GSK3β‑mediated Ser156 phosphorylation modulates a BH3‑like domain in BCL2L12 during TMZ‑induced apoptosis and autophagy in glioma cells

Abstract

BH3 domains, classified initially as BCL2 homology domains, participate in both apoptosis and autophagy. Beclin-1 contains a BH3 domain, which is required for binding to antiapoptotic BCL2 homologs and BCL2-mediated inhibition of autophagy. BCL2-like 12 (BCL2L12) also harbors a BH3-like domain, which is 12 residues long and contains a LXXXAE/D motif. In a yeast two-hybrid system performed in the present study, BCL2L12 shared similar binding partnerships to antiapoptotic BCL2 homologs, such as Beclin-1. In addition, this BH3-like domain was involved in antiapoptosis and drug-induced autophagy in glioma cell lines. Mutations in S156 and hydrophobic L213 to alanine counteracted the antiapoptotic properties of BCL2L12 and downregulated the activation of microtubule associated protein 1 light chain 3B (LC3B), autophagy-related (ATG)12-ATG5 conjugates and Beclin-1, compared with a BCL2L12 wild-type group. Molecular dynamics simulations revealed that phosphorylation at Ser156 of BCL2L12 (within α-6 and α-7 helices) influenced the BH3-like domain conformation (α-9 helix), indicating that glycogen synthase kinase (GSK) 3β-mediated Ser156 phosphorylation modulated a BH3-like domain in BCL2L12. Altogether, the present findings indicated that BCL2L12 may participate in anti-apoptosis and autophagy via a BH3-like domain and GSK3β-mediated phosphorylation at Ser156. Furthermore, blockade of temozolomide (TMZ)-induced autophagy by 3-methyladenine (3-MA) resulted in enhanced activation of apoptotic markers, as well as tumor suppresor protein p53 (p53) expression in U87MG cells. The present results suggested that p53 and O6-methylguanine DNA methyltransferase activation, and BCL2, BCL-extra large, Beclin-1 and BCL2L12 expression may be used as a detection panel to determine which patients can benefit from TMZ and ABT-737 combination treatment.

Thioridazine Enhances P62-Mediated Autophagy and Apoptosis Through Wnt/β-Catenin Signaling Pathway in Glioma Cells

“…Beclin-1 interacts with several binding partners and can both induce and suppress autophagy pathways [23]. While numerous commonly used anticancer drugs have been reported to induce apoptosis in cancer cells, autophagy was also frequently observed in response to these drugs, including THD, TMZ, ABT-737, and sorafenib [3,4,21,24,25]. In our previous study, we found that THD and its analogs might enhance LC3-II-induced autophagy in GBM cells (Figure 1D).…”

“…In addition, AMPK activation was involved in THD-induced autophagy [21]. Studies have revealed that treatment with ABT-737 (a BH3 mimetic agent) combined with TMZ exerted a superior effect on apoptosis induction in U87MG cells, which effectively reactivated apoptotic markers [3,4]. Thus, to investigate the effect of a combination of THD and TMZ, U87MG cells were treated with different doses of THD combined with 200 µM TMZ for 24 h. As illustrated in Figure 3C, the level of phospho-AMPK (Thr172) was upregulated in the U87MG cells after the combination treatment.…”

“…Therefore, developing more effective therapeutic strategies, such as drug synergism of TMZ with another compound, is crucial to improve the clinical outcome of GBM treatment. Notably, treatment of GBM cells with TMZ results in autophagy and apoptosis [3,4,5].…”

Interleukin-5 induces apoptotic defects in CD4+ T cells of patients with allergic rhinitis

“…Published data indicate that Bcl2L12 is an anti‐apoptotic molecule . To elucidate if Bcl2L12 is involved in the regulation of FasL expression, the expression of Bcl2L12 in peripheral CD4 + T cells were assessed.…”

Involvement of NOS2 Activity on Human Glioma Cell Growth, Clonogenic Potential, and Neurosphere Generation

“…Allen et al reported the origin of the U-87 MG cell line as mislabeled and unknown; they compared the original U-87MG cell line firstly identified at Uppsala University with the commercial U-87MG cell line from ATCC HTB 14TM. Genotyping analysis revealed that the ATCC and Uppsala U-87 MG cell lines were from distinct origins [ 57 ]; however, other recent studies [ 58 , 59 , 60 ] have demonstrated that the U-87MG ATCC cell line has several typical characteristics of glioblastoma through analyses of cell morphology and gene expression profile, even though the origin patient is unknown. Thus, U-87 MG can be used as a bonafide human glioblastoma cell line.…”