WNT10A variants: following the pattern of inheritance in tooth agenesis and self-reported family history of cancer.

OBJECTIVES: The aim of this study was the analysis of WNT10A variants in seven families of probands with various forms of tooth agenesis and self-reported family history of cancer. MATERIALS AND METHODS: We enrolled 60 young subjects (aged 13 to 17) from the Czech Republic with various forms of tooth agenesis. Dental phenotypes were assessed using Planmeca ProMax 3D (Planmeca Oy, Finland) with Planmeca Romexis software (version 2.9.2) together with oral examinations. After screening PAX9, MSX1, EDA, EDAR, AXIN2 and WNT10A genes on the Illumina MiSeq platform (Illumina, USA), we further analyzed the evolutionarily highly conserved WNT10A gene by capillary sequencing in the seven families. RESULTS: All the detected variants were heterozygous or compound heterozygous with various levels of phenotypic expression. The most severe phenotype (oligodontia) was found in a proband who was compound heterozygous for the previously identified WNT10A variant p.Phe228Ile and a newly discovered c.748G > A variant (p.Gly250Arg) of WNT10A. The newly identified variant causes substitution of hydrophobic glycine for hydrophilic arginine. CONCLUSIONS: We suggest that the amino acid changes in otherwise highly conserved sequences significantly affect the dental phenotype. No relationship between the presence of WNT10A variants and a risk of cancer has been found. CLINICAL RELEVANCE: Screening of PAX9, MSX1, EDA, EDAR, AXIN2 and WNT10A genes in hope to elucidate the pattern of inheritance in families.

DNA and RNA Binding Proteins: From Motifs to Roles in Cancer.

DNA and RNA binding proteins (DRBPs) are a broad class of molecules that regulate numerous cellular processes across all living organisms, creating intricate dynamic multilevel networks to control nucleotide metabolism and gene expression. These interactions are highly regulated, and dysregulation contributes to the development of a variety of diseases, including cancer. An increasing number of proteins with DNA and/or RNA binding activities have been identified in recent years, and it is important to understand how their activities are related to the molecular mechanisms of cancer. In addition, many of these proteins have overlapping functions, and it is therefore essential to analyze not only the loss of function of individual factors, but also to group abnormalities into specific types of activities in regard to particular cancer types. In this review, we summarize the classes of DNA-binding, RNA-binding, and DRBPs, drawing particular attention to the similarities and differences between these protein classes. We also perform a cross-search analysis of relevant protein databases, together with our own pipeline, to identify DRBPs involved in cancer. We discuss the most common DRBPs and how they are related to specific cancers, reviewing their biochemical, molecular biological, and cellular properties to highlight their functions and potential as targets for treatment.

Cryptic in vitro ubiquitin ligase activity of HDMX towards p53 is probably regulated by an induced fit mechanism.

HDMX and its homologue HDM2 are two essential proteins for the cell; after genotoxic stress, both are phosphorylated near to their RING domain, specifically at serine 403 and 395, respectively. Once phosphorylated, both can bind the p53 mRNA and enhance its translation; however, both recognize p53 protein and provoke its degradation under normal conditions. HDM2 has been well-recognized as an E3 ubiquitin ligase, whereas it has been reported that even with the high similarity between the RING domains of the two homologs, HDMX does not have the E3 ligase activity. Despite this, HDMX is needed for the proper p53 poly-ubiquitination. Phosphorylation at serine 395 changes the conformation of HDM2, helping to explain the switch in its activity, but no information on HDMX has been published. Here, we study the conformation of HDMX and its phospho-mimetic mutant S403D, investigate its E3 ligase activity and dissect its binding with p53. We show that phospho-mutation does not change the conformation of the protein, but HDMX is indeed an E3 ubiquitin ligase in vitro; however, in vivo, no activity was found. We speculated that HDMX is regulated by induced fit, being able to switch activity accordingly to the specific partner as p53 protein, p53 mRNA or HDM2. Our results aim to contribute to the elucidation of the contribution of the HDMX to p53 regulation.

Resistance mechanisms to inhibitors of p53-MDM2 interactions in cancer therapy: can we overcome them?

Since the discovery of the first MDM2 inhibitors, we have gained deeper insights into the cellular roles of MDM2 and p53. In this review, we focus on MDM2 inhibitors that bind to the p53-binding domain of MDM2 and aim to disrupt the binding of MDM2 to p53. We describe the basic mechanism of action of these MDM2 inhibitors, such as nutlin-3a, summarise the determinants of sensitivity to MDM2 inhibition from p53-dependent and p53-independent points of view and discuss the problems with innate and acquired resistance to MDM2 inhibition. Despite progress in MDM2 inhibitor design and ongoing clinical trials, their broad use in cancer treatment is not fulfilling expectations in heterogenous human cancers. We assess the MDM2 inhibitor types in clinical trials and provide an overview of possible sources of resistance to MDM2 inhibition, underlining the need for patient stratification based on these aspects to gain better clinical responses, including the use of combination therapies for personalised medicine.

p53 mRNA Metabolism Links with the DNA Damage Response.

Human cells are subjected to continuous challenges by different genotoxic stress attacks. DNA damage leads to erroneous mutations, which can alter the function of oncogenes or tumor suppressors, resulting in cancer development. To circumvent this, cells activate the DNA damage response (DDR), which mainly involves cell cycle regulation and DNA repair processes. The tumor suppressor p53 plays a pivotal role in the DDR by halting the cell cycle and facilitating the DNA repair processes. Various pathways and factors participating in the detection and repair of DNA have been described, including scores of RNA-binding proteins (RBPs) and RNAs. It has become increasingly clear that p53's role is multitasking, and p53 mRNA regulation plays a prominent part in the DDR. This review is aimed at covering the p53 RNA metabolism linked to the DDR and highlights the recent findings.

Tooth agenesis: What do we know and is there a connection to cancer?

Like all developmental processes, odontogenesis is highly complex and dynamically regulated, with hundreds of genes co-expressed in reciprocal networks. Tooth agenesis (missing one or more/all teeth) is a common human craniofacial anomaly and may be caused by genetic variations and/or environmental factors. Variants in PAX9, MSX1, AXIN2, EDA, EDAR, and WNT10A genes are associated with tooth agenesis. Currently, variants in ATF1, DUSP10, CASC8, IRF6, KDF1, GREM2, LTBP3, and components and regulators of WNT signaling WNT10B, LRP6, DKK, and KREMEN1 are at the forefront of interest. Due to the interconnectedness of the signaling pathways of carcinogenesis and odontogenesis, tooth agenesis could be a suitable marker for early detection of cancer predisposition. Variants in genes associated with tooth agenesis could serve as prognostic or therapeutic targets in cancer. This review aims to summarize existing knowledge of development and clinical genetics of teeth. Concurrently, the review proposes possible approaches for future research in this area, with particular attention to roles in monitoring, early diagnosis and therapy of tumors associated with defective tooth development.

Next generation sequencing reveals a novel nonsense mutation in MSX1 gene related to oligodontia.

Tooth agenesis is one of the most common craniofacial disorders in humans. More than 350 genes have been associated with teeth development. In this study, we enrolled 60 child patients (age 13 to 17) with various types of tooth agenesis. Whole gene sequences of PAX9, MSX1, AXIN2, EDA, EDAR and WNT10a genes were sequenced by next generation sequencing on the Illumina MiSeq platform. We found previously undescribed heterozygous nonsense mutation g.8177G>T (c.610G>T) in MSX1 gene in one child. Mutation was verified by Sanger sequencing. Sequencing analysis was performed in other family members of the affected child. All family members carrying g.8177G>T mutation suffered from oligodontia (missing more than 6 teeth excluding third molars). Mutation g.8177G>T leads to a stop codon (p.E204X) and premature termination of Msx1 protein translation. Based on previous in vitro experiments on mutation disrupting function of Msx1 homeodomain, we assume that the heterozygous g.8177G>T nonsense mutation affects the amount and function of Msx1 protein and leads to tooth agenesis.

CHAT gene polymorphism rs3810950 is associated with the risk of Alzheimer's disease in the Czech population.

BACKGROUND: Cholinergic hypothesis of Alzheimer's disease (AD) is based on the findings that a reduced and/or perturbed cholinergic activity in the central nervous system correlates with cognitive decline in patients with Alzheimer's disease. The hypothesis resulted in the development of centrally-acting agents potentiating cholinergic neurotransmission; these drugs, however, only slowed down the cognitive decline and could not prevent it. Consequently, the perturbation of the central cholinergic signalling has been accepted as a part of the Alzheimer's aetiology but not necessarily the primary cause of the disease. In the present study we have focused on the rs3810950 polymorphism of ChAT (choline acetyltransferase) gene that has not been studied in Czech population before. METHODS: We carried out an association study to test for a relationship between the rs3810950 polymorphism and Alzheimer's disease in a group of 1186 persons; 759 patients with Alzheimer's disease and 427 control subjects. Furthermore, we performed molecular modelling of the terminal domain (1st-126th amino acid residue) of one of the ChAT isoforms (M) to visualise in silico whether the rs3810950 polymorphism (A120T) can change any features of the tertiary structure of the protein which would have a potential to alter its function. RESULTS: The AA genotype of CHAT was associated with a 1.25 times higher risk of AD (p <  0.002) thus demonstrating that the rs3810950 polymorphism can have a modest but statistically significant effect on the risk of AD in the Czech population. Furthermore, the molecular modelling indicated that the polymorphism is likely to be associated with significant variations in the tertiary structure of the protein molecule which may impact its enzyme activity. CONCLUSIONS: Our findings are consistent with the results of the meta-analytical studies of the relationship between rs3810950 polymorphism and AD and provide further material evidence for a direct (primary) involvement of cholinergic mechanisms in the etiopathogenesis of AD, particularly as a factor in cognitive decline and perturbed conscious awareness commonly observed in patients with AD.

CD36 gene is associated with intraocular pressure elevation after intravitreal application of anti-VEGF agents in patients with age-related macular degeneration: Implications for the safety of the therapy.

BACKGROUND: The wet form of age-related macular degeneration (AMD) is characterized by pathological vascularization of the outer retinal layers. The condition responds to treatment with antibodies against vascular endothelial growth factor (VEGF), but the patients receiving such anti-VEGF therapy sometimes show undesirable acute short-term increases in the intraocular pressure (IOP). The cause of this adverse effect is unknown, and here, we are testing a hypothesis that it is related to CD36 gene polymorphisms. MATERIALS AND METHODS: A group of 134 patients with AMD were given three therapeutic doses of anti-VEGF antibody (ranibizumab) at monthly intervals. Their IOP was measured immediately before and 30 min after each injection. Patients' DNA was analyzed, and the changes in IOP were matched against seven polymorphisms of the CD36 gene. RESULTS: Three polymorphisms were found to be associated with increases in IOP: rs1049673 (p = 0.006), rs3211931 (p = 0.01), and rs1761667 (p = 0.043) at the time of the third injection only. Pronounced elevations (IOP > 25 mmHg) were associated with rs1049673 polymorphism: GC genotype (p < 0.01) and CC genotype (p < 0.05); both increasing the risk 2.6-fold, the presence of C-allele conferring a 1.5-fold greater risk and with rs3211931 polymorphism: AG genotype (p < 0.01) and GG genotype (p < 0.05); increasing the risk 2.6-fold (AG) and 2.7-fold (GG). CONCLUSIONS: CD36 receptor may be involved in mediating the effects of VEGF on IOP. The findings will help to identify the patients at risk of acutely elevated IOP following the anti-VEGF therapy.

Mutations in AXIN2 gene as a risk factor for tooth agenesis and cancer: A review.

AXIN2 gene plays a crucial role in morphogenesis of craniofacial area and is essential for tooth development. AXIN2 gene is one of the most studied genes associated with tooth agenesis, the most common defect of dentition in humans. Polymorphic variants in AXIN2 gene are discussed in relation to the occurrence of the tooth agenesis but also as an indication of the risk of cancer. Mutations in AXIN2 gene were found in patients with colorectal or hepatocellular carcinoma, prostate cancer, ovarium or lung cancer. These findings support the hypothesis that missing teeth may be a significant marker for predisposition for cancer.

Arachidonate 5-lipoxygenase (ALOX5) gene polymorphism is associated with Alzheimer's disease and body mass index.

Dementias of old age, in particular Alzheimer's disease (AD), pose a growing threat to the longevity and quality of life of individuals as well as whole societies world-wide. The risk factors are both genetic and environmental (life-style) and there is an overlap with similar factors predisposing to cardiovascular diseases (CVD). Using a case-control genetic approach, we have identified a SNP (rs10507391) in ALOX5 gene, previously associated with an increased risk of stroke, as a novel genetic risk factor for AD. ALOX5 gene encodes a 5'-lipoxygenase (5'-LO) activating protein (FLAP), a crucial component of the arachidonic acid/leukotriene inflammatory cascade. A-allele of rs4769874 polymorphism increases the risk of AD 1.41-fold (p<0.0001), while AA genotype does so 1.79-fold (p<0.0001). In addition, GG genotype of rs4769874 polymorphism is associated with a modest increase in body mass index (BMI). We discuss potential biochemical mechanisms linking the SNP to AD and suggest possible preventive pharmacotherapies some of which are based on commonly available natural products. Finally, we set the newly identified AD risk factors into a broader context of similar CVD risk factors to generate a more comprehensive picture of interacting genetics and life-style habits potentially leading to the deteriorating mental health in the old age.

Identification of Borrelia burgdorferi genospecies isolated from Ixodes ricinus ticks in the South Moravian region of the Czech Republic.

INTRODUCTION: During 2008-2012, a total of 466 ticks Ixodes ricinus removed from humans were collected and tested for the presence of Borrelia burgdorferi sensu lato (Bbsl). Ticks were collected in all districts of the South Moravian region of the Czech Republic (CZ). OBJECTIVE: The aim of this study was to determine the infestation of Bbsl in ticks Ixodes ricinus and the identification of genospecies of Bbsl group by DNA sequencing. MATERIAL AND METHODS: DNA isolation from homogenates was performed by UltraClean BloodSpin DNA kit (MoBio) and by automated instrument Prepito (Perkin-Elmer). Detection of spirochetes was carried out by RealTime PCR kit EliGene Borrelia LC (Elisabeth Pharmacon). Finally, all the positive samples were sequenced on an ABI 3130 Genetic Analyzer (Life Technologies) and identified in the BLAST (NCBI) database. RESULTS: A total positivity of the samples was 26%. For the first time in the Czech Republic, 5 of the isolated strains were genotyped as Borrelia spielmanii (7.1%). Other representatives of Bbsl were also observed: B. afzelii (70.0%), B. garinii (10.0%), B. valaisiana (8.6%), and B. burgdorferi s. s. (4.3%). CONCLUSION: A general view of the spreading of Bbsl in the South Moravian region was demonstrated. The most interesting result of the study is the finding of B. spielmanii for the first time in this region.

Novel PAX9 gene polymorphisms and mutations and susceptibility to tooth agenesis in the Czech population.

OBJECTIVES: Tooth agenesis is one of the most common developmental anomalies in humans. Genetic and environmental factors may be of etiological importance in this condition. Among genes involved in tooth morphogenesis, mutations in PAX9, MSX1, AXIN2, WNT10a, and EDA genes have been associated with tooth agenesis. The aim of our study was to investigate the relationship between the PAX9 gene variants and tooth agenesis in the Czech population. METHODS: The selected regions of the PAX9 gene were analysed by direct sequencing and compared with the reference sequence from the GenBank online database (NCBI). RESULTS: We found several novel variants in the PAX9 gene, e.g. insertion g.5100_5101insC (rs11373281) with simultaneous substitution g.5272C>G (rs4904155) in exon 1, and mutation g.10934C>T (Gly203Gly, rs61754301) in exon 3. In subjects with full dentition we observed polymorphisms g.10276A>G (rs12882923) and g.10289A>G (rs12883049) in IVS2 (intervening sequence 2) previously related to tooth agenesis in Polish study. CONCLUSIONS: In our study we excluded a direct effect of rs12882923 and rs12883049 polymorphisms on the dental agenesis in the Czech population. All described PAX9 genetic variants were present both in patients with tooth agenesis and controls. We expect that tooth agenesis in our cohort of patients is caused by mutations in regions different from PAX9 exons analyzed in our study.

A screen of a large Czech cohort of oligodontia patients implicates a novel mutation in the PAX9 gene.

Tooth agenesis is one of the most common developmental anomalies in humans. To date, many mutations involving paired box 9 (PAX9), msh homeobox 1 (MSX1), and axin 2 (AXIN2) genes have been identified. The aim of the present study was to perform screening for mutations and/or polymorphisms using the capillary sequencing method in the critical regions of PAX9 and MSX1 genes in a group of 270 individuals with tooth agenesis and in 30 healthy subjects of Czech origin. This screening revealed a previously unknown heterozygous g.9527G>T mutation in the PAX9 gene in monozygotic twins with oligodontia and three additional affected family members. The same variant was not found in healthy relatives. This mutation is located in intron 2, in the region recognized as the splice site between exon 2 and intron 2. We hypothesize that the error in pre-mRNA splicing may lead to lower expression of PAX9 protein and could have contributed to the development of tooth agenesis in the affected subjects.