Mutations In P63 Gene Research Articles

Barrett’s esophagus: genetic features

The aimof the study was to evaluate the genetic characteristics of the pathological process in patients with biopsy-proven PB.Materials and methods:Dynamic observation and treatment of patients with morphologically confi rmed diagnosis of Barrett’s esophagus (PB) was performed at the Bank of Russia Multidisciplinary medical center in Moscow in the period from 2014 to 2019.the study included 52 patients. Among them, men — 33 (63.4%) and women –19 (36.5%) aged from 28 to 70 years, the peak incidence was mainly in the age range from 50–71 years. As a result, morphological types of PB epithelium were identifi ed at the time of the study: cardiac — 8(15.3%), small — bowel — 25 (48%), large-bowel without dysplasia-17 (32.6%) and large-bowel with mild dysplasia foci –2 (3.8%). The expression of the p53, P63, and Ki-67 genes responsible for cell proliferation and diff erentiation was studied using an immunohistochemical method.Results.As a result of the study, it was found that genetic changes in patients with morphologically confi rmed PB increase from the cardiac type of epithelium in the segment to the detection of dysplasia foci on the background of colonic metaplasia. An exception is tokokishechnaya metaplasia, which may be an indirect sign of the development of highly diff erentiated epithelium in response to gastroesophageal or duodenogastroesophageal refl uxSummary.1. Mutation of the p 53 genes responsible for regulating cell transcription and activating apoptosis and the P63 gene responsible for cell diff erentiation occurs in all morphological types of PB, with the number of mutations increasing as metastatic changes progress in accordance with the Correa cascade 2. The combination of p53 and P63 gene mutations in almost equal proportions indicates parallel processes of cell proliferation and diff erentiation disorders. 3. Ki-67 expression increases from the cardiac type of epithelium in the segment to the detection of dysplasia foci on the background of metaplastic epithelium. An exception is tokokishechnaya metaplasia, which may be an indirect sign of the development of highly diff erentiated epithelium in response to gastroesophageal or duodenogastroesophageal refl ux.Conclusion.Studies have shown that there are a number of genetic features of the pathological process in patients with morphologically confi rmed PB, the combination of which is more reliable and reliable assessment of the risk of neoplastic changes than individual indicators. To date, it remains relevant to develop a marker panel that is suitable for use in clinical practice, informative for both assessing individual risk and stratifying risk groups, and useful for monitoring the eff ectiveness of treatment.

Infrared meibography and molecular assessment of p63 gene mutations in a Mexican patient with EEC syndrome

Infrared meibography and molecular assessment of p63 gene mutations in a Mexican patient with EEC syndrome

OTX2 regulates the expression of TAp63 leading to macular and cochlear neuroepithelium development.

OTX proteins, homologs of the Drosophila orthodenticle (Otd), are important for the morphogenesis of the neuroectoderm, and for the central nervous system formation. OTX1 and OTX2 are important for the cochlea and macula development, indeed when OTX1 is knocked down, these organs undergo developmental failure. Moreover OTX2 transfection revert this effect in OTX1(-/-) mice. The TA isoform of TP63, involved in Notch regulation pathway, has a critical function in the cochlear neuroepithelium differentiation. TAp63 positively regulates Hes5 and Atoh1 transcription. This pathway has been also demonstrated in p63(-/-) mice, and in patients p63 mutated, affected by Ectodermal Dysplasia (ED, OMIM 129810). These patients are affected by mild sensorineural deafness, most likely related to the mutation in p63 gene impairing the Notch pathway. We demonstrated the role of OTX2 on TAp63 regulation necessary for the correct formation of macular neuroepithelium and we confirmed the impairment of vestibular function caused by p63 mutations. Although the abnormalities found in our patient were still at a subclinical extent, aging could exacerbate this impairment and cause a decrease in quality of life.

P63-dependent and independent mechanisms of nectin-1 and nectin-4 regulation in the epidermis.

Nectins are immunoglobulin-like cell adhesion molecules mainly localized in adherens junctions. The transcription factor p63 is a master regulator of gene expression in stratified epithelia and controls several molecular processes. As mutations in the Pvrl1 and Pvrl4 genes encoding for nectins cause genetic disorders with phenotypes similar to p63-related syndromes, we investigated whether these proteins might be under p63 transcriptional control. Here, we show that in p63-null skin, Pvrl1 gene expression is strongly reduced, whereas Pvrl4 expression is unaffected. In human and mouse primary keratinocytes p63 depletion leads to a specific downregulation of the Pvrl1 gene. Consistent with a direct regulation, chromatin immunoprecipitation experiments (ChIP) indicate that p63 binds to two conserved intronic Pvrl1 enhancer regions. Ankyloblepharon–ectodermal defects–cleft lip/palate (AEC) syndrome is a rare autosomal dominant disorder, caused by mutations in p63 gene, mainly characterized by skin fragility. To test whether nectins may be affected in AEC syndrome, their expression was measured in keratinocytes obtained from patients with AEC or from a conditional mouse model for AEC syndrome. Pvrl1 expression was reduced in AEC keratinocytes, consistent with impaired p63 function. Surprisingly, Pvrl4 expression was similarly affected, in parallel with decreased expression of the transcription factor Irf6. Consistent with the well-characterized role of Irf6 in keratinocyte differentiation and its strong downregulation in AEC syndrome, Irf6 depletion caused reduced expression of Pvrl4 in wild-type keratinocytes. Taken together, our results indicate that Pvrl1 is a bona fide target gene of the transcription factor p63, whereas Pvrl4 regulation is linked to epidermal differentiation and is under Irf6 control.

Gene p63: In ectrodactyly-ectodermal dysplasia clefting, ankyloblepharon-ectodermal dysplasia, Rapp-Hodgkin syndrome

Introduction:An analysis was made of three different syndromes associated with p63 gene mutations, known as ectrodactyly–ectodermal dysplasia-clefting syndrome (EEC), ankyloblepharon–ectodermal dysplasia clefting syndrome (AEC or Hay–Wells) and Rapp–Hodgkin syndrome (RHS). The postoperative complications associated with their cleft reconstructions were also evaluated.Materials and Methods:Extensive demographic information, in particular of the clinical appearances, associated malformations, and the types and complications of the reconstructive surgical procedures, were recorded of these syndromic cases occurring in a database of 3621 facial cleft deformity patients. The data was analyzed using the Microsoft Excel program.Results:A total of 10 (0.28%) cases of p63 associated syndromes were recorded: EEC (6), RHS (3), and AEC (1). The following clinical cleft appearances were noted – EEC = 6: CLA 1 -right side unilateral (female); CLAP 4 – right side (1) + left side (1) unilateral (male + female); bilateral (2) (males); hPsP 1 (female) (divided in 3 Black, 2 White, 1 Indian); RHS = 3: CLAP 2 (White males); hPsP 1 (White female); AEC = 1: CLAP bilateral (White male). Other features of the syndromes were: skin, hand, foot, tooth, hair and nail involvement, and light sensitivity. Postoperative complications included: (i) stenosis of nasal opening, especially after reconstruction of the bilateral cleft lip and the columella lengthening (2 cases), (ii) premaxilla-prolabium fusion (2 cases), (iii) repeated occurrence of oro-nasal fistula in the hard palate (4 cases), and (iv) dysgnathial development of midfacial structures (3 cases).Discussion:Three different p63 associated syndromes (EEC, AEC, and RHS) were diagnosed (0.27% of the total facial cleft deformities database). The majority of the cases presented with a bilateral CLAP in males only. A number of females and males had unilateral CLA. The hPsP-cleft was recorded in females only. The associated ectodermal component most probably had a profoundly negative influence on postoperatively wound healing, which was observed in particular at the nasal openings, the premaxilla sulcus and in the hard palate mucosa. The reconstruction of p63 associated syndromes is a greater challenge than the usual cleft reconstruction to the surgeon.

Mutations in AEC syndrome skin reveal a role for p63 in basement membrane adhesion, skin barrier integrity and hair follicle biology

AEC (ankyloblepharon-ectodermal defects-clefting) syndrome is an autosomal dominant ectodermal dysplasia disorder caused by mutations in the transcription factor p63. Clinically, the skin is dry and often fragile; other features can include partial eyelid fusion (ankyloblepharon), hypodontia, orofacial clefting, sparse hair or alopecia, and nail dystrophy. To investigate how p63 gene mutations affect gene and protein expression in AEC syndrome skin. We performed microarray analysis on samples of intact and eroded AEC syndrome skin compared with control skin. Changes were verified by quantitative real-time reverse transcription-polymerase chain reaction and, for basal keratinocyte-associated genes, by immunohistochemistry and analysis of microdissected skin. We identified significant upregulation of six genes and downregulation of 69 genes in AEC syndrome skin, with the main changes in genes implicated in epidermal adhesion, skin barrier formation and hair follicle biology. There was reduced expression of genes encoding the basement membrane proteins FRAS1 and collagen VII, as well as the skin barrier-associated small proline-rich proteins 1A and 4, late cornified envelope protein 5A, hornerin, and lipid transporters including ALOX15B. Reduced expression of the hair-associated keratins 25, 27, 31, 33B, 34, 35, 81 and 85 was also noted. We also confirmed similar alterations in gene expression for 26 of the 75 genes in eroded AEC scalp skin. This study identifies specific changes in skin structural biology and signalling pathways that result from mutant p63 and provides new molecular insight into the AEC syndrome phenotype.

P63 and FGFR: when development meets proliferation.

See related article in EMBO Molecular Medicine http://dx.doi.org/10.1002/emmm.201100199 In a rich and comprehensive piece of work, Ferone et al report in this issue of EMBO Molecular Medicine the first mouse model of the AEC (Ankyloblepharon‐Ectodermal defects‐Cleft lip/palate, OMIM 106260) syndrome (Ferone et al, 2012). The mechanistic insights are of likely general relevance for a number of conditions resulting from deranged keratinocyte growth control, including cancer. AEC is part of a group of genetic syndromes with compromised skin development that go under the general name of ectodermal dysplasias (EDs). These are caused by mutations of genes with disparate functions, including transcription factors like p63. This close cousin of p53 plays a key role in ectodermal development as first demonstrated by the lack of stratified epithelia and their adnexa in mice with homozygous deletion of the gene. Importantly, no such alterations occur in mice with heterozygous p63 deletion, which are phenotypically normal. In the human population, at least five ED malformation syndromes have been linked to p63 gene mutations (Rinne et al, 2006). These are heterozygous missense mutations likely to cause the disorders by interfering with the function of wild type p63, which controls transcription by binding to DNA in a tetrameric form (Crum & McKeon, 2010). p63 can be produced in multiple isoforms as the result of transcription from two different promoters and differential splicing. The predominant p63 isoform expressed in stratified epithelia is ΔNp63α, which contains, in its C‐terminus region, asterile‐alpha‐motif (SAM) domain thought to be mediating interactions with other proteins and, possibly, lipid or RNA molecules (Crum & McKeon, 2010). The different ED syndromes result from p63 mutations that tend to cluster at different locations (Rinne et al, 2006). The AEC syndrome is mostly caused by mutations in the p63 …

Genotype-phenotype analysis of a Chinese family with split hand/split foot and syndactyly

To determine the causative gene mutation in a Chinese family with split hand/split foot malformation (SHFM) and explore the genotype-phenotype relationship. Genomic DNA was extracted from peripheral blood samples of the patients and their family members. Polymerase chain reaction (PCR) was performed to amplify all the exons of P63 gene and HOXD13 gene. Then the PCR products were sequenced bidirectionally to screen mutations. A heterozygous 956G>A transversion in exon 7 of P63 gene was identified in all patients, which resulted in the substitution of histidine residue for arginine at position 280 of P63 protein (R280H). This mutation was not found in the unaffected family members. Patients in this pedigree are characterized by symmetrical split hand and split foot with syndactyly. This condition is caused by the R280H mutation in P63 gene.

P63 (TP73L) a key player in embryonic urogential development with significant dysregulation in human bladder exstrophy tissue

Human bladder exstrophy-epispadias complex (BEEC) comprises a spectrum of urogenital anomalies in which part or all of the distal urinary tract fails to close. Several lines of evidence implicate genetic factors in the formation of BEEC. Among them a murine p63+/+ knockout model showed the full picture of classic exstrophy of the bladder and other urogenital defects within the BEEC spectrum. This led us to study in depth the role of p63 in urogenital development in mice and investigate the implication of p63 in human BEEC. Whole mount in situ analysis in mice was carried out to investigate the ventro-caudal expression of the p63 transcript at gestational days (GD) 9.5-12.5, the equivalent of human gestational weeks 4-6 (postulated time of BEEC organogenesis in humans). In addition, p63 expression analysis was performed in human blood and bladder derived samples of 15 BEEC newborns accompanied by sequencing analysis of their genomic DNA. We also conducted sequencing analysis of genomic DNA in additional 22 BEEC patients. In mouse embryos, p63 expression was detected at days 9.5-12.5 in the cloacal membrane and urethral epithelium, supporting its role in the morphogenesis of the external genitalia and the bladder. Tissue-specific expression of a novel and already-known mRNA isoforms were established and a reproducible dysregulation of variable p63 isoforms was observed in 11 of 15 patients indicating altered gene expression. However, no obvious p63 gene mutations were identified in any of the patients. Our findings strongly suggest that p63 is not only involved in embryonic formation of the urogenital and ventrocaudal anatomy but is also highly dysregulated in human BEEC bladder tissue. Since p63 has been shown to self-regulate its expression through a balance of its isoforms, the dysregulation observed may contribute to the formation of BEEC.

Rapp-Hodgkin syndrome and the tail of p63

We report the clinical and molecular abnormalities in a 19-year-old woman with Rapp-Hodgkin ectodermal dysplasia syndrome. The physical features include mid-facial hypoplasia, uncombable hair, cleft palate and bifid uvula, lacrimal duct obstruction and dry skin. Sequencing of the p63 gene reveals a new heterozygous frameshift mutation, 1787delG, in exon 14. The frameshift results in changes to the tail of p63 with the addition of 68 missense amino acids downstream and a delayed termination codon that extends the protein length by 21 amino acids. These changes are predicted to disrupt the normal repressive function of the transactivation inhibitory domain leading to gain-of-function for at least two isoforms of the p63 transcription factor. The expanding p63 mutation database demonstrates that there is overlap between Rapp-Hodgkin syndrome and several other ectodermal dysplasia syndromes, notably Hay-Wells syndrome, and that characterization of the functional consequences of these p63 gene mutations at a molecular and cellular level is likely to provide further insight into the clinical spectrum of these developmental malformation syndromes.

P63 gene mutations and human developmental syndromes.

The P63 gene is a recently discovered member of the p53 family. While P53 is ubiquitously expressed, p63 is expressed specifically in embryonic ectoderm and in the basal regenerative layers of epithelial tissues in the adult. Complete abrogation of P63 gene function in an animal model points to the relevance of P63 for the proper development of ectodermally derived tissues. The p63 knockout mouse dies at birth and has truncation of the limbs, as well as absence of epidermis, prostate, breast, and urothelial tissues, apparently reflecting ectodermal stem cell loss. A number of dominant human syndromes have been mapped to chromosome 3q27 and ultimately to mutations in the p63 gene. These syndromes have abnormal limb development and/or ectodermal dysplasia and include ectrodactyly, ectodermal dysplasia, clefting syndrome; ankyloblepharon, ectodermal dysplasia, clefting syndrome; acro-dermato-ungual-lacrimal-tooth syndrome; limb-mammary syndrome; as well as nonsyndromic split hand/foot malformation. The pattern of heterozygous mutations is distinct for each of these syndromes. Consistent with this syndrome-specific mutational pattern, the functional consequences of mutations on the p63 proteins also vary, invoking dominant-negative and gain-of-function mechanisms rather than a simple loss of function.

P63 Gene Mutations in EEC Syndrome, Limb-Mammary Syndrome, and Isolated Split Hand–Split Foot Malformation Suggest a Genotype-Phenotype Correlation

p63 mutations have been associated with EEC syndrome (ectrodactyly, ectodermal dysplasia, and cleft lip/palate), as well as with nonsyndromic split hand-split foot malformation (SHFM). We performed p63 mutation analysis in a sample of 43 individuals and families affected with EEC syndrome, in 35 individuals affected with SHFM, and in three families with the EEC-like condition limb-mammary syndrome (LMS), which is characterized by ectrodactyly, cleft palate, and mammary-gland abnormalities. The results differed for these three conditions. p63 gene mutations were detected in almost all (40/43) individuals affected with EEC syndrome. Apart from a frameshift mutation in exon 13, all other EEC mutations were missense, predominantly involving codons 204, 227, 279, 280, and 304. In contrast, p63 mutations were detected in only a small proportion (4/35) of patients with isolated SHFM. p63 mutations in SHFM included three novel mutations: a missense mutation (K193E), a nonsense mutation (Q634X), and a mutation in the 3' splice site for exon 5. The fourth SHFM mutation (R280H) in this series was also found in a patient with classical EEC syndrome, suggesting partial overlap between the EEC and SHFM mutational spectra. The original family with LMS (van Bokhoven et al. 1999) had no detectable p63 mutation, although it clearly localizes to the p63 locus in 3q27. In two other small kindreds affected with LMS, frameshift mutations were detected in exons 13 and 14, respectively. The combined data show that p63 is the major gene for EEC syndrome, and that it makes a modest contribution to SHFM. There appears to be a genotype-phenotype correlation, in that there is a specific pattern of missense mutations in EEC syndrome that are not generally found in SHFM or LMS.

Light in the confusion of ectodermal dysplasia syndrome. Mutations in p63 gene induce different phenotype expressions

Light in the confusion of ectodermal dysplasia syndrome. Mutations in p63 gene induce different phenotype expressions

Hay-Wells syndrome is caused by heterozygous missense mutations in the SAM domain of p63.

Hay-Wells syndrome, also known as ankyloblepharon-ectodermal dysplasia-clefting (AEC) syndrome (OMIM 106260), is a rare autosomal dominant disorder characterized by congenital ectodermal dysplasia, including alopecia, scalp infections, dystrophic nails, hypodontia, ankyloblepharon and cleft lip and/or cleft palate. This constellation of clinical signs is unique, but some overlap can be recognized with other ectodermal dysplasia syndromes, for example ectrodactyly--ectodermal dysplasia--cleft lip/palate (EEC; OMIM 604292), limb--mammary syndrome (LMS; OMIM 603543), acro-dermato-ungual-lacrimal-tooth syndrome (ADULT; OMIM 103285) and recessive cleft lip/palate--ectodermal dysplasia (CLPED1; OMIM 225060). We have recently demonstrated that heterozygous mutations in the p63 gene are the major cause of EEC syndrome. Linkage studies suggest that the related LMS and ADULT syndromes are also caused by mutations in the p63 gene. Thus, it appears that p63 gene mutations have highly pleiotropic effects. We have analysed p63 in AEC syndrome patients and identified missense mutations in eight families. All mutations give rise to amino acid substitutions in the sterile alpha motif (SAM) domain, and are predicted to affect protein--protein interactions. In contrast, the vast majority of the mutations found in EEC syndrome are amino acid substitutions in the DNA-binding domain. Thus, a clear genotype--phenotype correlation can be recognized for EEC and AEC syndromes.