1.Expression of NOB1 and its significance in colorectal cancer.
Journal of Southern Medical University 2012;32(3):420-422
OBJECTIVETo investigate the expression of NOB1 in colorectal cancer and its relationship with the clinicopathological characteristics.
METHODSThe expression of NOB1 was detected immunohistochemically in 60 primary colorectal cancer tissues and the corresponding normal epithelia (3.0 cm away from the cancer margin) and graded according to the staining intensity and the percentage of positively stained tumor cells.
RESULTSNOB1 overexpression was found in 32 of the 60 cases (53.3%). NOB1 overexpression in the adjacent non-neoplastic tissues was found in 10 of the cases (16.7%), a rate significantly lower than that in the cancer tissues (P<0.05). NOB1 expression was not correlated to such tumor characteristics as gender, age, histological differentiation grade, depth of invasion and lymph node metastasis (P>0.05).
CONCLUSIONSNOB1 expression is higher in colorectal cancer than in normal colorectal tissues, suggesting its involvement in the tumorigenesis and progression of colorectal cancer.
Colorectal Neoplasms ; genetics ; metabolism ; pathology ; Female ; Humans ; Immunohistochemistry ; Male ; Middle Aged ; Nuclear Proteins ; genetics ; metabolism ; RNA-Binding Proteins ; genetics ; metabolism
2.Polyglutamine-expanded ataxin-3 is degraded by autophagy.
Han XIAO ; Jianguang TANG ; Zhiping HU ; Jieqiong TAN ; Beisha TANG ; Zheng JIANG
Chinese Journal of Medical Genetics 2010;27(1):23-28
OBJECTIVETo investigate the role of autophagy on the pathogenesis of spinocerebellar ataxia 3/Machado-Joseph disease (SCA3/MJD).
METHODSHEK293 cells expressing polyglutamine-expanded ataxin-3 were used as cell model for SCA3/MJD. The level of polyglutamine-expanded ataxin-3 was detected after cells were treated with different inhibitors or inducer of autophagy.
RESULTSInhibition of autophagy increased aggregate formation and cell death in HEK293 cells expressing mutated ataxin-3, and vice versa.
CONCLUSIONThe data suggested that autophagy is involved in the degradation of mutant ataxin-3, resulting in a decrease in the proportions of aggregate-containing cells and cell death in HEK293 cells expressing polyglutamine-expanded ataxin-3. It is possible that autophagy may be applied as a potential therapeutic approach for SCA3/MJD.
Ataxin-3 ; Autophagy ; Cell Line ; Humans ; Machado-Joseph Disease ; genetics ; metabolism ; physiopathology ; Mutation ; Nerve Tissue Proteins ; genetics ; metabolism ; Nuclear Proteins ; genetics ; metabolism ; Peptides ; metabolism ; Repressor Proteins ; genetics ; metabolism
3.The potential role of nuclear matrix attachment regions (MARs) in regulation of gene expression.
Ke-Wei ZHANG ; Jian-Mei WANG ; Cheng-Chao ZHENG
Chinese Journal of Biotechnology 2004;20(1):6-9
Gene transfer technology is being used to enhance agronomic performance or improve quality traits in a wide variety of crop species. However, it is sometimes severely handicapped by difficulty in obtaining material in which transgene expression is predictable and stable over many generations. Because integration seemed to occur randomly in the plant genome, it was thought that some transgenes would be integrated in a relatively uncondensed, transcriptionally active chromatin environment, while others in a condensed, transcriptionally inert chromatin structure. Nuclear matrix attachment regions (MARs) are defined as DNA sequences that bind preferentially to the proteins of the nuclear matrix. They typically are localized at the borders of gene domains, implicating them in the formation of individual loops of higher order chromatin structure and transcription regulation. When MARs are positioned on either side of a transgene their presence usually results in higher and more stable espression in transgenic plants, most likely by minimizing gene silencing. In this review, we focus mainly on novel findings and our observations concerning the function of MARs in transcription regulation. Our objective is not only to summarize the current data and present several possible models to explain MAR effects on the transcription regulation, but also to point out some open questions involving the utilization of MARs in constructing high efficient expression vectors.
Chromatin
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physiology
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DNA
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metabolism
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Gene Expression Regulation, Plant
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Models, Genetic
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Nuclear Matrix
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metabolism
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Nuclear Proteins
;
metabolism
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Transcription, Genetic
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Transgenes
;
genetics
4.Structural and biochemical characterization of DAXX-ATRX interaction.
Zhuang LI ; Dan ZHAO ; Bin XIANG ; Haitao LI
Protein & Cell 2017;8(10):762-766
5.Clinical Significance of Low Expression of LncRNA CASC15 in Acute Myeloid Leukemia with NPM1 Mutations.
Pei-Hui XIA ; Zi-Jun XU ; Ye JIN ; Ji-Chun MA ; Xiang-Mei WEN ; Qian YUAN ; Jia-Yan LENG ; Jun QIAN ; Jiang LIN
Journal of Experimental Hematology 2022;30(3):659-670
:
AbstractObjective: To identify the expression and methylation patterns of lncRNA CASC15 in bone marrow (BM) samples of acute myeloid leukemia (AML) patients, and further explore its clinical significance.
METHODS:
Eighty-two de novo AML patients and 18 healthy donors were included in the study. Meanwhile, seven public datasets from Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) were included to confirm the expression and methylation data of CASC15. Receiver operating characteristic (ROC) curve analysis was applied to determine the discriminative capacity of CASC15 expression to identify AML. The patients were divided into CASC15high group and CASC15low group by X-tile method, and the prognostic value of CASC15 was identified by Kaplan-Meier method and univariate and multivariate Cox regression analysis.
RESULTS:
The expression level of CASC15 was significantly decreased in BM cells of AML patients compared with healthy donors (P<0.001). ROC curve analysis suggested that CASC15 expression might be a potential biomarker to discriminate AML from controls. The expression of CASC15 was high at the early stage of hematopoiesis, and reached a peak at the stage of multipotent progenitors differentiation, then decreased rapidly, and was at a range of low level fluctuations in the subsequent process. Among FAB subtypes, CASC15 expression in M0 was significantly higher than that in M1-M7. Clinically, CASC15low patients were more likely to have NPM1 mutations than CASC15high patients (P=0.048), while CASC15high patients had a significantly higher frequency of IDH1 and RUNX1 mutations (P=0.021 and 0.014, respectively). Moreover, CASC15low group had a shorter overall survival (OS) in patients with NPM1 mutations. Furthermore, multivariate analysis confirmed that CASC15 expression was a significant independent risk factor for OS in NPM1 mutated AML patients. In addition, CASC15 methylation level in BM samples of AML patients was significantly decreased compared with healthy donors. Patients with CASC15 high methylation had poor OS and disease-free survival.
CONCLUSION
The expression of CASC15 is decreased in AML, and low CASC15 expression may predict adverse prognosis in AML patients with NPM1 mutations. Moreover, CASC15 methylation level in AML is significantly decreased, and high CASC15 methylation may predict poor prognosis in AML.
Humans
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Leukemia, Myeloid, Acute/metabolism*
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Mutation
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Nuclear Proteins/genetics*
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Nucleophosmin/genetics*
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Prognosis
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RNA, Long Noncoding/genetics*
6.Overexpression of CHIP in chronic myeloid leukemia K562 cells induces mitotic abnormality.
Ying GAO ; Yan WANG ; Xu-Hui ZHANG ; Guo-Zhu CHEN ; Zhi-Yan DU ; Yuan-Ji XU ; Xiao-Dan YU
Journal of Experimental Hematology 2008;16(4):763-767
This study was aimed to investigate the possible influence of a novel E3 ubiquitin ligase CHIP (carboxyl terminus of Hsc70/Hsp70-interacting protein) on biological characteristics of cancer cells. Stable overexpression models in CML K562 cells were established via lipofectamine-mediated wild type CHIP and its TPR or U-box deletion mutants gene transfection. Followed G418 pressure selection, K562-CHIP stable transfected cell clones were obtained by limited dilution. The proliferation status and cell cycle were observed by MTT assay and FACS. The expression of related proteins and morphological changes were detected by Western blot and Wright-Giemsa staining. The results showed that overexpression of wild type CHIP did not inhibit cell proliferation, but slightly increased cell ratio of G(2)/M phase. CHIP gene had no effect on the stability of BCR-ABL kinase protein. HDAC inhibitor FK228-induced BCR-ABL degradation did not enhanced by CHIP. Notably the enlarged cells and abnormal mitotic cells remarkably increased in K562 WT-CHIP cells, indicating that CHIP may involve in the regulation of mitotic process. It is concluded that wild type CHIP induces mitotic abnormity in K562 cells.
Heat-Shock Proteins
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genetics
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metabolism
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Humans
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K562 Cells
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Mitosis
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Nuclear Pore Complex Proteins
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genetics
;
metabolism
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Proto-Oncogene Proteins
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genetics
;
metabolism
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Sequence Deletion
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Transfection
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Ubiquitin-Protein Ligases
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genetics
;
metabolism
7.Recent advances in molecular genetics of spinocerebellar ataxia type 3/Machado-Joseph disease.
Dandan JIA ; Hong JIANG ; Beisha TANG
Chinese Journal of Medical Genetics 2008;25(6):660-662
To date, nearly 28 distinct genetic loci of autosomal dominant cerebellar ataxias have been identified, among them 18 disease-causing genes have been cloned. Of these, Machado-Joseph disease (MJD), also named as spinocerebellar ataxia type 3 (SCA3), is perhaps the most common subtype among different races and origins in the world. It is a neurodegenerative disease caused by the expansion of a CAG repeat in the coding region of the MJD1 gene, with obvious clinical and genetic heterogeneity. In this review, authors covered the recent advances in molecular genetic of SCA3/MJD.
Ataxin-3
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Humans
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Machado-Joseph Disease
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genetics
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Molecular Biology
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Mutation
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Nerve Tissue Proteins
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chemistry
;
genetics
;
metabolism
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Nuclear Proteins
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chemistry
;
genetics
;
metabolism
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Repressor Proteins
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chemistry
;
genetics
;
metabolism
8.Molecular Mechanism of Action of hnRNP K and RTN3 in the Replication of Enterovirus 71.
Li LI ; Haiyan ZHONG ; Mao FAN ; Liyue KUI ; Huiying LI ; Jianying ZHANG
Chinese Journal of Virology 2015;31(2):197-200
Enterovirus 71 (EV71) is a neurotropic pathogen that can induce hand, foot and mouth disease in children. There is an appreciable mortality rate after EV71 infections. The mechanism of action of EV71 replication is not known. Recent work has identified some of cell factors of the host that participate in the synthesis of the RNA and proteins of EV71 (e.g., hnRNP K, reticulon 3 (RTN 3)). In that work, researchers used a competitive assay to show that hnRNP K can interact with EV71 5' UTR, which is required for efficient synthesis of viral RNA. Using a yeast two-hybrid system, other researchers demonstrated that RTN 3 interacts with the N-terminal domain of EV71 2C, which is crucial for replication of viral RNA. Here, we discuss recent work focusing on the molecular mechanisms of hnRNP K and RTN 3 in the synthesis of the RNA and proteins of EV71.
Animals
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Carrier Proteins
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genetics
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metabolism
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Enterovirus A, Human
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genetics
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physiology
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Enterovirus Infections
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genetics
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metabolism
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virology
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Heterogeneous-Nuclear Ribonucleoprotein K
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Host-Pathogen Interactions
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Humans
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Membrane Proteins
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genetics
;
metabolism
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Nerve Tissue Proteins
;
genetics
;
metabolism
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Ribonucleoproteins
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genetics
;
metabolism
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Viral Proteins
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genetics
;
metabolism
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Virus Replication
9.Mutation analysis of p31(comet) gene, a negative regulator of Mad2, in human hepatocellular carcinoma.
Mi Yong YUN ; Sang Bum KIM ; Sunhoo PARK ; Chul Ju HAN ; Young Hoon HAN ; Sun Hee YOON ; Sang Hoon KIM ; Chang Min KIM ; Dong Wook CHOI ; Myung Haing CHO ; Gil Hong PARK ; Kee Ho LEE
Experimental & Molecular Medicine 2007;39(4):508-513
Failure of mitotic checkpoint machinery leads to the chromosomal missegregation and nuclear endoreduplication, thereby driving the emergence of aneuploidy and tetraploidy population. Although abnormal nuclear ploidy and the resulting impairment of mitotic checkpoint function are typical physiological event leading to human hepatocellular carcinoma, any mutational change of mitotic checkpoint regulators has not yet been discovered. Therefore, we investigated the mutation of p31(comet), a recently identified mitotic checkpoint regulator, in human hepatocellular carcinoma. Of 51 human hepatocellular carcinoma tissue and 6 cell lines tested, five samples exhibited nucleotide sequence variations dispersed on four sites within the entire coding sequence. Among these sites with sequence substitutions, three were found to be missense mutation accompanied with amino acid change but one was a silent mutation. Of these sequence substitutions, two were present in both tumor and non-tumor liver tissues, suggesting the possibility of polymorphism. The present findings indicate that p31(comet) does not have an impact on the formation of aneuploidy and tetraploidy found in human hepatocellular carcinoma.
Adaptor Proteins, Signal Transducing
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Calcium-Binding Proteins/*metabolism
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Carcinoma, Hepatocellular/genetics/*metabolism
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Carrier Proteins/*genetics/metabolism
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Cell Cycle Proteins/*genetics/*metabolism
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Cell Line, Tumor
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Humans
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Liver Neoplasms/genetics/*metabolism
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*Mutation
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Nuclear Proteins
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Polyploidy
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Repressor Proteins/*metabolism
10.Subcellular localization of ataxin-3 and its effect on the morphology of cytoplasmic organoids.
Feifei WEI ; Han XIAO ; Zhiping HU ; Hainan ZHANG ; Chunyu WANG ; Heping DAI ; Jianguang TANG
Chinese Journal of Medical Genetics 2015;32(3):353-357
OBJECTIVETo explore the subcellular localization of ataxin-3 and the effect of polyglutamine (polyQ) expansion mutation on the morphology of mitochondrion, golgi apparatus and endoplasmic reticulum.
METHODSTransient transfection was employed to build cell models expressing wild-type or mutant ataxin-3 proteins. Indirect immunofluorescence was applied to identify markers of organelle membrane. The results were observed under a laser scanning confocal microscope.
RESULTSNo co-localization was observed for ataxin-3 protein and mitochondrial marker TOM20, but the percentage of cells with mitochondrial fragmentation has increased in cells expressing mutant ataxin-3 (P<0.05). No co-localization was observed for ataxin-3 protein and golgi marker GM130, and mutant ataxin-3 did not cause golgi fragmentation. Wide type and polyQ-expanded ataxin-3 both showed partial co-localization with ER marker calnexin. The latter showed more overlap with calnexin, and the overlapping signals were mostly located in the places where aggregates were situated.
CONCLUSIONPolyQ-expanded ataxin-3 protein may indirectly affect the integrity of mitochondria, but may cause no effect on the structure and functions of golgi apparatus. Endoplasmic reticulum may be another place where extended ataxin-3 protein can induce cytotoxicity in addition to the nucleus.
Ataxin-3 ; Cytoplasm ; genetics ; metabolism ; Endoplasmic Reticulum ; genetics ; metabolism ; HeLa Cells ; Humans ; Machado-Joseph Disease ; genetics ; metabolism ; Mitochondria ; genetics ; metabolism ; Nerve Tissue Proteins ; genetics ; metabolism ; Nuclear Proteins ; genetics ; metabolism ; Protein Transport ; Repressor Proteins ; genetics ; metabolism