Adult granulosa cell tumors (AGCTs) of the ovary are characterized by their propensity for late recurrences and are primarily managed surgically due to the limited efficacy of systemic treatment. The FOXL2 p.C134W somatic mutation has been identified in ∼95% of AGCT cases, and TERT promoter alterations have been linked to worse overall survival. This study highlights the potential prognostic significance of FOXO1 mutations, suggesting that they may be associated with poorer overall survival and shorter time to recurrence. A total of 183 primary AGCTs and 44 recurrences without corresponding primary tumors were analyzed. The primary AGCTs were categorized into 3 groups: 77 nonrecurrent tumors, 18 tumors that later recurred (including 9 cases with matched primary-recurrence pairs), and 88 tumors with unknown recurrence status. Targeted next-generation sequencing was conducted on 786 cancer-related genes to investigate their genetic profile. The study aimed to identify the molecular alterations associated with AGCT pathogenesis and recurrence rate, comparing primary versus recurrent tumors, and primary recurrent versus primary nonrecurrent cases. Our findings confirmed the high prevalence (99%) of the FOXL2 p.C134W mutation in AGCTs. Secondary truncating FOXL2 mutations were observed in 5% of cases. Two cases with typical AGCT morphology were FOXL2 wild-type, harboring mutations in KRAS or KMT2D instead, suggesting alternative genetic pathways. TERT promoter mutations were found in 43% of cases, more frequently in recurrences. Other recurrent mutations detected in the cohort included KMT2D (10%), FOXO1 (7%), CHEK2 (5%), TP53 (3.5%), PIK3CA (3.5%), and AKT1 (3%). Two recurrent, FOXL2-mutated cases also carried DICER1 mutations. One tumor exhibited MSI-high status and a tumor mutation burden of 19 mut/Mb.Our results indicate the need for further investigation into the role of FOXO1 as a potential prognostic marker in AGCTs.
- MeSH
- dospělí MeSH
- forkhead box protein O1 * genetika metabolismus MeSH
- lidé středního věku MeSH
- lidé MeSH
- lokální recidiva nádoru * genetika MeSH
- mutace * MeSH
- nádor z folikulárních buněk * genetika patologie MeSH
- nádory vaječníků * genetika patologie MeSH
- prognóza MeSH
- progrese nemoci MeSH
- protein FOXL2 genetika MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- telomerasa genetika MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
G-quadruplexes (G4s) are functional elements of the human genome, some of which inhibit DNA replication. We investigated replication of G4s within highly abundant microsatellite (GGGA, GGGT) and transposable element (L1 and SVA) sequences. We found that genome-wide, numerous motifs are located preferentially on the replication leading strand and the transcribed strand templates. We directly tested replicative polymerase ε and δ holoenzyme inhibition at these G4s, compared to low abundant motifs. For all G4s, DNA synthesis inhibition was higher on the G-rich than C-rich strand or control sequence. No single G4 was an absolute block for either holoenzyme; however, the inhibitory potential varied over an order of magnitude. Biophysical analyses showed the motifs form varying topologies, but replicative polymerase inhibition did not correlate with a specific G4 structure. Addition of the G4 stabilizer pyridostatin severely inhibited forward polymerase synthesis specifically on the G-rich strand, enhancing G/C strand asynchrony. Our results reveal that replicative polymerase inhibition at every G4 examined is distinct, causing complementary strand synthesis to become asynchronous, which could contribute to slowed fork elongation. Altogether, we provide critical information regarding how replicative eukaryotic holoenzymes navigate synthesis through G4s naturally occurring thousands of times in functional regions of the human genome.
- MeSH
- aminochinoliny MeSH
- DNA-polymerasa II * antagonisté a inhibitory metabolismus MeSH
- DNA-polymerasa III * antagonisté a inhibitory metabolismus MeSH
- DNA chemie MeSH
- G-kvadruplexy * MeSH
- genom lidský * MeSH
- holoenzymy metabolismus MeSH
- kyseliny pikolinové farmakologie MeSH
- lidé MeSH
- mikrosatelitní repetice MeSH
- proteiny vázající poly-ADP-ribosu MeSH
- replikace DNA * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Transcriptional activity and gene expression are critical for the development of mature, meiotically competent oocytes. Our study demonstrates that the absence of cyclin-dependent kinase 12 (CDK12) in oocytes leads to complete female sterility, as fully developed oocytes capable of completing meiosis I are absent from the ovaries. Mechanistically, CDK12 regulates RNA polymerase II activity in growing oocytes and ensures the maintenance of the physiological maternal transcriptome, which is essential for protein synthesis that drives further oocyte growth. Notably, CDK12-deficient growing oocytes exhibit a 71% reduction in transcriptional activity. Furthermore, impaired oocyte development disrupts folliculogenesis, leading to premature ovarian failure without terminal follicle maturation or ovulation. In conclusion, our findings identify CDK12 as a key master regulator of the oocyte transcriptional program and gene expression, indispensable for oocyte growth and female fertility. A schematic illustrating the effects of loss of CDK12 in mammalian oocytes on the regulation of transcription by polymerase II and the concomitant effects on translation. This disruption leads to an aberrant transcriptome and translatome, resulting in the absence of fully mature oocytes and ultimately female sterility.
- MeSH
- cyklin-dependentní kinasy * metabolismus genetika MeSH
- meióza genetika MeSH
- myši MeSH
- oocyty * metabolismus MeSH
- RNA-polymerasa II metabolismus MeSH
- transkriptom genetika MeSH
- ženská infertilita * genetika patologie metabolismus MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
The exon junction complex (EJC) is a key player in metazoan mRNA quality control and is placed upstream of the exon-exon junction after splicing. Its inner core is composed of Magoh, Y14, eIF4AIII and BTZ and the outer core of proteins involved in mRNA splicing (CWC22), export (Yra1), translation (PYM) and nonsense mediated decay (NMD, UPF1/2/3). Trypanosoma brucei encodes only two genes with introns, but all mRNAs are processed by trans-splicing. The presence of three core EJC proteins and a potential BTZ homologue (Rbp25) in trypanosomes has been suggested to adapt of the EJC function to mark trans-spliced mRNAs. We analysed trypanosome EJC components and noticed major differences between eIF4AIII and Magoh/Y14: (i) whilst eIF4AIII is essential, knocking out both Magoh and Y14 elicits only a mild growth phenotype (ii) eIF4AIII localization is mostly nucleolar, while Magoh and Y14 are nucleolar and nucleoplasmic but excluded from the cytoplasm (iii) eIF4AIII associates with nucleolar proteins and the splicing factor CWC22, but not with Y14 or Magoh, while Magoh and Y14 associate with each other, but not with eIF4AIII, CWC22 or nucleolar proteins. Our data argue against the presence of a functional EJC in trypanosomes, but indicate that eIF4AIII adopted non-EJC related, essential functions, while Magoh and Y14 became redundant. Trypanosomes also possess homologues to the NMD proteins UPF1 and UPF2. Depletion of UPF1 causes only a minor reduction in growth and phylogenetic analyses show several independent losses of UPF1 and UPF2, as well as complete loss of UPF3 in the Kinetoplastida group, indicating that UPF1-dependent NMD is not essential. Regardless, we demonstrate that UPF1 depletion restores the mRNA levels of a PTC reporter. Altogether, we show that the almost intron-less trypanosomes are in the process of losing the canonical EJC/NMD pathways: Y14 and Magoh have become redundant and the still-functional UPF1-dependent NMD pathway is not essential.
- MeSH
- eukaryotický iniciační faktor 4A metabolismus genetika MeSH
- exony genetika MeSH
- messenger RNA genetika metabolismus MeSH
- nonsense mediated mRNA decay * MeSH
- protozoální proteiny * metabolismus genetika MeSH
- sestřih RNA MeSH
- Trypanosoma brucei brucei * metabolismus genetika MeSH
- Publikační typ
- časopisecké články MeSH
Somatic hypermutation (SHM) and class switch recombination (CSR) diversify immunoglobulin (Ig) genes and are initiated by the activation-induced deaminase (AID), a single-stranded DNA cytidine deaminase thought to engage its substrate during RNA polymerase II (RNAPII) transcription. Through a genetic screen, we identified numerous potential factors involved in SHM, including elongation factor 1 homolog (ELOF1), a component of the RNAPII elongation complex that functions in transcription-coupled nucleotide excision repair (TC-NER) and transcription elongation. Loss of ELOF1 compromises SHM, CSR, and AID action in mammalian B cells and alters RNAPII transcription by reducing RNAPII pausing downstream of transcription start sites and levels of serine 5 but not serine 2 phosphorylated RNAPII throughout transcribed genes. ELOF1 must bind to RNAPII to be a proximity partner for AID and to function in SHM and CSR, and TC-NER is not required for SHM. We propose that ELOF1 helps create the appropriate stalled RNAPII substrate on which AID acts.
- MeSH
- AICDA (aktivací indukovaná cytidindeamináza) MeSH
- B-lymfocyty * imunologie metabolismus MeSH
- cytidindeaminasa metabolismus genetika MeSH
- fosfoproteiny * genetika metabolismus MeSH
- fosforylace MeSH
- genetická transkripce MeSH
- lidé MeSH
- myši knockoutované MeSH
- myši MeSH
- oprava DNA MeSH
- přesmyk imunoglobulinových tříd * MeSH
- RNA-polymerasa II metabolismus genetika MeSH
- somatická hypermutace imunoglobulinových genů * MeSH
- transkripční elongační faktory * genetika metabolismus MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
We designed and synthesized a set of four 2'-deoxyribonucleoside 5'-O-triphosphates (dNTPs) bearing cationic substituents (protonated amino, methylamino, dimethylamino and trimethylammonium groups) attached to position 5 of pyrimidines or position 7 of 7-deazapurines through hex-1-ynyl or propargyl linker. These cationic dNTPs were studied as substrates in enzymatic synthesis of modified and hypermodified DNA using KOD XL DNA polymerase. In primer extension (PEX), we successfully obtained DNA containing one, two, three, or (all) four modified nucleotides, each bearing a different cationic modification. The cationic dNTPs were somewhat worse substrates compared to previously studied dNTPs bearing hydrophobic or anionic modifications, but the polymerase was still able to synthesize sequences up to 73 modified nucleotides. We also successfully combined one cationic modification with one anionic and two hydrophobic modifications in PEX. In polymerase chain reaction (PCR), we observed exponential amplification only in the case of one cationic modification, while the combination of more cationic nucleotides gave either very low amplification or no PCR product. The hypermodified oligonucleotides prepared by PEX were successfully re-PCRed and sequenced by Sanger sequencing. Biophysical studies of hybridization, denaturation, and circular dichroism spectroscopy showed that the presence of cationic modifications increases the stability of duplexes.
Telomeres, essential for maintaining genomic stability, are typically preserved through the action of telomerase, a ribonucleoprotein complex that synthesizes telomeric DNA. One of its two core components, telomerase RNA (TR), serves as the template for this synthesis, and its evolution across different species is both complex and diverse. This review discusses recent advancements in understanding TR evolution, with a focus on plants (Viridiplantae). Utilizing novel bioinformatic tools and accumulating genomic and transcriptomic data, combined with corresponding experimental validation, researchers have begun to unravel the intricate pathways of TR evolution and telomere maintenance mechanisms. Contrary to previous beliefs, a monophyletic origin of TR has been demonstrated first in land plants and subsequently across the broader phylogenetic megagroup Diaphoretickes. Conversely, the discovery of plant-type TRs in insects challenges assumptions about the monophyletic origin of TRs in animals, suggesting evolutionary innovations coinciding with arthropod divergence. The review also highlights key challenges in TR identification and provides examples of how these have been addressed. Overall, this work underscores the importance of expanding beyond model organisms to comprehend the full complexity of telomerase evolution, with potential applications in agriculture and biotechnology.
- MeSH
- fylogeneze MeSH
- molekulární evoluce * MeSH
- RNA * genetika metabolismus MeSH
- rostliny genetika MeSH
- telomerasa * genetika metabolismus MeSH
- telomery * metabolismus genetika MeSH
- Viridiplantae genetika metabolismus MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
In RNA interference (RNAi), long double-stranded RNA is cleaved by the Dicer endonuclease into small interfering RNAs (siRNAs), which guide degradation of complementary RNAs. While RNAi mediates antiviral innate immunity in plants and many invertebrates, vertebrates have adopted a sequence-independent response and their Dicer produces siRNAs inefficiently because it is adapted to process small hairpin microRNA precursors in the gene-regulating microRNA pathway. Mammalian endogenous RNAi is thus a rudimentary pathway of unclear significance. To investigate its antiviral potential, we modified the mouse Dicer locus to express a truncated variant (DicerΔHEL1) known to stimulate RNAi and we analyzed how DicerΔHEL1/wt mice respond to four RNA viruses: coxsackievirus B3 and encephalomyocarditis virus from Picornaviridae; tick-borne encephalitis virus from Flaviviridae; and lymphocytic choriomeningitis virus (LCMV) from Arenaviridae. Increased Dicer activity in DicerΔHEL1/wt mice did not elicit any antiviral effect, supporting an insignificant antiviral function of endogenous mammalian RNAi in vivo. However, we also observed that sufficiently high expression of DicerΔHEL1 suppressed LCMV in embryonic stem cells and in a transgenic mouse model. Altogether, mice with increased Dicer activity offer a new benchmark for identifying and studying viruses susceptible to mammalian RNAi in vivo.
- MeSH
- DEAD-box RNA-helikasy genetika metabolismus MeSH
- malá interferující RNA genetika MeSH
- myši inbrední C57BL MeSH
- myši MeSH
- přirozená imunita * genetika MeSH
- ribonukleasa III * genetika metabolismus MeSH
- RNA interference * MeSH
- virus encefalomyokarditidy genetika imunologie MeSH
- virus lymfocytární choriomeningitidy imunologie genetika MeSH
- viry klíšťové encefalitidy genetika imunologie MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Differences in survival according to the pTERT mutation subtypes (-124C > T, -146C > T, and tandem -138_139CC > TT) have been observed. The present study aimed to describe the clinical as the histopathological and molecular cutaneous melanoma features according to the presence of the three most prevalent pTERT mutation subtypes (-124C > T, -146C > T, and tandem -138_139CC > TT). A retrospective cross-sectional study including 684 patients was designed, and a Partial Least-Squares Discriminant Analysis (PLS-DA) was performed. After the PSL-DA, it was observed that the tandem -138_139CC > TT subtype differs from the other subtypes. The model demonstrated that the -124C > T and the -138_139 CC > TT subtypes were associated with fast-growing melanomas (OR 0.5, CI 0.29-0.86, p = .012) and with Breslow >2 mm (OR 0.6, CI 0.37-0.97, p = .037), compared to the -146C > T mutation. Finally, the -124C > T appeared to be more associated with the presence of TILs (non-brisk) than the -146C > T (OR 0.6, CI 0.40-1.01, p = .05). These findings confirmed that the -124C > T and the tandem -138_139 CC > TT subtypes are both highly associated with the presence of features of aggressiveness; however, only the -124C > T was highly associated with TILs. This difference could explain the worse survival rate associated with the tandem -138_139CC > TT mutations.
- MeSH
- lidé MeSH
- melanom * genetika patologie mortalita MeSH
- mutace MeSH
- nádory kůže genetika patologie mortalita MeSH
- promotorové oblasti (genetika) * genetika MeSH
- průřezové studie MeSH
- retrospektivní studie MeSH
- telomerasa * genetika MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The PB2 subunit of the influenza virus polymerase complex is essential for viral replication, primarily through a mechanism known as cap-snatching. In this process, PB2 binds to the 5' cap structure of host pre-mRNAs, enabling the viral polymerase to hijack the host transcriptional machinery. This binding facilitates the cleavage and integration of the capped RNA fragment into viral mRNA, thereby promoting efficient viral replication. Inhibiting the PB2-cap interaction is therefore crucial, as it directly disrupts the viral replication cycle. Consequently, targeting PB2 with specific inhibitors is a promising strategy for antiviral drug development against influenza. However, there are currently no available methods for the high-throughput screening of potential inhibitors. The development of new inhibitor screening methods of potential PB2 binders is the focus of this study. In this study, we present two novel methods, DIANA and AlphaScreen, for screening influenza PB2 cap-binding inhibitors and evaluate their effectiveness compared to the established differential scanning fluorimetry (DSF) technique. Using a diverse set of substrates and compounds based on the previously described PB2 binder pimodivir, we thoroughly assessed the capabilities of these new methods. Our findings demonstrate that both DIANA and AlphaScreen are highly effective for PB2 inhibitor screening, offering distinct advantages over traditional techniques such as isothermal titration calorimetry (ITC) and surface plasmon resonance (SPR). These advantages include improved scalability, reduced sample requirements, and the capacity for label-free detection. Notably, DIANA's ability to determine Ki values from a single-well measurement significantly enhances its practicality and efficiency in inhibitor screening. This research represents a significant step forward in the development of more efficient and scalable screening strategies, helping advance efforts in the discovery of antiviral drugs against influenza.
- MeSH
- antivirové látky * farmakologie chemie MeSH
- fluorometrie metody MeSH
- lidé MeSH
- piperidiny farmakologie MeSH
- pyridiny MeSH
- pyrimidiny MeSH
- pyrroly MeSH
- RNA čepičky metabolismus MeSH
- RNA-dependentní RNA-polymerasa antagonisté a inhibitory metabolismus MeSH
- rychlé screeningové testy * metody MeSH
- virové proteiny * antagonisté a inhibitory metabolismus MeSH
- virus chřipky A účinky léků MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
