To explore the molecular mechanism of chromatin remodeling involved in the regulation of transcriptional activation of specific genes by a myogenic regulatory factor Myogenin, we used NIH3T3 fibroblasts with a stably ...To explore the molecular mechanism of chromatin remodeling involved in the regulation of transcriptional activation of specific genes by a myogenic regulatory factor Myogenin, we used NIH3T3 fibroblasts with a stably integrated Hl.l-GFP fusion protein to monitor histone HI movement directly by fluorescence recovery after photobleaching (FRAP) in living cells. The observation from FRAP experiments with myogenin transfected fibroblasts showed that the exchange rate of histone HI in chromatin was obviously increased, indicating that forced expression of exogenous Myogenin can induce chromatin remodeling. The hyper-acetylation of histones H3 and H4 from myogenin transfected fibroblasts was detected by triton-acid-urea (TAU)/SDS (2-D) electrophoresis and Western blot with specific antibodies against acetylated N-termini of histones H3 and H4. RT-PCR analysis indicated that the nAChR β-subunit gene was expressed in the transfected fibroblasts. These results suggest that the expression of exogenous Myogenin can induce chromatin remodeling and activate the transcription of Myogenin-targeted gene in non-muscle cells.展开更多
AIM： TO characterize a culture model of rat CCA cells, which were derived from a transplantable TTA-induced CCA and designated as Chang Gung CCA （CGCCA）. METHODS： The CGCCA cells were cultured at in vitro passage ...AIM： TO characterize a culture model of rat CCA cells, which were derived from a transplantable TTA-induced CCA and designated as Chang Gung CCA （CGCCA）. METHODS： The CGCCA cells were cultured at in vitro passage 12 times on a culture dish in DMEM medium. To measure the doubling time, 103 cells were plated in a 96-well plate containing the growth medium. The cells were harvested 4 to 10 d after seeding, and a standard MTT assay was used to measure the growth. The phenotype of CACCA cell and xenograft was determined by immunohistochemical study. We also determine the chromosomal alterations of CGCCA, G-banding and spectral karyotyping studies were performed. The CGCCA cell line was transplanted into the nude mice for examining its tumorigenicity. 2-Deoxy-2-（18F）fluoro-D- glucose （FDG） autoradiography was also performed to evaluate the FDG uptake of the tumor xenograft. RESULTS： The doubling time for the CGCCA cell line was 32 h. After transplantation into nude mice, FDG autoradiography showed that the tumors formed at the cell transplantation site had a latency period of 4-6 wk with high FDG uptake excluding necrosis tissue. Moreover, immunohistochemical staining revealed prominent cytoplasmic expression of c-erb-B2, CK19, c-Met, COX-n, EGFR, MUC4, and a negative expression of K-ras. All data confirmed the phenotypic features of the CGCCA cell line coincide with the xenograft mice tumors, indicating cells containing the tumorigenicity of CCA originated from CCA. In addition, karyotypic band- ing analysis showed that the diploid （2n） cell status combines with ring and giant rod marker chromosomes in these clones; either both types simultaneously appeared or only one type of marker chromosome in a pair appeared in a cell. The major materials contained in the marker chromosome were primarily identified from chromosome 4. CONCLUSION： The current CGCCA cell line may be used as a non-K-ras effect CCA model and to obtain information and reveal novel pathways for CCA. Further applications regarding tumor markers or therapeutic targeting of CCA should be addressed accordingly.展开更多
Chromosomal alterations are the main causes of genetic diseases. One of the characteristics of certain genetic syndromes is ID （intellectual disability） presented by the individual in varying degrees. The study of t...Chromosomal alterations are the main causes of genetic diseases. One of the characteristics of certain genetic syndromes is ID （intellectual disability） presented by the individual in varying degrees. The study of the ID, its etiology, association or not with chromosomal abnormalities and a clinical diagnosis associated with the examination of karyotype are important aspects to consider when providing genetic counseling for families. Due to the lack of similar studies and of easy access to cytogenetic services for the Amazonian population, this study aimed to contribute to the advancement of this line of study in the state, analyzing the karyotype of individuals with ID, not Down Syndrome treated at the APAE-Manaus and identifying the main types of chromosomal alterations in the individuals analyzed. Analyzes were performed of the clinical diagnosis through investigation of the data from the interview and medical records as well as analysis of the karyotype of 31 patients with non-Down syndrome ID, attended in the APAE-Manaus. Of these subjects, 20 were female and 11 male. The results showed only 2 cases of chromosome abnormalities are detectable by classical cytogenetics, one of mosaic Turner syndrome and one a heterochromatic variant. It is therefore necessary to complement the study with the addition of molecular techniques for the investigation of microdeletions and/or other alterations not detectable through the banding technique, mainly for individuals whose dysmorphisms indicate a suspected syndrome.展开更多
Objective To gain a better understanding of genetic changes in Cantonese nasopharyngeal carcinoma (NPC) Methods Comparative genomic hybridization (CGH) was performed on 17 primary nasopharyngeal carcinomas R...Objective To gain a better understanding of genetic changes in Cantonese nasopharyngeal carcinoma (NPC) Methods Comparative genomic hybridization (CGH) was performed on 17 primary nasopharyngeal carcinomas Results A novel copy number gain an chromosome 4q and loss of chromosome 1p were found at a high frequency (>50%) Conclusions Current analysis revealed a comprehensive profile of the chromosomal regions showing gain of chromosomes 4q, 12q, and 1q as well as loss of chromosomes 1p, 3p, 11q, 14q, 15q, 13q, Xq, 9q, 10p, 10q, and 16q Frequently altered loci may encode oncogenes or tumor suppressor genes involved in the development of primary NPC展开更多
文摘To explore the molecular mechanism of chromatin remodeling involved in the regulation of transcriptional activation of specific genes by a myogenic regulatory factor Myogenin, we used NIH3T3 fibroblasts with a stably integrated Hl.l-GFP fusion protein to monitor histone HI movement directly by fluorescence recovery after photobleaching (FRAP) in living cells. The observation from FRAP experiments with myogenin transfected fibroblasts showed that the exchange rate of histone HI in chromatin was obviously increased, indicating that forced expression of exogenous Myogenin can induce chromatin remodeling. The hyper-acetylation of histones H3 and H4 from myogenin transfected fibroblasts was detected by triton-acid-urea (TAU)/SDS (2-D) electrophoresis and Western blot with specific antibodies against acetylated N-termini of histones H3 and H4. RT-PCR analysis indicated that the nAChR β-subunit gene was expressed in the transfected fibroblasts. These results suggest that the expression of exogenous Myogenin can induce chromatin remodeling and activate the transcription of Myogenin-targeted gene in non-muscle cells.
文摘AIM： TO characterize a culture model of rat CCA cells, which were derived from a transplantable TTA-induced CCA and designated as Chang Gung CCA （CGCCA）. METHODS： The CGCCA cells were cultured at in vitro passage 12 times on a culture dish in DMEM medium. To measure the doubling time, 103 cells were plated in a 96-well plate containing the growth medium. The cells were harvested 4 to 10 d after seeding, and a standard MTT assay was used to measure the growth. The phenotype of CACCA cell and xenograft was determined by immunohistochemical study. We also determine the chromosomal alterations of CGCCA, G-banding and spectral karyotyping studies were performed. The CGCCA cell line was transplanted into the nude mice for examining its tumorigenicity. 2-Deoxy-2-（18F）fluoro-D- glucose （FDG） autoradiography was also performed to evaluate the FDG uptake of the tumor xenograft. RESULTS： The doubling time for the CGCCA cell line was 32 h. After transplantation into nude mice, FDG autoradiography showed that the tumors formed at the cell transplantation site had a latency period of 4-6 wk with high FDG uptake excluding necrosis tissue. Moreover, immunohistochemical staining revealed prominent cytoplasmic expression of c-erb-B2, CK19, c-Met, COX-n, EGFR, MUC4, and a negative expression of K-ras. All data confirmed the phenotypic features of the CGCCA cell line coincide with the xenograft mice tumors, indicating cells containing the tumorigenicity of CCA originated from CCA. In addition, karyotypic band- ing analysis showed that the diploid （2n） cell status combines with ring and giant rod marker chromosomes in these clones; either both types simultaneously appeared or only one type of marker chromosome in a pair appeared in a cell. The major materials contained in the marker chromosome were primarily identified from chromosome 4. CONCLUSION： The current CGCCA cell line may be used as a non-K-ras effect CCA model and to obtain information and reveal novel pathways for CCA. Further applications regarding tumor markers or therapeutic targeting of CCA should be addressed accordingly.
文摘Chromosomal alterations are the main causes of genetic diseases. One of the characteristics of certain genetic syndromes is ID （intellectual disability） presented by the individual in varying degrees. The study of the ID, its etiology, association or not with chromosomal abnormalities and a clinical diagnosis associated with the examination of karyotype are important aspects to consider when providing genetic counseling for families. Due to the lack of similar studies and of easy access to cytogenetic services for the Amazonian population, this study aimed to contribute to the advancement of this line of study in the state, analyzing the karyotype of individuals with ID, not Down Syndrome treated at the APAE-Manaus and identifying the main types of chromosomal alterations in the individuals analyzed. Analyzes were performed of the clinical diagnosis through investigation of the data from the interview and medical records as well as analysis of the karyotype of 31 patients with non-Down syndrome ID, attended in the APAE-Manaus. Of these subjects, 20 were female and 11 male. The results showed only 2 cases of chromosome abnormalities are detectable by classical cytogenetics, one of mosaic Turner syndrome and one a heterochromatic variant. It is therefore necessary to complement the study with the addition of molecular techniques for the investigation of microdeletions and/or other alterations not detectable through the banding technique, mainly for individuals whose dysmorphisms indicate a suspected syndrome.
基金ThestudywasgrantedfromNational 973Program (No G19980 5 12 0 2 )andtheNationalExcellentYouthScienceFoundation (typeB No 3 9
文摘Objective To gain a better understanding of genetic changes in Cantonese nasopharyngeal carcinoma (NPC) Methods Comparative genomic hybridization (CGH) was performed on 17 primary nasopharyngeal carcinomas Results A novel copy number gain an chromosome 4q and loss of chromosome 1p were found at a high frequency (>50%) Conclusions Current analysis revealed a comprehensive profile of the chromosomal regions showing gain of chromosomes 4q, 12q, and 1q as well as loss of chromosomes 1p, 3p, 11q, 14q, 15q, 13q, Xq, 9q, 10p, 10q, and 16q Frequently altered loci may encode oncogenes or tumor suppressor genes involved in the development of primary NPC
