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The transcription factor GLI3 is a member of the GLI family and has been shown to be regulated by canonical hedgehog (HH) signaling through smoothened (SMO). Little is known about SMO-independent regulation of GLI3. Here, we identify TLR signaling as a novel pathway regulating GLI3 expression. We show that GLI3 expression is induced by LPS/TLR4 in human monocyte cell lines and peripheral blood CD14

Although the Sonic hedgehog (SHH) signaling pathway has been implicated in promoting malignant phenotypes of prostate cancer, details on how it is activated and exerts its oncogenic role during prostate cancer development and progression is less clear. Here, we show that GLI3, a key SHH pathway effector, is transcriptionally upregulated during androgen deprivation and posttranslationally stabilized in prostate cancer cells by mutation of speckle-type POZ protein (SPOP). GLI3 is a substrate of SPOP-mediated proteasomal degradation in prostate cancer cells and prostate cancer driver mutations in SPOP abrogate GLI3 degradation. Functionally, GLI3 is necessary and sufficient for the growth and migration of androgen receptor (AR)–positive prostate cancer cells, particularly under androgen-depleted conditions. Importantly, we demonstrate that GLI3 physically interacts and functionally cooperates with AR to enrich an AR-dependent gene expression program leading to castration-resistant growth of xenografted prostate tumors. Finally, we identify an AR/GLI3 coregulated gene signature that is highly correlated with castration-resistant metastatic prostate cancer and predictive of disease recurrence. Together, these findings reveal that hyperactivated GLI3 promotes castration-resistant growth of prostate cancer and provide a rationale for therapeutic targeting of GLI3 in patients with castration-resistant prostate cancer (CRPC). Implications: We describe two clinically relevant mechanisms leading to hyperactivated GLI3 signaling and enhanced AR/GLI3 cross-talk, suggesting that GLI3-specific inhibitors might prove effective to block prostate cancer development or delay CRPC.

BACKGROUND: GLI3 encodes a zinc finger transcription factor that plays a role in the sonic hedgehog pathway. Germline pathogenic GLI3 variants are associated with Greig cephalopolysyndactyly and Pallister-Hall syndromes, two syndromes involving brain malformation and polydactyly. METHODS: We identified patients with pathogenic GLI3 variants and brain malformations in the absence of polydactyly or other skeletal malformation. RESULTS: Two patients were identified. Patient #1 is a 4-year-old boy with hypotonia and global developmental delay. Brain MRI showed a focal cortical dysplasia, but he had no history of seizures. Genetic testing identified a de novo likely pathogenic GLI3 variant: c.4453A>T, p.Asn1485Tyr. Patient #2 is a 4-year-old boy with hypotonia, macrocephaly, and global developmental delay. His brain MRI showed partial agenesis of the corpus callosum, dilatation of the right lateral ventricle, and absent hippocampal commissure. Genetic testing identified a de novo pathogenic GLI3 variant: c.4236_4237del, p.Gln1414AspfsTer21. Neither patient had polydactyly or any apparent skeletal abnormality. CONCLUSIONS: These patients widen the spectrum of clinical features that may be associated with GLI3 pathogenic variants to include hypotonia, focal cortical dysplasia, and other brain malformations, in the absence of apparent skeletal malformation. Further study is needed to determine if GLI3 pathogenic variants are a more common cause of focal cortical dysplasia or corpus callosum agenesis than presently recognized.

RESEARCH QUESTION: Are glioma-associated oncogene homolog 1, 2, and 3 (GLI1, 2, and 3) and protein patched homolog 1 (PTCH1) specific markers for precursor theca cells in human ovaries as in mouse ovaries? DESIGN: To study the GDF9-HH-GLI pathway and assess whether GLI1 and 3 and PTCH1 are specific markers for precursor theca cells in the human ovary, growth differentiation factor 9 (GDF9), Indian Hedgehog (IHH), Desert Hedgehog (DHH), Sonic Hedgehog (SHH), PTCH1 and GLI1, 2 and 3 were investigated in fetal (n=9), prepubertal (n=9), reproductive-age (n=15), and postmenopausal (n=8) human ovarian tissue. Immunohistochemistry against GDF9, IHH, DHH, SHH, PTCH1, GLI1, GLI2, and GLI3 was performed on human ovarian tissue sections fixed in 4% formaldehyde and embedded in paraffin. Western blotting was carried out on extracted proteins from the same samples used in the previous step to prove the antibodies’ specificity. The quantitative real-time polymerase chain reaction was performed to identify mRNA levels for Gdf9, Ihh, Gli1, Gli2, and Gli3 in menopausal ovaries. RESULTS: Our results showed that, in contrast to mice, all studied proteins were expressed in primordial follicles of fetal, prepubertal, and reproductive-age human ovaries and stromal cells of reproductive-age and postmenopausal ovaries. Intriguingly, Gdf9, Ihh, and Gli3 mRNA, but not Gli1 and 2, was detected in postmenopausal ovaries. Moreover, GLI1, GLI3, and PTCH1 are not limited to a specific population of cells. They were spread throughout the organ, which means they are not specific markers for precursor theca cells in human ovaries. CONCLUSION: These results could provide a basis for understanding how this pathway modulates follicle development and ovarian cell steroidogenesis in human ovaries. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10815-021-02161-w.

Glioma-associated oncogene homolog 3 (GLI3), whose main function is to inhibit GLI1, has been associated with neuronal differentiation in medulloblastoma. However, it is not clear what molecular subtype(s) show increased GLI3 expression. GLI3 levels were assessed by immunohistochemistry in 2 independent cohorts, including a total of 88 cases, and found to be high in both WNT- and SHH-activated medulloblastoma. Analysis of bulk mRNA expression data and single cell RNA sequencing studies confirmed that GLI1 and GLI3 are highly expressed in SHH-activated medulloblastoma, whereas GLI3 but not GLI1 is highly expressed in WNT-activated medulloblastoma. Immunohistochemical analysis has shown that GLI3 is expressed inside the neuronal differentiated nodules of SHH-activated medulloblastoma, whereas GLI1/2 are expressed in desmoplastic areas. In contrast, GLI3 is diffusely expressed in WNT-activated medulloblastoma, whereas GLI1 is suppressed. Our data suggest that GLI3 may be a master regulator of neuronal differentiation and morphology in these subgroups.

Purpose. The epithelial–mesenchymal transition (EMT) is a key hallmark of cancer which promotes malignant progression, especially during the process of cancer invasion. A better understanding of EMT will help elucidate the molecular mechanism underlying colorectal cancer (CRC) metastasis and may provide new insights into the identification of potential biomarkers and therapeutic targets. Methods. A series of bioinformatic approaches were combined and identify GLI3 as a potential key regulator in EMT. In vitro experiments were performed to knockdown GLI3 expression in two CRC cell lines and to reveal the oncogenic role of GLI3 in CRC. qRT-PCR and western blot were performed to show the influence of GLI3 in EMT and downstream pathways. The Kaplan-Meier analysis and log-rank test were used to evaluate the prognostic value of GLI3 in CRC patients. Results. GLI3 was identified as a key regulator in coexpression and protein-protein interaction (PPI) networks involved in EMT. Bioinformatic analyses indicated that GLI3 had a high correlation with EMT markers in CRC. In vitro experiments showed that GLI3 knockdown attenuated the migratory and invasive capacities of CRC cells via influencing EMT property, especially by regulating phosphorylation of ERK signaling pathway. In addition, higher expression of GLI3 predicts worse prognosis in CRC patients. Conclusions. In summary, we presented the first evidence that GLI3 could promote the migratory and invasive capacities of CRC cells by regulating the EMT process. Our study might provide some useful clues to a better understanding of GLI3 in EMT during CRC progression.

Polydactyly is a common congenital malformation characterized by the presence of supernumerary fingers or toes. In this case study, we sought to identify the causative pathogenic factor in a family from a northern region of China affected by non-syndromic postaxial polydactyly (PAP).After recruiting a three-generation family with PAP, whole-exome sequencing was performed to identify the causative variant. In silico analysis and Sanger sequencing were used to validate the variant.We identified a novel heterozygous frameshift variant (NM_000168.6:c.4540delG, p.Asp1514Thrfs*5) in the transcriptional activator (TA1) domain of the GLI3 gene.The novel frameshift variant identified in this study further confirms the relationship between non-syndromic PAP and GLI3 and extends the previously established mutational and phenotypic spectra of GLI3.

Purpose Thyroid hemiagenesis (THA) is an inborn absence of one thyroid lobe of largely unknown etiopathogenesis, affecting 0.05–0.5% population. The aim of the study was an identification of genetic factors responsible for thyroid maldevelopment in two siblings with THA. Methods We evaluated a three-generation THA family with two sisters presenting the disorder. Proband (Patient II:3) was diagnosed at the age of 45 due to neck asymmetry. Left lobe agenesis and nontoxic multinodular goiter were depicted. Proband’s sister (Patient II:6) was euthyroid, showed up at the age of 39 due to neck discomfort and left-sided THA was demonstrated. Affected individuals were subjected to whole-exome sequencing (WES) (Illumina, TruSeq Exome Kit) and all identified variants were evaluated for pathogenicity. Sanger sequencing was used to confirm WES data and check segregation among first-degree relatives. Results In both siblings, a compound heterozygous mutations NM_000168.6: c.[2179G>A];[4039C>A] (NP_000159.3: p.[Gly727Arg];[Gln1347Lys]) were identified in the GLI3 gene, affecting exon 14 and 15, respectively. According to the American College of Medical Genetics, variants are classified as of uncertain significance, and were found to be very rare (GnomAD MAF 0.007131 and 0.00003187). The segregation mapping and analysis of relatives indicated causativeness of compound heterozygosity. Conclusions We demonstrated for the first time a unique association of THA phenotype and the presence of compound heterozygous mutations p.[Gly727Arg];[Gln1347Lys] of GLI3 gene in two siblings.

The evolutionarily conserved hedgehog (Hh) pathway is essential for organogenesis and plays critical roles in postnatal tissue maintenance and renewal. A unique feature of the vertebrate Hh pathway is that signal transduction requires the primary cilium (PC) where major pathway components are dynamically enriched. These factors include smoothened (SMO) and patched, which constitute the core reception system for sonic hedgehog (SHH) as well as GLI transcription factors, the key mediators of the pathway. Here, we report biallelic loss-of-function variations in SMO in seven individuals from five independent families; these variations cause a wide phenotypic spectrum of developmental anomalies affecting the brain (hypothalamic hamartoma and microcephaly), heart (atrioventricular septal defect), skeleton (postaxial polydactyly, narrow chest, and shortening of long bones), and enteric nervous system (aganglionosis). Cells derived from affected individuals showed normal ciliogenesis but severely altered Hh-signal transduction as a result of either altered PC trafficking or abnormal activation of the pathway downstream of SMO. In addition, Hh-independent GLI2 accumulation at the PC tip in cells from the affected individuals suggests a potential function of SMO in regulating basal ciliary trafficking of GLI2 when the pathway is off. Thus, loss of SMO function results in abnormal PC dynamics of key components of the Hh signaling pathway and leads to a large continuum of malformations in humans.

The Indian hedgehog (IHH) signaling pathway is an important pathway for bone growth and development. The aim of the present study was to examine the role of the IHH signaling pathway in the development of the ossification of ligamentum flavum (OLF) at the cellular and tissue levels. The expression levels and localization of the osteogenic genes Runt-related transcription factor 2 (RUNX2), Osterix, alkaline phosphatase (ALP), osteocalcin (OCN) and IHH were evaluated in OLF tissues by reverse transcription-quantitative PCR (RT-qPCR) and immunohistochemistry. Non-ossified ligamentum flavum (LF) sections were used as control samples. The tissue explant method was used to obtain cultured LF cells. In addition, OLF cells were subjected to cyclic stretch application for 0, 6, 12 or 24 h. The expression levels of osteogenic genes, and the IHH signaling pathway genes IHH, Smoothened (SMO), GLI family zinc finger 1 (GLI1), GLI2 and GLI3 were evaluated with RT-qPCR and western blotting. Osteogenic differentiation was further evaluated by assessing ALP activity and staining. Moreover, the effect of cyclopamine (Cpn), an IHH signaling inhibitor, on osteogenic differentiation was examined. The RT-qPCR and immunohistochemical results indicated that the mRNA and protein expression levels of RUNX2, Osterix, ALP, OCN and IHH were significantly higher in the OLF group compared with the LF group. Furthermore, application of cyclic stretch to OLF cells resulted in greater ALP activity, and significant increases in mRNA and protein expression levels of RUNX2, Osterix, ALP and OCN in a time-d00ependent manner. Cyclic stretch application also led to significant increases in IHH signaling pathway genes, including IHH, SMO, GLI1 and GLI2, while no significant effect was found on GLI3 expression level. In addition, it was found that Cpn significantly reversed the effect of cyclic stretch on the ALP activity, and the expression levels of RUNX2, Osterix, ALP, OCN, GLI1 and GLI2. Collectively, the present results suggested that the IHH signaling pathway may mediate the effect of cyclic stretch on the OLF cells.

Objectives:In December 2019, a new type of coronavirus, called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), appeared in Wuhan, China. Serious outbreaks of coronavirus disease 2019 (COVID-19), related to the SARS-CoV-2 virus, have occurred throughout China and the world. Therefore, we intend to shed light on its potential clinical and epidemiological characteristics.Methods:In this retrospective study, we included 50 confirmed fatal cases of SARS-CoV-2 reported on Chinese official media networks from January 16, 2020, to February 5, 2020. All the cases were confirmed by local qualified medical and health institutions. Specific information has been released through official channels. According to the contents of the reports, we recorded in detail the gender, age, first symptom date, death date, primary symptoms, chronic fundamental diseases, and other data of the patients, and carried out analyses and discussion.Results:In total, 50 fatal cases were reported: median age was 70 y old, and males were 2.33 times more likely to die than females. The median number of days from the first symptom to death was 13, and that length of time tended to be shorter among people aged 65 and older compared with those younger than 65 (12 days vs 17 days;P= 0.046). Therefore, the older patients had fewer number of days from the first symptom to death (r = -0.40;P= 0.012).Conclusions:In our study, we found that most of the deaths were elderly men with chronic fundamental diseases, and their COVID-19 progression to death time was shorter. At the same time, we demonstrated that older men are more likely to become infected with COVID-19, and the risk of death is positively correlated with age.

The transcription factor GLI3 is a member of the Hedgehog (Hh/HH) signaling pathway that can exist as a full length (Gli3-FL/GLI3-FL) or repressor (Gli3-R/GLI3-R) form. In response to HH activation, GLI3-FL regulates HH genes by targeting the GLI1 promoter. In the absence of HH signaling, GLI3 is phosphorylated leading to its partial degradation and the generation of GLI3-R which represses HH functions. GLI3 is also involved in tissue development, immune cell development and cancer. The absence ofGli3in mice impaired brain and lung development andGLI3mutations in humans are the cause of Greig cephalopolysyndactyly (GCPS) and Pallister Hall syndromes (PHS). In the immune system GLI3 regulates B, T and NK-cells and may be involved in LPS-TLR4 signaling. In addition, GLI3 was found to be upregulated in multiple cancers and was found to positively regulate cancerous behavior such as anchorage-independent growth, angiogenesis, proliferation and migration with the exception in acute myeloid leukemia (AML) and medulloblastoma where GLI plays an anti-cancerous role. Finally, GLI3 is a target of microRNA. Here, we will review the biological significance of GLI3 and discuss gaps in our understanding of this molecule.

GLI family zinc finger 3 (Gli3), as the upstream transcriptional activator of hedgehog signaling, has previously been demonstrated to participate in the process of liver fibrosis. The present study aimed to investigate the potential functions of microRNA (miR)‑200a and Gli3 in the progression of liver fibrosis. The expression levels of miR‑200a and Gli3 in cells and tissues were determined by PCR and western blotting; the interaction of Gli3 and miR‑200a was evaluated by bioinformatics analysis and dual‑luciferase reporter assay. miR‑200a was significantly reduced in serum samples from clinical patients, liver tissues of a carbon tetrachloride (CCl4)‑induced rat model and activated LX2 cells. The expression of α‑smooth muscle actin (α‑SMA) and albumin at the mRNA and protein levels was increased and decreased in LX2 cells, respectively. However, the expression levels of α‑SMA and albumin were reversed and Gli3 expression was markedly decreased in LX2 cells when transfected with miR‑200a mimics. In addition, the dual‑-luciferase reporter assay confirmed the target interaction between miR‑200a and Gli3. Finally, following the administration of miR‑200a mimics to CCl4‑induced rats, it was revealed that the alterations of α‑SMA, albumin and Gli3 presented a similar trend to that in LX2 cells with miR‑200a mimics transfection. Taken together, these results indicated that downregulation of miR‑200a might enhance the formation of liver fibrosis, probably by targeting Gli3, and elevated miR‑200a may attenuate the progression of liver fibrosis by suppressing Gli3. These findings suggested that miR‑200a may function as a novel anti‑fibrotic agent in liver fibrosis via inhibition of the expression of Gli3.

The purpose of this study was to determine the effects of Kinesin family member 3A (KIF3A) on primary cilia and myofibroblast differentiation during silicosis by regulating Sonic hedgehog (SHH) signalling. Methods: Changes in primary cilia during silicosis and myofibroblast differentiation were detected in silicotic patients, experimental silicotic rats, and a myofibroblast differentiation model induced by SiO2. We also explored the mechanisms underlying KIF3A regulation of Glioma-associated oncogene homologs (GLIs) involved in myofibroblast differentiation. Results: Primary cilia (marked by ARL13B and Ac-α-Tub) and ciliary-related proteins (IFT 88 and KIF3A) were increased initially and then decreased as silicosis progressed. Loss and shedding of primary cilia were also found during silicosis. Treatment of MRC-5 fibroblasts with silica and then transfection of KIF3A-siRNA blocked activation of SHH signalling, but increased GLI2FL as a transcriptional activator of SRF, and reduced the inhibitory effect of GLI3R on ACTA2. Conclusion: Our findings indicate that primary cilia are markedly altered during silicosis and the loss of KIF3A may promote myofibroblast differentiation induced by SiO2.

Polydactyly and syndactyly are congenital limb deformities, segregating in an autosomal-dominant fashion. The variants in the GLI3 gene are closely related to congenital limb malformations. However, the causes underlying polydactyly and syndactyly are not well understood.We conducted a whole-exome sequencing on two four-generation Chinese families with polydactyly and syndactyly. Then c.2374CT and c.1728CA mutant plasmids were transfected to HEK293T cells and mice limb bud cells to explore the functional consequences of these variants. Western blot and real-time quantitative PCR were used to analyze the expression of GLI3 and Shh.In these two families, the known GLI3 variant (NM_000168.6:c.2374CT) and the novel GLI3 variant (NM_000168.6:c.1728CA) contributed to polydactyly and syndactyly. Additionally, the GLI3 c.2374CT mutant plasmid led to truncated GLI3 protein, and the GLI3 c.1728CA mutant plasmid led to degraded GLI3 protein. Simultaneously, we demonstrated that the GLI3-mutant plasmids led to decreased Shh expression in mice limb bud cells.We demonstrated that the novel GLI3 variant (c.1728CA) and known GLI3 variant (c.2374CT) contributed to the malformations in two four-generation pedigrees with polydactyly and syndactyly by affecting SHH signaling.

Mutations in the embryonic ectoderm development (EED) cause Weaver syndrome, but whether and how EED affects embryonic brain development remains elusive. Here, we generated a mouse model in which Eed was deleted in the forebrain to investigate the role of EED. We found that deletion of Eed decreased the number of upper-layer neurons but not deeper-layer neurons starting at E16.5. Transcriptomic and genomic occupancy analyses revealed that the epigenetic states of a group of cortical neurogenesis-related genes were altered in Eed knockout forebrains, followed by a decrease of H3K27me3 and an increase of H3K27ac marks within the promoter regions. The switching of H3K27me3 to H3K27ac modification promoted the recruitment of RNA-Pol2, thereby enhancing its expression level. The small molecule activator SAG or Ptch1 knockout for activating Hedgehog signaling can partially rescue aberrant cortical neurogenesis. Taken together, we proposed a novel EED-Gli3-Gli1 regulatory axis that is critical for embryonic brain development.

Sonic Hedgehog/GLI3 signaling is critical in regulating digit number, such that Gli3-deficiency results in polydactyly and Shh-deficiency leads to digit number reductions. SHH/GLI3 signaling regulates cell cycle factors controlling mesenchymal cell proliferation, while simultaneously regulating Grem1 to coordinate BMP-induced chondrogenesis. SHH/GLI3 signaling also coordinates the expression of additional genes, however their importance in digit formation remain unknown. Utilizing genetic and molecular approaches, we identified HES1 as a downstream modifier of the SHH/GLI signaling axis capable of inducing preaxial polydactyly (PPD), required for Gli3-deficient PPD, and capable of overcoming digit number constraints of Shh-deficiency. Our data indicate that HES1, a direct SHH/GLI signaling target, induces mesenchymal cell proliferation via suppression of Cdkn1b, while inhibiting chondrogenic genes and the anterior autopod boundary regulator, Pax9. These findings establish HES1 as a critical downstream effector of SHH/GLI3 signaling in the development of PPD., Author summary Sonic Hedgehog/GLI3 signaling is critical in regulating digit number, such that Gli3-deficiency results in additional digits and Shh-deficiency leads to digit number reductions. SHH/GLI3 signaling within the developing limb regulates numerous genes critical for proper autopod (hand/foot) development, however not all target genes are known to be truly important for digit formation. Utilizing genetic and molecular approaches, we identified HES1 as a downstream modifier of the SHH/GLI signaling axis capable of inducing preaxial polydactyly (PPD), required for Gli3-deficient PPD, and capable of overcoming digit number constraints of Shh-deficiency. We further propose a mechanistic model by which HES1 coordinates the expression of genes important for proper digit development. These findings establish HES1 as a critical downstream effector of SHH/GLI3 signaling in the development of PPD.

Significance In this study, we show that the inactivation of the gli3 gene in medaka fish results in the formation of larger dorsal and paired fins. These mutant fins display multiple radial bones and fin rays which resemble polydactyly in Gli3-deficient mice. Our molecular and genetic analyses indicate that the size of fish fins is controlled by an ancient mechanism mediated by SHH-GLI signaling that appeared prior to the evolutionary appearance of paired fins. We also show that the key regulatory networks that mediate the expansion of digit progenitor cells in tetrapods were already in place in the fins of the last common ancestor between ray and lobe-finned fishes, suggesting an ancient similarity between distal fins and digits., One of the central problems of vertebrate evolution is understanding the relationship among the distal portions of fins and limbs. Lacking comparable morphological markers of these regions in fish and tetrapods, these relationships have remained uncertain for the past century and a half. Here we show that Gli3 functions in controlling the proliferative expansion of distal progenitors are shared among dorsal and paired fins as well as tetrapod limbs. Mutant knockout gli3 fins in medaka (Oryzias latipes) form multiple radials and rays, in a pattern reminiscent of the polydactyly observed in Gli3-null mutant mice. In limbs, Gli3 controls both anterior–posterior patterning and cell proliferation, two processes that can be genetically uncoupled. In situ hybridization, quantification of proliferation markers, and analysis of regulatory regions reveal that in paired and dorsal fins, gli3 plays a main role in controlling proliferation but not in patterning. Moreover, gli3 down-regulation in shh mutant fins rescues fin loss in a manner similar to how Gli3 deficiency restores digits in the limbs of Shh mutant mouse embryos. We hypothesize that the Gli3/Shh gene pathway preceded the origin of paired appendages and was originally involved in modulating cell proliferation. Accordingly, the distal regions of dorsal fins, paired fins, and limbs retain a deep regulatory and functional homology that predates the origin of paired appendages.

Emerging evidence demonstrates that lncRNAs play pivotal roles in tumor energy metabolism; however, the detailed mechanisms of lncRNAs in the regulation of tumor glycolysis remain largely unknown.The expression of SLC2A1-AS1 was investigated by TCGA, GEO dataset and qRT-PCR. The binding of GLI3 to SLC2A1-AS1 promoter was detected by Luciferase Reporter Assay System and Ago2-RIP assay. FISH was performed to determine the localization of SLC2A1-AS1 in ESCC cells. Double Luciferase Report assay was used to investigate the interaction of miR-378a-3p with SLC2A1-AS1 and Glut1. Gain-of-function and Loss-of-function assay were performed to dissect the function of SLC2A1-AS1/miR-378a-3p/Glut1 axis in ESCC progression in vitro and in vivo.We identified a novel lncRNA SLC2A1-AS1 in ESCC. SLC2A1-AS1 was frequently overexpressed in ESCC tissues and cells, and its overexpression was associated with TNM stage, lymph node metastasis and poor prognosis of ESCC patients. Importantly, GLI3 and SLC2A1-AS1 formed a regulatory feedback loop in ESCC cells. SLC2A1-AS1 promoted cell growth in vitro and in vivo, migration and invasion, and suppressed apoptosis, leading to EMT progression and increased glycolysis in ESCC cells. SLC2A1-AS1 functioned as ceRNA for sponging miR-378a-3p, resulting in Glut1 overexpression in ESCC cells. MiR-378a-3p inhibited cell proliferation and invasion as well as induced apoptosis, resulting in reduced glycolysis, which was partly reversed by SLC2A1-AS1 or Glut1 overexpression in ESCC cells.SLC2A1-AS1 plays important roles in ESCC development and progression by regulating glycolysis, and SLC2A1-AS1/miR-378a-3p/Glut1 regulatory axis may be a novel therapeutic target in terms of metabolic remodeling of ESCC patients.

Greig cephalopolysyndactyly syndrome (GCPS) is a rare genetic disorder (about 200 cases reported), characterized by macrocephaly, hypertelorism, and polysyndactyly. Most of the reported GCPS cases are the results of heterozygous loss of function mutations affecting the GLI3 gene (OMIM# 175700), while a small proportion of cases arise from large deletions on chromosome 7p14 encompassing the GLI3 gene. To our knowledge, only 6 patients have been reported to have a deletion with an exact size (given by genomic coordinates) and a gene content larger than 1 Mb involving the GLI3 gene. This report presents a patient with Greig cephalopolysyndactyly contiguous gene syndrome (GCP-CGS) diagnosed with a large, 18 Mb deletion on chromosome 7p14.2-p11.2. Similar cases are reviewed in the literature for a more accurate comparison between genotype and phenotype.

Chromatin remodeling and genomic alterations impact spatio-temporal regulation of gene expression, which is central to embryonic development. The analysis of mouse and chicken limb development provides important insights into the morphoregulatory mechanisms, however little is known about the regulatory differences underlying their morphological divergence. Here, we identify the underlying shared and species-specific epigenomic and genomic variations. In mouse forelimb buds, we observe striking synchrony between the temporal dynamics of chromatin accessibility and gene expression, while their divergence in chicken wing buds uncovers species-specific regulatory heterochrony. In silico mapping of transcription factor binding sites and computational footprinting establishes the developmental time-restricted transcription factor-DNA interactions. Finally, the construction of target gene networks for HAND2 and GLI3 transcriptional regulators reveals both conserved and species-specific interactions. Our analysis reveals the impact of genome evolution on the regulatory interactions orchestrating vertebrate limb bud morphogenesis and provides a molecular framework for comparative Evo-Devo studies., The vertebrate limb bud is a paradigm to uncover the fundamental mechanisms that govern embryogenesis and evolutionary diversification. Here the authors compare mouse and chicken limb bud development to study the impact of genome evolution on conserved and divergent gene regulatory interactions.

The ventricular–subventricular zone (V-SVZ) is a postnatal germinal niche. It holds a large population of neural stem cells (NSCs) that generate neurons and oligodendrocytes for the olfactory bulb and (primarily) the corpus callosum, respectively. These NSCs are heterogeneous and generate different types of neurons depending on their location. Positional identity among NSCs is thought to be controlled in part by intrinsic pathways. However, extrinsic cell signaling through the secreted ligand Sonic hedgehog (Shh) is essential for neurogenesis in both the dorsal and ventral V-SVZ. Here we used a genetic approach to investigate the role of the transcription factors GLI2 and GLI3 in the proliferation and cell fate of dorsal and ventral V-SVZ NSCs. We find that while GLI3 is expressed in stem cell cultures from both dorsal and ventral V-SVZ, the repressor form of GLI3 is more abundant in dorsal V-SVZ. Despite this high dorsal expression and the requirement for other Shh pathway members, GLI3 loss affects the generation of ventrally-, but not dorsally-derived olfactory interneurons in vivo and does not affect trilineage differentiation in vitro. However, loss of GLI3 in the adult dorsal V-SVZ in vivo results in decreased numbers of OLIG2-expressing progeny, indicating a role in gliogenesis.

Introduction and objectives Liver fibrosis is a major characteristic of most chronic liver diseases which leads to accumulation of extracellular matrix (ECM) proteins. Hedgehog (Hh) pathway activated by Gli genes participated in the pathogenesis of liver fibrosis. However, the regulatory role of miR-125b in liver fibrosis via targeting Gli genes remains unknown. Materials and methods RT-qPCR and western blot were employed to the expression levels of mRNA and protein, respectively. The fibrosis level of liver tissue was determined by Masson's trichrome staining. The interaction between miR-125b and Gli3 was tested by luciferase reporter assay. In addition, LX2 cells were activated and CCl4-induced rat model was used in this study. Results miR-125b was significantly declined in serum samples of the clinical liver fibrosis patient, activated LX2 cells and the liver tissues of the CCl4-induced rat model. Furthermore, in cellular level, the alpha-smooth muscle actin (α-SMA) and Albumin expressions were ascending and descending in LX2 cells, respectively, with the decline of miR-125b. However, when transfecting with miR-125b mimic, the expressions of α-SMA and Albumin was reversed and Gli3 expression was notably repressed in LX2 cells. The target interaction between miR-125b and Gli3 was determined by dual-luciferase assays. It was further discovered that the changes of α-SMA, Albumin, and Gli3 were similar to the expression trend in LX2 cells with miR-125b mimic transfection. Conclusion These results suggested that miR-125b might be protective against liver fibrosis via regulating Gli3 and it might be a promising target in the development of novel therapies to treat pathological fibrotic disorders.

Background Polydactyly is a phenotypically and genetically highly heterogeneous limb malformation with preaxial, postaxial, and central subtypes. The aim of this study was to identify genetically pathogenic factor in a Chinese nonsyndromic polydactyly family. Results Seven family members and 100 healthy controls were recruited, and the genetically pathogenic factor of the polydactyly family was investigated by targeted exome sequencing. Targeted exome sequencing revealed a novel frameshift mutation c.2148delA (p.Gln716Hisfs*17) of GLI3 in the family. This GLI3 variant was absent in 100 healthy controls and predicted to be highly damaging to the function of the GLI3 by causing half truncation of the protein. Conclusion This novel variant extended the mutational and phenotypic spectra of GLI3 and demonstrated the feasibility of targeted exome sequencing in clinical application of molecular diagnosis.

Inverse gradients of transcriptional repressors antagonize the transcriptional effector response to morphogens. However, the role of such inverse regulation might not manifest solely from lack of repressors. Sonic hedgehog (Shh) patterns the forebrain by being expressed ventrally; however, absence of antagonizing Gli3 repressor paradoxically cause insufficient pathway activation. Interestingly, lack of the primary cilia-localized G-protein-coupled receptor, Gpr161 increases Shh signaling in the mouse neural tube from coordinated lack of Gli3 repressor and Smoothened-independent activation. Here, by deleting Gpr161 in mouse neuroepithelial cells and radial glia at early mid-gestation we detected derepression of Shh signaling throughout forebrain, allowing determination of the pathophysiological consequences. Accumulation of cerebrospinal fluid (hydrocephalus) was apparent by birth, although usual causative defects in multiciliated ependymal cells or aqueduct were not seen. Rather, the ventricular surface was expanded (ventriculomegaly) during embryogenesis from radial glial overproliferation. Cortical phenotypes included polymicrogyria in the medial cingulate cortex, increased proliferation of intermediate progenitors and basal radial glia, and altered neocortical cytoarchitectonic structure with increased upper layer and decreased deep layer neurons. Finally, periventricular nodular heterotopia resulted from disrupted neuronal migration, while the radial glial scaffold was unaffected. Overall, suppression of Shh pathway during early mid-gestation prevents ventricular overgrowth, and regulates cortical gyration and neocortical/periventricular cytoarchitecture.

In Sonic hedgehog (SHH) signaling, GLI family zinc finger (GLI)-mediated diverse gene transcription outcomes are strictly regulated and are important for SHH function in both development and disease. However, how the GLI factors differentially regulate transcription in response to variable SHH activities is incompletely understood. Here, using a newly generated, tagged Gli3 knock-in mouse (Gli3(TAP)), we performed proteomic analyses and identified the chromatin-associated SAFB-like transcription modulator (SLTM) as a GLI-interacting protein that context-dependently regulates GLI activities. Using immunoprecipitation and immunoblotting, RT-quantitative PCR, and ChIP assays, we show that SLTM interacts with all three GLI proteins and that its cellular levels are regulated by SHH. We also found that SLTM enhances GLI3 binding to chromatin and increases GLI3 repressor (GLI3R) form protein levels. In a GLI3-dependent manner, SLTM promoted the formation of a repressive chromatin environment and functioned as a GLI3 co-repressor. In the absence of GLI3 or in the presence of low GLI3 levels, SLTM co-activated GLI activator (GLIA)-mediated target gene activation and cell differentiation. Moreover, in vivo Sltm deletion generated through CRISPR/Cas9-mediated gene editing caused perinatal lethality and SHH-related abnormal ventral neural tube phenotypes. We conclude that SLTM regulates GLI factor binding to chromatin and contributes to the transcriptional outcomes of SHH signaling via a novel molecular mechanism.

Proper Hedgehog (HH) signaling is essential for embryonic development, while aberrant HH signaling drives pediatric and adult cancers. HH signaling is frequently dysregulated in pancreatic cancer, yet its role remains controversial, with both tumor-promoting and tumor-restraining functions reported. Notably, the GLI family of HH transcription factors (GLI1, GLI2, GLI3), remain largely unexplored in pancreatic cancer. We therefore investigated the individual and combined contributions of GLI1-3 to pancreatic cancer progression. At pre-cancerous stages, fibroblast-specific Gli2/Gli3 deletion decreases immunosuppressive macrophage infiltration and promotes T cell infiltration. Strikingly, combined loss of Gli1/Gli2/Gli3 promotes macrophage infiltration, indicating that subtle changes in Gli expression differentially regulate immune infiltration. In invasive tumors, Gli2/Gli3 KO fibroblasts exclude immunosuppressive myeloid cells and suppress tumor growth by recruiting natural killer cells. Finally, we demonstrate that fibroblasts directly regulate macrophage and T cell migration through the expression of Gli-dependent cytokines. Thus, the coordinated activity of GLI1-3 directs the fibroinflammatory response throughout pancreatic cancer progression.

This study investigated the influences of EphA10 and Gli3 on breast cancer (BC) cell proliferation, invasion and migration. Immunohistochemistry was used to reveal the expressions of EphA10 and Gli3 in 18 intraductal carcinomas, 124 invasive carcinomas, 50 paracancerous tissues (2 cm away from the tumor, when possible or available), 50 lobular hyperplastic tissues and 30 normal breast tissues. qRT-PCR and Western blotting were applied to detect the expressions of EphA10 and Gli3 in invasive BC cells (MDA-MB-231, BT20 and Hs578T) and normal human mammary epithelial cells (MCF10A). MDA-MB-231 and BT20 cells were transfected with sh-EphA10, sh-Gli3 or sh-EphA10+sh-Gli3. CCK-8 was used to test the proliferation of transfected MDA-MB-231 and BT20 cells. Transwell and scratch assays were used for evaluation of invasion and migration of the transfected cells. EphA10 and Gli3 were highly expressed in invasive carcinomas and invasive BC cells. The expressions of EphA10 and Gli3 were associated with the clinicopathological characteristics and poor prognosis of patients with invasive BC. Knockdown of EphA10 or Gli3 suppressed activities of BC cells. Knockdown of both EphA10 and Gli3 was more effective than knockdown of Gli3 alone. Taken together, coexpression of EphA10 and Gli3 promotes BC cell proliferation, invasion and migration.

The Zic family of zinc finger transcription factors plays a critical role in multiple developmental processes. Using loss-of-function studies, we find that Zic5 is important for the differentiation of retinal pigmented epithelium (RPE) and the rod photoreceptor layer through suppressing Hedgehog (Hh) signaling. Further, Zic5 interacts with the critical Hh signaling molecule, Gli3, through the zinc finger domains of both proteins. This Zic5-Gli3 interaction disrupts Gli3/Gli3 homodimerization, resulting in Gli3 protein stabilization via a reduction in Gli3 ubiquitination. During embryonic Hh signaling, the activator form of Gli is normally converted to a repressor form through proteosome-mediated processing of Gli3, and the ratio of Gli3 repressor to full-length (activator) form of Gli3 determines the Gli3 repressor output required for normal eye development. Our results suggest Zic5 is a critical player in regulating Gli3 stability for the proper differentiation of RPE and rod photoreceptor layer during Xenopus eye development.

Loss of function variants of GLI3 are associated with a variety of forms of polysyndactyly: Pallister-Hall syndrome (PHS), Greig-Cephalopolysyndactyly syndrome (GCPS), and isolated polysyndactyly (IPD). Variants affecting the N-terminal and C-terminal thirds of the GLI3 protein have been associated with GCPS, those within the central third with PHS. Cases of IPD have been attributed to variants affecting the C-terminal third of the GLI3 protein. In this study, we further investigate these genotype-phenotype correlations. Sequencing of GLI3 was performed in patients with clinical findings suggestive of a GLI3-associated syndrome. Additionally, we searched the literature for reported cases of either manifestation with mutations in the GLI3 gene. Here, we report 48 novel cases from 16 families with polysyndactyly in whom we found causative variants in GLI3 and a review on 314 previously reported GLI3 variants. No differences in location of variants causing either GCPS or IPD were found. Review of published data confirmed the association of PHS and variants affecting the GLI3 protein's central third. We conclude that the observed manifestations of GLI3 variants as GCPS or IPD display different phenotypic severities of the same disorder and propose a binary division of GLI3-associated disorders in either PHS or GCPS/polysyndactyly.

The hippocampus is a brain area central for cognition. Mutations in the human SOX2 transcription factor cause neurodevelopmental defects, leading to intellectual disability and seizures, together with hippocampal dysplasia. We generated an allelic series of Sox2 conditional mutations in mouse, deleting Sox2 at different developmental stages. Late Sox2 deletion (from E11.5, via Nestin-Cre) affects only postnatal hippocampal development; earlier deletion (from E10.5, Emx1-Cre) significantly reduces the dentate gyrus (DG), and the earliest deletion (from E9.5, FoxG1-Cre) causes drastic abnormalities, with almost complete absence of the DG. We identify a set of functionally interconnected genes (Gli3, Wnt3a, Cxcr4, p73 and Tbr2), known to play essential roles in hippocampal embryogenesis, which are downregulated in early Sox2 mutants, and (Gli3 and Cxcr4) directly controlled by SOX2; their downregulation provides plausible molecular mechanisms contributing to the defect. Electrophysiological studies of the Emx1-Cre mouse model reveal altered excitatory transmission in CA1 and CA3 regions.

Development of the forebrain critically depends on the Sonic Hedgehog (Shh) signaling pathway, as illustrated in humans by the frequent perturbation of this pathway in holoprosencephaly, a condition defined as a defect in the formation of midline structures of the forebrain and face. The Shh pathway requires functional primary cilia, microtubule-based organelles present on virtually every cell and acting as cellular antennae to receive and transduce diverse chemical, mechanical or light signals. The dysfunction of cilia in humans leads to inherited diseases called ciliopathies, which often affect many organs and show diverse manifestations including forebrain malformations for the most severe forms. The purpose of this review is to provide the reader with a framework to understand the developmental origin of the forebrain defects observed in severe ciliopathies with respect to perturbations of the Shh pathway. We propose that many of these defects can be interpreted as an imbalance in the ratio of activator to repressor forms of the Gli transcription factors, which are effectors of the Shh pathway. We also discuss the complexity of ciliopathies and their relationships with forebrain disorders such as holoprosencephaly or malformations of cortical development, and emphasize the need for a closer examination of forebrain defects in ciliopathies, not only through the lens of animal models but also taking advantage of the increasing potential of the research on human tissues and organoids., This work was supported by funding to SSM from the Fondation pour la Recherche Médicale (Equipe FRM EQU201903007943) and from the Fondation ARC (PJA 20171206591).

Breast cancer continues to be a serious public health problem. The role of the hedgehog pathway in normal development of the mammary gland as well as in carcinogenesis and progression of breast cancer is the subject of intense investigation, revealing functional interactions with cell surface heparan sulfate. Nevertheless, its influence on breast cancer prognosis, and its relation to specific sulfation motifs in heparan sulfate have only been poorly studied in large patient cohorts. Using the public database KMplotter that includes gene expression and survival data of 3951 patients, we found that the higher expression of SHH, HHAT, PTCH1, GLI1, GLI2, and GLI3 positively influences breast cancer prognosis. Stratifying patients according to the expression of hormone receptors, histological grade, lymph node metastasis, and systemic therapy, we observed that GLI1, GLI2, and GLI3 expression, as well as co-expression of SHH and ELP1 were associated with worse relapse-free survival in patients with HER2-positive tumors. Moreover, GLI1 expression in progesterone receptor-negative tumors and GLI3 expression in grade 3 tumors correlated with poor prognosis. SHH, in a panel of cell lines representing different breast cancer subtypes, and HHAT, PTCH1, GLI1, GLI2, and GLI3 were mostly expressed in cell lines classified as HER2-positive and basal-like. Expression of SHH, HHAT, GLI2, and GLI3 was differentially affected by overexpression of the heparan sulfate sulfotransferases HS2ST1 and HS3ST2 in vitro. Although high HS2ST1 expression was associated with poor prognosis in KMplotter analysis, high levels of HS3ST2 were associated with a good prognosis, except for ER-positive breast cancer. We suggest the GLI transcription factors as possible markers for the diagnosis, treatment, and prognosis of breast cancer especially in HER2-positive tumors, but also in progesterone receptor-negative and grade-3 tumors. The pathway interaction and prognostic impact of specific heparan sulfate sulfotransferases provide novel perspectives regarding a therapeutical targeting of the hedgehog pathway in breast cancer.

Hedgehog signaling pathway has been previously elucidated to be inappropriately activated in many human cancers, including ovarian and breast cancer. However, mechanistic contribution of GLI3, one of the terminal effectors of the pathway, to ovarian and mammary cancer development is underexplored. In this study, we investigated whether GLI3 is necessary for the growth and migration of ovarian and breast cancer cells and further explored the underlying mechanism of GLI3-mediated oncogenesis. We report that GLI3 knockdown inhibited growth and migration of androgen receptor (AR)-positive ovarian and breast cancer cells, but not AR-negative ovarian and breast cancer cells. Furthermore, knockdown of AR expression was effective in inhibiting the growth and migration of AR-positive ovarian and breast cancer cells in the presence of GLI3, but not in GLI3 knockdown cells. Similarly, ectopic expression of AR promoted the growth and migration of AR-negative ovarian and breast cancer cells in the presence of GLI3, but not in GLI3 knockdown cells. GLI3 and AR co-immunoprecipitated each other. GLI3 expression was negatively associated with overall survival of ovarian or breast patients whose tumors expressed a high level of AR. Our findings suggest that GLI3 and AR not only physically interact, but also are mutually dependent for their malignancy-promoting activity in ovarian and breast cancer cells. GLI3-specific inhibitors may be novel therapeutics for AR-expressing ovarian and breast cancers.

Despite a common understanding that Gli TFs are utilized to convey a Hh morphogen gradient, genetic analyses suggest craniofacial development does not completely fit this paradigm. Using the mouse model (Mus musculus), we demonstrated that rather than being driven by a Hh threshold, robust Gli3 transcriptional activity during skeletal and glossal development required interaction with the basic helix-loop-helix TF Hand2. Not only did genetic and expression data support a co-factorial relationship, but genomic analysis revealed that Gli3 and Hand2 were enriched at regulatory elements for genes essential for mandibular patterning and development. Interestingly, motif analysis at sites co-occupied by Gli3 and Hand2 uncovered mandibular-specific, low-affinity, ‘divergent’ Gli-binding motifs (dGBMs). Functional validation revealed thesedGBMs conveyed synergistic activation of Gli targets essential for mandibular patterning and development. In summary, this work elucidates a novel, sequence-dependent mechanism for Gli transcriptional activity within the craniofacial complex that is independent of a graded Hh signal.