Dataset Information

Histone deacetylase inhibitors mediate selective degradation of nuclear uracil-DNA glycosylase 2 and increased genomic uracil

ABSTRACT: HDAC inhibitors (HDACi) belong to a new group of chemotherapeutics that are increasingly used to treat B-cell-derived malignancies. Such malignancies regularly carry mutational signatures that conform to off-target induction of uracil by the AID/APOBEC family of cytidine deaminases, or downstream processing of uracil. . HDACi suppress thymidylate synthase increasing the cellular dUTP/dTTP ratio and leading to increased pressure on uracil repair machinery due to misincorporated uracil lesions. To investigate potential effect upon other enzymes involved in genomic uracil induction and processing, Jurkat (T-cell lymphoma) and SUDHL5 (B-cell lymphoma) cells were treated with pan-HDACi SAHA prior to SILAC based MS/MS investigation. HDACi treatment mediated significant differential expression of xx and xx proteins in Jurkat and SUDHL5, respectively, and had a substantial impact upon enzymes involved in in pyrimidine metabolism. Surprisingly, uracil N-glycosylase, UNG, was strongly downregulated by HDACi treatment. Further analysis in HEK and HeLa cells revealed that HDACis induce specific loss of the nuclear isoform UNG2 independent of transcription and cell-cycle alterations. More than 80% of UNG2 is degraded proteasomally after 24 hours treatment with SAHA, MS275, Valproate or Na-butyrate, indicating a universal ability of HDACis to mediate loss of UNG2. Targeted MS/MS analysis in HEK cells against a panel of proteins involved in DNA repair, translesion synthesis and nucleotide metabolism, revealed that UNG2 was the most pronounced differentially expressed among these after HDACi treatment. 48 hour treatment lead to a 30-40% increase in uracil lesions in the nuclear genome of HeLa and HEK cells and MS275 treatment in murine CH12F3 cell line mediated robust UNG2-loss accompanied by reduced class switch recombination. Furthermore, our analysis identified the PCNA-associated factor PAF15 among the downregulated proteins. PAF15 is overexpressed in many cancers and suppress TLS by inducing double monoubiquitinylation of PCNA and recruitment of the replicative polymerases. In summary, our findings demonstrate that HDAC inhibition affects the levels of proteins involved in DNA base excision repair, translesion synthesis and pyrimidine metabolism. These findings are important for a wide range of clinical applications of HDACi, such as in rheumatology, HIV-, and cancer treatment.

INSTRUMENT(S): Q Exactive

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Blood Cell, Blood

DISEASE(S): Lymphoma

SUBMITTER: Animesh Sharma

LAB HEAD: Geir Slupphaug

PROVIDER: PXD008293 | Pride | 2020-04-14

REPOSITORIES: Pride

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Dataset's files

Source:

			Action	DRS
	150820_JURKAT_SAHA_TECH4.raw	Raw
	150820_JURKAT_SAHA_TECH5.raw	Raw
	150820_JURKAT_SAHA_TECH6.raw	Raw
	150820_SUDHL5_SAHA_TECH4.raw	Raw
	150820_SUDHL5_SAHA_TECH5.raw	Raw

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Publications

HDACi mediate UNG2 depletion, dysregulated genomic uracil and altered expression of oncoproteins and tumor suppressors in B- and T-cell lines.

Iveland Tobias S TS Hagen Lars L Sharma Animesh A Sousa Mirta M L MML Sarno Antonio A Wollen Kristian Lied KL Liabakk Nina Beate NB Slupphaug Geir G

Journal of translational medicine 20200407 1

<h4>Background</h4>HDAC inhibitors (HDACi) belong to a new group of chemotherapeutics that are increasingly used in the treatment of lymphocyte-derived malignancies, but their mechanisms of action remain poorly understood. Here we aimed to identify novel protein targets of HDACi in B- and T-lymphoma cell lines and to verify selected candidates across several mammalian cell lines.<h4>Methods</h4>Jurkat T- and SUDHL5 B-lymphocytes were treated with the HDACi SAHA (vorinostat) prior to SILAC-based ...[more]

PMID: 32264925

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Project description:Esophageal cancers (ECs) are highly aggressive tumors with poor prognosis and few treatment options. This study investigated the possibility of treating esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC) cells by inhibitors of broad and specific histone deacetylases (HDACi; SAHA, MS-275, FK228) and/or of DNMT (Azacytidine, AZA). Drug targets (HDAC1,2,3 and DNMT1) were present in non-neoplastic (HET-1A), ESCC (OE21) and EAC (OE33) cell lines. All cell lines responded to HDACi by reduced HDAC activity and increased histone acetylation as well as to AZA by up-regulation of p21. Expression of drug targets remained largely unaffected by HDACi and AZA treatment. Importantly, cell viability, apoptosis, cell cycle dynamics and DNA damage were only affected by HDACi and/or AZA in ESCC and EAC, but not the non-neoplastic cells. This was specifically seen for the combination of MS-275 and AZA, leading to enhanced cancer cell selectivity and drug efficiency. By transcriptome analyses of MS-275, AZA and MS-275/AZA treated cells, known (e.g. p21) as well as novel regulated genes significantly associated with the cellular effects post HDACi and/or AZA treatment in ESCC and EAC cells were identified. Finally, human EC tissue specimens frequently expressed the actionable drug targets HDAC1/2/3 and DNMT1. In summary, a combined HDACi (MS-275)/AZA treatment is cancer cell selective and efficient in vitro. Since the majority of ECs express the drug targets in situ, this paves the way for further investigations of HDACi/AZA treatment in esophageal cancer cells and their translation into a clinico-pathological setting. To elucidate the transcriptome response to HDAC inhibitors of normal esophageal cells and esophageal tumor cells, total RNA was isolated from non-neoplastic esophageal epithelial cells (Het1A cells) a well as from two esophageal tumor cell lines (OE21 and OE33), respectively. Cells were treated with either MS-275, Azacytidine (AZA) or in combination of both. DMSO treatment was used as control in each case. Total RNA was isolated from cells 24 h after treatment and experiments were performed in biological triplicates.