Prevence vzniku nádorů u nosičů dědičných alterací nádorových predispozičních genů vyžaduje jasnou identifikaci zodpovědných patogenních mutací. Při analýze nádorové predispozice je odhalena řada variant s nejasným významem (VUS) komplikujících klinickou interpretaci výsledků. Pokud VUS postihují proces sestřihu transkriptu příslušného genu, lze je považovat za patogenní. V projektu se zaměříme na vyhodnocení změn sestřihového vzorce mRNA transkriptů u nosičů dědičných variant genů predisponujících ke vzniku dědičné formy karcinomu (ca) prsu a ovarií (CHEK2, PALB2, NBN, TP53, RAD51C/D, MLH1, MSH2/6, BRIP1). Nejprve provedeme identifikaci jejich sestřihových variant v normálních tkáních (leukocyty, mamární a tuková tkáň) zdravých osob bez přítomnosti dědičných variant pomocí multiplexní PCR (mPCR) umožňující amplifikaci všech sestřihových oblastí s následnou charakterizací sekvenovánín nové generace (NGS). Vyšetření RNA od nosičů VUS umožní kvalitativně (fragmentační a mPCR/NGS analýza) i kvantitativně (qPCR) identifikovat VUS způsobující změny sestřihového vzorce příslušného genu.; Clinical management that enables efficient cancer prevention in carriers of germ-line alterations in cancer susceptibility genes requires and unequivocal characterization of the pathogenic mutation. Current cancer predisposition analyses reveal many variants of unknown clinical significance (VUS) which complicate the clinical interpretation of results. The VUS that change splicing of corresponding gene product may be considered as pathogenic. Our project aims to identify splicing alterations in carriers of VUS in genes predisposing to breast and ovarian cancer (CHEK2, PALB2, NBN, TP53, RAD51C/D, MLH1, MSH2/6, BRIP1). First, we aim to perform a comprehensive characterization of naturally occurring splicing variants of analyzed genes in normal lymphocytes, mammary and adipose tissues from non-cancer individuals using multiplex (m)PCR/next generation sequencing (NGS) analysis. Subsequently, the analyses of RNA from carriers of VUS will enable to characterize the qualitative (fragment analysis, mPCR/NGS) and quantitative (qPCR) changes in splicing pattern of corresponding genes.

• MeSH
• dědičný syndrom nádoru prsu a vaječníků genetika   klasifikace   MeSH
• genetická predispozice k nemoci genetika   klasifikace   MeSH
• geny nádorové genetika   MeSH
• prekurzory RNA MeSH
• sestřih RNA genetika   MeSH
• sestřihové faktory MeSH
• vysoce účinné nukleotidové sekvenování MeSH

• Konspekt
• Patologie. Klinická medicína
• NLK Obory
• onkologie
• genetika, lékařská genetika
• gynekologie a porodnictví
• NLK Publikační typ
• závěrečné zprávy o řešení grantu AZV MZ ČR

Hepatocyte nuclear factor-1-beta (HNF1B) is a transcription factor and putative biomarker of solid tumours. Recently, we have revealed a variety of HNF1B mRNA alternative splicing variants (ASVs) with unknown, but potentially regulatory, functions. The aim of our work was to quantify the most common variants and compare their expression in tumour and non-tumour tissues of the large intestine, prostate, and kidney. The HNF1B mRNA variants 3p, Δ7, Δ7-8, and Δ8 were expressed across all the analysed tissues in 28.2-33.5%, 1.5-2%, 0.8-1.7%, and 2.3-6.9% of overall HNF1B mRNA expression, respectively, and occurred individually or in combination. The quantitative changes of ASVs between tumour and non-tumour tissue were observed for the large intestine (3p, Δ7-8), prostate (3p), and kidney samples (Δ7). Decreased expression of the overall HNF1B mRNA in the large intestine and prostate cancer samples compared with the corresponding non-tumour samples was observed (p = 0.019 and p = 0.047, respectively). The decreased mRNA expression correlated with decreased protein expression in large intestine carcinomas (p < 0.001). The qualitative and quantitative pattern of the ASVs studied by droplet digital PCR was confirmed by next-generation sequencing, which suggests the significance of the NGS approach for further massive evaluation of the splicing patterns in a variety of genes.

• MeSH
• alternativní sestřih * MeSH
• hepatocytární jaderný faktor 1-beta genetika   metabolismus   MeSH
• lidé MeSH
• messenger RNA genetika   metabolismus   MeSH
• nádorové biomarkery genetika   metabolismus   MeSH
• nádory genetika   metabolismus   MeSH
• polymerázová řetězová reakce MeSH
• protein - isoformy MeSH
• regulace genové exprese u nádorů MeSH
• retrospektivní studie MeSH
• RNA nádorová genetika   metabolismus   MeSH
• vysoce účinné nukleotidové sekvenování MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH

Alternative pre-mRNA splicing increases transcriptome plasticity by forming naturally-occurring alternative splicing variants (ASVs). Alterations of splicing processes, caused by DNA mutations, result in aberrant splicing and the formation of aberrant mRNA isoforms. Analyses of hereditary cancer predisposition genes reveal many DNA variants with unknown clinical significance (VUS) that potentially affect pre-mRNA splicing. Therefore, a comprehensive description of ASVs is an essential prerequisite for the interpretation of germline VUS in high-risk individuals. To identify ASVs in a gene of interest, we have proposed an approach based on multiplex PCR (mPCR) amplification of all theoretically possible exon-exon junctions and subsequent characterization of size-selected and pooled mPCR products by next-generation sequencing (NGS). The efficiency of this method is illustrated by a comprehensive analysis of BRCA1 ASVs in human leukocytes, normal mammary, and adipose tissues and stable cell lines. We revealed 94 BRCA1 ASVs, including 29 variants present in all tested samples. While differences in the qualitative expression of BRCA1 ASVs among the analyzed human tissues were minor, larger differences were detected between tissue and cell line samples. Compared with other ASV analysis methods, this approach represents a highly sensitive and rapid alternative for the identification of ASVs in any gene of interest.

• MeSH
• alternativní sestřih * MeSH
• izoformy RNA MeSH
• lidé MeSH
• multiplexová polymerázová řetězová reakce metody   MeSH
• mutace * MeSH
• nádory prsu genetika   MeSH
• protein BRCA1 genetika   MeSH
• výpočetní biologie MeSH
• vysoce účinné nukleotidové sekvenování metody   MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

Hepatocyte nuclear factor-1-beta (HNF1B) is a transcription factor crucial for the development of several tissues, and a promising biomarker of certain solid tumours. Thus far, two HNF1B alternative splicing variants (ASVs) have been described, however, the complete spectrum, prevalence and role of HNF1B ASVs in tumorigenesis are unclear. Considering the equivocal data about HNF1B ASVs and expression presented in literature, our aim was to characterize the spectrum of HNF1B mRNA splicing variants across different tissues. Here, we characterize HNF1B ASVs with high sensitivity in carcinomas of the uterine corpus, large intestine, kidney, pancreas, and prostate, with selected paired healthy tissues, using the previously described multiplex PCR and NGS approach. We identified 45 ASVs, of which 43 were novel. The spectrum and relative quantity of expressed ASVs mRNA differed among the analysed tissue types. Two known (3p, Δ7_8) and two novel (Δ7, Δ8) ASVs with unknown biological functions were detected in all the analysed tissues in a higher proportion. Our study reveals the wide spectrum of HNF1B ASVs in selected tissues. Characterization of the HNF1B ASVs is an important prerequisite for further expression studies to delineate the HNF1B splicing pattern, potential ASVs functional impact, and eventual refinement of HNF1B's biomarker role.

• MeSH
• alternativní sestřih genetika   MeSH
• biologické markery metabolismus   MeSH
• hepatocytární jaderný faktor 1-beta genetika   metabolismus   MeSH
• ledviny metabolismus   patologie   MeSH
• lidé MeSH
• messenger RNA genetika   metabolismus   MeSH
• multiplexová polymerázová řetězová reakce MeSH
• pankreas metabolismus   patologie   MeSH
• sestřih RNA genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Germline CHEK2 pathogenic variants confer an increased risk of female breast cancer (FBC). Here we describe a recurrent germline intronic variant c.1009-118_1009-87delinsC, which showed a splice acceptor shift in RNA analysis, introducing a premature stop codon (p.Tyr337PhefsTer37). The variant was found in 21/10,204 (0.21%) Czech FBC patients compared to 1/3250 (0.03%) controls (p = 0.04) and in 4/3639 (0.11%) FBC patients from an independent German dataset. In addition, we found this variant in 5/2966 (0.17%) Czech (but none of the 443 German) ovarian cancer patients, three of whom developed early-onset tumors. Based on these observations, we classified this variant as likely pathogenic.

• MeSH
• checkpoint kinasa 2 * genetika   MeSH
• dospělí MeSH
• genetická predispozice k nemoci * genetika   MeSH
• introny * genetika   MeSH
• lidé středního věku MeSH
• lidé MeSH
• nádory prsu * genetika   MeSH
• nádory vaječníků genetika   MeSH
• prekurzory RNA genetika   MeSH
• sestřih RNA * genetika   MeSH
• zárodečné mutace * MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Česká republika MeSH
• Německo MeSH

Značná část lidských chorob má genetickou příčinu a pro úspěšnou léčbu je často nezbytné přesně určit, která mutace chorobu způsobuje. Identifikace kauzálních mutací však není vždy jednoznačná, a to i tehdy, máme-li k dispozici relevantní sekvence DNA. Moderní celogenomové metody odhalí řadu sekvenčních variant, u kterých není příčinná souvislost s chorobou zřejmá. Mnohé varianty ovlivňují genovou expresi změnou sestřihu pre-mRNA, ale tento efekt nemusí být odhalen, pokud nebylo již dříve prokázáno, že daná oblast obsahuje regulační elementy sestřihu (SRE). Jejich identifikace je proto klíčovým faktorem pro vyhodnocení vlivu takových mutací na vznik choroby. Projekt si klade za cíl lokalizovat funkční SRE a pokusit se nalézt obecná pravidla jejich výskytu v cílových sekvencích. Proto bude provedena systematická experimentální analýza vybraných oblastí genů, které jsou zodpovědné za vznik závažných lidských chorob. Získaná mapa míst náchylných k mutacím vyvolávajícím změny sestřihu bude využita jako pomocný nástroj pro diagnostiku aberantního sestřihu u nově identifikovaných mutací.; Significant proportion of human diseases is genetically determined and successful treatment is dependent on precise diagnosis of causal mutations. However, their identification is not always so unambiguous, although relevant sequence data is available. Modern genomic methods are able to uncover a considerable number of sequence variants with unknown impact on disease. Sequence variants frequently influence the gene expression through alteration of pre-mRNA splicing, but this effect can be hidden, if the splicing regulatory function of mutated regions was not proven in advance. The identification of splicing regulatory elements (SREs) is therefore a crucial step in evaluation of each mutation as potentially pathogenic. The aim of the project is to localize functional SREs and to try to define some rules for their occurrence by performing a systematic experimental analysis of ten regions in genes involved in disease development. Acquired „hot spot“ map of splicing affecting regions should act as an additional tool for diagnostics of aberrant splicing in newly identified gene variants.

• MeSH
• genetická predispozice k nemoci MeSH
• genetické nemoci vrozené genetika   MeSH
• lidé MeSH
• mutace genetika   MeSH
• sestřih RNA genetika   MeSH
• Check Tag
• lidé MeSH

• Konspekt
• Patologie. Klinická medicína
• NLK Obory
• genetika, lékařská genetika
• NLK Publikační typ
• závěrečné zprávy o řešení grantu AZV MZ ČR

The nonsense-mediated mRNA decay (NMD) pathway rapidly detects and degrades mRNA containing premature termination codons (PTCs). UP-frameshift 1 (UPF1), the master regulator of the NMD process, has two alternatively-spliced isoforms; one carries 353-GNEDLVIIWLR-363 insertion in the 'regulatory loop (involved in mRNA binding)'. Such insertion can induce catalytic and/or ATPase activity, as determined experimentally; however, the kinetics and molecular level information are not fully understood. Herein, applying all-atom molecular dynamics, we probe the binding specificity of UPF1 with different GC- and AU-rich mRNA motifs and the influence of insertion to the viable control over UPF1 catalytic activity. Our results indicate two distinct conformations between 1B and RecA2 domains of UPF1: 'open (isoform_2; without insertion)' and 'closed (isoform_1; with insertion)'. These structural movements correspond to an important stacking pattern in mRNA motifs, i.e., absence of stack formation in mRNA, with UPF1 isoform_2 results in the 'open conformation'. Particularly, for UPF1 isoform_1, the increased distance between 1B and RecA2 domains has resulted in reducing the mRNA-UPF1 interactions. Lower fluctuating GC-rich mRNA motifs have better binding with UPF1, compared with AU-rich sequences. Except CCUGGGG, all other GC-rich motifs formed a 4-stack pattern with UPF1. High occupancy R363, D364, T627, and G862 residues were common binding GC-rich motifs, as were R363, N535, and T627 for the AU-rich motifs. The GC-rich motifs behave distinctly when bound to either of the isoforms; lower stability was observed with UPF1 isoform_2. The cancer-associated UPF1 variants (P533L/T and A839T) resulted in decreased protein-mRNA binding efficiency. Lack of mRNA stacking poses in the UPF1P533T system significantly decreased UPF1-mRNA binding efficiency and increased distance between 1B-RecA2. These novel findings can serve to further inform NMD-associated mechanistic and kinetic studies.

• MeSH
• alternativní sestřih * MeSH
• fosforylace MeSH
• lidé MeSH
• messenger RNA genetika   metabolismus   MeSH
• nonsense mediated mRNA decay * MeSH
• protein - isoformy MeSH
• regulace genové exprese * MeSH
• RNA-helikasy genetika   metabolismus   MeSH
• trans-aktivátory genetika   metabolismus   MeSH
• vazba proteinů MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Ubiquitin-like 5 (UBL5), which is supposed to be involved in regulation of feed intake, energy metabolism, obesity and type 2 diabetes, is located at position 62.1 cM on the pig chromosome 2 region harbouring quantitative trait loci for carcass and meat quality. The 4,354 bp genomic sequence (FR798948) of the porcine gene encompassing the promoter and entire gene was cloned by polymerase chain reaction. Comparative sequencing revealed 13 polymorphisms in noncoding regions. Synthesis of full-length cDNA sequences using rapid amplification of 5' and 3' ends showed three splice variants. Variants 1 and 2 differ in transcription length for the untranslated part of exon 1 with deduced protein of 73 amino acid (aa) residues and 100 % identities between human, mouse and other species. Variant 3, with 4 bp deletion at the 3' end of exon 2, encodes a truncated protein with 28 aa residues. In a Wild boar×Meishan F2 population (n = 334) with 47 recorded traits, loci FR798948:g.2788G>A and FR798948:g.2141T>C were associated at nominal P < 0.05 with fat deposition, growth and fattening and muscling but after adjustment for multiple testing (Benjamini and Hochberg, J R Stat Soc B 57:289-300, 1995) only eight fat deposition traits showed suggestive association with FR798948:g.2788G>A at adjusted P < 0.10. In a Meishan×Large White (MLW) cross (n = 562) with six trait records available, FR798948:g.2141T>C showed suggestive association with growth (adjusted P = 0.0690). As association mapping conducted in the outbred MLW population is more precise than in the three generation F2 population the UBL5 gene tends to be associated with growth rather than with fat accretion.

• MeSH
• genetické asociační studie * MeSH
• genom * MeSH
• klonování DNA MeSH
• messenger RNA * MeSH
• polymorfismus genetický * MeSH
• pořadí genů MeSH
• prasata genetika   MeSH
• promotorové oblasti (genetika) MeSH
• sestřih RNA * MeSH
• ubikvitiny genetika   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Skipping of BRCA2 exon 3 (∆E3) is a naturally occurring splicing event, complicating clinical classification of variants that may alter ∆E3 expression. This study used multiple evidence types to assess pathogenicity of 85 variants in/near BRCA2 exon 3. Bioinformatically predicted spliceogenic variants underwent mRNA splicing analysis using minigenes and/or patient samples. ∆E3 was measured using quantitative analysis. A mouse embryonic stem cell (mESC) based assay was used to determine the impact of 18 variants on mRNA splicing and protein function. For each variant, population frequency, bioinformatic predictions, clinical data, and existing mRNA splicing and functional results were collated. Variant class was assigned using a gene-specific adaptation of ACMG/AMP guidelines, following a recently proposed points-based system. mRNA and mESC analysis combined identified six variants with transcript and/or functional profiles interpreted as loss of function. Cryptic splice site use for acceptor site variants generated a transcript encoding a shorter protein that retains activity. Overall, 69/85 (81%) variants were classified using the points-based approach. Our analysis shows the value of applying gene-specific ACMG/AMP guidelines using a points-based approach and highlights the consideration of cryptic splice site usage to appropriately assign PVS1 code strength.

• MeSH
• alternativní sestřih MeSH
• geny BRCA2 * MeSH
• lidé MeSH
• messenger RNA genetika   metabolismus   MeSH
• místa sestřihu RNA * MeSH
• myši MeSH
• protein BRCA2 genetika   metabolismus   MeSH
• sestřih RNA MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Mutations in the C1 inhibitor (C1INH) encoding gene, SERPING1, are associated with hereditary angioedema (HAE) which manifests as recurrent submucosal and subcutaneous edema episodes. The major C1INH function is the complement system inhibition, preventing its spontaneous activation. The presented study is focused on SERPING1 exon 3, an alternative and extraordinarily long exon (499 bp). Endogenous expression analysis performed in the HepG2, human liver, and human peripheral blood cells revealed several exon 3 splicing variants alongside exon inclusion: a highly prevalent exon skipping variant and less frequent +38 and -15 variants with alternative 3' splice sites (ss) located 38 and 15 nucleotides downstream and upstream from the authentic 3' ss, respectively. An exon skipping variant introducing a premature stop codon, represented nearly one third of all splicing variants and surprisingly appeared not to be degraded by NMD. The alternative -15 3' ss was used to a small extent, although predicted to be extremely weak. Its use was shown to be independent of its strength and highly sensitive to any changes in the surrounding sequence. -15 3' ss seems to be co-regulated with the authentic 3' ss, whose use is dependent mainly on its strength and less on the presence of intronic regulatory motifs. Subtle SERPING1 exon 3 splicing regulation can contribute to overall C1INH plasma levels and HAE pathogenesis.

• MeSH
• alternativní sestřih genetika   MeSH
• buněčné jádro genetika   MeSH
• buňky Hep G2 MeSH
• exony genetika   MeSH
• inhibiční protein komplementu C1 genetika   MeSH
• lidé MeSH
• malá interferující RNA metabolismus   MeSH
• místa sestřihu RNA genetika   MeSH
• mutace genetika   MeSH
• nonsense mediated mRNA decay genetika   MeSH
• sekvence nukleotidů MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH