ABSTRACT
AIM: To explore the effect of Bcl-2 small molecule inhibitor ABT-737 on the growth and angiogenesis mimicry of SKOV3 cells in a co-culture system of Tumour-associated macrophages (TAMs) and human ovarian cancer cells SKOV3. METHODS: PMA and IL-4 was used to induce THP-1 cells into TAMs cells in vitro; MTT method was used to detect the cell survival rate of SKOV3 cells after 24 hours of treatment with different concentrations of ABT-737 culture medium; a co-culture system of SKOV3 cells and TAMs cells was established; the experimental groups were divided into control group, SKOV3+ABT-737 group (containing 5.0 μmol/L ABT-737 cultured cells), TAMs+SKOV3 group (SKOV3 cells co-cultured with TAMs cells), TAMs+SKOV3+ABT-737 group (SKOV3 cells Co-cultured with TAMs cells, and added ABT-737 containing 5.0 μmol/L), cells after 24 h was collected, MTT method was used to detect cell survival rate, EdU staining for cell proliferation, ranswell chamber experiment for cell migration and invasion, Flowcytometry for cell apoptosis, the vascular mimicry experiment for the ability of cells to form blood vessels, Western blot for the expression of vascular endothelial growth factor (VEGF), matrix metalloproteinase-2 (MMP-2) and MMP-9 in cells. RESULTS: THP-1 cells were successfully induced for TAMs cells; the survival rate of SKOV3 cells decreased under the action of ABT-737 (P<0.01); compared with the control group, the survival rate of SKOV3 cells in the SKOV3+ABT-737 group decreased, the number of EdU-labeled positive cells decreased, the number of cell migration and invasion also decreased, the rate of apoptosis increased, and the duct branches decreased, The protein expression of VEGF, MMP-2, MMP-9 decreased (P<0.01); Compared with the TAMs+SKOV3 group, the cell survival rate of the TAMs+SKOV3+ABT-737 group decreased, the number of EdU-labeled positive cells and the number of cell migration and invasion also decreased, the apoptosis rate increased, and the duct branches decreased. At the same time, the protein expression of VEGF, MMP-2, MMP-9 decreased (P<0.01). CONCLUSION: ABT-737 can inhibit SKOV3 cell proliferation, metastasis, apoptosis and angiogenesis in a co-culture system, and affect tumor progression.
ABSTRACT
Aim: To investigate the promoting effect of Bcl-2/Bcl-xL inhibitor ABT-737 on apoptosis of gastric cancer cells induced by small molecule Mcl-1 inhibitor UMI-77, and to explore its possible mechanism. Methods: The response of gastric cancer MGC-803 and HGC-27 cells to different concentrations of UMI-77 was detected by MTS assay. In the UMI-77-resistant cell lines, the effect of treatment with UMI-77/ABT-737 alone or in combination on cell viability was detected by MTS assay. The apoptotic rate and the changes of the mitochondrial membrane potential were analyzed by flow cytometry. The cleavage of caspase-9, caspase-3 and PARP-1, as well as the expression level of Bcl-2 family members and IAP proteins, were determined by Western blot. Results: Compared with MGC-803 cells, HGC-27 cells were resistant to UMI-77. Treatment with ABT-737 alone in HGC-27 cells also induced minimal level of cell death. While treatment with both agents induced much greater decreased cell viability. All the dead cells were positive for Annexin V and mitochondrial membrane potential collapsed. Caspase-9, caspase-3 and its substrate PARP-1 were cleaved. All of these proved that the sensitization effect was achieved by activating the mitochondrial apoptotic pathway. Protein levels of XIAP, cIAP1 and cIAP2 decreased after treatment with UMI-77 plus ABT-737. It also resulted in the increase of NOXA and Bcl-2 along with the decline of PUMA and Mcl-1. Conclusions: The combination of UMI-77 and ABT-737 could significantly increase the sensitivity of gastric cancer cells to the Mcl-1 small molecule inhibitor UMI-77.
ABSTRACT
PURPOSE: This study aimed to validate the synergistic effect of ABT-737 on docetaxel using MDA-MB-231, a triple negative breast cancer (TNBC) cell line overexpressing B-cell lymphoma-2 (Bcl-2). METHODS: Western blot analysis was performed to assess expression levels of Bcl-2 family proteins and caspase-related molecules. Cell viability was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Cell cycle distribution was determined by flow cytometry analysis. Benzyloxycarbonyl-Val-Ala-Asp(OMe)-fluoromethylketone (z-VAD-fmk) was used for pretreatment to assess the role of caspases. RESULTS: Cell viability of MDA-MB-231 after combination treatment with ABT-737 and docetaxel was significantly lower than that after docetaxel or ABT-737 monotherapy based on MTT assay (both P < 0.001), with a combination index of 0.41. The proportion of sub-G1 population after combination treatment was significantly higher than that after docetaxel or ABT-737 monotherapy (P = 0.001, P = 0.003, respectively). Pretreatment with z-VAD-fmk completely restored cell viability of MDA-MB-231 from apoptotic cell death induced by combination therapy (P = 0.001). Although pro-caspase-8 or Bid did not show significant change in expression level, pro-casepase-9 showed significantly decreased expression after combination treatment. Cleaved caspase-3 showed increased expression while poly (ADP-ribose) polymerase cleavage was induced after combination treatment. However, hypoxia-inducible factor 1-alpha and aldehyde dehydrogenase 1 totally lost their expression after combination treatment. CONCLUSION: Combination of ABT-737 with docetaxel elicits synergistic therapeutic effect on MDA-MB-231, a TNBC cell line overexpressing Bcl-2, mainly by activating the intrinsic pathway of apoptosis. Therefore, adjunct of ABT-737 to docetaxel might be a new therapeutic option to overcome docetaxel resistance of TNBCs overexpressing Bcl-2.