Combined application of Embelin and tumor necrosis factor-related apoptosis-inducing ligand inhibits proliferation and invasion in osteosarcoma cells via caspase-induced apoptosis

Abstract

Embelin, as an inhibitor of the X-linked inhibitor of apoptosis protein (XIAP), may induce apoptosis in various types of cancer cells. The present study aimed to determine the effect of Embelin on the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis of osteosarcoma cells. Embelin and TRAIL were applied to U2OS and MG63 cells, respectively or in combination. MTT was initially used to detect the difference in survival rates between the group receiving combined application of 100 ng/ml TRAIL and 20 µmol/l Embelin and the individual application groups. Light microscopic quantification was used to detect the morphology of the osteosarcoma cells in each group. Determination of cell apoptosis was subsequently performed using flow cytometry. The invasive ability of the cells was detected by a Transwell assay, prior to relative protein expression being determined by western blot analysis. Based on all the test data, it was revealed that the survival rates and the invasive ability were significantly lower following the combined application of 100 ng/ml TRAIL and 20 µmol/l Embelin than following the individual application of either (P<0.01). Additionally, upregulating expression of caspases, as well as death receptor 5, and downregulating expression of XIAP and matrix metalloproteinase 9 (MMP-9), had more significant effects in the combined group compared with the individual group and the control group. All these results suggested that Embelin may enhance TRAIL-induced apoptosis and inhibit the invasion of human osteosarcoma cells.

The XIAP inhibitor embelin sensitises malignant rhabdoid tumour cells to TRAIL treatment via enhanced activation of the extrinsic apoptotic pathway

“…Of note, the recovery of cells from TRAIL was inhibited by embelin co-treatment which resulted in synergistically enhanced cell death and caspase activity in BT12 and BT16 cells. The present results are supported by the literature where embelin has been reported to enhance TRAIL-mediated cell death in acute myeloid leukaemia, malignant glioma, pancreatic, inflammatory breast, and non-small cell lung cancer cell lines (47)(48)(49)(50)(51)(52)(53)(54). Previous reports have differed in their proposed mechanism with changes in expression of anti-apoptotic proteins FLIP, XIAP, survivin and Bcl-2 family members, alongside altered regulation of the NF-κB and ERK pathways among the factors implicated.…”

“…However, clinical trials with TRAIL have yielded disappointing outcomes, with resistance being a primary issue (15)(16)(17)(18)(19). In recent years, reports have demonstrated enhanced susceptibility of cancer cells to TRAIL upon cotreatment with the XIAP inhibitor embelin (47)(48)(49)(50)(51)(52)(53)(54). The present study, therefore, assessed the efficacy of TRAIL and embelin cotreatment in MRT cell lines.…”

“…Having shown the expression of XIAP in a range of MRT cell lines, and their resistance to TRAIL treatment, the present study next assessed if embelin could sensitise MRT cell lines to TRAIL. BT12, BT16 and G401 cell lines were treated with a range of concentrations of TRAIL, both alone and in combination with 10 μM embelin, for 24, 48 and 72 h. This concentration of embelin is at the lowest end of the range (10-50 µM) previously demonstrated to enhance susceptibility to TRAIL (47)(48)(49)(50)(51)(52)(53)(54). It was selected for the present study, as lower doses are preferable in cancer therapeutics in order to minimise potential side effects.…”

“…Its chemotherapeutic and radiation sensitising capacity has also been demonstrated in various cancers (45,46). Additionally, there are an increasing number of studies reporting that embelin can sensitise both cancer cell lines and xenograft models to TRAIL (47)(48)(49)(50)(51)(52)(53)(54). To the best of our knowledge, there is only one published report on TRAIL treatment in MRT cell lines, which found 3 of 6 tested cell lines to be sensitive to TRAIL (55).…”

CAR-engineered NK cells; a promising therapeutic option for treatment of hematological malignancies

“…CAR-NK was transduced from CB with a structure that included coding segments for CAR for CD19, interleukin (IL)-15 (to increase cell proliferation and persistence), and an inducible caspase-9 (iC9)-based suicide gene, according to Liu and his colleagues. The CAR-modified NK’s antitumor activity and survival were significantly improved by the synthesis of IL-15, compared to normal CAR-NK, and the expression of iC9 improved the cells’ safety [ 101 ].…”