Small nucleolar RNAs(snoRNAs)represent a class of non-coding RNAs that play pivotal roles in post-transcriptional RNA processing and modification,thereby contributing significantly to the maintenance of cellular funct...Small nucleolar RNAs(snoRNAs)represent a class of non-coding RNAs that play pivotal roles in post-transcriptional RNA processing and modification,thereby contributing significantly to the maintenance of cellular functions related to protein synthesis.SnoRNAs have been discovered to possess the ability to influence cell fate and alter disease progression,holding immense potential in controlling human diseases.It is suggested that the dysregulation of snoRNAs in cancer exhibits differential expression across various cancer types,stages,metastasis,treatment response and/or prognosis in patients.On the other hand,colorectal cancer(CRC),a prevalent malignancy of the digestive system,is characterized by high incidence and mortality rates,ranking as the third most common cancer type.Recent research indicates that snoRNA dysregulation is associated with CRC,as snoRNA expression significantly differs between normal and cancerous conditions.Consequently,assessing snoRNA expression level and function holds promise for the prognosis and diagnosis of CRC.Nevertheless,current comprehension of the potential roles of snoRNAs in CRC remains limited.This review offers a comprehensive survey of the aberrant regulation of snoRNAs in CRC,providing valuable insights into the discovery of novel biomarkers,therapeutic targets,and potential tools for the diagnosis and treatment of CRC and furnishing critical cues for advancing research into CRC and the judicious selection of therapeutic targets.展开更多
By using the DNA specific cytochemical staining method (NAMA_Ur) and conventional electron microscopic technique, the authors examined the configuration of intranucleolar DNA in Allium cepa L. cells and found that...By using the DNA specific cytochemical staining method (NAMA_Ur) and conventional electron microscopic technique, the authors examined the configuration of intranucleolar DNA in Allium cepa L. cells and found that nucleolar DNA within the fibrillar center (FC) underwent a structural transformation process from condensed to extended state. The authors' observations also displayed a continuous arrangement process of nucleolar DNA, i.e., the extranucleolar DNA entered FC through the nucleolar organizer region (NOR) channel, then extended to the periphery of FC or to the border between FC and dense fibrillar component (DFC), and distributed along the periphery of FC. Thence, by passing through the NOR channel between FCs, the nucleolar DNA continued to transfer to other FCs and arranged in the same above_mentioned forms.展开更多
Human normal endometrium was examined in ultrathin sections. Nucleolar channel system (NCS) appeared in the endometrial epithelial cells during the early and mid secretory phase of menstrual cycle. The NCS was a hollo...Human normal endometrium was examined in ultrathin sections. Nucleolar channel system (NCS) appeared in the endometrial epithelial cells during the early and mid secretory phase of menstrual cycle. The NCS was a hollow ball like structure of different sizes and was composed of 2 to 5 rows of tubules embedded in an amorphous matrix. On its surface there were numerous electron dense particles resembling ribosonies. It was usually located within or associated with the nucleolus. Sometimes, it was close to the nuclear envelope or protruding out from the nucleus. On occasion, NCS with simplified structure was found in the perinuclear cytoplasm. Concepts concerning the genesis, involution and function(s) of the NCS were discussed.展开更多
Objective To determine whether formation of the nucleolar channel system (NCS) in human endometrium depends on the presence of progesteronal steroids. Materials & Methods Tissues of late proliferative endometrium ...Objective To determine whether formation of the nucleolar channel system (NCS) in human endometrium depends on the presence of progesteronal steroids. Materials & Methods Tissues of late proliferative endometrium were obtained from 5 normally cycling women of reproductive age. Half of each tissue was cultured in the DMEM medium containing diethylstilbesterol (25 μg/mL) plus medroxyprogesterone acetate (25 μg/mL) (E + P culture). As a control, the other half was cultured in the medium alone. After 100 h incubation, the tissues were assessed for the formation of NCS with transmission electron microscope.Results NCS was observed in the endometrial epithelium treated with E + P or the medium alone. Moreover, giant mitochondria and glycogen accumulation were both seen in epithelia derived from both types of cultures.Conclusion Progesterone would be not indispensable for the formation of NCS in human endometrium. Transition of proliferative endometrium to the secretory stage in vitro could occur even in the absence of both estrogen and progesterone.展开更多
Cancer has become the most life-threatening disease in the world.Mutations in and aberrant expression of genes encoding proteins and mutations in noncoding RNAs,especially long noncoding RNAs(lncRNAs),have significant...Cancer has become the most life-threatening disease in the world.Mutations in and aberrant expression of genes encoding proteins and mutations in noncoding RNAs,especially long noncoding RNAs(lncRNAs),have significant effects in human cancers.LncRNAs have no protein-coding ability but function extensively in numerous physiological and pathological processes.Small nucleolar RNA host gene 3(SNHG3)is a novel lncRNA and has been reported to be differentially expressed in various tumors,such as liver cancer,gastric cancer,and glioma.However,the interaction mechanisms for the regulation between SNHG3 and tumor progression are poorly understood.In this review,we summarize the results of SNHG3 studies in humans,animal models,and cells to underline the expression and role of SNHG3 in cancer.SNHG3 expression is upregulated in most tumors and is detrimental to patient prognosis.SNHG3 expression in lung adenocarcinoma remains controversial.Concurrently,SNHG3 affects oncogenes and tumor suppressor genes through various mechanisms,including competing endogenous RNA effects.A deeper understanding of the contribution of SNHG3 in clinical applications and tumor development may provide a new target for cancer diagnosis and treatment.展开更多
By using silver colloid staining technique,nucleolar organizer region-associated proteins(AgNORs)were studied quantatively in paraffin sections of 12 casesof polypoid adenomas,10 cases of villous adenomas,22 cases of ...By using silver colloid staining technique,nucleolar organizer region-associated proteins(AgNORs)were studied quantatively in paraffin sections of 12 casesof polypoid adenomas,10 cases of villous adenomas,22 cases of colonadenocarcinomas,and 10 cases of normal colonic mucosa as control.The resultsshowed that the mean number of AgNORs per nucleus in the villous adcnoma was similarto that of adenocaranoma,which significantly exceeded those of the normal mucosa andthe polypoid adenoma.The granules of AgNORs in adcnocarcinoma were much largerand more irregular in sizc and shape.It is suggested that benign villous adenoma is akind of lesion between polypoid adenoma and adenocarcinoma,and AgNOR techniquemay be very helpful in differential diagnosis of colon tumors.展开更多
Objective： To evaluate the relation between argyrophilic nucleolar organizer region （AgNOR）-associated proteins and clinicopathological parameters and survival in non-small-cell lung cancer （NSCLC）. Methods： A t...Objective： To evaluate the relation between argyrophilic nucleolar organizer region （AgNOR）-associated proteins and clinicopathological parameters and survival in non-small-cell lung cancer （NSCLC）. Methods： A total of 207 surgical specimens diagnosed as NSCLC were included in this study. Double-staining procedures were performed using antigen Ki-67 （clone MIB-1） and silver nitrate by immunohistochemical and AgNOR-staining methods. Results： The AgNOR area in MIB-l-positive cells of NSCLC is related to clinicopathological parameters under the TNM （tumor, node, and metastasis） system. The survival of patients with small AgNOR area in MIB-1-positive cells is better than that of patients with large AgNOR area. Molecular, biological （AgNOR area in MIB-l-positive cells）, and clinicopathological （greatest tumor dimension, metastases to regional lymph nodes, histology, and differentiation） parameters are independent prognostic factors of NSCLC.Conclusion： The AgNOR area in MIB- 1-positive cells is related to clinicopathological parameters and survival in NSCLC.展开更多
The present work studied the application of AgNOR count to differential diagnosis between cutaneous T cell lymphoma (CTCL) and cutaneous pseudolymphoma (CPL). Paraffin sections from 50 mycosis fungoides (22 MFI-Premyc...The present work studied the application of AgNOR count to differential diagnosis between cutaneous T cell lymphoma (CTCL) and cutaneous pseudolymphoma (CPL). Paraffin sections from 50 mycosis fungoides (22 MFI-Premycotic stage, 24 MF Ⅰ infiltrative stage and 4 MF Ⅲ - tumor stage), 2 nonepidermotropic cutaneous T cell lymphoma (NECTCL) and 9 CPL were investigated. In each case, 200 cells randomly selected were examined using a × 100 oil immersion lens. The mean number, standard deviation and standard error of the mean of AgNOR counts were as follows: MFⅠ 1.17±0.09, SEM = 0.01; MⅡ 1.17±0.01, SEM = 0.01; MF Ⅲ. 3.55±0.87, SEM = 0.43; NECTCL 4.5±0.28, SEM -0.199; CPL 1.17±0.1, SEM ± 0.03. The results revealed a highly significant difference between CTCL (MFⅢ+NECTCL) and CPL (t = 4.75, P<0.001), tumor stage (MF Ⅲ) and pretumor stage (MFI, MF Ⅱ) of mycosis fungoides (t = 4.75, P<0.001). Thus. AgNOR count is valuable in differential diagnosis.展开更多
The argyrophil method for nucleolar organizer regions (AgNOR) known as the AgNor technique and mucin histochemical stain were applied to Investigate the dysplasia and cancaration in ulcerative colitis Including 58 cas...The argyrophil method for nucleolar organizer regions (AgNOR) known as the AgNor technique and mucin histochemical stain were applied to Investigate the dysplasia and cancaration in ulcerative colitis Including 58 cases of biopsy specimens and three cases operative specimens. The numbers of AgNOR have been gradully increased with the grades of dasplasls. Similarly the percentage of sialomucin having vicinal diols on side chain of sialic acid also gradully Increased with the grades of dysplasia. The AgNOR reflects rDNA transcriptional activity responsible for degrees of differentiation of cell. Epithelial cells secreting a heterogeneous mucin, could be taken as a signal of abnormal cellular differentiation. AgNOR and mucln chages might be assumed as a criteria In representing malignant transformation.展开更多
AIM: To investigate the subcellular localization and the function of mouse transducin β-like 3(Tbl3).METHODS: The coding sequence of mouse Tbl3 was cloned from the c DNAs of a promyelocyte cell line by reverse transc...AIM: To investigate the subcellular localization and the function of mouse transducin β-like 3(Tbl3).METHODS: The coding sequence of mouse Tbl3 was cloned from the c DNAs of a promyelocyte cell line by reverse transcription-polymerase chain reaction. Fusion constructs of Tbl3 and enhanced green fluorescent protein(EGFP) were transfected into fibroblasts and examined by fluorescence microscopy to reveal the subcellular localization of tbl3. To search for nucleolar targeting sequences, scanning deletions of Tbl3-EGFP were constructed and transfected into fibroblasts. To explore the possible function of Tbl3, small hairpin RNAs(sh RNAs) were used to knock down endogenous Tbl3 in mouse promyelocytes and fibroblasts. The effects of Tbl3 knockdown on ribosomal RNA(r RNAs) synthesis or processing were studied by labeling cells with 5,6-3H-uridine followed by a chase with fresh medium for various periods. Total RNAs were purified from treated cells and subjected to gel electrophoresis and Northern analysis. Ribosome profiling by sucrose gradient centrifugation was used to compare the amounts of 40 S and 60 S ribosome subunits as well as the 80 S monosome. The impact of Tbl3 knockdown on cell growth and proliferation was examined by growth curves and colony assays.RESULTS: The largest open reading frame of mouse Tbl3 encodes a protein of 801 amino acids(AA) with an apparent molecular weight of 89-90 kilodalton. It contains thirteen WD40 repeats(an ancient protein-protein interaction motif) and a carboxyl terminus that is highly homologous to the corresponding region of the yeast nucleolar protein, utp13. Virtually nothing is known about the biological function of Tbl3. All cell lines surveyed expressed Tbl3 and the level of expression correlated roughly with cell proliferation and/or biosynthetic activity. Using Tbl3-EGFP fusion constructs we obtained the first direct evidence that Tbl3 is targeted to the nucleoli in mammalian cells. However, no previously described nucleolar targeting sequences were found in Tbl3, suggesting that the WD40 motif and/or other topological features are responsible for nucleolar targeting. Partial knockdown(by 50%-70%) of mouse Tbl3 by shR NA had no discernable effects on the processing of the 47 S pre-ribosomal RNA(pre-r RNA) or the steady-state levels of the mature 28 S, 18 S and 5.8S r RNAs but consistently increased the expression level of the 47 S pre-rR NA by two to four folds. The results of the current study corroborated the previous finding that there was no detectable rR NA processing defects in zebra fish embryos with homozygous deletions of zebra fish Tbl3. As ribosome production consumes the bulk of cellular energy and biosynthetic precursors, dysregulation of pre-rR NA synthesis can have negative effects on cell growth, proliferation and differentiation. Indeed, partial knockdown of Tbl3 in promyelocytes severely impaired their proliferation. The inhibitory effect of Tbl3 knockdown was also observed in fibroblasts, resulting in an 80% reduction in colony formation. Taken together, these results indicate that Tbl3 is a newly recognized nucleolar protein with regulatory roles at very early stages of ribosome biogenesis, perhaps at the level of rR NA gene transcription. CONCLUSION: Tbl3 is a newly recognized nucleolar protein with important regulatory roles in ribosome biogenesis.展开更多
Small nucleolar RNAs (snoRNAs) are non-coding RNA (ncRNA) molecules,which are associated with specific proteins to form small nucleolar ribonucleoparticles.However,the function of snoRNAs in cancer still remains elusi...Small nucleolar RNAs (snoRNAs) are non-coding RNA (ncRNA) molecules,which are associated with specific proteins to form small nucleolar ribonucleoparticles.However,the function of snoRNAs in cancer still remains elusive.Recently,several independent lines of evidence have indicated that these ncRNAs might have crucial roles in controlling tumorigenesis,and snoRNAs could be potential biomarkers for cancer.展开更多
Pathogen effectors target diverse subcellular organelles to manipulate the plant immune system.Although the nucleolus has emerged as a stress marker and several effectors are localized in the nucleolus,the roles of nu...Pathogen effectors target diverse subcellular organelles to manipulate the plant immune system.Although the nucleolus has emerged as a stress marker and several effectors are localized in the nucleolus,the roles of nucleolar-targeted effectors remain elusive.In this study,we showed that Phytophthora infestans infection of Nicotiana benthamiana results in nucleolar inflation during the transition from the biotrophic to the necrotrophic phase.Multiple P.infestans effectors were localized in the nucleolus:Pi23226 induced cell death in N.benthamiana and nucleolar inflation similar to that observed in the necrotrophic stage of infection,whereas its homolog Pi23015 and a deletion mutant(Pi23226DC)did not induce cell death or affect nucleolar size.RNA immunoprecipitation and individual-nucleotide-resolution UV crosslinking and immunoprecipitation sequencing analysis indicated that Pi23226 bound to the 30 end of 25S rRNA precursors,resulting in accumulation of unprocessed 27S pre-rRNAs.The nucleolar stress marker NAC082 was strongly upregulated under Pi23226-expressing conditions.Pi23226 subsequently inhibited global protein translation in host cells by interacting with ribosomes.Pi23226 enhanced P.infestans pathogenicity,indicating that Pi23226-induced ribosome malfunction and cell death were beneficial for pathogenesis in the host.Our results provide evidence for the molecular mechanism underlying RNA-binding effector activity in host ribosome biogenesis and lead to new insights into the nucleolar action of effectors in pathogenesis.展开更多
人核仁磷酸化蛋白1(Nucleolar and coiledbody phosphoprotein 1,NOLC1)在癌症的发生发展过程中起着至关重要的调控作用,为探讨NOLC1对肺癌细胞的作用,本研究通过Gateway系统构建重组NOLC1腺病毒载体,成功包装NOLC1腺病毒后,分别感染正...人核仁磷酸化蛋白1(Nucleolar and coiledbody phosphoprotein 1,NOLC1)在癌症的发生发展过程中起着至关重要的调控作用,为探讨NOLC1对肺癌细胞的作用,本研究通过Gateway系统构建重组NOLC1腺病毒载体,成功包装NOLC1腺病毒后,分别感染正常人类胚胎肺细胞(HEL)和非小细胞肺癌细胞(A549细胞),过表达NOLC1。通过MTT实验、AnnexinV-APC/PI双染法和线粒体膜电位实验,证明与HEL细胞相比,NOLC1的过表达对A549细胞的活性降低、凋亡增加、线粒体膜电位下降影响较为显著;通过Real-time PCR检测Caspase家族、TNF与受体家族和BCL2家族基因的表达,发现过表达NOLC1明显上调了A549细胞中促凋亡基因的表达,下调了抗凋亡基因的表达,其中两种重要的促凋亡蛋白CASP8和BAX均显著上调,但是在HEL细胞中这种影响不明显。研究结果表明过表达NOLC1蛋白通过对线粒体通路和死亡受体通路的共同作用,对非小细胞癌具有显著的抗肿瘤活性。展开更多
Purified nucleoli of HeLa cells were treated sequentially with nonionic detergent, nucleic acid enzyme, low salt and high salt. The residual nucleolar structure termed nucleolar skeleton (nucleolar matrix) was shown a...Purified nucleoli of HeLa cells were treated sequentially with nonionic detergent, nucleic acid enzyme, low salt and high salt. The residual nucleolar structure termed nucleolar skeleton (nucleolar matrix) was shown as a fine network under electron microscope with DGD embedding-unembedding technique. Such structures of BHK-21 cell and mouse liver cell are similar to that of HeLa cell. The protein composition of the nucleolar skeleton of HeLa cells was analyzed. The protein composition of such nucleolar residual shows obvious difference from the compositions of nuclear matrix and chromosome scaffold. The major protein composition of the nucleolar skeleton of HeLa cells contains 6-7 polypeptides. Their molecular weights are about 48, 43, 36 and 33 ku. Further studies show that actin and fib-rillarin are two major protein components of nucleolar skeleton of HeLa cells.展开更多
基金the National Natural Science Foundation of China,No.82273457Guangdong Basic and Applied Basic Research Foundation,No.2021A1515012180 and No.2023A1515012762+1 种基金Special Grant for Key Area Programs of Guangdong Department of Education,No.2021ZDZX2040and Science and Technology Special Project of Guangdong Province,No.210715216902829.
文摘Small nucleolar RNAs(snoRNAs)represent a class of non-coding RNAs that play pivotal roles in post-transcriptional RNA processing and modification,thereby contributing significantly to the maintenance of cellular functions related to protein synthesis.SnoRNAs have been discovered to possess the ability to influence cell fate and alter disease progression,holding immense potential in controlling human diseases.It is suggested that the dysregulation of snoRNAs in cancer exhibits differential expression across various cancer types,stages,metastasis,treatment response and/or prognosis in patients.On the other hand,colorectal cancer(CRC),a prevalent malignancy of the digestive system,is characterized by high incidence and mortality rates,ranking as the third most common cancer type.Recent research indicates that snoRNA dysregulation is associated with CRC,as snoRNA expression significantly differs between normal and cancerous conditions.Consequently,assessing snoRNA expression level and function holds promise for the prognosis and diagnosis of CRC.Nevertheless,current comprehension of the potential roles of snoRNAs in CRC remains limited.This review offers a comprehensive survey of the aberrant regulation of snoRNAs in CRC,providing valuable insights into the discovery of novel biomarkers,therapeutic targets,and potential tools for the diagnosis and treatment of CRC and furnishing critical cues for advancing research into CRC and the judicious selection of therapeutic targets.
文摘By using the DNA specific cytochemical staining method (NAMA_Ur) and conventional electron microscopic technique, the authors examined the configuration of intranucleolar DNA in Allium cepa L. cells and found that nucleolar DNA within the fibrillar center (FC) underwent a structural transformation process from condensed to extended state. The authors' observations also displayed a continuous arrangement process of nucleolar DNA, i.e., the extranucleolar DNA entered FC through the nucleolar organizer region (NOR) channel, then extended to the periphery of FC or to the border between FC and dense fibrillar component (DFC), and distributed along the periphery of FC. Thence, by passing through the NOR channel between FCs, the nucleolar DNA continued to transfer to other FCs and arranged in the same above_mentioned forms.
文摘Human normal endometrium was examined in ultrathin sections. Nucleolar channel system (NCS) appeared in the endometrial epithelial cells during the early and mid secretory phase of menstrual cycle. The NCS was a hollow ball like structure of different sizes and was composed of 2 to 5 rows of tubules embedded in an amorphous matrix. On its surface there were numerous electron dense particles resembling ribosonies. It was usually located within or associated with the nucleolus. Sometimes, it was close to the nuclear envelope or protruding out from the nucleus. On occasion, NCS with simplified structure was found in the perinuclear cytoplasm. Concepts concerning the genesis, involution and function(s) of the NCS were discussed.
基金This study was supported by the National Science Fund of P.R.China (No.39970765)
文摘Objective To determine whether formation of the nucleolar channel system (NCS) in human endometrium depends on the presence of progesteronal steroids. Materials & Methods Tissues of late proliferative endometrium were obtained from 5 normally cycling women of reproductive age. Half of each tissue was cultured in the DMEM medium containing diethylstilbesterol (25 μg/mL) plus medroxyprogesterone acetate (25 μg/mL) (E + P culture). As a control, the other half was cultured in the medium alone. After 100 h incubation, the tissues were assessed for the formation of NCS with transmission electron microscope.Results NCS was observed in the endometrial epithelium treated with E + P or the medium alone. Moreover, giant mitochondria and glycogen accumulation were both seen in epithelia derived from both types of cultures.Conclusion Progesterone would be not indispensable for the formation of NCS in human endometrium. Transition of proliferative endometrium to the secretory stage in vitro could occur even in the absence of both estrogen and progesterone.
基金Supported by the National Science and Technology Major Project of China,No. 2018ZX10302206 and 2017ZX10202203
文摘Cancer has become the most life-threatening disease in the world.Mutations in and aberrant expression of genes encoding proteins and mutations in noncoding RNAs,especially long noncoding RNAs(lncRNAs),have significant effects in human cancers.LncRNAs have no protein-coding ability but function extensively in numerous physiological and pathological processes.Small nucleolar RNA host gene 3(SNHG3)is a novel lncRNA and has been reported to be differentially expressed in various tumors,such as liver cancer,gastric cancer,and glioma.However,the interaction mechanisms for the regulation between SNHG3 and tumor progression are poorly understood.In this review,we summarize the results of SNHG3 studies in humans,animal models,and cells to underline the expression and role of SNHG3 in cancer.SNHG3 expression is upregulated in most tumors and is detrimental to patient prognosis.SNHG3 expression in lung adenocarcinoma remains controversial.Concurrently,SNHG3 affects oncogenes and tumor suppressor genes through various mechanisms,including competing endogenous RNA effects.A deeper understanding of the contribution of SNHG3 in clinical applications and tumor development may provide a new target for cancer diagnosis and treatment.
文摘By using silver colloid staining technique,nucleolar organizer region-associated proteins(AgNORs)were studied quantatively in paraffin sections of 12 casesof polypoid adenomas,10 cases of villous adenomas,22 cases of colonadenocarcinomas,and 10 cases of normal colonic mucosa as control.The resultsshowed that the mean number of AgNORs per nucleus in the villous adcnoma was similarto that of adenocaranoma,which significantly exceeded those of the normal mucosa andthe polypoid adenoma.The granules of AgNORs in adcnocarcinoma were much largerand more irregular in sizc and shape.It is suggested that benign villous adenoma is akind of lesion between polypoid adenoma and adenocarcinoma,and AgNOR techniquemay be very helpful in differential diagnosis of colon tumors.
文摘Objective： To evaluate the relation between argyrophilic nucleolar organizer region （AgNOR）-associated proteins and clinicopathological parameters and survival in non-small-cell lung cancer （NSCLC）. Methods： A total of 207 surgical specimens diagnosed as NSCLC were included in this study. Double-staining procedures were performed using antigen Ki-67 （clone MIB-1） and silver nitrate by immunohistochemical and AgNOR-staining methods. Results： The AgNOR area in MIB-l-positive cells of NSCLC is related to clinicopathological parameters under the TNM （tumor, node, and metastasis） system. The survival of patients with small AgNOR area in MIB-1-positive cells is better than that of patients with large AgNOR area. Molecular, biological （AgNOR area in MIB-l-positive cells）, and clinicopathological （greatest tumor dimension, metastases to regional lymph nodes, histology, and differentiation） parameters are independent prognostic factors of NSCLC.Conclusion： The AgNOR area in MIB- 1-positive cells is related to clinicopathological parameters and survival in NSCLC.
文摘The present work studied the application of AgNOR count to differential diagnosis between cutaneous T cell lymphoma (CTCL) and cutaneous pseudolymphoma (CPL). Paraffin sections from 50 mycosis fungoides (22 MFI-Premycotic stage, 24 MF Ⅰ infiltrative stage and 4 MF Ⅲ - tumor stage), 2 nonepidermotropic cutaneous T cell lymphoma (NECTCL) and 9 CPL were investigated. In each case, 200 cells randomly selected were examined using a × 100 oil immersion lens. The mean number, standard deviation and standard error of the mean of AgNOR counts were as follows: MFⅠ 1.17±0.09, SEM = 0.01; MⅡ 1.17±0.01, SEM = 0.01; MF Ⅲ. 3.55±0.87, SEM = 0.43; NECTCL 4.5±0.28, SEM -0.199; CPL 1.17±0.1, SEM ± 0.03. The results revealed a highly significant difference between CTCL (MFⅢ+NECTCL) and CPL (t = 4.75, P<0.001), tumor stage (MF Ⅲ) and pretumor stage (MFI, MF Ⅱ) of mycosis fungoides (t = 4.75, P<0.001). Thus. AgNOR count is valuable in differential diagnosis.
文摘The argyrophil method for nucleolar organizer regions (AgNOR) known as the AgNor technique and mucin histochemical stain were applied to Investigate the dysplasia and cancaration in ulcerative colitis Including 58 cases of biopsy specimens and three cases operative specimens. The numbers of AgNOR have been gradully increased with the grades of dasplasls. Similarly the percentage of sialomucin having vicinal diols on side chain of sialic acid also gradully Increased with the grades of dysplasia. The AgNOR reflects rDNA transcriptional activity responsible for degrees of differentiation of cell. Epithelial cells secreting a heterogeneous mucin, could be taken as a signal of abnormal cellular differentiation. AgNOR and mucln chages might be assumed as a criteria In representing malignant transformation.
基金Supported by In part by a grant from the St.Perres Fund,No.11-02011
文摘AIM: To investigate the subcellular localization and the function of mouse transducin β-like 3(Tbl3).METHODS: The coding sequence of mouse Tbl3 was cloned from the c DNAs of a promyelocyte cell line by reverse transcription-polymerase chain reaction. Fusion constructs of Tbl3 and enhanced green fluorescent protein(EGFP) were transfected into fibroblasts and examined by fluorescence microscopy to reveal the subcellular localization of tbl3. To search for nucleolar targeting sequences, scanning deletions of Tbl3-EGFP were constructed and transfected into fibroblasts. To explore the possible function of Tbl3, small hairpin RNAs(sh RNAs) were used to knock down endogenous Tbl3 in mouse promyelocytes and fibroblasts. The effects of Tbl3 knockdown on ribosomal RNA(r RNAs) synthesis or processing were studied by labeling cells with 5,6-3H-uridine followed by a chase with fresh medium for various periods. Total RNAs were purified from treated cells and subjected to gel electrophoresis and Northern analysis. Ribosome profiling by sucrose gradient centrifugation was used to compare the amounts of 40 S and 60 S ribosome subunits as well as the 80 S monosome. The impact of Tbl3 knockdown on cell growth and proliferation was examined by growth curves and colony assays.RESULTS: The largest open reading frame of mouse Tbl3 encodes a protein of 801 amino acids(AA) with an apparent molecular weight of 89-90 kilodalton. It contains thirteen WD40 repeats(an ancient protein-protein interaction motif) and a carboxyl terminus that is highly homologous to the corresponding region of the yeast nucleolar protein, utp13. Virtually nothing is known about the biological function of Tbl3. All cell lines surveyed expressed Tbl3 and the level of expression correlated roughly with cell proliferation and/or biosynthetic activity. Using Tbl3-EGFP fusion constructs we obtained the first direct evidence that Tbl3 is targeted to the nucleoli in mammalian cells. However, no previously described nucleolar targeting sequences were found in Tbl3, suggesting that the WD40 motif and/or other topological features are responsible for nucleolar targeting. Partial knockdown(by 50%-70%) of mouse Tbl3 by shR NA had no discernable effects on the processing of the 47 S pre-ribosomal RNA(pre-r RNA) or the steady-state levels of the mature 28 S, 18 S and 5.8S r RNAs but consistently increased the expression level of the 47 S pre-rR NA by two to four folds. The results of the current study corroborated the previous finding that there was no detectable rR NA processing defects in zebra fish embryos with homozygous deletions of zebra fish Tbl3. As ribosome production consumes the bulk of cellular energy and biosynthetic precursors, dysregulation of pre-rR NA synthesis can have negative effects on cell growth, proliferation and differentiation. Indeed, partial knockdown of Tbl3 in promyelocytes severely impaired their proliferation. The inhibitory effect of Tbl3 knockdown was also observed in fibroblasts, resulting in an 80% reduction in colony formation. Taken together, these results indicate that Tbl3 is a newly recognized nucleolar protein with regulatory roles at very early stages of ribosome biogenesis, perhaps at the level of rR NA gene transcription. CONCLUSION: Tbl3 is a newly recognized nucleolar protein with important regulatory roles in ribosome biogenesis.
文摘Small nucleolar RNAs (snoRNAs) are non-coding RNA (ncRNA) molecules,which are associated with specific proteins to form small nucleolar ribonucleoparticles.However,the function of snoRNAs in cancer still remains elusive.Recently,several independent lines of evidence have indicated that these ncRNAs might have crucial roles in controlling tumorigenesis,and snoRNAs could be potential biomarkers for cancer.
基金supported by National Research Foundation of Korea(NRF)grants funded by the Korean government(MSIT)(NRF-2018R1A5A1023599[SRC],NRF-2021R1A2B5B03001613,and NRF-2019R1C1C1008698).
文摘Pathogen effectors target diverse subcellular organelles to manipulate the plant immune system.Although the nucleolus has emerged as a stress marker and several effectors are localized in the nucleolus,the roles of nucleolar-targeted effectors remain elusive.In this study,we showed that Phytophthora infestans infection of Nicotiana benthamiana results in nucleolar inflation during the transition from the biotrophic to the necrotrophic phase.Multiple P.infestans effectors were localized in the nucleolus:Pi23226 induced cell death in N.benthamiana and nucleolar inflation similar to that observed in the necrotrophic stage of infection,whereas its homolog Pi23015 and a deletion mutant(Pi23226DC)did not induce cell death or affect nucleolar size.RNA immunoprecipitation and individual-nucleotide-resolution UV crosslinking and immunoprecipitation sequencing analysis indicated that Pi23226 bound to the 30 end of 25S rRNA precursors,resulting in accumulation of unprocessed 27S pre-rRNAs.The nucleolar stress marker NAC082 was strongly upregulated under Pi23226-expressing conditions.Pi23226 subsequently inhibited global protein translation in host cells by interacting with ribosomes.Pi23226 enhanced P.infestans pathogenicity,indicating that Pi23226-induced ribosome malfunction and cell death were beneficial for pathogenesis in the host.Our results provide evidence for the molecular mechanism underlying RNA-binding effector activity in host ribosome biogenesis and lead to new insights into the nucleolar action of effectors in pathogenesis.
文摘Purified nucleoli of HeLa cells were treated sequentially with nonionic detergent, nucleic acid enzyme, low salt and high salt. The residual nucleolar structure termed nucleolar skeleton (nucleolar matrix) was shown as a fine network under electron microscope with DGD embedding-unembedding technique. Such structures of BHK-21 cell and mouse liver cell are similar to that of HeLa cell. The protein composition of the nucleolar skeleton of HeLa cells was analyzed. The protein composition of such nucleolar residual shows obvious difference from the compositions of nuclear matrix and chromosome scaffold. The major protein composition of the nucleolar skeleton of HeLa cells contains 6-7 polypeptides. Their molecular weights are about 48, 43, 36 and 33 ku. Further studies show that actin and fib-rillarin are two major protein components of nucleolar skeleton of HeLa cells.
