Crosstalk between DNA methylation and histone acetylation triggers GDNF high transcription in glioblastoma cells

Abstract

Background: Glial cell line-derived neurotrophic factor (GDNF) is highly expressed in glioblastoma (GBM) and blocking its expression can inhibit the initiation and development of GBM. GDNF is a dual promoter gene, and the promoter II with two enhancers and two silencers plays a major role in transcription initiation. We had previously reported that histone hyperacetylation and DNA hypermethylation in GDNF promoter II region result in high transcription of GDNF in GBM cells, but the mechanism remains unclear. In this study, we investigated whether these modifications synergistically regulate high GDNF transcription in GBM. Results: Cyclic AMP response element binding protein (CREB) expression and phosphorylation at S133 were significantly increased in human GBM tissues and GBM cell lines (U251 and U343). In U251 GBM cells, high expressed CREB significantly enhanced GDNF transcription and promoter II activity. CREB regulated GDNF transcription via the cyclic AMP response elements (CREs) in enhancer II and silencer II of GDNF promoter II. However, the two CREs played opposite regulatory roles. Interestingly, hypermethylation of CRE in silencer II occurred in GBM tissues and cells which led to decreased and increased phosphorylated CREB (pCREB) binding to silencer II and enhancer II, respectively. Moreover, pCREB recruited CREB binding protein (CBP) with histone acetylase activity to the CRE of GDNF enhancer II, thereby increasing histone H3 acetylation and RNA polymerase II recruitment there and at the transcription start site (TSS), and promoted GDNF high transcription in U251 cells. The results indicated that high GDNF transcription was attributable to DNA hypermethylation in CRE of GDNF silencer II increasing pCREB binding to CRE in enhancer II, which enhanced CBP recruitment, histone H3 acetylation, and RNA polymerase II recruitment there and at the TSS. Conclusions: Our results demonstrate that pCREB-induced crosstalk between DNA methylation and histone acetylation at the GDNF promoter II enhanced GDNF high transcription, providing a new perspective for GBM treatment.

Genetic Determinism Exists for the Global DNA Methylation Rate in Sheep

“…It particularly interacts with other transcriptional activators such p300/CBP-associated factor and CREB binding protein (CREBBP) as part of a multi-subunit coactivation complex. The CREBBP gene, also located near a significant QTL position (OAR 24: 3.1 Mb) has been recently reported to be involved in the crosstalk between DNA methylation and histone acetylation ( Zhang et al, 2020 ). Finally, two lysine acetyltransferase coding genes of the MYST family, KAT6A (lysine acetyltransferase 6A, also named MOZ , OAR26: 35.3 Mb) and KAT7 (lysine acetyltransferase 7, also named HBO1 , OAR11: 36.4 Mb) has been reported to play a key role in acetylation of lysine residues in histone H3 and/or H4 ( Kitabayashi et al, 2001 ).…”

Mesenchymal Transformation: The Rosetta Stone of Glioblastoma Pathogenesis and Therapy Resistance

“…Epigenetic regulation by histone modification, DNA methylation, and chromatin remodeling plays a critical role in pathological conditions, for instance, tumor initiation, progression, and EMT. [58][59][60] Malignant GBM transformation by aberrant histone alteration is evident in recent literature. [61][62][63] In particular, abnormal histone modification induces inactivation of cancer repressor genes, leading to abnormal GBM growth.…”

Inhibition of Aurora-A improves insulin resistance by ameliorating islet inflammation and controlling interleukin-6 in a diabetic mouse model

“…Western blot was performed as described previously [15]. The frozen pancreatic tissues were cut into pieces and homogenized in ice-cold cellular lysis buffer (150 mM NaCl, 10 mM Tris-HCl, 5 mM EDTA, 1 mM EGTA, and 10% Triton X-100) containing a protease inhibitor cocktail.…”