microRNAs (miRNAs) are endogenous, small noncoding RNA molecules discovered in animals, plants and viruses. They play a critical role in developmental and physiological processes and are implicated in the pathogenesis of many human cancers. Presently, human cancer, including colorectal cancer, is recognized as both a genetic and epigenetic disease. Changes induced by miRNAs are considered as epigenetic changes. Experiments were largely performed to analyze the colorectal microRNAome and bio-networking involving miRNAs. This review focuses on recent advances in colorectal miRNA expression profiles. Further, we discuss the regulatory network of miRNAs in the initiation and carcinogenesis of colon cancer in order to open up an avenue of anticancer therapy based on the epigenetic regulation by miRNAs.
Animals ; Colonic Neoplasms ; genetics ; Epigenesis, Genetic ; genetics ; Humans ; MicroRNAs ; genetics

Hereditary spinocerebellar ataxias(SCA) are mainly caused by trinucleotide (CAG/CAA) repeat expansion in open reading frames of corresponding gene. However, SCA8, SCA10 and SCA12 are caused by nucleotide repeat expansion in noncoding region. Recent researches focus on the pathogenesis and hereditary traits, including the instability of nucleotide repeat, the alteration of penetrance, the bias of gender inheritance and the anticipation. The pathogenesis of these three SCA subtypes is different from other subtypes because the repeat expansion in noncoding region has mild influence on translation of polyQ protein. We suggest that the interference on DNA transcription by the abnormal nucleotide expansion, the post-transcriptional toxic effect of abnormal RNA, and the mechanism of bidirectional expression of repeat expansion transcripts play a critical role on SCA8, SCA10 and SCA12 pathogenesis.
Humans ; Models, Biological ; Spinocerebellar Ataxias ; genetics ; Trinucleotide Repeat Expansion ; genetics

OBJECTIVETo establish and improve the method of bisulfite sequencing for methylation status of imprinted genes in single human oocytes.

METHODSSingle superovulated immature human oocyte was embedded into low melting point agarose, followed by bisulfite treatment and polymerase chain reaction (PCR) amplification of the H19 and MEST genes. The PCR products were then subjected to TA cloning and sequencing to determine the methylation status.

RESULTSWith the modified methods of embedding and bisulfite treatment, we achieved a high PCR success rate of 82.46%, with the somatic cell contamination rate as low as 7.14%. The sequencing results showed no non-CpG cytosine and exact conformity to the theoretical sequences.

CONCLUSIONThe bisulfite sequencing method we used to determine the methylation status of imprinted genes at the single-cell level was highly efficient and reliable, which can serve as a foundation for the further study of the influences of human assisted reproductive technology on genomic imprinting.

DNA Methylation ; Female ; Genomic Imprinting ; genetics ; Humans ; Oocytes ; metabolism ; Polymerase Chain Reaction ; Sequence Analysis, DNA ; methods

OBJECTIVETo investigate the association of -1131T>C and c.553G>T polymorphisms and their haplotypes in apolipoprotein A5(ApoA5) gene with cereberovascular disease in Chinese.

METHODSUsing polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), we analyzed two ApoA5 genetic variants in 272 patients with cerebral infarction (CI) and 316 control individuals respectively. The levels of serum lipid profiles were measured with biochemical methodsìand the other clinical characters were obtained by case file investigation.

RESULTSThe odds ratio (OR) for CI in -1131CC genotype carriers was 2.10 (95%CI 1.01-4.37). The distribution of T-T and T-G haplotypes had obvious differences between CI patients and control individuals. The OR for CI in C-G and T-G haplotype carriers were 1.34 and 0.71(95% CI 1.02-1.76 and 0.55-0.92) respectively, compared with the others. Furthermore, the major haplotypes had significant differences of serum TG(P< 0.05).

CONCLUSIONThe ApoA5 -1131T>C polymorphism may be associated with an increased risk of CI in the Chinese population, but the influence of blood lipids can not be ignored.

Aged ; Apolipoproteins A ; genetics ; Carotid Artery Diseases ; complications ; genetics ; Cerebral Infarction ; complications ; genetics ; Female ; Genetic Predisposition to Disease ; genetics ; Haplotypes ; genetics ; Humans ; Male ; Middle Aged ; Polymerase Chain Reaction ; Polymorphism, Genetic ; genetics ; Polymorphism, Restriction Fragment Length

OBJECTIVETo investigate the association of single nucleotide polymorphisms (SNPs) in matrix metalloproteinase-2 (MMP-2) and tissue inhibitor of metalloproteinase-2 (TIMP-2) with the risk of endometriosis and adenomyosis.

METHODSGenotypes of MMP-2 and TIMP-2 were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method among 298 endometriosis patients, 180 adenomyosis patients and 324 matched control women.

RESULTSNo significant difference was found in allele frequencies and genotype distributions of MMP-2 -1306C/T polymorphism between endometriosis patients and control women (P> 0.05). However, there were significant differences in genotype and allele distributions of MMP-2 -1306C/T polymorphism between adenomyosis patients and control women (P< 0.05). Compared with CT+TT genotypes, CC genotype significantly increases the risk of adenomyosis, with an odds ratio of 1.83 (95% CI was 1.13-2.96). No significant difference was shown in allele frequencies and genotype distributions of the MMP-2 -735C/T polymorphism among the three groups (P>0.05). MMP-2 -1306C/T and -735C/T polymorphisms displayed linkage disequilibrium (D'=0.74). There was no significant difference in haplotype distributions of the two MMP-2 SNPs among the three groups ( P> 0.05). No significant difference was found in allele frequencies of TIMP-2 -418G/C polymorphism among the three groups (P> 0.05). However, the frequency of TIMP-2 CC genotype in endometriosis patients (0.7%) was significantly lower than that in the control women (3.7%) (P< 0.05).

CONCLUSIONThe C allele of MMP-2 -1306C/T polymorphism did not modify the risk of developing endometriosis but significantly increase the risk of developing adenomyosis. The MMP-2 -735C/T and TIMP-2 -418G/C polymorphisms were not associated with the risk of developing endometriosis or adenomyosis.

Adult ; Endometriosis ; genetics ; Female ; Gene Frequency ; genetics ; Genetic Predisposition to Disease ; genetics ; Genotype ; Humans ; Linkage Disequilibrium ; genetics ; Matrix Metalloproteinase 2 ; genetics ; Middle Aged ; Polymorphism, Single Nucleotide ; genetics ; Tissue Inhibitor of Metalloproteinase-2 ; genetics

OBJECTIVETo study the genetic stability of an immortalized cell line transformed by Epstein-Barr virus (EBV) after long subculture process.

METHODSIn the present study, the genetic stability including chromosome diploidy, karyotypes and microsatellite DNA were evaluated with chromosome banding techniques and microsatellite DNA detection. The telomerase activity of the immortalized cell line was detected by using the telomerase assay kit.

RESULTSFrom passage 1 to 30, there were no change of the diploidy, karyotypes of chromosome and microsatellite DNA, and the telomerase activity is negative.

CONCLUSIONThis study indicates that the immortalized cell line remains stable genetically within limited passages.

Cell Transformation, Viral ; genetics ; Herpesvirus 4, Human ; genetics ; Humans ; Lymphocytes ; cytology ; metabolism ; virology ; Microsatellite Repeats ; genetics ; Polymerase Chain Reaction

OBJECTIVETo explore the relationship of polymorphisms in the ubiquitin carboxy-terminal hydrolase-L1 (UCH-L1) gene with Parkinson's disease(PD)in Shanghai Han Nationality.

METHODSThe distribution of a Serine18Tyrosine polymorphism in exon 3(C/A) and a Serine89Phenylalanine polymorphism in exon 4(C/T)of UCH-L1 gene were detected in 164 PD cases and 172 healthy controls, using polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP) method.

RESULTS(1)The C allelic frequency in exon 3 of UCH-L1 gene in PD patients(62.2%) was significantly higher than that of the healthy controls(51.7%) (OR=1.53, P=0.006), as was the C/C genotype(OR=1.90, P=0.008). (2)There was no significant difference in the distribution of the C/T allele and genotypes in exon 4 between PD patients and healthy controls.

CONCLUSIONThe C allele in exon 3 of UCH-L1 gene might be one of the risk factors for PD in Shanghai Han Nationality, but the polymorphisms of C/T in exon 4 showed no association with the onset of PD.

Adult ; Aged ; Aged, 80 and over ; China ; Exons ; genetics ; Female ; Gene Frequency ; genetics ; Genetic Predisposition to Disease ; genetics ; Genotype ; Humans ; Male ; Middle Aged ; Parkinson Disease ; genetics ; Polymerase Chain Reaction ; Polymorphism, Genetic ; genetics ; Polymorphism, Restriction Fragment Length ; genetics ; Ubiquitin Thiolesterase ; genetics

OBJECTIVETo explore the association of the Thr241Met polymorphism of X-ray cross-complementing group 3 (XRCC3) gene with genetic susceptibility to aflatoxin B1(AFB-1)-related hepatocellular carcinoma (HCC)in Guangxi population.

METHODSWe conducted a hospital-based case-control study, including 257 HCC cases and 711 controls without cancers or liver diseases. The XRCC3 Thr241Met polymorphism was analyzed by PCR.

RESULTSThe XRCC3 genotypes XRCC3-Thr/Met or XRCC3-Met/Met were related with an elevated risk of HCC. The risk of HCC was associated with the number of mutant Met copies (adjusted OR were 2.20 and 8.56 for XRCC3-Thr/Met and Met/Met, respectively); moreover, there seemed to be combined effects for HCC risk between the variant genotypes and AFB1-DNA adduct levels from peripheral blood leukocytes (adjusted OR was 2.34 to 20.44, P < 0.01).

CONCLUSIONThese results suggested that XRCC3 polymorphism may be associated with the risk of AFB1- related HCC among the Guangxi population, and interacts with AFB1 exposure in the development of HCC induced by AFB1.

Aflatoxin B1 ; toxicity ; Carcinoma, Hepatocellular ; chemically induced ; genetics ; Case-Control Studies ; China ; DNA-Binding Proteins ; genetics ; Genetic Predisposition to Disease ; genetics ; Genotype ; Humans ; Polymerase Chain Reaction ; Polymorphism, Genetic ; genetics ; Polymorphism, Restriction Fragment Length ; genetics

OBJECTIVETo study the anti-invasion effect of SEPT7 gene on U251MG glioma cells and its possible molecular mechanism.

METHODSRecombinant adenovirus vector carrying SEPT7 gene (rAd5-SEPT7) was transduced to human glioma cell line U251MG, and empty adenovirus vector was used as control. Tumor invasion was examined by Transwell method and 3 D-Matrigel assay, and tumor cell migration by wound-healing method and 2 D-Matrigel assay. Three major molecular events associated with cell motility and migration, including changes of expression in MMP2, MMP9, MT1-MMP, TIMP1 and TIMP2, the alteration of integrin alpha(v)beta(3) expression, and the structural change of cytoskeleton protein, tubulin-alpha, in U251 cells transduced with rAd5-SEPT7 were studied by Western blotting, immunofluorescence and laser scanning confocal microscope, respectively.

RESULTSThe invasive and migratory capabilities of cells transduced with rAd5-SEPT7 were inhibited. The expression of extracellular matrix metalloproteinases MMP-2, MMP-9, MT1-MMP and integrin alpha(v)beta(3) was significantly decreased, while the expression of matrix metalloproteinase inhibitor TIMP1, TIMP2 was upregulated. Intracellular cytoskeleton protein-tubulin-alpha in U251 cells exhibited prominent morphological changes which including the appearance of distortion and aggregation resulting from redistribution of tubulin-alpha, and this feature of alteration was similar to the tubulin-alpha structure in normal non-tumor cells.

CONCLUSIONSEPT7 gene can inhibit the invasion and migration ability of U251 glioma cells. Its molecular mechanism may include that SEPT7 gene reverses the imbalanced state of MMPs/TIMPs, downregulates the expression of integrin alpha(v)beta(3) and alters the structure of tubulin-alpha of U251MG glioma cells. It is suggested that SEPT7 gene could be a good candidate for gene therapy of gliomas.

Adenoviridae ; genetics ; Blotting, Western ; Cell Cycle Proteins ; genetics ; physiology ; Cell Line, Tumor ; Cell Movement ; genetics ; Genetic Vectors ; genetics ; Glioma ; metabolism ; pathology ; Humans ; Integrin alphaVbeta3 ; metabolism ; Matrix Metalloproteinase 14 ; metabolism ; Matrix Metalloproteinase 2 ; metabolism ; Matrix Metalloproteinase 9 ; metabolism ; Microscopy, Confocal ; Neoplasm Invasiveness ; genetics ; Septins ; Tissue Inhibitor of Metalloproteinase-1 ; metabolism ; Tissue Inhibitor of Metalloproteinase-2 ; metabolism

OBJECTIVETo describe a community-based model for prevention and control of severe alpha and beta thalassemias in Zhuhai city of Guangdong province.

METHODSCouples for premarital medical examination or regular healthcare examination in pregnancy were enrolled in this prospective screening program, which was supported by the two-level network composed of 6 local hospitals for testing thalassemias and follow-up for genetic counseling. A conventional heterozygote screening strategy was used to determine alpha and beta thalassemia traits in women and their partners according to the standard procedures of hematological phenotype analysis. Then confirmative diagnosis of alpha and beta thalassemia was performed on those couples suspected at-risk for severe thalassemia by using the PCR-based molecular diagnostic assays. The couples at-risk for severe thalassemia were counseled and offered prenatal diagnosis and termination of pregnancy in case of an affected fetus.

RESULTSDuring the period between January 1998 and December 2005, the screened records included 85522 young females and their partners for premarital screening and 10439 pregnant women for prenatal screening, with 71.38% coverage of total population recorded in this city for premarital screening. Six thousands five hundreds and sixty-three individuals in total were found to be the carriers of thalassemias, with 4312 for alpha thalassemia (4.5%) and 2251 for beta thalassemia (2.3%), respectively. One hundred and forty-eight couples were diagnosed to be at-risk for thalassemias, including 103 for alpha thalassemia and 45 for beta thalassemia, respectively. Successful prenatal diagnosis was made for 142 (98 for alpha thalassemia and 44 for beta thalassemia) out of 148 (95.9%) pregnancies at-risk for severe thalassemias. Twenty-three cases of hydrops fetalis, 4 of Hb H diseases and 14 of beta thalassemia were identified. All 41 pregnancies with affected fetuses were voluntarily terminated. Thus, this has led to a marked decrease of severe thalassemia syndrome since the program started.

CONCLUSIONWe presented the first community-based prospective screening program in China for control of alpha and beta thalassemia in Zhuhai city with a population of 1.29 million through premarital or prenatal screening. This model could be used for control of thalassemias and other hemoglobinopathies in other regions of China and also in other developing countries.

China ; Humans ; Prenatal Diagnosis ; methods ; alpha-Thalassemia ; diagnosis ; genetics ; beta-Thalassemia ; diagnosis ; genetics