PMC

Pharmacological inhibition of GSK-3 suppresses viability of breast cancer cells. (A) Whole cell lysate was prepared from breast cancer cells, separated by SDS-PAGE (50 μg/well), transferred to PVDF membrane, and immunoblotted as indicated. (B) Relative cell growth was measured by MTS assay in MDA-MB-468 and SKBR3 breast cancer cells treated with 9-ING-41 (9ING41) and 9-ING-87 (9ING87) for 72 hours as indicated. (C) Breast cancer cells were treated with GSK-3 inhibitors 9-ING-41 (9ING41) and 9-ING-87 (9ING87) for 36 hours and Western immunoblotting was performed as indicated. (D) Representative pictures of Hoechst staining of breast cancer cells treated with 9-ING-41 and 9-ING-87 as indicated for 48 hours. Fragmented apoptotic nuclei show intense Hoechst staining.

Pharmacological inhibition of GSK-3 potentiates the effect of conventional chemotherapeutic drugs in breast cancer cells. (A) GSK-3 inhibitors 9-ING-87 and 9-ING-41 show lowest GI50 in growth inhibition of SKBR3 breast cancer cells as compared to other GSK-3 inhibitors AR-A014418, SB-216763 and LY2090314. (B) Relative cell growth was measured by MTS assay in breast malignant (SKBR3) and benign (MCF10A) cells treated with 9-ING-41 (0.5 μM), 9-ING-87 (1 μM) and AR-A014418 (20 μM) for 72 hours as indicated. (C) Relative cell growth was measured by MTS assay in breast cancer cell lines treated with 0.5 μM, 2 μM and 10 μM of 9-ING-41 for 3 hours and 72 hours as indicated. (D) Breast cancer cell lines were treated with 9-ING-41, CPT-11 or combination of 9-ING-41 with CPT-11 for 3 hours at indicated. After the treatment, drugs were replaced with fresh media and relative cell growth was measured by MTS assay after 72 hours. Columns, mean; bars, SE.

Treatment with CPT-11 + 9-ING-41 leads to a regression of breast BC-2 PDX (ER+/PR+/HER2−) tumors. (A) Treatment history of breast cancer patient (case BC-2). Breast PDX tumor model was established after orthotopic injection of metastatic pleural effusion cells (obtained from breast cancer patient) in NSG mouse. Breast PDX tumor pieces were re-transplanted orthotopically to 16 mice (1 tumor per mouse). Tumors were size matched and mice were randomized into 4 treatment groups: control (DMSO; n = 4 mice), CPT-11 (20 mg/kg, n = 4 mice), 9-ING-41 (70 mg/kg, n = 4 mice) and CPT-11 + 9-ING-41 (n = 4 mice). (B) Vehicle or drugs were injected as indicated by arrows. Points, mean tumor volume; bars, SE. (C) Weight of resected tumors was measured. Columns, mean tumor weight; bars, SE. (D) Representative pictures of PDX subQ tumors from each group of animals. (E) Representative pictures of GSK-3β, phospho-Glycogen Synthase and β-catenin expression in control and 9-ING-41-treated BC-2 PDX tumors.

Treatment with 9-ING-41 enhances the antitumor effect of CPT-11 in breast BC-1 PDX (ER+/PR+/HER2−) tumors. (A) Treatment history of breast cancer patient (case BC-1). Breast PDX tumor model was established after orthotopic injection of metastatic pleural effusion cells (obtained from breast cancer patient) in NSG mouse. Breast PDX tumor pieces were re-transplanted orthotopically to 20 mice (1 tumor per mouse). Tumors were size matched and mice were randomized into 4 treatment groups: control (DMSO; n = 4 mice), CPT-11 (5 mg/kg, n = 5 mice), 9-ING-41 (70 mg/kg, n = 5 mice) and CPT-11 + 9-ING-41 (n = 5 mice). (B) Vehicle or drugs were injected as indicated by arrows. Points, mean tumor volume; bars, SE. (C) Weight of resected tumors was measured. Columns, mean tumor weight; bars, SE. (D) Representative pictures of PDX subQ tumors from each group of animals. (E) Representative pictures of GSK-3β, phospho-Glycogen Synthase and β-catenin expression in control and 9-ING-41-treated BC-1 PDX tumors.