Search

Objective: To investigate the expression of acidic nuclear phosphoprotein 32A (ANP32A), Ataxin-3 and four half LIM domain proteins 1 (FHL1) in colorectal cancer and their relationship with liver metastasis. Methods: The protein levels of ANP32A, Ataxin-3 and FHL1 protein in 120 cases of colorectal cancer were detected by immunohistochemistry, the positive expression rate was analyzed. Among thems, 44 cases with liver metastasis were regarded as liver metastasis group, 76 cases without liver metastasis were re- garded as non liver metastasis group, the positive expression rates of ANP32A, Ataxin-3 and FHL1 were compared between the two groups, the influencing factors of colorectal cancer liver metastasis were analyzed, and the correlation between ANP32A, Ataxin-3 and FHL1 protein were analyzed. Results: The positive expression rate of ANP32A protein in colorectal cancer tissues was higher than that in adjacent tissues, and the positive expression rates of Ataxin-3 and FHL1 protein in colorectal cancer tissues were lower than those in adjacent tissues (P<0.05). Univariate analysis showed that the positive expression rate of ANP32A protein in liver metastasis group was significantly higher than that in non liver metastasis group, and the positive expression rates of Ataxin-3 and FHL1 protein in liver metastasis group were significantly lower than those in non liver metastasis group (P<0.05). The proportion of patients with low differentiation, T3-T4 invasion depth and lymph node metastasis in liver metastasis group was significantly higher than that in non liver metastasis group (P<0.05). Multivariate logistic regression analysis showed that positive expression of ANP32A protein, low differentiation of primary cancer, depth of invasion T3-T4 and lymph node metastasis were risk factors for liver metastasis of colorectal cancer (P<0.05). Positive expression of Ataxin-3 and FHL1 protein were protective factors for liver metastasis of colorectal cancer (P<0.05). Spearman correlation analysis showed that the positive expression rate of ANP32A was negatively correlated with the positive expression rate of Ataxin-3 and FHL1(P<0.05), and the positive expression rate of Ataxin-3 was positively correlated with the positive expression rate of FHL1 (P<0.05). Conclusion: The high expression of ANP32A and the low expression of Ataxin-3 and FHL1 are closely related to the occurrence and liver metastasis of colorectal cancer. Positive expression of ANP32A, low differentiation of primary cancer, depth of invasion T3-T4 and lymph node metastasis were risk factors for liver metastasis of colorectal cancer. Positive expression of Ataxin-3 and FHL1 protein were protective factors for liver metastasis of colorectal cancer. [ABSTRACT FROM AUTHOR]

Objective: To 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., Methods: Transient 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., Results: No 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., Conclusion: PolyQ-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.

Autosomal dominant cerebellar ataxias (ADCAs) comprise a group of genetically heterogeneous neurodegenerative disorders among which spinocerebellar ataxia type 3 (SCA3) represents the most common form of SCAs worldwide. The fragments of SCA3/MJD gene,which is the member of family GXPL1,were amplified by polymerase chain reaction (PCR). The PCR products of SCA3/MJD gene were detected with capillary electrophoresis (CE) and sequencing to evaluate the size of CAG repeats, feature in the transmission and the mutation in the family with SCA3 in Guangxi province. The results showed that the exon 10 of the SCA3/MJD gene contains 64-71 CAG repeats in all of the affected individuals and three asymptomatic carriers of the family. The number of the CAG repeats during transmission in the normal individuals carrying CGG allele remains consistent, suggesting that CGG allele could have no effect on intergenerational stability of CAG repeats in normal individuals. In addition, two novel point mutations were identified: IVS9-113 T > C in the intronic region and a missense mutation 220 G > A (Glu > Gly) in the encoding region. These two novel point mutations have not been reported and the effect of the mutations on the phenotype of SCA3 is not clear.

Objective: To clone an A3IP gene and investigate its cellular and histological localization based on previous research which has identified part of A3IP sequence interacting with carboxyl-terminal of ataxin-3., Methods: Bioinformatic and Northern blotting were applied to clone the A3IP gene and detect the expression of its transcripts in various human tissues and brain regions. Western blotting and immunofluorescence staining were applied to detect expression of A3IP protein in cultured cells. Immunohistochemistry staining was applied to study the expression of A3IP protein in various human tissues and brain regions., Results: cDNA cloning of A3IP gene's reading frame and its sequence assembly were completed. Three transcripts (1 kb, 1.35 kb and 6 kb, respectively) of A3IP were found to express in various human tissues and brain regions. A3IP pEGFP expresses in cytoplasm of cultured COS-7 cells and various human tissues and brain regions including cerebral cortex, cerebellum, muscle, peripheral nerve, liver and kidney., Conclusion: The cloned A3IP gene encodes A3IP, a novel ataxin-3 interacting protein. Three transcripts of A3IP are expressed in various human tissues and brain regions. A3IP is a cytosolic protein.

Objective: To identify the type of a pedigree with spinocerebellar ataxia, and carry out asymptomatic carrier detection and prenatal diagnosis., Methods: The blood samples of two patients in the spinocerebellar ataxia pedigree were collected. Based on the clinical characteristics of the pedigree and the disease incidence in China, the regions containing the CAG repeat of the SCA1, SCA2 and SCA3/MJD genes were amplified by polymerase chain reaction (PCR). The numbers of CAG repeats in the normal and abnormal allele fragments were identified by using agarose gel electrophoresis and DNA sequencing. We further carried out tests on the children of the patients and fetus to identify the presence of the abnormal allele., Results: The numbers of CAG repeat in the SCA1 and SCA2 genes were in the normal range. The CAG repeat number in one allele of SCA3/MJD gene was in the normal range, while that in the other allele was in the abnormal range. One of the children of the patients and the fetus carried the abnormal allele., Conclusion: It was confirmed that the pedigree was SCA3/MJD by gene diagnosis. One of the children of the patients was asymptomatic carrier and the fetus also carried the abnormal allele.

Objective: To investigate the clinical manifestation and the mutation characteristics of intermedial allele associated with a disease phenotype of a Machado-Joseph disease (MJD) family., Methods: Polymerase chain reaction, capillary electrophoresis, molecular cloning and sequencing were performed to detect the ATXN3 gene in an spinocerebellar ataxia(SCA) family. The fragments of expanded alleles were subcloned into the pGEM-T plasmids and sequenced., Results: The expanded repeats at the MJD locus were confirmed by molecular technique. The proband had 43 CAG repeats at the MJD locus. He had two sons with 41 and 64 repeats in the expanded allele respectively., Conclusion: A 43 CAG repeat allele was unstable upon inter-generational transmission. The change of the CAG repeat was bidirectional. This is the shortest expanded allele associated with a disease phenotype in the MJD gene reported to date. The identification of the MJD family has reduced the amplitude between the normal and expanded allele repeats.

Objective: To investigate the role of autophagy on the pathogenesis of spinocerebellar ataxia 3/Machado-Joseph disease (SCA3/MJD)., Methods: HEK293 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., Results: Inhibition of autophagy increased aggregate formation and cell death in HEK293 cells expressing mutated ataxin-3, and vice versa., Conclusion: The 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.

Objective: To establish a stable, accurate and intuitive method for detecting the CAG trinucleotide repeats of MJD1 gene., Methods: The CAG trinucleotide polymorphism of the MJD1 gene was analyzed by recombinant DNA technology and DNA sequencing in 35 spinocerebellar ataxia 3/Machado-Joseph disease (SCA3/MJD) patients from Mainland China., Results: The range of the CAG repeat of the 35 patients was 65-81 (mean = 72.96 +/- 4.24). The CAG repeats contained two CAAs and one AAG variations in the CAG motif in all the patients and majority of the healthy controls. There was a CGG/GGG polymorphism at the 3' end of the CAG repeat. The GGG allele was consistently associated with smaller CAG repeats in healthy controls. On the other hand, the CGG allele consistently existed in the patients., Conclusion: Recombinant DNA technology can stably, accurately and intuitively detect the CAG trinucleotide repeat of the MJD1 gene. It should be used as a major technique to diagnose the SCA3/MJD and analyze the polymorphism of CAG sequence.

Objective: To study the clinical features and gene mutation analysis in Machado-Joseph disease of spinocerebellar ataxia type 3 in littoral of Zhejiang., Methods: Clinical manifestation and brain MRI data 18 patients with SCA in family were analyzed. The gene mutations of 18 patients and 10 family numbers without abnormal presentation, and 12 healthy persons of controls., Results: The gene mutations of 18 patients is SCA3/MJD, and 2 asymptomatic SCA3/MJD had been detected in SCA family. Normal alleles of SCA3/MJD have CAG repeats ranging from 14 to 27, patients from 67 to 82, asymptomatic and carrier SCA3/MJD from 28 to 45. The main features of 18 patients included gait ataxia, ambiguity in speech and action clumsiness. Brain MRI showed remarkable atrophy on cerebellum and brain stem., Conclusion: CAG expansions were related to SCA3/MJD. The clinical manifestations are ataxia and dysarthria. The detection of repeated times CAG can provide an effective way for the genetic and asymptomatic diagnosis.

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.

We investigated the clinical features and gene mutation in a pedigree of spinocerebellar ataxia (SCA). A series of clinical tests was performed including visual examination, retinal angiography, visual evoked potential, electroretinogram and magnetic resonance imaging. Genomic DNA of the family members and normal controls was used for amplification of the (CAG)n repeats of SCA1, SCA2, SCA3, SCA6, SCA7, SCA17 and DRPLA genes by PCR. The number of (CAG)n was determined by 8% denaturing polyacrylamide gel electrophoresis and direct sequencing. The main features of 2 patients were ataxia, visual failure, retinal degeneration, cerebellar and pontine atrophy. A mutation in SCA7 gene was detected, while no mutations were found in SCA1, SCA2, SCA3, SCA6, SCA17 or DRPLA gene. Therefore, this is a pedigree of SCA7. Analysis of the CAG trinucleotide repeat expansion at the SCA7 locus can provide valuable insights into SCA7.

Objective: To determine the frequency of different subtypes of spinocerebellar ataxias (SCAs) in the Han nationality of Hunan province in China., Methods: The mutations of SCA1, SCA2, SCA3, SCA6, SCA7, SCA17, and dentatorulral-pallidoluysian (DRPLA) were detected with the polymerase chain reaction (PCR), denaturing polyacrylamide gel and DNA sequencing techniques in 139 autosomal dominant SCA families and 61 sporadic SCA patients., Results: Of the 139 families, 11 (7.9%) were positive for SCA1, 9(6.5%) were positive for SCA2, 71 (51.1%) were positive for SCA3, 4 (2.9%) were positive for SCA6, 2 (1.4%) were positive for SCA7, and none was positive for SCA17 and DRPLA. There was 1 SCA2 patient, 3 SCA3 patients, 1 SCA6 patient in the 61 sporadic SCA patients., Conclusion: The frequency of SCA3 is substantially higher than that of SCA1 and SCA2 in the autosomal dominant SCA patients in the Han nationality of Hunan province. SCA6 and SCA7 are rare subtypes.

Objective: To screen for proteins interacting with ataxin-3 by yeast two-hybrid system 3, and to discuss the function of ataxin-3 and pathogenesis of spinocerebellar ataxia type 3 and Machado-Joseph disease (SCA3/MJD)., Methods: First we sub-cloned the full reading frame of both wild-type and mutant ataxin-3 into carrier pGBKT7 (ataxin-3-bait), and then screened human brain cDNA library with ataxin-3-bait., Results: We found five positive clones in 6.5 x 10(6) transformers. After sequencing, we knew all of them were novel ataxin-3 interacting proteins. Three were corresponded to the known sequences coding the known proteins, which were human Rho GDP dissociation inhibitor alpha, small ubiquitin-like modifier 1, and human neuronal amiloride-sensitive cation channel 2. Another two of the five were unknown., Conclusion: Small ubiquitin-like modifier 1 probably interacted with ataxin-3, suggesting that the sumoylation probably participated in post-translation modifying of ataxin-3 and pathogenesis of SCA3/MJD.

Objective: To construct the eukaryotic expression vector of MJD1 with normal copies of CAG trinucleotide repetition and MJD1 with CAG trinucleotide repetition expansion mutation respectively, and to determine whether the polyglutamine expansion in ataxin-3 could lead to the formation of intranuclear aggregation., Methods: The coding sequence of wild-type MJD1 and mutant MJD1 was amplified by PCR from pAS2-1-MJD20Q and pAS2-1-MJD68Q respectively. After being digested with BamH I and Hind III, the PCR products were inserted into pcDNA3. 1-Myc-His(-) B. The recombinant plasmids pcDNA3.1-Myc-His(-) B-MJD20Q and pcDNA3.1-Myc-His(-) B-MJD68Q were identified by enzyme digestion analysis and DNA sequencing. The recombinant plasmid was transfected into SH-SYSY cells and the expression of MJD1 in the transfected cells was analyzed by Western blot. The immunofluorescence of the transfected cells was examined using a confocal microscope to observe the formation of intranuclear aggregation., Results: Enzyme digestion analysis and DNA sequencing showed that the target gene was cloned into pcDNA3. 1-Myc-His(-) B. The expression of MJD1 in the transfected cells was confirmed by Western blot; The SH-SY5Y cells transfected with pcDNA3. 1-Myc-His(-) B-MJD68Q showed the formation of intranuclear aggregation, but the cells transfected with pcDNA3.1-Myc-His(-) B-MJD20Q did not show such phenomenon., Conclusion: The eukaryotic expression vectors of MJD1 has been successfully constructed; The polyglutamine expansion in ataxin-3 could lead to the formation of intranuclear aggregation.

Objective: To investigate the normal range of (CAG)n in spinocerebellar ataxia type 1 (SCA1) gene and spinocerebellar ataxia type 3 (SCA3/MJD) gene in 110 normal subjects of Han population in Northeastern China, to assess the genotypes for clinically diagnosed spinocerebellar ataxia(SCA) individuals including 25 patients from 8 families and 6 sporadic patients, and to make presymptomatic and prenatal diagnosis., Methods: DNA fragments from the normal subjects and the patients were detected by fluorescence-PCR. Homozygosities were selected for DNA sequencing., Results: The normal ranges of (CAG)n of SCA1 and SCA3/MJD were 20-39 and 14-38 repeats respectively, SCA1 was found mostly to be 26 and 27 repeats, allele frequency 34.09% and 20.91%; heterozygosity was 84.55%, SCA3/MJD was found mostly to be 14 repeats, allele frequency 39.55%, heterozygosity was 78.18%.(CAG)(68) of SCA3/MJD gene of one affected individual had been found in a family but no CAG mutative expansion in related members was observed., Conclusion: The normal ranges of CAG repeats vary with areas and races. SCAs genotyping is the first choice in presymptomatic and prenatal diagnosis.

Objective: To assess the frequency of the SCA1, SCA2, MJD/SCA3 CAG trinucleotide repeat expansions ((CAG)n) among individuals diagnosed with hereditary spinocerebellar ataxia (SCA) from Chinese families., Method: The SCA1, SCA2, MJD/SCA3 (CAG)n mutation were detected with the polymerose chain reaction (PCR), denaturing polyacrylamide gel and silver staining technique in 79 patients with autosomal dominant SCA from 50 Chinese families., Results: Among 50 kindreds, 2% (1/50) had the SCA1, (CAG)n, 6% (3/50) had the SCA2, (CAG)n, whereas 48% (24/50) were positive for the MJD/SCA3 (CAG)n. Thus, together SCA1, SCA2, and MJD/SCA3 represent 56% (28/50) of the autosomal dominant ataxias in our group. In two SCA1 patients the CAG repeat was expanded to 53-62 repeats, whereas in normal ivdividuals was 12-36 repeats. In seven SCA2 patients the CAG repeat was expanded to 43-47 repeats, whereas in normal ivdividuals was 22-30 repeats. In forty-two MJD/SCA3 patients the CAG repeat was expanded to 63-78 repeats, whereas in normal ivdividuals was 15-38 repeats. The SCA1, SCA2, MJD/SCA3 (CAG)n mutation were excluded in the other 28 SCA patients from 22 families., Conclusion: The frequency of MJD/SCA3 is substantially higher than that of SCA1 and SCA2 in the autosomal dominant SCA from Chinese families. Chinese patients with MJD/SCA3 are non-Portuguese patients with MJD/SCA3. Clinical expressions of the various SCAs overlap one another, making a diagnostic classification based on phenotype inaccurate in many instances. It is important for SCA clinical study to make a SCA gene diagnosis and genomic classification.