Survivin Inhibitor YM-155 Sensitizes Tumor Necrosis Factor– Related Apoptosis-Inducing Ligand-Resistant Glioma Cells to Apoptosis through Mcl-1 Downregulation and by Engaging the Mitochondrial Death Pathway

Abstract

Induction of apoptosis by the death ligand tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a promising antitumor therapy. However, not all tumor cells are sensitive to TRAIL, highlighting the need for strategies to overcome TRAIL resistance. Inhibitor of apoptosis family member survivin is constitutively activated in various cancers and blocks apoptotic signaling. Recently, we demonstrated that YM-155, a small molecule inhibitor, downregulates not only survivin in gliomas but also myeloid cell leukemia sequence 1 (Mcl-1), and it upregulates proapoptotic Noxa levels. Because Mcl-1 and survivin are critical mediators of resistance to various anticancer therapies, we questioned whether YM-155 could sensitize resistant glioma cells to TRAIL. To address this hypothesis, we combined YM-155 with TRAIL and examined the effects on cell survival and apoptotic signaling. TRAIL or YM-155 individually induced minimal killing in highly resistant U373 and LNZ308 cell lines, but combining TRAIL with YM-155 triggered a synergistic proapoptotic response, mediated through mitochondrial dysfunction via activation of caspases-8, -9, -7, -3, poly-ADPribose polymerase, and Bid. Apoptosis induced by combination treatments was blocked by caspase-8 and pan-caspase inhibitors. In addition, knockdown of Mcl-1 by RNA interference overcame apoptotic resistance to TRAIL. Conversely, silencing Noxa by RNA interference reduced the combined effects of YM-155 and TRAIL on apoptosis. Mechanistically, these findings indicate that YM-155 plays a role in counteracting glioma cell resistance to TRAIL-induced apoptosis by downregulating Mcl-1 and survivin and amplifying mitochondrial signaling through intrinsic and extrinsic apoptotic pathways. The significantly enhanced antitumor activity of the combination of YM-155 and TRAIL may have applications for therapy of malignant glioma.

ABT-199, a BH3 mimetic that specifically targets Bcl-2, enhances the antitumor activity of chemotherapy, bortezomib and JQ1 in “double hit” lymphoma cells

“…Single agent studies. We next determined the sensitivity of the cell lines to chemotherapy drugs used to treat DHL, as well as bortezomib, currently used for the treatment of myeloma and mantle cell lymphoma, and YM-155, an inhibitor of expression of Mcl-1 and survivin [16][17][18] . The DHL cell lines were sensitive to nM concentrations of MTX, cytarabine, doxorubicin, and, bortezomib, a proteasome inhibitor.…”

Inhibition of Phosphatidylinositol 3-Kinase/AKT Signaling by NVP-BKM120 Promotes ABT-737–Induced Toxicity in a Caspase-Dependent Manner through Mitochondrial Dysfunction and DNA Damage Response in Established and Primary Cultured Glioblastoma Cells

“…Cells were seeded in 96-well plates (5000 cells/ well) in 100 ml of growth medium and incubated at 37°C for 24 hours before the addition of inhibitors or vehicle for 3 days. Cell growth assays were done using the CellTiter96 Aqueous Non-Radioactive Cell Proliferation Assay kit (Promega, Madison, WI), per manufacturer's instructions, to evaluate the effect the inhibitors and doses as described previously (Premkumar et al, 2013b). Absorbance was measured at a wavelength of 490 nm, and the absorbance values of treated cells are presented as a percentage of the absorbance of untreated cells.…”

“…Apoptosis induction in vehicle-or inhibitor-treated cells was assayed by the detection of membrane externalization of phosphatidylserine using an annexin V assay kit (Molecular Probes, Invitrogen) as described previously (Premkumar et al, 2013b). Cells (2 Â 10 5 ) were harvested at various intervals after treatment, washed with ice-cold phosphate-buffered saline (PBS), and resuspended in 200 ml of binding buffer.…”

miR-494 Sensitizes Gastric Cancer Cells to TRAIL Treatment Through Downregulation of Survivin

“…5C). As YM-155 has been proved to be a inhibitor of survivin [27], we co-treated the gastric cancer cells with YM-155 and TRAIL to evaluate the role of survivin in TRAIL-induced cytotoxicity. Our results showed that YM-155 significantly enhanced the TRAIL-induced cell death in BGC-823 and MGC-803 cells, similarly with miR-494 (Fig.…”

“…As overexpression of survivin has been reported to be responsible for inhibition of mitochondrial apoptosis [27], we next investigated the effect of miR-494 on regulating the TRAIL-induced mitochondrial apoptosis pathway. Results of flow cytometry showed that the TRAIL-induced decrease of mitochondrial membrane potential can be expanded by miR-494.…”