Molecular and cellular effects of a novel hydroxamate-based HDAC inhibitor – belinostat – in glioblastoma cell lines: a preliminary report

Abstract

SummaryHistone deacetylase (HDAC) inhibitors are now intensively investigated as potential cytostatic agents in many malignancies. Here, we provide novel information concerning the influence of belinostat (Bel), a hydroxamate-based pan-HDAC inhibitor, on glioblastoma LN-229 and LN-18 cells. We found that LN-229 cells stimulated with 2 μmol/L of Bel for 48 h resulted in 70 % apoptosis, while equivalent treatment of LN-18 cells resulted in only 28 % apoptosis. In LN-229 cells this effect was followed by up-regulation of pro-apoptotic genes including Puma, Bim, Chop and p21. In treated LN-18 cells only p21 was markedly overexpressed. Simultaneously, LN-229 cells treated with 2 μmol/L of Bel for 48 h exhibited down-regulation of molecular chaperones GRP78 and GRP94 at the protein level. In contrast, in LN-18 cells Western blot analysis did not show any marked changes in GRP78 nor GRP94 expression. Despite noticeable overexpression of p21, there were no signs of evident G1 nor G2/M cell cycle arrest, however, the reduction in number of the S phase cells was observed in both cell lines. These results collectively suggest that Bel can be considered as potential anti-glioblastoma agent. To our knowledge this is the first report presenting the effects of belinostat treatment in glioblastoma cell lines.

Silica nanoparticle-induced oxidative stress and mitochondrial damage is followed by activation of intrinsic apoptosis pathway in glioblastoma cells

“…5,6,46 Downstream of ER stress, the unfolded protein response is initiated, with one of two potential outcomes: activation of prosurvival pathways via increased expression of chaperone proteins GRP78, GRP94, and ORP150, or activation of a proapoptotic pathway through enhanced expression of CHOP. 15,16 Therefore, increased levels of ER chaperones and CHOP are considered markers of ER stress. In this study, we observed altered expression of GRP78 and GRP94 at mRNA and protein levels in a manner dependent on time and dose of SiNPs.…”

“…Primer sequences for DDIT3 (CHOP), BAX, BCL2L11 (BIM), BCL2, BCL2L1 (BCL-X L ), PUMA, NOXA, and housekeeping RPL13A have been described in our previous work. 15,16 Sequences of the other PCR primers were previously described as: HSPA5 (GRP78), 22 SOD1, 23 SOD2, 23 CAT, 23 COX2, 24 and IL1B. 24 Additional evaluation of primer accuracy was done using Primer-BLAST software.…”

“…A number of other factors, such as molecular heterogeneity, anaplastic cancer cells, and difficulties in targeting therapeutics specifically to transformed cells, are among the limitations halting development of effective glioblastoma therapies. [15][16][17] To address this need for new therapeutic strategies, the field of nanomedicine is currently being explored in the management of brain malignancies. 17 To date, several reports illustrating the utility of SiNPs for brain-tumor treatment have been published.…”

Epigenetic Regulation of Multidrug Resistance Protein 1 and Breast Cancer Resistance Protein Transporters by Histone Deacetylase Inhibition

“…HDAC inhibitors induce antitumor effects by: (1) inducing the expression of tumor suppressors including p53 and p21, promoting cell cycle arrest, and inhibiting cell proliferation (Davis et al, 2000;Richon et al, 2000;Kim et al, 2001); (2) activating extrinsic and intrinsic apoptosis by upregulating death receptors and proapoptotic proteins (Kawagoe et al, 2002;Nakata et al, 2004;Insinga et al, 2005); and (3) inhibiting angiogenesis through induction of anti-angiogenic genes and repression of pro-angiogenic genes Deroanne et al, 2002;Kwon et al, 2002). Clinical studies are being actively performed to test the effects of HDAC inhibitors in other types of cancer including glioblastoma (Galanis et al, 2009;Bailey et al, 2016;Kusaczuk et al, 2016;Choi et al, 2017;Barneh et al, 2018;Monga et al, 2018).…”

Histone deacetylase 6 promotes growth of glioblastoma through the MKK7/JNK/c‐Jun signaling pathway

“…Acetylation homeostasis is a steady acetylation status of histones and non‐histone proteins, which is precisely controlled by histone acetyl‐transferase and histone deacetylase (HDAC) (Kusaczuk et al ). The dynamic balance confers stability to the cellular homeostasis by spatially and temporally coordinating the expression of genes that are vital for cellular fate.…”