaired t test). d Tumor-killing effect study of Sgc8c-M and MMAE in MIA PaCa-2 xenografts. Mice received 7 mg/kg Sgc8c-M or 0.359 mg/kg MMAE every four days for three cycles (q4d × 3) with Ki67 and pHH3 analyzed 24 h after the final dose (n = 3, one-way ANOVA). Scale bars, 20 μm. Data are presented as mean ± SEM. *P < 0.05, **P < 0.01
Supplier Page from Sino Biological, Inc. for Human CCK4 / PTK7 Protein (ECD, His Tag)