RESUMO
Objective: Endometrial cancer (EC) is a heterogeneous disease with recurrence rates ranging from 15 to 20%. The discrimination of cases with a worse prognosis aims, in part, to reduce the length of surgical staging in cases with a better prognosis. This study aimed to evaluate the association between Insulin-like growth factor II mRNA-binding protein 3 (IMP3) expression and prognostic and morphological factors in EC. Methods: This retrospective, cross-sectional, analytical study included 79 EC patients - 70 endometrioid carcinoma (EEC) and 9 serous carcinoma (SC) - and 74 benign endometrium controls. IMP3 expression was evaluated by immunohistochemistry-based TMA (Tissue Microarray), and the results were associated with morphological and prognostic factors, including claudins 3 and 4, estrogen and progesterone receptors, TP53, and KI67. Results: IMP3 expression was significantly higher in SC compared to EEC in both extent (p<0.001) and intensity (p=0.044). It was also significantly associated with worse prognostic factors, including degree of differentiation (p=0.024, p<0.001), staging (p<0.001; p<0.001) and metastasis (p=0.002; p<0.001). IMP3 expression was also significant in extent (p=0.002) in endometrial tumors compared with controls. In addition, protein TP53 and KI67 showed significant associations in extent and intensity, respectively. Conclusion: IMP3 expression was associated with worse prognostic factors studied. These findings suggest that IMP3 may be a potential biomarker for EC poorer prognosis.
Assuntos
Carcinoma Endometrioide , Neoplasias do Endométrio , Proteínas de Ligação a RNA , Humanos , Feminino , Neoplasias do Endométrio/patologia , Neoplasias do Endométrio/genética , Neoplasias do Endométrio/metabolismo , Neoplasias do Endométrio/mortalidade , Prognóstico , Pessoa de Meia-Idade , Estudos Retrospectivos , Proteínas de Ligação a RNA/metabolismo , Proteínas de Ligação a RNA/genética , Estudos Transversais , Idoso , Carcinoma Endometrioide/patologia , Carcinoma Endometrioide/metabolismo , Carcinoma Endometrioide/genética , Adulto , Biomarcadores Tumorais/metabolismo , Biomarcadores Tumorais/genética , Ribonucleoproteínas Nucleolares PequenasRESUMO
Small nucleolar RNAs (snoRNAs) are earning increasing attention from research communities due to their critical role in the post-transcriptional modification of various RNAs. These snoRNAs, along with their associated proteins, are crucial in regulating the expression of a vast array of genes in different human diseases. Primarily, snoRNAs facilitate modifications such as 2'-O-methylation, N-4-acetylation, and pseudouridylation, which impact not only ribosomal RNA (rRNA) and their synthesis but also different RNAs. Functionally, snoRNAs bind with core proteins to form small nucleolar ribonucleoproteins (snoRNPs). These snoRNAs then direct the protein complex to specific sites on target RNA molecules where modifications are necessary for either standard cellular operations or the regulation of pathological mechanisms. At these targeted sites, the proteins coupled with snoRNPs perform the modification processes that are vital for controlling cellular functions. The unique characteristics of snoRNAs and their involvement in various non-metabolic and metabolic diseases highlight their potential as therapeutic targets. Moreover, the precise targeting capability of snoRNAs might be harnessed as a molecular tool to therapeutically address various disease conditions. This review delves into the role of snoRNAs in health and disease and explores the broad potential of these snoRNAs as therapeutic agents in human pathologies.
Assuntos
RNA Nucleolar Pequeno , Ribonucleoproteínas Nucleolares Pequenas , Humanos , RNA Nucleolar Pequeno/genética , RNA Nucleolar Pequeno/metabolismo , Ribonucleoproteínas Nucleolares Pequenas/metabolismo , Ribonucleoproteínas Nucleolares Pequenas/genética , Animais , Processamento Pós-Transcricional do RNA , Neoplasias/genética , Neoplasias/metabolismoRESUMO
Embryo development in Arabidopsis (Arabidopsis thaliana) starts off with an asymmetric division of the zygote to generate the precursors of the embryo proper and the supporting extraembryonic suspensor. The suspensor degenerates as the development of the embryo proper proceeds beyond the heart stage. Until the globular stage, the suspensor maintains embryonic potential and can form embryos in the absence of the developing embryo proper. We report a mutant called meerling-1 (mrl-1), which shows a high penetrance of suspensor-derived polyembryony due to delayed development of the embryo proper. Eventually, embryos from both apical and suspensor lineages successfully develop into normal plants and complete their life cycle. We identified the causal mutation as a genomic rearrangement altering the promoter of the Arabidopsis U3 SMALL NUCLEOLAR RNA-ASSOCIATED PROTEIN 18 (UTP18) homolog that encodes a nucleolar-localized WD40-repeat protein involved in processing 18S preribosomal RNA. Accordingly, root-specific knockout of UTP18 caused growth arrest and accumulation of unprocessed 18S pre-rRNA. We generated the mrl-2 loss-of-function mutant and observed asynchronous megagametophyte development causing embryo sac abortion. Together, our results indicate that promoter rearrangement decreased UTP18 protein abundance during early stage embryo proper development, triggering suspensor-derived embryogenesis. Our data support the existence of noncell autonomous signaling from the embryo proper to prevent direct reprogramming of the suspensor toward embryonic fate.
Assuntos
Proteínas de Arabidopsis , Arabidopsis , Mutação , Ribonucleoproteínas Nucleolares Pequenas , Sementes , Arabidopsis/genética , Arabidopsis/embriologia , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas , Mutação/genética , RNA Ribossômico/genética , Sementes/genética , Sementes/crescimento & desenvolvimento , Ribonucleoproteínas Nucleolares Pequenas/genética , Ribonucleoproteínas Nucleolares Pequenas/metabolismoRESUMO
Telomerase is a ribonucleoprotein (RNP) enzyme that extends telomeric repeats at eukaryotic chromosome ends to counterbalance telomere loss caused by incomplete genome replication. Human telomerase is comprised of two distinct functional lobes tethered by telomerase RNA (hTR): a catalytic core, responsible for DNA extension; and a Hinge and ACA (H/ACA) box RNP, responsible for telomerase biogenesis. H/ACA RNPs also have a general role in pseudouridylation of spliceosomal and ribosomal RNAs, which is critical for the biogenesis of the spliceosome and ribosome. Much of our structural understanding of eukaryotic H/ACA RNPs comes from structures of the human telomerase H/ACA RNP. Here we report a 2.7 Å cryo-electron microscopy structure of the telomerase H/ACA RNP. The significant improvement in resolution over previous 3.3 Å to 8.2 Å structures allows us to uncover new molecular interactions within the H/ACA RNP. Many disease mutations are mapped to these interaction sites. The structure also reveals unprecedented insights into a region critical for pseudouridylation in canonical H/ACA RNPs. Together, our work advances understanding of telomerase-related disease mutations and the mechanism of pseudouridylation by eukaryotic H/ACA RNPs.
Assuntos
Ribonucleoproteínas , Telomerase , Humanos , Ribonucleoproteínas/genética , Telomerase/genética , Microscopia Crioeletrônica , Ribonucleoproteínas Nucleolares Pequenas/genética , RNA/genética , RNA RibossômicoRESUMO
The DEAD-box helicase Dbp4 plays an essential role during the early assembly of the 40S ribosome, which is only poorly understood to date. By applying the yeast two-hybrid method and biochemical approaches, we discovered that Dbp4 interacts with the Efg1-Bud22 dimer. Both factors associate with early pre-90S particles and smaller complexes, each characterized by a high presence of the U14 snoRNA. A crosslink analysis of Bud22 revealed its contact to the U14 snoRNA and the 5' domain of the nascent 18S rRNA, close to its U14 snoRNA hybridization site. Moreover, depletion of Bud22 or Efg1 specifically affects U14 snoRNA association with pre-ribosomal complexes. Accordingly, we concluded that the role of the Efg1-Bud22 dimer is linked to the U14 snoRNA function on early 90S ribosome intermediates chaperoning the 5' domain of the nascent 18S rRNA. The successful rRNA folding of the 5' domain and the release of Efg1, Bud22, Dpb4, U14 snoRNA and associated snoRNP factors allows the subsequent recruitment of the Kre33-Bfr2-Enp2-Lcp5 module towards the 90S pre-ribosome.
Assuntos
Ribonucleoproteínas Nucleolares Pequenas , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Ribonucleoproteínas Nucleolares Pequenas/genética , Ribossomos/metabolismo , Precursores de RNA/metabolismo , RNA Ribossômico 18S/genética , RNA Ribossômico 18S/química , RNA Nucleolar Pequeno/genética , RNA Nucleolar Pequeno/química , Proteínas de Saccharomyces cerevisiae/química , Saccharomyces cerevisiae/metabolismoRESUMO
BACKGROUND: Colorectal cancer (CRC) is a prevalent type of gastrointestinal cancer, and its poor prognosis is mainly attributed to the occurrence of invasion and metastasis. CYP1B1-AS1, as non-coding RNA, plays an important role in tumorigenesis and progression. However, the mechanism by which CYP1B1-AS1 acts in CRC is not yet understood. AIMS: The objective of this study was to investigate how CYP1B1-AS1 contributes to the development of CRC, and provide a base for CRC diagnosis and treatment. METHODS: RT-qPCR was used to detect the expression level of CYP1B1-AS1 in CRC and adjacent tissues. CCK-8, Edu, scratch healing, and transwell experiments were used to detect the changes of proliferation, migration, and invasion ability of CRC cells after overexpression or knockdown of CYP1B1-AS1 respectively. The RNA binding protein NOP58 combined with CYP1B1-AS1 was verified by RIP and RNA Pull-down experiments. Functional recovery experiments validated the interaction between CYP1B1-AS1 and NOP58 in CRC cells. The changes of EMT-related proteins were detected by Western blot, and the half-life of transcription factor SNAIL mRNA were detected by RT-qPCR after overexpression or knockdown of NOP58. RESULTS: CYP1B1-AS1 was found to be significantly downregulated in CRC compared to adjacent noncancerous tissues. Experiments conducted in vitro and in vivo confirmed that upregulation of CYP1B1-AS1 significantly inhibited the proliferation, migration, and invasion of CRC cells. In addition, CYP1B1-AS1 can directly bind to NOP58 and negatively regulate NOP58. The effect of overexpression CYP1B1-AS1 was reversed by NOP58 overexpression. NOP58 regulates the EMT process of CRC cells by affecting the stability of EMT-related transcription factor SNAIL mRNA, and then affects the progress of CRC. CONCLUSION: This research proves that CYP1B1-AS1 can inhibit the occurrence of EMT in CRC by binding with NOP58, thus delaying the progress of CRC. This finding indicates that CYP1B1-AS1 may be a novel biomarker to improve the diagnosis and treatment of CRC.
Assuntos
Neoplasias Colorretais , MicroRNAs , RNA Longo não Codificante , Humanos , Linhagem Celular Tumoral , MicroRNAs/genética , Fatores de Transcrição/genética , Neoplasias Colorretais/patologia , RNA Mensageiro , Proliferação de Células/genética , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Movimento Celular/genética , Regulação Neoplásica da Expressão Gênica , Citocromo P-450 CYP1B1/genética , Citocromo P-450 CYP1B1/metabolismo , Proteínas Nucleares/genética , Ribonucleoproteínas Nucleolares Pequenas/genética , Ribonucleoproteínas Nucleolares Pequenas/metabolismoRESUMO
Glioblastoma (GBM) ranks among the most lethal of human cancers, containing glioma stem cells (GSCs) that display therapeutic resistance. Here, we report that the lncRNA INHEG is highly expressed in GSCs compared to differentiated glioma cells (DGCs) and promotes GSC self-renewal and tumorigenicity through control of rRNA 2'-O-methylation. INHEG induces the interaction between SUMO2 E3 ligase TAF15 and NOP58, a core component of snoRNP that guides rRNA methylation, to regulate NOP58 sumoylation and accelerate the C/D box snoRNP assembly. INHEG activation enhances rRNA 2'-O-methylation, thereby increasing the expression of oncogenic proteins including EGFR, IGF1R, CDK6 and PDGFRB in glioma cells. Taken together, this study identifies a lncRNA that connects snoRNP-guided rRNA 2'-O-methylation to upregulated protein translation in GSCs, supporting an axis for potential therapeutic targeting of gliomas.
Assuntos
Neoplasias Encefálicas , Glioblastoma , Glioma , RNA Longo não Codificante , Humanos , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Metilação , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Ribonucleoproteínas Nucleolares Pequenas/metabolismo , Células-Tronco Neoplásicas/metabolismo , Glioma/genética , Glioma/metabolismo , Glioblastoma/genética , Glioblastoma/metabolismo , Linhagem Celular TumoralRESUMO
The conserved H/ACA RNPs consist of one H/ACA RNA and 4 core proteins: dyskerin, NHP2, NOP10, and GAR1. Its assembly requires several assembly factors. A pre-particle containing the nascent RNAs, dyskerin, NOP10, NHP2 and NAF1 is assembled co-transcriptionally. NAF1 is later replaced by GAR1 to form mature RNPs. In this study, we explore the mechanism leading to the assembly of H/ACA RNPs. We performed the analysis of GAR1, NHP2, SHQ1 and NAF1 proteomes by quantitative SILAC proteomic, and analyzed purified complexes containing these proteins by sedimentation on glycerol gradient. We propose the formation of several distinct intermediate complexes during H/ACA RNP assembly, notably the formation of early protein-only complexes containing at least the core proteins dyskerin, NOP10, and NHP2, and the assembly factors SHQ1 and NAF1. We also identified new proteins associated with GAR1, NHP2, SHQ1 and NAF1, which can be important for box H/ACA assembly or function. Moreover, even though GAR1 is regulated by methylations, the nature, localization, and functions of these methylations are not well known. Our MS analysis of purified GAR1 revealed new sites of arginine methylations. Additionally, we showed that unmethylated GAR1 is correctly incorporated in H/ACA RNPs, even though with less efficiency than methylated ones.
Assuntos
Proteômica , Ribonucleoproteínas , Ribonucleoproteínas/genética , Ribonucleoproteínas Nucleolares Pequenas/genética , Ribonucleoproteínas Nucleolares Pequenas/metabolismo , Proteínas de Ligação a RNA , RNA/genéticaRESUMO
Polyamines have been discovered for hundreds of years and once considered as a class of phytohormones. Polyamines play critical roles in a range of developmental processes. However, the molecular mechanisms of polyamine signaling pathways remain poorly understood. Here, we measured the contents of main types of polyamines, and found that endogenous level of thermospermine (T-Spm) in Arabidopsis thaliana is comparable to those of classic phytohormones and is significantly lower than those of putrescine (Put), spermidine (Spd), and spermine (Spm). We further found a nodule-like structure around the junction area connecting the shoot and root of the T-Spm biosynthetic mutant acl5 and obtained more than 50 suppressors of acl5nodule structure (san) through suppressor screening. An in-depth study of two san suppressors revealed that NAP57 and NOP56, core components of box H/ACA and C/D snoRNPs, were essential for T-Spm-mediated nodule-like structure formation and plant height. Furthermore, analyses of rRNA modifications showed that the overall levels of pseudouridylation and 2'-O-methylation were compromised in san1 and san2 respectively. Taken together, these results establish a strong genetic relationship between rRNA modification and T-Spm-mediated growth and development, which was previously undiscovered in all organisms.
Assuntos
Arabidopsis , Espermina , Espermina/metabolismo , Arabidopsis/metabolismo , Ribonucleoproteínas Nucleolares Pequenas/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Poliaminas/metabolismoRESUMO
5-Methylcytosine (m5C) is a base modification broadly found on various RNAs in the human transcriptome. In eukaryotes, m5C is catalyzed by enzymes of the NSUN family composed of seven human members (NSUN1-7). NOP2/NSUN1 has been primarily characterized in budding yeast as an essential ribosome biogenesis factor required for the deposition of m5C on the 25S ribosomal RNA (rRNA). Although human NOP2/NSUN1 has been known to be an oncogene overexpressed in several types of cancer, its functions and substrates remain poorly characterized. Here, we used a miCLIP-seq approach to identify human NOP2/NSUN1 RNA substrates. Our analysis revealed that NOP2/NSUN1 catalyzes the deposition of m5C at position 4447 on the 28S rRNA. We also find that NOP2/NSUN1 binds to the 5'ETS region of the pre-rRNA transcript and regulates pre-rRNA processing through non-catalytic complex formation with box C/D snoRNAs. We provide evidence that NOP2/NSUN1 facilitates the recruitment of U3 and U8 snoRNAs to pre-90S ribosomal particles and their stable assembly into snoRNP complexes. Remarkably, expression of both WT and catalytically inactive NOP2/NSUN1 in knockdown background rescues the rRNA processing defects and the stable assembly of box C/D snoRNP complexes, suggesting that NOP2/NSUN1-mediated deposition of m5C on rRNA is not required for ribosome synthesis.
Assuntos
Proteínas Nucleares/metabolismo , Ribonucleoproteínas Nucleolares Pequenas , tRNA Metiltransferases/metabolismo , 5-Metilcitosina/metabolismo , Humanos , Precursores de RNA/metabolismo , RNA Ribossômico/metabolismo , RNA Ribossômico 28S/metabolismo , RNA Nucleolar Pequeno/metabolismo , Ribonucleoproteínas Nucleolares Pequenas/genética , Ribonucleoproteínas Nucleolares Pequenas/metabolismo , Ribossomos/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismoRESUMO
Regulation of protein synthesis is critical for control of gene expression in all cells. Ribosomes are ribonucleoprotein machines responsible for translating cellular proteins. Defects in ribosome production, function, or regulation are detrimental to the cell and cause human diseases, such as progressive encephalopathy with edema, hypsarrhythmia, and optic atrophy (PEHO) syndrome. PEHO syndrome is a devastating neurodevelopmental disorder caused by mutations in the ZNHIT3 gene, which encodes an evolutionarily conserved nuclear protein. The precise mechanisms by which ZNHIT3 mutations lead to PEHO syndrome are currently unclear. Studies of the human zinc finger HIT-type containing protein 3 homolog in budding yeast (Hit1) revealed that this protein is critical for formation of small nucleolar ribonucleoprotein complexes that are required for rRNA processing and 2'-O-methylation. Here, we use budding yeast as a model system to reveal the basis for the molecular pathogenesis of PEHO syndrome. We show that missense mutations modeling those found in PEHO syndrome patients cause a decrease in steady-state Hit1 protein levels, a significant reduction of box C/D snoRNA levels, and subsequent defects in rRNA processing and altered cellular translation. Using RiboMethSeq analysis of rRNAs isolated from actively translating ribosomes, we reveal site-specific changes in the rRNA modification pattern of PEHO syndrome mutant yeast cells. Our data suggest that PEHO syndrome is a ribosomopathy and reveal potential new aspects of the molecular basis of this disease in translation dysregulation.
Assuntos
Edema Encefálico , Doenças Neurodegenerativas , Proteínas Nucleares , Atrofia Óptica , Ribonucleoproteínas Nucleolares Pequenas , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Espasmos Infantis , Fatores de Transcrição , Edema Encefálico/genética , Humanos , Recém-Nascido , Mutação , Doenças Neurodegenerativas/genética , Proteínas Nucleares/genética , Atrofia Óptica/genética , RNA Nucleolar Pequeno/metabolismo , Ribonucleoproteínas Nucleolares Pequenas/genética , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética , Espasmos Infantis/genética , Fatores de Transcrição/genéticaRESUMO
Small nucleolar RNAs (snoRNAs) are commonly acknowledged as a class of homogeneous non-coding RNAs that guide ribosomal RNA modifications. However, snoRNAs referred to as orphans have largely unknown functions. Here, we systematically profile chromatin-associated snoRNAs (casnoRNAs) in mammalian cells and identify a subgroup of orphan casnoRNAs responding to DNA damage stress, among which SNORA73 shows the most marked reduction in chromatin enrichment. Downregulated SNORA73 maintains cancer genome stability and differentiation block in hematopoietic malignancy. Mechanistically, casnoRNA the 5' end non-canonical structure of SNORA73 is critical for its function and binding to poly (ADP-ribose) polymerase 1 (PARP1). SNORA73 inhibits PARP1 auto-PARylation to affect cancer genome stability by forming a small nucleolar ribonucleoprotein (snoRNP) with PARP1 and canonical H/ACA proteins DKC1/NHP2. Our findings reveal the role of an orphan snoRNA serving as casnoRNA and highlights a link between non-canonical structure of snoRNA and their functional diversity.
Assuntos
Cromatina , RNA Nucleolar Pequeno , Animais , Proteínas de Ciclo Celular/metabolismo , Diferenciação Celular/genética , Cromatina/genética , Dano ao DNA/genética , RNA Nucleolar Pequeno/genética , RNA Nucleolar Pequeno/metabolismo , Ribonucleoproteínas Nucleolares Pequenas/genéticaRESUMO
BACKGROUND: Human U three protein 14a (hUTP14a) is a nucleolar protein which promotes carcinogenesis by causing degradation of the tumor suppressor protein, p53. AIMS: This study aimed to investigate hUTP14a expression in hepatocellular carcinoma (HCC) and its value as a predictor for HCC recurrence after treatment with microwave ablation (MWA). MATERIALS AND METHODS: The hUTP14a expression was evaluated using immunohistochemistry on ultrasound-guided fine needle aspiration biopsy material from the tumor and the surrounding cirrhotic nontumor tissues. The relation between hUTP14a expression and clinic-pathologic variables was analyzed. RESULTS: Nuclear hUTP14a showed significant high expression in HCC tumor tissue compared with corresponding nontumor tissue (P<0.001). Tumoral hUTP14a expression was significantly higher in patients who experienced recurrence than those who were recurrence-free after MWA (P<0.001). CONCLUSION: We concluded that, hUTP14a has an oncogenic potential, as it is highly expressed in HCC tissues compared with surrounding nontumor cirrhotic tissues. Moreover, nuclear hUTP14a could be used as a promising prognostic biomarker for prediction of HCC recurrence after treatment with MWA.
Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/cirurgia , Humanos , Cirrose Hepática , Neoplasias Hepáticas/patologia , Micro-Ondas/uso terapêutico , Ribonucleoproteínas Nucleolares Pequenas/metabolismo , Resultado do TratamentoRESUMO
Monitoring mitochondrial function is crucial for organismal survival. This task is performed by mitochondrial surveillance or quality control pathways, which are activated by signals originating from mitochondria and relayed to the nucleus (retrograde response) to start transcription of protective genes. In Caenorhabditis elegans, several systems are known to play this role, including the UPRmt, MAPKmt, and the ESRE pathways. These pathways are highly conserved and their loss compromises survival following mitochondrial stress. In this study, we found a novel interaction between the box C/D snoRNA core proteins (snoRNPs) and mitochondrial surveillance and innate immune pathways. We showed that box C/D, but not box H/ACA, snoRNPs are required for the full function of UPRmt and ESRE upon stress. The loss of box C/D snoRNPs reduced mitochondrial mass, mitochondrial membrane potential, and oxygen consumption rate, indicating overall degradation of mitochondrial function. Concomitantly, the loss of C/D snoRNPs increased immune response and reduced host intestinal colonization by infectious bacteria, improving host resistance to pathogenesis. Our data may indicate a model wherein box C/D snoRNP machinery regulates a "switch" of the cell's activity between mitochondrial surveillance and innate immune activation. Understanding this mechanism is likely to be important for understanding multifactorial processes, including responses to infection and aging.
Assuntos
Mitocôndrias , Ribonucleoproteínas Nucleolares Pequenas , Animais , Caenorhabditis elegans/microbiologia , Imunidade Inata/genética , Mitocôndrias/genética , Mitocôndrias/metabolismo , RNA Nucleolar Pequeno , Ribonucleoproteínas Nucleolares Pequenas/genética , Ribonucleoproteínas Nucleolares Pequenas/metabolismoRESUMO
Neddylation is a posttranslational modification that attaches ubiquitin-like protein Nedd8 to protein targets via Nedd8-specific E1-E2-E3 enzymes and modulates many important biological processes. Nedd8 attaches to a lysine residue of a substrate, not for degradation, but for modulation of substrate activity. We previously identified the HECT-type ubiquitin ligase Smurf1, which controls diverse cellular processes, is activated by Nedd8 through covalent neddylation. Smurf1 functions as a thioester bond-type Nedd8 ligase to catalyze its own neddylation. Numerous ubiquitination substrates of Smurf1 have been identified, but the neddylation substrates of Smurf1 remain unknown. Here, we show that Smurf1 interacts with RRP9, a core component of the U3 snoRNP complex, which is involved in pre-rRNA processing. Our in vivo and in vitro neddylation modification assays show that RRP9 is conjugated with Nedd8. RRP9 neddylation is catalyzed by Smurf1 and removed by the NEDP1 deneddylase. We identified Lys221 as a major neddylation site on RRP9. Deficiency of RRP9 neddylation inhibits pre-rRNA processing and leads to downregulation of ribosomal biogenesis. Consequently, functional studies suggest that ectopic expression of RRP9 promotes tumor cell proliferation, colony formation, and cell migration, whereas unneddylated RRP9, K221R mutant has no such effect. Furthermore, in human colorectal cancer, elevated expression of RRP9 and Smurf1 correlates with cancer progression. These results reveal that Smurf1 plays a multifaceted role in pre-rRNA processing by catalyzing RRP9 neddylation and shed new light on the oncogenic role of RRP9.
Assuntos
Carcinogênese/metabolismo , Proteína NEDD8/metabolismo , Proteínas de Neoplasias/metabolismo , Processamento de Proteína Pós-Traducional , Ribonucleoproteínas Nucleolares Pequenas/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Substituição de Aminoácidos , Animais , Carcinogênese/genética , Células HCT116 , Células HT29 , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Mutação de Sentido Incorreto , Proteína NEDD8/genética , Proteínas de Neoplasias/genética , Ribonucleoproteínas Nucleolares Pequenas/genética , Ubiquitina-Proteína Ligases/genéticaRESUMO
Preoperative histopathological classification determines the primary surgical approach in endometrial carcinoma (EC) patients but has only moderate agreement between preoperative and postoperative diagnosis. The aim of the PIpelle Prospective ENDOmetrial carcinoma (PIPENDO) study is to determine whether histopathological assessment and a small panel of diagnostic biomarkers decreases discrepancies between preoperative and postoperative diagnosis in EC. Preoperative endometrial tissue of 378 included patients with EC was stained with 15 different antibodies. Clinically relevant discrepancies in grade or histological subtype between original preoperative and reviewed postoperative diagnosis were observed in 75 (20%) patients. Highest clinically relevant discrepancy was found in grade 2 ECs (20%), compared to 5% and 14% in respectively grade 1 and 3 endometrioid endometrial carcinomas (EECs). A practical two-biomarker panel with PR and p53 improved diagnostic accuracy (AUC = 0.92; 95%CI = 0.88-0.95) compared to solely morphological evaluation (AUC = 0.86). In preoperative high-grade EC, the diagnostic accuracy of histological subtype was improved by a three-immunohistochemical biomarker panel (PR, IMP3, and L1CAM) (AUC = 0.93; 95%CI = 0.88-0.98) compared to solely morphological evaluation (AUC = 0.81). In conclusion to improve correct preoperative diagnosis in EC, we recommend use of a panel of at least two easily accessible immunohistochemical biomarkers (PR and p53), only in grade 2 ECs. Overall, this will reduce clinically relevant discrepancies in tumor grade and subtype with postoperative diagnosis with 6% (from 20% to 14%). Addition of PR, IMP3, and L1CAM for histological subtyping in high-grade EECs resulted in a further decrease in discrepancies with 8% (from 20% to 12%).
Assuntos
Biomarcadores Tumorais/análise , Carcinoma Endometrioide/diagnóstico , Neoplasias do Endométrio/diagnóstico , Idoso , Feminino , Humanos , Imuno-Histoquímica , Pessoa de Meia-Idade , Molécula L1 de Adesão de Célula Nervosa/análise , Molécula L1 de Adesão de Célula Nervosa/biossíntese , Receptores de Progesterona/análise , Receptores de Progesterona/biossíntese , Ribonucleoproteínas Nucleolares Pequenas/análise , Ribonucleoproteínas Nucleolares Pequenas/biossíntese , Proteína Supressora de Tumor p53/análise , Proteína Supressora de Tumor p53/biossínteseRESUMO
BACKGROUND: MEK1/ERK signaling pathway plays an important role in most tumor progression, including colorectal cancer (CRC), however, MEK1-targeting therapy has little effective in treating CRC patients, indicating there may be a complex mechanism to activate MEK1/ERK signaling pathway except RAS activated mechanism. METHODS: To investigate the clinical significance of IMP3, we analyzed its expression levels in publicly available dataset and samples from Fudan University Shanghai Cancer Center. The effects of IMP3 on proliferation, migration, and invasion were determined by in vitro and in vivo experiments. To investigate the role of IMP3 in colon carcinogenesis, conditional IMP3 knockout C57BL/6 mice was generated. The IMP3/MEKK1/MEK/ERK signaling axis in CRC was screened and validated by RNA-sequencing, RNA immunoprecipitation, luciferase reporter and western blot assays. RESULTS: We find RNA binding protein IMP3 directly bind to MEKK1 mRNA 3'-UTR, which regulates its stability, promote MEKK1 expression and sequentially activates MEK1/ERK signaling. Functionally, IMP3 promote the malignant biological process of CRC cells via MEKK1/MEK1/ERK signaling pathway both in vitro and in vivo, Moreover, IMP3-/- mice show decreased the expression of MEKK1 as well as colorectal tumors compared with wild-type mice after treatment with azoxymethane/dextran sodium sulfate. Clinically, the expression of IMP3 and MEKK1 are positive correlated, and concomitant IMP3 and MEKK1 protein levels negatively correlate with metastasis in CRC patients. In addition, MEK1 inhibitor in combination with shRNA-IMP3 have a synergistic effect both in vitro and in vivo. CONCLUSION: Our study demonstrates that IMP3 regulates MEKK1 in CRC, thus activating the MEK1/ERK signaling in the progression of colorectal cancer, Furthermore, these results provide new insights into potential applications for combining MEK1 inhibitors with other target therapy such as IMP3 in preclinical trials for CRC patients.
Assuntos
Neoplasias Colorretais/metabolismo , MAP Quinase Quinase Quinase 1/metabolismo , Sistema de Sinalização das MAP Quinases , RNA Mensageiro/metabolismo , Animais , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Progressão da Doença , Humanos , Masculino , Camundongos , RNA Mensageiro/genética , Ribonucleoproteínas Nucleolares Pequenas/genética , Ribonucleoproteínas Nucleolares Pequenas/metabolismoRESUMO
Posttranscriptional modifications of RNA play an important role in promoting the maturation and functional diversity of many RNA species. Accordingly, understanding the enzymes and mechanisms that underlie RNA modifications is an important aspect in advancing our knowledge of the continually expanding RNA modification field. However, of the more than 160 currently identified RNA modifications, a large portion remains without quantitative detection assays for their biochemical characterization. Here, we describe the tritium release assay as a convenient tool allowing for the quantitative assessment of in vitro RNA pseudouridylation by stand-alone or box H/ACA RNA-guided pseudouridine synthases. This assay enables quantification of RNA pseudouridylation over a time course to effectively compare pseudouridylation activity between different substrates and/or different recombinant enzymes as well as to determine kinetic parameters. With the help of a quench-flow apparatus, the tritium release assay can be adapted for rapid kinetic measurements under single-turnover conditions to dissect reaction mechanisms. As examples, we show the formation of pseudouridines by a reconstituted Saccharomyces cerevisiae H/ACA small ribonucleoprotein (snoRNP) and an Escherichia coli stand-alone pseudouridine synthase.
Assuntos
Transferases Intramoleculares/genética , Pseudouridina/genética , RNA/genética , Ribonucleoproteínas Nucleolares Pequenas/genética , Escherichia coli/genética , Cinética , Processamento Pós-Transcricional do RNA/genética , RNA Guia de Cinetoplastídeos/genética , Saccharomyces cerevisiae/genéticaRESUMO
Immunohistochemical level of IMP3-protein in patients with rectal cancer in clinical stage II (141), were correlated with sociodemographic, pathohistological and clinical indicators and duration of overall-survival and progression-free-survival. Vascular invasion was associated with IMP3-positive immunostaining (p < 0.001). Vascular invasion ratio in the group of poorly-differentiated-tumors was 21 times higher than in the group of well-differentiated-tumors. IMP3-positive patients lived 2.2 times shorter than negative (p < 0.001). Patients with well-differentiated-tumors lived 1.7 times longer than the subjects with poorly-differentiated-tumors (p < 0.001). Patients without vascular invasion lived 2.7 times longer than the subjects with vascular invasion (p < 0.001). The risk of mortality was 2.3 times higher for IMP3 positive patients (p = 0.027) and 10.4 higher for the patients with vascular invasion (p < 0.001). IMP3-negative participants had 2.3 times longer free interval without disease (p < 0.001). The free interval without disease was 3.6 times longer in the group without vascular invasion (p < 0.001). The risk of disease relapse in the IMP3 positive group was 5.3 times higher (p < 0.001) and with vascular invasion was 8 times longer (p < 0.001). The risk of disease relapse was 6.8 times higher in the group with vascular invasion (p < 0.001). Patients with rectal cancer and high IMP3-protein level will have a shorter overall survival relative to patients without or with low levels of IMP3. The analysis of IMP3 expression by immunohistochemistry pointed IMP3 as an independent prognostic factor of clinical stage II rectal cancer.
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Biomarcadores Tumorais/metabolismo , Neoplasias Retais/patologia , Regulação para Cima , Idoso , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , Proteínas de Ligação a RNA/metabolismo , Neoplasias Retais/metabolismo , Neoplasias Retais/mortalidade , Ribonucleoproteínas Nucleolares Pequenas/metabolismo , Análise de SobrevidaRESUMO
INTRODUCTION: NOP58 ribonucleoprotein, a core component of box C/D small nucleolar ribonucleoproteins, is involved in various cell physiological processes. However, its role in hepatocellular carcinoma (HCC) remains very unclear. We aim to investigate NOP58 expression and its probable prognostic value in patients with HCC based on The Cancer Genome Atlas (TCGA) database. METHODS: RNA sequencing data and clinicopathological characteristics of patients with HCC were collected from TCGA database. Expression of NOP58 in HCC tissues and normal tissues was analyzed by Wilcoxon rank-sum test. Patients were divided into high and low subgroups according to median expression of NOP58. Logistic regression, gene set enrichment analysis (GSEA), and single-sample gene set enrichment analysis (ssGSEA) were conducted to annotate biological function and immune infiltration of NOP58. RESULTS: NOP58 was significantly overexpressed in HCC tissues and correlated with significantly high tumor stage [odds ratio (OR) 10.01, 95% confidence interval (CI) 10.01-10.03; P = 0.003], advanced pathologic stage (OR 10.02, 95% CI 10.01-10.03; P < 0.001), advanced histologic stage (OR 10.03, 95% CI 10.02-10.04; P < 0.001), vascular invasion (OR 10.02, 95% CI 10.01-10.03; P = 0.003), poor performance status (OR 10.01, 95% CI 10.01-10.03; P = 0.003), and Mut-TP53 status (OR 10.02, 95% CI 10.01-10.03; P < 0.001). Elevated NOP58 expression had poor disease-specific survival (DSS; P < 0.001), progression-free interval (P = 0.006), and overall survival (OS; P < 0.001). NOP58 expression was independently correlated with OS (HR 1.731, 95% CI 10.037-2.890; P = 0.036). GSEA demonstrated that various cell cycle pathways along with RB-1 pathway, interleukin-10 signaling, regulation of TP53 activity, and P53 downstream pathway were differentially enriched in NOP58 high expression phenotype. NOP58 expression was positively correlated with infiltrating the levels of T helper type 2 (Th2) cells. CONCLUSIONS: Overexpression of NOP58 is negatively correlated with overall survival in patients with HCC and might be a potential biomarker for prognosis of HCC.