A multi-ancestry GWAS of Fuchs corneal dystrophy highlights the contributions of laminins, collagen, and endothelial cell regulation.

Fuchs endothelial corneal dystrophy (FECD) is a leading indication for corneal transplantation, but its molecular etiology remains poorly understood. We performed genome-wide association studies (GWAS) of FECD in the Million Veteran Program followed by multi-ancestry meta-analysis with the previous largest FECD GWAS, for a total of 3970 cases and 333,794 controls. We confirm the previous four loci, and identify eight novel loci: SSBP3, THSD7A, LAMB1, PIDD1, RORA, HS3ST3B1, LAMA5, and COL18A1. We further confirm the TCF4 locus in GWAS for admixed African and Hispanic/Latino ancestries and show an enrichment of European-ancestry haplotypes at TCF4 in FECD cases. Among the novel associations are low frequency missense variants in laminin genes LAMA5 and LAMB1 which, together with previously reported LAMC1, form laminin-511 (LM511). AlphaFold 2 protein modeling, validated through homology, suggests that mutations at LAMA5 and LAMB1 may destabilize LM511 by altering inter-domain interactions or extracellular matrix binding. Finally, phenome-wide association scans and colocalization analyses suggest that the TCF4 CTG18.1 trinucleotide repeat expansion leads to dysregulation of ion transport in the corneal endothelium and has pleiotropic effects on renal function.

ß-Catenin regulates ovarian granulosa cell cycle and proliferation in laying hens by interacting with TCF4.

Ovarian follicle development depends on the proliferation and differentiation of granulosa cells and is a complex biological process. The Wnt/ß-catenin signaling pathway can regulate ovarian follicle development, and ß-catenin, encoded by catenin beta 1 (CTNNB1), is the core component of this pathway. Although several studies of the mechanisms by which the Wnt/ß-catenin pathway regulates cell proliferation in humans and mammals have reported, it remains unclear how ß-catenin functions in poultry. To investigate the function of ß-catenin in laying hens' follicle development, we evaluated the effect of CTNNB1 on cell cycle, proliferation, and apoptosis in ovarian granulosa cells (GCs) isolated from laying hens. We demonstrated that CTNNB1 significantly affected the expression of cyclin D1 (CCND1) and v-myc avian myelocytomatosis viral oncogene homolog (c-Myc) (P < 0.01 and P < 0.05), key genes related to cell cycle and proliferation, to promote cell cycle progression from G1 to S phase, and thus accelerate granulosa cell proliferation. CTNNB1 did not however affect apoptosis or the expression of related genes baculoviral IAP repeat containing 5 (BIRC5) and BCL2 apoptosis regulator (Bcl-2). Overexpression of transcription factor 7-like 2 (TCF4) resulted in increased expression of CCND1, accelerated cell cycle progression, and granulosa cell proliferation. Direct physical interaction between ß-catenin and TCF4 was demonstrated by immunofluorescence and coimmunoprecipitation. The proliferation of granulosa cells was inhibited by silencing CCND1; overexpression of TCF4 in CCND1-silenced cells restored their proliferation rate to normal levels. These results indicate that the interaction of TCF4 and ß-catenin promotes CCND1 expression which in turn accelerates the cell cycle process of laying hen hierarchical follicular granulosa cells.

Clinical and genetic characterization of 47 Chinese pediatric patients with Pitt-Hopkins syndrome: a retrospective study.

BACKGROUND: Pitt-Hopkins syndrome (PTHS) is a neurodevelopmental disorder that remains underdiagnosed and its clinical presentations and mutation profiles in a diverse population are yet to be evaluated. This retrospective study aims to investigate the clinical and genetic characteristics of Chinese patients with PTHS. METHODS: The clinical, biochemical, genetic, therapeutic, and follow-up data of 47 pediatric patients diagnosed with PTHS between 2018 and 2021 were retrospectively analyzed. RESULTS: The Chinese PTHS patients presented with specific facial features and exhibited global developmental delay of wide severity range. The locus heterogeneity of the TCF4 gene in the patients was highlighted, emphasizing the significance of genetic studies for accurate diagnosis, albeit no significant correlations between genotype and phenotype were observed in this cohort. The study also reports the outcomes of patients who underwent therapeutic interventions, such as ketogenic diets and biomedical interventions. CONCLUSIONS: The findings of this retrospective analysis expand the phenotypic and molecular spectra of PTHS patients. The study underscores the need for a long-term prospective follow-up study to assess potential therapeutic interventions.

Effect of Octamer-Binding Transcription Factor 4 Overexpression on the Neural Induction of Human Dental Pulp Stem Cells.

Stem cell-based therapy is a potential alternative strategy for brain repair, with neural stem cells (NSC) presenting as the most promising candidates. Obtaining sufficient quantities of NSC for clinical applications is challenging, therefore alternative cell types, such as neural crest-derived dental pulp stem cells (DPSC), may be considered. Human DPSC possess neurogenic potential, exerting positive effects in the damaged brain through paracrine effects. However, a method for conversion of DPSC into NSC has yet to be developed. Here, overexpression of octamer-binding transcription factor 4 (OCT4) in combination with neural inductive conditions was used to reprogram human DPSC along the neural lineage. The reprogrammed DPSC demonstrated a neuronal-like phenotype, with increased expression levels of neural markers, limited capacity for sphere formation, and enhanced neuronal but not glial differentiation. Transcriptomic analysis further highlighted the expression of genes associated with neural and neuronal functions. In vivo analysis using a developmental avian model showed that implanted DPSC survived in the developing central nervous system and respond to endogenous signals, displaying neuronal phenotypes. Therefore, OCT4 enhances the neural potential of DPSC, which exhibited characteristics aligning with neuronal progenitors. This method can be used to standardise DPSC neural induction and provide an alternative source of neural cell types.

A TCF4-dependent gene regulatory network confers resistance to immunotherapy in melanoma.

To better understand intrinsic resistance to immune checkpoint blockade (ICB), we established a comprehensive view of the cellular architecture of the treatment-naive melanoma ecosystem and studied its evolution under ICB. Using single-cell, spatial multi-omics, we showed that the tumor microenvironment promotes the emergence of a complex melanoma transcriptomic landscape. Melanoma cells harboring a mesenchymal-like (MES) state, a population known to confer resistance to targeted therapy, were significantly enriched in early on-treatment biopsies from non-responders to ICB. TCF4 serves as the hub of this landscape by being a master regulator of the MES signature and a suppressor of the melanocytic and antigen presentation transcriptional programs. Targeting TCF4 genetically or pharmacologically, using a bromodomain inhibitor, increased immunogenicity and sensitivity of MES cells to ICB and targeted therapy. We thereby uncovered a TCF4-dependent regulatory network that orchestrates multiple transcriptional programs and contributes to resistance to both targeted therapy and ICB in melanoma.

Nanopore sequencing method for CTG18.1 expansion in TCF4 in late-onset Fuchs endothelial corneal dystrophy and a comparison of the structural features of cornea with first-degree relatives.

BACKGROUND: To evaluate the relationship between the number of trinucleotide repeats (TNR) in late-onset Fuchs corneal endothelial dystrophy (FCED) and to compare the endothelial properties of FCED, first-degree relatives, and controls. METHODS: Blood samples were collected from FCEDs to determine TNR number. The FCED patients, first-degree relatives, and controls were examined with specular microscopy for central corneal thickness (CCT), endothelial cell density (ECD), pleomorphism and polymegatism, and with corneal topography for specific indicators such as (i) displacement of thinnest point of cornea, (ii) loss of isopachs, (iii) focal posterior surface depression towards anterior chamber. RESULTS: This study included 92 patients with FCED, 92 first-degree relatives, and 96 controls. CCT was thickest in FCEDs (558.0 µm) (p < 0.05) while there was no difference between relatives (533.0 µm) and controls (530.4 µm) (p = 0.845). ECD was decreased in both FCED (2069.2 mm2) and relatives (2171.4 mm2) than controls (2822.9 mm2) (p < 0.05 in both). The presence of pleomorphism and polymegatism was significant in patients with FCED (93.4% and 93.4%, respectively), relatives (86.9% and 86.04%, respectively), and controls (8.33% and 1.04%, respectively) (p < 0.05). Specific topographic indicators differed among the groups (p < 0.05). The mean repeat number of the FCED patients was 17.48 ± 4.54 (12-25) times. The TNR number of FCED cases correlated with the relative CCT (p < 0.05, R = 0.615) and cell density (p = 0.009, R = -0.499). CONCLUSIONS: A strong association between the corneal endothelium in relatives and TNR number of FCEDs was defined. Relatives tended to have fewer corneal endothelial cells, even though they did not have clinical findings.

ß-catenin/TCF4-induced SCUBE3 upregulation promotes ovarian cancer development via HIF-1 signaling pathway.

The precise involvement and mechanistic role of the signal peptide-CUB-EGF-like domain-containing protein 3 (SCUBE3) in ovarian cancer (OV) remain poorly understood. Here, leveraging comprehensive data from the Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases, we unveil the selective overexpression of SCUBE3 in ovarian cancer tissues and cells. Intriguingly, elevated SCUBE3 expression levels correlate with an unfavorable prognosis in patients. Through meticulous manipulation of SCUBE3 expression, we elucidate its consequential impact on in vitro proliferation and invasion of ovarian cancer cells, as well as in vivo tumor growth in mice. Our multifaceted investigations, encompassing luciferase reporter assays, chromatin immunoprecipitation (ChIP) experiments, and mining of public databases, successfully identify SCUBE3 as a direct downstream target gene of TCF4-a pivotal positive regulator within the ß-catenin/TCF4 complex. Furthermore, utilizing a recessive mutant mouse line (kta41) harboring a functionally impaired point mutation at position 882 in the SCUBE3 gene, we uncover SCUBE3's involvement in the intricate regulation of angiogenesis and epithelial-mesenchymal transition (EMT). Strikingly, Spearman correlation coefficient analysis unveils a close association between SCUBE3 and HIF1A in OV, with SCUBE3 exerting tight control over HIF1A mRNA expression. Moreover, functional inhibition of HIF1A significantly impedes the pro-proliferative and invasive capabilities of SCUBE3-overexpressing ovarian cancer cells. Collectively, our findings underscore the pivotal role of SCUBE3 in driving ovarian cancer progression, shedding light on its intricate molecular mechanisms and establishing it as a potential therapeutic target for this devastating disease.

Pathogenic variants in SOX11 mimicking Pitt-Hopkins syndrome phenotype.

Pitt-Hopkins syndrome (PTHS) is a rare neurodevelopmental disorder characterised by severe intellectual disability (ID), distinctive facial features and autonomic nervous system dysfunction, caused by TCF4 haploinsufficiency. We clinically diagnosed with PTHS a 14 6/12 -year-old female, who had a normal status of TCF4. The pathogenic c.667del (p.Asp223MetfsTer45) variant in SOX11 was identified through whole exome sequencing (WES). SOX11 variants were initially reported to cause Coffin-Siris syndrome (CSS), characterised by growth restriction, moderate ID, coarse face, hypertrichosis and hypoplastic nails. However, recent studies have provided evidence that they give rise to a distinct neurodevelopmental disorder. To date, SOX11 variants are associated with a variable phenotype, which has been described to resemble CSS in some cases, but never PTHS. By reviewing both clinically and genetically 32 out of 82 subjects reported in the literature with SOX11 variants, for whom detailed information are provided, we found that 7/32 (22%) had a clinical presentation overlapping PTHS. Furthermore, we made a confirmation that overall SOX11 abnormalities feature a distinctive disorder characterised by severe ID, high incidence of microcephaly and low frequency of congenital malformations. Purpose of the present report is to enhance the role of clinical genetics in assessing the individual diagnosis after WES results.

Transcriptomic meta-analysis reveals ERRα-mediated oxidative phosphorylation is downregulated in Fuchs' endothelial corneal dystrophy.

BACKGROUND: Late-onset Fuchs' endothelial corneal dystrophy (FECD) is a degenerative disease of cornea and the leading indication for corneal transplantation. Genetically, FECD patients can be categorized as with (RE+) or without (RE-) the CTG trinucleotide repeat expansion in the transcription factor 4 gene. The molecular mechanisms underlying FECD remain unclear, though there are plausible pathogenic models proposed for RE+ FECD. METHOD: In this study, we performed a meta-analysis on RNA sequencing datasets of FECD corneal endothelium including 3 RE+ datasets and 2 RE- datasets, aiming to compare the transcriptomic profiles of RE+ and RE- FECD. Gene differential expression analysis, co-expression networks analysis, and pathway analysis were conducted. RESULTS: There was a striking similarity between RE+ and RE- transcriptomes. There were 1,184 genes significantly upregulated and 1,018 genes significantly downregulated in both RE+ and RE- cases. Pathway analysis identified multiple biological processes significantly enriched in both-mitochondrial functions, energy-related processes, ER-nucleus signaling pathway, demethylation, and RNA splicing were negatively enriched, whereas small GTPase mediated signaling, actin-filament processes, extracellular matrix organization, stem cell differentiation, and neutrophil mediated immunity were positively enriched. The translational initiation process was downregulated in the RE+ transcriptomes. Gene co-expression analysis identified modules with relatively distinct biological processes enriched including downregulation of mitochondrial respiratory chain complex assembly. The majority of oxidative phosphorylation (OXPHOS) subunit genes, as well as their upstream regulator gene estrogen-related receptor alpha (ESRRA), encoding ERRα, were downregulated in both RE+ and RE- cases, and the expression level of ESRRA was correlated with that of OXPHOS subunit genes. CONCLUSION: Meta-analysis increased the power of detecting differentially expressed genes. Integrating differential expression analysis with co-expression analysis helped understand the underlying molecular mechanisms. FECD RE+ and RE- transcriptomic profiles are much alike with the hallmark of downregulation of genes in pathways related to ERRα-mediated OXPHOS.

USP10 promotes the progression of triple-negative breast cancer by enhancing the stability of TCF4 protein.

Investigating the role of ubiquitin-specific peptidase 10 (USP10) in triple-negative breast cancer (TNBC). Analyzed USP10 expression levels in tumors using public databases. Detected USP10 mRNA and protein levels in cell lines. Examined USP10 expression in tumor tissues from breast cancer patients. Conducted USP10 knockdown experiments and analyzed changes in cell proliferation and metastasis. Confirmed protein-protein interactions with USP10 through mass spectrometry, Co-IP, and fluorescence experiments. Assessed impact of USP10 on transcription factor 4 (TCF4) ubiquitination and validated TCF4's influence on TNBC cells. We initially identified a pronounced overexpression of USP10 across multiple tumor types, including TNBC. Subsequently, we observed a conspicuous upregulation of USP10 expression levels in breast cancer cell lines compared to normal breast epithelial cells. However, upon subsequent depletion of USP10 within cellular contexts, we noted a substantial attenuation of malignant proliferation and metastatic potential in TNBC cells. In subsequent experimental analyses, we elucidated the physical interaction between USP10 and the transcription factor TCF4, whereby USP10 facilitated the deubiquitination modification of TCF4, consequently promoting its protein stability and contributing to the initiation and progression of TNBC. Collectively, this study demonstrates that USP10 facilitated the deubiquitination modification of TCF4, consequently promoting its protein stability and contributing to the initiation and progression of TNBC.

IFNγ synergies with cold atmospheric plasma in triggering colorectal cancer cell ferroptosis via the IFNγ/IFNR2/APC/TCF4/GPX4 axis.

Colorectal cancer accounts for the second most common cancer-related lethality. Intestinal stem cells are responsible for enteric homeostasis maintenance that, once being transformed, become colorectal cancer stem cells. Arresting cancer stemness represents an innovative strategy for colorectal cancer management. Using intestinal stem cell organoids as the primary model, we screened common inflammatory cytokines to identify key players targeting cancer stemness. We also explored the downstream signaling that drives the functionalities of the identified cytokine through both experimental investigations and computational predictions. As the results, we identified IFNγ as the key cytokine capable of arresting intestinal stem cells via the IFNγ/IFNGR2/APC/TCF4/GPX4 axis, proposed its role in killing colorectal cancer stem cells via triggering GPX4-dependent ferroptosis, and demonstrated its synergistic anti-cancer effect with cold atmospheric plasma in killing colorectal cancer cells that is worthy to be experimentally validated.

Evaluating Gene Expression and Methylation Profiles of TCF4, MBP, and EGR1 in Peripheral Blood of Drug-Free Patients with Schizophrenia: Correlations with Psychopathology, Intelligence, and Cognitive Impairment.

Discovery and validation of new, reliable diagnostic and predictive biomarkers for schizophrenia (SCZ) are an ongoing effort. Here, we assessed the mRNA expression and DNA methylation of the TCF4, MBP, and EGR1 genes in the blood of patients with SCZ and evaluated their relationships to psychopathology and cognitive impairments. Quantitative real-time PCR and quantitative methylation-specific PCR methods were used to assess the expression level and promoter DNA methylation status of these genes in 70 drug-free SCZ patients and 72 healthy controls. The correlation of molecular changes with psychopathology and cognitive performance of participants was evaluated. We observed downregulation of TCF4 and upregulation of MBP mRNA levels in SCZ cases, relative to controls in our study. DNA methylation status at the promoter region of TCF4 demonstrated an altered pattern in SCZ as well. Additionally, TCF4 mRNA levels were inversely correlated with PANSS and Stroop total errors and positively correlated with WAIS total score and working memory, consistent with previous studies by our group. In contrast, MBP mRNA level was significantly positively correlated with PANSS and Stroop total errors and inversely correlated with WAIS total score and working memory. These epigenetic and expression signatures can help to assemble a peripheral biomarker-based diagnostic panel for SCZ.

MPZL1 suppresses the cancer stem-like properties of lung cancer through ß-catenin/TCF4 signaling.

This study was designed to explore the influence of myelin protein zero-like protein 1 (MPZL1) on the stem-like properties of cancer cells and the underlying mechanism in lung adenocarcinoma. Real-time quantitative polymerase chain reaction (RT-qPCR) was utilized to evaluate mRNA expression level. CCK8, wound healing, and transwell assays were applied to assess cell proliferation, migration, and invasion. Tumorsphere-formation assay was utilized to assess cancer stem cell-like properties. LF3 was used to block the ß-catenin/Transcription factor 4 (TCF-4) signaling. Xenograft nude mouse model was conducted; tumor weight and volume were recorded. Western blot assay was utilized to detect the expression levels of CD44, CD133, ß-catenin, TCF-4, and MPZL1. Following MPZL1 knockdown, the mRNA expression levels of MPZL1, ß-catenin, and TCF-4 were inhibited, while the mRNA expression levels of the above genes were increased after the MPZL1 overexpression. MPZL1 knockdown suppressed cell proliferation, migration, and invasion, reduced the tumorsphere-formation capacity, and restrained the expression levels of CD44 and CD133. However, MPZL1 overexpression promoted the cell proliferation, migration, and invasion, enhanced the tumorsphere-formation capacity, and increased the expression levels of CD44 and CD133. Interestingly, LF3 treatment partially revised the effect of MPZL1 overexpression. These findings were further corroborated by in vivo experiments. We concluded that MPZL1 could suppress the lung adenocarcinoma cells' proliferation, migration, invasion, and lung cancer stem cells characteristics. The underlying mechanism is involved in the activation of ß-catenin/TCF-4 signaling.

Oridonin promotes endoplasmic reticulum stress via TP53-repressed TCF4 transactivation in colorectal cancer.

BACKGROUND: The incidence of colorectal cancer and cancer death rate are increasing every year, and the affected population is becoming younger. Traditional Chinese medicine therapy has a unique effect in prolonging survival time and improving the prognosis of patients with colorectal cancer. Oridonin has been reported to have anti-cancer effects in a variety of tumors, but the exact mechanism remains to be investigated. METHODS: Cell Counting Kit-8 assay (CCK8) and 5-Ethynyl-2'-deoxyuridine (EdU) staining assay, Tranwell, and Wound healing assays were performed to measure cell proliferation, invasion, and migration capacities, respectively. The protein and mRNA expression levels of various molecules were reflected by Western blot and Reverse Transcription quantitative Polymerase Chain Reaction (qRT-PCR). Transcription Factor 4 (TCF4) and its target genes were analyzed by Position Weight Matrices (PWMs) software and the Gene Expression Omnibus (GEO) database. Immunofluorescence (IF) was performed to visualize the expression and position of Endoplasmic Reticulum (ER) stress biomarkers. The morphology of the ER was demonstrated by the ER tracker-red. Reactive Oxygen Species (ROS) levels were measured using a flow cytometer (FCM) or fluorescent staining. Calcium ion (Ca2+) concentration was quantified by Fluo-3 AM staining. Athymic nude mice were modeled with subcutaneous xenografts. RESULTS: Oridonin inhibited the proliferation, invasion, and migration of colorectal cancer, and this effect was weakened in a concentration-dependent manner by ER stress inhibitors. In addition, oridonin-induced colorectal tumor cells showed increased expression of ER stress biomarkers, loose morphology of ER, increased vesicles, and irregular shape. TCF4 was identified as a regulator of ER stress by PWMs software and GEO survival analysis. In vitro and in vivo experiments confirmed that TCF4 inhibited ER stress, reduced ROS production, and maintained Ca2+ homeostasis. In addition, oridonin also activated TP53 and inhibited TCF4 transactivation, further exacerbating the elevated ROS levels and calcium ion release in tumor cells and inhibiting tumorigenesis in colorectal cancer cells in vivo. CONCLUSIONS: Oridonin upregulated TP53, inhibited TCF4 transactivation, and induced ER stress dysregulation in tumor cells, promoting colorectal cancer cell death. Therefore, TCF4 may be one of the important nodes for tumor cells to regulate ER stress and maintain protein synthesis homeostasis. And the inhibition of the TP53/TCF4 axis plays a key role in the anti-cancer effects of oridonin.

LNP-miR-155 cy5 Inhibitor Regulates the Copper Transporter via the ß-Catenin/TCF4/SLC31A1 Signal for Colorectal Cancer Therapy.

Lipid nanoparticle (LNP) delivery systems are widely used in the delivery of small-molecule drugs and nucleic acids. In this study, we prepared LNP-miR-155 by lipid nanomaterial technology and investigated the effects of LNP-miR-155 on ß-catenin/transcription factor 4 (TCF4)/solute carrier family 31 member 1/copper transporter 1 (SLC31A1/CTR1) signaling and copper transport in colorectal cancer. For this, we used an LNP-miR-155 cy5 inhibitor and LNP-miR-155 cy5 mimics for the transfection of HT-29/SW480 cells. The transfection efficiency and uptake efficiency were detected by immunofluorescence. Relevant cell assays confirmed that the LNP-miR-155 cy5 inhibitor mediates the regulation of copper transport through the ß-catenin/TCF4/SLC31A1 axis. The LNP-miR-155 cy5 inhibitor reduced cell proliferation, migration, and colony formation and promoted cell apoptosis. We also confirmed that miR-155 downregulates HMG box-containing protein 1 (HBP1) and adenomatous polyposis coli (APC) in cells and activates the function of ß-catenin/TCF4 signaling. In addition, we found that the copper transporter, SLC31A1, is highly expressed in colorectal cancer cells. Furthermore, we also found that the complex ß-catenin/TCF4 promotes the transcription of SLC31A1 by binding to its promoter region, which sustains the transport of copper from the extracellular region to the intracellular region and increases the activities of Cu2+-ATPase and superoxide dismutase (SOD). In summary, the LNP-miR-155 cy5 inhibitor regulates ß-catenin/TCF4 by downregulating SLC31A1-mediated copper transport and intracellular copper homeostasis.

The TCF4 Trinucleotide Repeat Expansion of Fuchs' Endothelial Corneal Dystrophy: Implications for the Anterior Segment of the Eye.

Purpose: In the United States, 70% of Fuchs' endothelial corneal dystrophy (FECD) cases are caused by an intronic trinucleotide repeat expansion in the TCF4 gene. CUG repeat RNA transcripts from this expansion accumulate as nuclear foci in the corneal endothelium. In this study, we sought to detect foci in other anterior segment cell types and assess their molecular impact. Methods: We examined CUG repeat RNA foci appearance, expression of downstream affected genes, gene splicing, and TCF4 RNA expression in corneal endothelium, corneal stromal keratocytes, corneal epithelium, trabecular meshwork cells, and lens epithelium. Results: CUG repeat RNA foci, the hallmark of FECD in corneal endothelium (found in 84% of endothelial cells), are less detectable in trabecular meshwork cells (41%), much less prevalent in stromal keratocytes (11%) or corneal epithelium (4%), and absent in lens epithelium. With few exceptions including mis-splicing in the trabecular meshwork, differential gene expression and splicing changes associated with the expanded repeat in corneal endothelial cells are not observed in other cell types. Expression of the TCF4 transcripts including full-length isoforms containing the repeat sequence at the 5' end is much higher in the corneal endothelium or trabecular meshwork than in the corneal stroma or corneal epithelium. Conclusions: Expression of the CUG repeat containing TCF4 transcripts is higher in the corneal endothelium, likely contributing to foci formation and the large molecular and pathologic impact on those cells. Further studies are warranted to examine any glaucoma risk and impact of the observed foci in the trabecular meshwork of these patients.

SUMO1 degrader induces ER stress and ROS accumulation through deSUMOylation of TCF4 and inhibition of its transcription of StarD7 in colon cancer.

Small molecule degraders of small ubiquitin-related modifier 1 (SUMO1) induce SUMO1 degradation in colon cancer cells and inhibits the cancer cell growth; however, it is unclear how SUMO1 degradation leads to the anticancer activity of the degraders. Genome-wide CRISPR-Cas9 knockout screen has identified StAR-related lipid transfer domain containing 7 (StarD7) as a critical gene for the degrader's anticancer activity. Here, we show that both StarD7 mRNA and protein are overexpressed in human colon cancer and its knockout significantly reduces colon cancer cell growth and xenograft progression. The treatment with the SUMO1 degrader lead compound HB007 reduces StarD7 mRNA and protein levels and increases endoplasmic reticulum (ER) stress and reactive oxygen species (ROS) production in colon cancer cells and three-dimensional (3D) organoids. The study further provides a novel mechanism of the compound anticancer activity that SUMO1 degrader-induced decrease of StarD7 occur through degradation of SUMO1, deSUMOylation and degradation of T cell-specific transcription 4 (TCF4) and thereby inhibition of its transcription of StarD7 in colon cancer cells, 3D organoids and patient-derived xenografts (PDX).

[Genetic analysis of a child with Pitt-Hopkins syndrome due to a novel variant of TCF4 gene derived from low percentage maternal mosaicism].

OBJECTIVE: To explore the genetic etiology of a child with Pitt-Hopkins syndrome. METHODS: A child who had presented at the Medical Genetics Center of Gansu Provincial Maternal and Child Health Care Hospital on February 24, 2021 and his parents were selected as the study subjects. Clinical data of the child was collected. Genomic DNA was extracted from peripheral blood samples of the child and his parents and subjected to trio-whole exome sequencing (trio-WES). Candidate variant was verified by Sanger sequencing. Karyotype analysis was also carried out for the child, and her mother was subjected to ultra-deep sequencing and prenatal diagnosis upon her subsequent pregnancy. RESULTS: The clinical manifestations of the proband included facial dysmorphism, Simian crease, and mental retardation. Genetic testing revealed that he has carried a heterozygous c.1762C>T (p.Arg588Cys) variant of the TCF4 gene, for which both parents had a wild-type. The variant was unreported previously and was rated as likely pathogenic based on the guidelines of the American College of Medical Genetics and Genomics (ACMG). Ultra-deep sequencing indicated that the variant has a proportion of 2.63% in the mother, suggesting the presence of low percentage mosaicism. Prenatal diagnosis of amniotic fluid sample suggested that the fetus did not carry the same variant. CONCLUSION: The heterozygous c.1762C>T variant of the TCF4 gene probably underlay the disease in this child and has derived from the low percentage mosaicism in his mother.