Anti-BCL2L1 monoclonal antibody, clone 3I23

Glioma is an aggressive and lethal type of brain tumor that originates from glial cells. Glioblastoma cells confer considerable resistance to induction of apoptosis, which may be due to overexpression of anti-apoptotic proteins, or the reduction of the level of some pro-apoptotic proteins. MicroRNAs (miRNAs) can affect the cell biology pathways, including replication, autophagy, necrosis, and apoptosis by regulating gene expression. In this study, using bioinformatics methods, we selected the anti-apoptotic genes, BCL2L1 and MCL1, and microRNA that targeted them (miR-342). In the next step, the Lentiviral particles that contain miR-342 (LV-miR-342) were synthesized in HEK293T cell lines. Glioblastoma cell lines, U251 and U87, were transduced with LV-miR-342. The gene expression and apoptosis induction were then assayed by real-time PCR and flow cytometry respectively. The present study showed that increasing the expression of miR-342 reduced the expression of the antiapoptotic genes, BCL2L1 and MCL1. The results of luciferase assay reports confirmed that miR-342 targeted BCL2L1 and MCL1. In addition, flow cytometry analysis indicated that miR-342 overexpression induced apoptosis in glioblastoma cells. As well as, Western blotting results confirmed a decrease in BCL2L1 protein following overexpression of miR-342 in glioblastoma cells. These findings may provide a novel therapeutic target for the treatment of glioblastoma.

Anaplastic thyroid carcinoma (ATC) is an aggressive human tumor with a median survival of 6 months. We previously developed an agonistic anti-death receptor 4 MAB, AY4, and demonstrated the antitumor effects of AY4 in head and neck cancer cells. Presently, we show that ATC cells are sensitive to AY4 and that the sensitivity correlates with the reduced expression level of Bcl-xL and reactive oxygen species (ROS) generation. AY4 induced death of C-643, U-HTH 7, HTH83, and SW1736 cells. To elucidate the role of ROS generation in AY4-induced apoptosis of ATC cells, U-HTH 7 and SW1736 cells were pretreated with an antioxidant (N-acetyl cysteine, NAC) followed by AY4 treatment. The cell death was blocked by NAC. AY4-induced cell death was accompanied by the downregulation of the anti-apoptotic protein, Bcl-xL (BCL2L1). To examine the link between the apoptotic response and Bcl-xL protein expression, U-HTH 7 cells were transfected with Bcl-xL plasmid. The consequence of the overexpression of Bcl-xL appeared to decrease AY4-mediated cell death by blocking ROS generation in U-HTH 7 cells. By contrast, Bcl-xL knockdown using small interfering RNA of Bcl-xL enhanced AY4 sensitivity in HTH83 and C-643 cells and rendered the cells sensitive to AY4-induced cell death. The results support the conclusion that the expression level of Bcl-xL is important in the AY4-induced apoptosis of ATC cells through ROS generation. AY4 may be a promising tool for ATC therapy.