Haploinsufficiency of ZFHX3, encoding a key player in neuronal development, causes syndromic intellectual disability.

Neurodevelopmental disorders (NDDs) result from impaired development and functioning of the brain. Here, we identify loss-of-function (LoF) variation in ZFHX3 as a cause for syndromic intellectual disability (ID). ZFHX3 is a zinc-finger homeodomain transcription factor involved in various biological processes, including cell differentiation and tumorigenesis. We describe 42 individuals with protein-truncating variants (PTVs) or (partial) deletions of ZFHX3, exhibiting variable intellectual disability and autism spectrum disorder, recurrent facial features, relative short stature, brachydactyly, and, rarely, cleft palate. ZFHX3 LoF associates with a specific methylation profile in whole blood extracted DNA. Nuclear abundance of ZFHX3 increases during human brain development and neuronal differentiation. ZFHX3 was found to interact with the chromatin remodeling BRG1/Brm-associated factor complex and the cleavage and polyadenylation complex, suggesting a function in chromatin remodeling and mRNA processing. Furthermore, ChIP-seq for ZFHX3 revealed that it predominantly binds promoters of genes involved in nervous system development. We conclude that loss-of-function variants in ZFHX3 are a cause of syndromic ID associating with a specific DNA methylation profile.

A novel neurodevelopmental syndrome caused by loss-of-function of the Zinc Finger Homeobox 3 (ZFHX3) gene.

Neurodevelopmental disorders (NDDs) result from impaired development and functioning of the brain. Here, we identify loss-of-function variation in ZFHX3 as a novel cause for syndromic intellectual disability (ID). ZFHX3, previously known as ATBF1, is a zinc-finger homeodomain transcription factor involved in multiple biological processes including cell differentiation and tumorigenesis. Through international collaboration, we collected clinical and morphometric data (Face2Gene) of 41 individuals with protein truncating variants (PTVs) or (partial) deletions of ZFHX3 . We used data mining, RNA and protein analysis to identify the subcellular localization and spatiotemporal expression of ZFHX3 in multiple in vitro models. We identified the DNA targets of ZFHX3 using ChIP seq. Immunoprecipitation followed by mass spectrometry indicated potential binding partners of endogenous ZFHX3 in neural stem cells that were subsequently confirmed by reversed co-immunoprecipitation and western blot. We evaluated a DNA methylation profile associated with ZFHX3 haploinsufficiency using DNA methylation analysis on whole blood extracted DNA of six individuals with ZFHX3 PTVs and four with a (partial) deletion of ZFHX3 . A reversed genetic approach characterized the ZFHX3 orthologue in Drosophila melanogaster . Loss-of-function variation of ZFHX3 consistently associates with (mild) ID and/or behavioural problems, postnatal growth retardation, feeding difficulties, and recognizable facial characteristics, including the rare occurrence of cleft palate. Nuclear abundance of ZFHX3 increases during human brain development and neuronal differentiation in neural stem cells and SH-SY5Y cells, ZFHX3 interacts with the chromatin remodelling BRG1/Brm-associated factor complex and the cleavage and polyadenylation complex. In line with a role for chromatin remodelling, ZFHX3 haploinsufficiency associates with a specific DNA methylation profile in leukocyte-derived DNA. The target genes of ZFHX3 are implicated in neuron and axon development. In Drosophila melanogaster , z fh2, considered to be the ZFHX3 orthologue, is expressed in the third instar larval brain. Ubiquitous and neuron-specific knockdown of zfh2 results in adult lethality underscoring a key role for zfh2 in development and neurodevelopment. Interestingly, ectopic expression of zfh2 as well as ZFHX3 in the developing wing disc results in a thoracic cleft phenotype. Collectively, our data shows that loss-of-function variants in ZFHX3 are a cause of syndromic ID, that associates with a specific DNA methylation profile. Furthermore, we show that ZFHX3 participates in chromatin remodelling and mRNA processing.

CARD14 Signalling Ensures Cell Survival and Cancer Associated Gene Expression in Prostate Cancer Cells.

Prostate cancer (PCa) is one of the most common cancer types in men and represents an increasing global problem due to the modern Western lifestyle. The signalling adapter protein CARD14 is specifically expressed in epithelial cells, where it has been shown to mediate NF-κB signalling, but a role for CARD14 in carcinoma has not yet been described. By analysing existing cancer databases, we found that CARD14 overexpression strongly correlates with aggressive PCa in human patients. Moreover, we showed that CARD14 is overexpressed in the LNCaP PCa cell line and that knockdown of CARD14 severely reduces LNCaP cell survival. Similarly, knockdown of BCL10 and MALT1, which are known to form a signalling complex with CARD14, also induced LNCaP cell death. MALT1 is a paracaspase that mediates downstream signalling by acting as a scaffold, as well as a protease. Recent studies have already indicated a role for the scaffold function of MALT1 in PCa cell growth. Here, we also demonstrated constitutive MALT1 proteolytic activity in several PCa cell lines, leading to cleavage of A20 and CYLD. Inhibition of MALT1 protease activity did not affect PCa cell survival nor activation of NF-κB and JNK signalling, but reduced expression of cancer-associated genes, including the cytokine IL-6. Taken together, our results revealed a novel role for CARD14-induced signalling in regulating PCa cell survival and gene expression. The epithelial cell type-specific expression of CARD14 may offer novel opportunities for more specific therapeutic targeting approaches in PCa.