MicroRNA-27a promotes proliferation and suppresses apoptosis by targeting PLK2 in laryngeal carcinoma.

BACKGROUND: miRNA-27a has been confirmed as an important regulator in carcinogenesis and other pathological processes. Whether and how it plays a role in the laryngeal carcinoma is unknown. METHODS: Mature miRNA-27a expression in laryngeal cancer was detected by qRT-PCR. Gain-of-function studies using mature miR-27a were performed to investigate cell proliferation and apoptosis in the Hep2 cells. In silico database analysis and luciferase reporter assay were applied to predict and validate the direct target, respectively. Loss-of-function assays were performed to investigate the functional significance of the miR-27a target gene. qRT-PCR and Western blot were used to evaluate mRNA and protein levels of the target, respectively. RESULTS: miR-27a was significantly up-regulated in the laryngeal tumor tissues compared to the adjacent non-tumor tissues. In silico database analysis result revealed that PLK2 is a potential target of miR-27a. luciferase reporter assay result showed the direct inhibition of miR-27a on PLK2-3'UTR. In the cases with miR-27a up-regulation, PLK2 protein expression level was significantly lower in cancer tissues than that in the adjacent non-tumor tissues, which showed a negative correlation with miR-27a expression level. Both miR-27a and knockdown of PLK2 caused the increase of the cell viability and colony formation and inhibition of the late apoptosis in the Hep2 cell lines. Moreover, miR-27a but not PLK2 also repressed the early apoptosis in the Hep2 cells. Additionally, no alteration of the Hep2 cell cycle induced by miR-27a was detected. CONCLUSIONS: miR-27a acts as an oncogene in laryngeal squamous cell carcinoma through down-regulation of PLK2 and may provide a novel clue into the potential mechanism of LSCC oncogenesis or serve as a useful biomarker in diagnosis and therapy in laryngeal cancer.

Promoter hypermethylation-induced transcriptional down-regulation of the gene MYCT1 in laryngeal squamous cell carcinoma.

BACKGROUND: MYCT1, previously named MTLC, is a novel candidate tumor suppressor gene. MYCT1 was cloned from laryngeal squamous cell cancer (LSCC) and has been found to be down-regulated in LSCC; however, the regulatory details have not been fully elucidated. METHODS: Here, we sought to investigate the methylation status of the CpG islands of MYCT1 and mRNA levels by bisulfite-specific PCR (BSP) based on sequencing restriction enzyme digestion, reverse transcription and real-time quantitative polymerase chain reaction (RQ-PCR). The function of specific sites in the proximal promoter of MYCT1 in LSCC was measured by transient transfection, luciferase assays, electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation assay (ChIP). RESULTS: The results suggested hypermethylation of 12 CpG sites of the promoter in both laryngeal cancer tissues and the laryngeal cancer line Hep-2 cell. The hypermethylation of the site CGCG (-695 to -692), which has been identified as the c-Myc binding site, was identified in laryngeal cancer tissues (59/73) compared to paired mucosa (13/73); in addition, statistical analysis revealed that the methylation status of this site significantly correlated with cancer cell differentiation(p < 0.01). The mRNA level of MYCT1 increased in Hep-2 cells treated with 5-aza-C (p < 0.01). The luciferase activity from mutant transfectants pGL3-MYCT1m (-852/+12, mut-695-C > A, mut-693-C > G) was significantly reduced compared with the wild type pGL3-MYCT1 (-852/+12), while the luciferase activity from wild transfectants pGL3-MYCT1 (-852/+12) rose after 5-aza treatment in Hep-2 cells. Finally, EMSA and ChIP confirmed that the methylation of the CGCG (-695 to -692) site prevented c-Myc from binding of the site and demethylation treatment of the 5' flanking region of MYCT1 by 5-aza induced the increased occupation of the core promoter by c-Myc (p < 0.01). CONCLUSION: In summary, this study concluded that hypermethylation contributed to the transcriptional down-regulation of MYCT1 and could inhibit cancer cell differentiation in LSCC. DNA methylation of the CGCG site (-695 to -692) of MYCT1 altered the promoter activity by interfering with its binding to c-Myc in LSCC. Epigenetic therapy of reactivating MYCT1 by 5-aza should be further evaluated in clinical trails of LSCC.

14-3-3epsilon contributes to tumour suppression in laryngeal carcinoma by affecting apoptosis and invasion.

BACKGROUND: 14-3-3epsilon regulates a wide range of biological processes, including cell cycle control, proliferation, and apoptosis, and plays a significant role in neurogenesis and the formation of malignant tumours. However, the exact function and regulatory mechanism of 14-3-3epsilon in carcinogenesis have not been elucidated. METHODS: The expression of 14-3-3epsilon was assessed by RT-PCR and western blotting. The invasiveness and viability of Hep-2 cells were determined by the transwell migration assay and MTT assay, respectively. Cell cycle and apoptosis of Hep-2 cells were detected by flow cytometry. RESULTS: The mRNA and protein expression of 14-3-3epsilon in larynx squamous cell carcinoma (LSCC) tissues were significantly lower than those in clear surgical margin tissues. Statistical analysis showed that the 14-3-3epsilon protein level in metastatic lymph nodes was lower than that in paired tumour tissues. In addition, the protein level of 14-3-3epsilon in stage III or IV tumours was significantly lower than that in stage I or II tumours. Compared with control Hep-2 cells, the percentages of viable cells in the 14-3-3epsilon-GFP and negative control GFP groups were 36.68 +/- 14.09% and 71.68 +/- 12.10%, respectively. The proportions of S phase were 22.47 +/- 3.36%, 28.17 +/- 3.97% and 46.15 +/- 6.82%, and the apoptotic sub-G1 populations were 1.23 +/- 1.02%, 2.92 +/- 1.59% and 13.72 +/- 3.89% in the control, negative control GFP and 14-3-3epsilon-GFP groups, respectively. The percentages of the apoptotic cells were 0.84 +/- 0.25%, 1.08 +/- 0.24% and 2.93 +/- 0.13% in the control, negative control GFP and 14-3-3epsilon-GFP groups, respectively. The numbers of cells that penetrated the filter membrane in the control, negative control GFP and 14-3-3epsilon-GFP groups were 20.65 +/- 1.94, 17.63 +/- 1.04 and 9.1 +/- 0.24, respectively, indicating significant differences among the different groups. CONCLUSIONS: Decreased expression of 14-3-3epsilon in LSCC tissues contributes to the initiation and progression of LSCC. 14-3-3epsilon can promote apoptosis and inhibit the invasiveness of LSCC.

Reduced ACTC1 expression might play a role in the onset of congenital heart disease by inducing cardiomyocyte apoptosis.

BACKGROUND: The Cardiac α actin 1 gene (ACTC1) has been related to familial atrial septal defects. This study was set to explore a potential role of this gene in the formation of sporadic congenital heart disease (CHD). METHODS AND RESULTS: Assessment of cardiac tissue samples from 33 patients with sporadic CHD (gestational age (GA) 18 weeks-49 months) with real-time RT-PCR, Western blotting and immunohistochemistry has revealed a markedly decreased ACTC1 expression in the majority of samples (78.8%) compared with autopsied normal heart tissue from aged-matched subjects (GA 17 weeks-36 months). Also, as shown by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay, the proportion of apoptotic cardiomyocytes in samples featuring down-regulated ACTC1 expression (Group 1) was significantly greater than those with normal expression (Group 2) and the controls (P<0.01). The proportion of apoptotic cells strongly correlated with the expression of ACTC1 (r=-0.918, P<0.01). A study of 2 essential genes involved in apoptosis, Caspase-3 and Bcl-2, confirmed that the former has significantly increased expression, whilst the latter has decreased expression in Group 1 than in the other groups (P<0.01). Transfection of a small interfering RNA targeting, Actc1 (Actc1-siRNA), to a cardiomyocyte cell line, H9C2, also detected more apoptotic cells. CONCLUSIONS: Reduced ACTC1 expression might play a role in the onset of CHD through induction of cardiomyocyte apoptosis.

[Teaching experience in integrated course of human development and genetics].

Establishment of integrated course system in human development and genetics is an important part of course reformation, and the improvement of this system is achieved by integrating the content of course, stabilizing teaching force, building teaching materials and applying problem-based learning. Integrity-PBL teaching model is founded and proved to be feasible and effective by teaching practice. Therefore, it maybe play an important role in improving teaching effect and cultivating ability of students to analyse and solve problems.

[The mechanism of TBX5 abnormal expression in simple congenital heart disease].

To explore the mechanism of TBX5 abnormal expression in simple congenital heart disease (CHD), 100 CHD venous blood, 50 CHD heart tissues, and 5 non-CHD heart tissues were involved in this study. The mutation and methylation in the 1 200 bp region upstream of TBX5 gene were detected by high-performance liquid chromatography (DHPLC) and methylation-sensitive restriction endonuclease (MS-RE), respectively. The binding site of NKX2-5 to Tbx5 predicted by P-MATCH software was validated by EMSA (Electrophoretic mobility shift assay). Tbx5 gene expression in mouse cardiac muscle cell H9C2(2-1) transfected with NKX2-5 expression vector was evaluated. No mutation was found in all patients. Both non-CHD and CHD heart tissues had the same methylation in the two CpG islands. Exogenous Nkx2-5 efficiently activated the transcription of the endogenous Tbx5 gene in H9C2 (2-1) cells. EMSA showed that the special binding band appeared when Nkx2-5 existed. These results indicates that the down expression of TBX5 might not be caused by mutation and methylation in the 1 200 bp region upstream of gene, and might be regulated by abnormal expression of NKX2-5 gene in heart muscle of CHD.

[Research of HOXD13 and FHL1 in idiopathic congenital talipes equinovarus].

To investigate the relationship of HOXD13 and FHL1 in idiopathic congenital talipes equinovarus(ICTEV), 84 samples from patients with ICTEV were used in the study. Mutation in the coding region of HOXD13 was detected by denaturing gradinent electrophoresis. The mRNA and protein levels of HOXD13 and FHL1 were evaluated by RT-PCR and immunohistochemistry, respectively. The binding site of FHL1 to HOXD13 predicted by PMATCH software was validated by EMSA( Electrophoretic mobility shift assay,EMSA).No mutation was found in the coding region of HOXD13 in 84 samples from patients with ICTEV. Both HOXD13(33.3%) and FHL1(46.6%) were down-regulated in ICTEV muscle tissue. The result of EMSA showed that the special binding band appeared when HOXD13 existed. The results shows that HOXD13 gene mutation was not involved in outbreak in idiopathic congenital talipes equinovarus, but changes of HOXD13 and FHL1 gene expression related to the development of talipes equinovarus malformation. HOXD13 might play an role in ICTEV through regulating FHL1 expression.

[Effect of cobalt chloride on S100A4 expression in human gastric cancer cell BGC823].

S100A4 is an important metastasis-associated gene. Researches have confirmed the close correlation between overexpression of S100A4 gene and gastric cancer's infiltration, lymph node metastasis and in vitro invasiveness of gastric cancer cells. In order to investigate the mechanism of overexpression of S100A4 gene, hypoxia mimetic cobalt chloride (CoCl2) was used to treat gastric cancer cell BGC823, and then the expression of S100A4 mRNA and protein in BGC823 cells were detected by RT-PCR, immunohistochemistry, immunofluorescence, and Western blotting analysis. After treatment with CoCl2, the expression of S100A4 mRNA and protein in BGC823 cell was increased. These results suggested that hypoxia mimetic cobalt chloride could increase the expression of S100A4 gene in gastric cancer cell BGC823.

[Association study between mutations of transcription regulator sequences of COL1A1 gene and idiopathic con-genital talipes equinovarus].

RT-PCR was used to detect the expressions of COL1A1 mRNA in 20 patients with idiopathic congenital talipes equinovarus (ICTEV). The primers were designed by Primer 5 according to sequences of -1 031 bp~ +30 bp and the first intron of COL1A1. PCR-DGGE was used to screen the mutations in COL1A1 gene. Expression of COL1A1 on mRNA levels showed significantly higher in patients with ICTEV than in normal persons (t=12.680, P < 0.05). By DNA sequencing, a -161(T--> C) heterozygous mutation and a+ 274(C-->G) homozygous mutation were detected, and both were new identified mutations. These results indicated that the mutations in transcription regulator sequences of COL1A1 could cause ICTEV.

Study of the SH3-domain GRB2-like 2 gene expression in laryngeal carcinoma.

BACKGROUND: Laryngeal carcinoma is a common malignant tumor of the upper respiratory tract, and in 95% of cases the tumor is laryngeal squamous cell carcinoma (LSCC). The abnormity of SH3-domain GRB2-like 2 (SH3GL2) gene was found in LSCC. In order to clarify the relationship between SH3GL2 gene and LSCC, we evaluated the expression of the SH3GL2 gene in LSCC. METHOD: Real-time PCR, immunohistochemistry and Western blotting were used to detect the mRNA and protein expression and find the various rules of SH3GL2 gene in LSCC. RESULTS: The result of real-time PCR showed that the expression level of SH3GL2 mRNA in LSCC tissue was apparently down-regulated; immunohistochemical analysis showed that SH3GL2 protein was mainly located in cytoplasm, the rate of positive cells and SH3GL2 protein expression level were fluctuated with the pathological classification of LSCC; the result of Western blotting showed that SH3GL2 protein was down-regulated significantly in LSCC samples, especially in metastatic lymph nodes. CONCLUSIONS: These results suggest that SH3GL2 is a LSCC related gene and its expression level is fluctuated with the pathological classification which indicate that SH3GL2 participates in the development and progression of LSCC. And it may be considered as a novel tumor marker to find both a new anti-oncogene and relative factors of invasion and metastasis of laryngeal carcinoma.

Decreased expression of DICER1 in gastric cancer.

BACKGROUND: The role of epigenetics in gene expression regulation and development significantly enhances our understanding of carcinogenesis. All the tumor related genes may be the target of epigenetical or genetic regulation. We selected some epigenetically regulated genes for cDNA array analysis and observed variability in the expression of the DICER1 gene in distinct stages of gastric cancer. The aim of this study was to assess the correlation between the expression of DICER1, an epigenetically regulated gene, and gastric cancer. METHODS: To detect the expression of 506 tumor-associated genes, including DICER1, in the matched cancerous mucosa, pre-malignant lesion (adjacent mucosa), non-cancerous gastric mucosa and distant lymphocyte metastatic lesion in 3 cases of gastric cancers using cDNA array. DICER1 mRNA expression and DICER1 protein expression were further analyzed by Real-time PCR and Western blot in 32 cases of progressive gastric cancer. DICER1 protein expression was also detected in 33 early and 30 progressive gastric cancers by the immunohistochemistry (IHC) method. RESULTS: In 3 cases of gastric cancer cDNA array showed dramatically decreased expression of DICER1 in pre-malignant lesion, cancerous mucosa and distant lymphocyte metastatic lesions compared with matched noncancerous gastric mucosa, pre-malignant lesion and cancerous mucosa. Real-time PCR results showed that the expression level of DICER1 mRNA in gastric cancer was significantly down-regulated compared to normal gastric tissue (P < 0.05). The IHC assay also showed that the expression of DICER1 was significantly decreased in progressive gastric cancer. Among the 63 cases of gastric cancers, 13/33 early (39.4%) and 19/30 (63.3%) progressive cancers showed negative expression of DICER1 (50.8%). The difference in expression of DICER1 between early and progressive gastric cancers was significant (P < 0.01). The result of Western blotting showed that DICER1 protein was down-regulated significantly in advanced gastric cancer (P < 0.05). CONCLUSIONS: DICER1 expression is decreased during the progression of gastric cancer, especially in progressive gastric cancers, which indicating DICER1 may play an important role in the development of cancer and the epigenetical regulation involved.

[Application study on inversion diagnosis of F8 gene in hemophilia A].

OBJECTIVE: To establish an effective method of genetic diagnosis on hemophilia A (HA) by detecting the inversion mutation in intron 22 of F8 gene. METHODS: Intron 22 inversion mutation in F8 gene was detected by using long distance-polymerase chain reaction (LD-PCR) and inversion-PCR (I-PCR) in 31 HA patients. The mothers of HA patients with intron 22 inversion mutation were selected to carrier diagnosis and amniotic fluid of the pregnant women with inversion mutation was collected at intermediate stage of gestation, and used to prenatal genetic diagnosis. RESULTS: Seven patients showed F8 gene inversion mutation in thirty-one patients. Three in four mothers of HA patients with intron 22 inversion mutation were diagnosed as carriers. The prenatal diagnosis result indicated that the fetus conceived in the HA-carrier woman was normal individual. CONCLUSION: The detection of intron 22 inversion mutation by LD-PCR and I-PCR is time-saving, and can be used in prenatal diagnosis on HA.

[Analysis of chromosome aberrations in the cell derived from primary cell culture of laryngeal carcinoma and the Hep-2 cell line].

OBJECTIVE: To search for characteristic chromosome changes in primary laryngeal squamous cell carcinoma (LSCC) and Hep-2 cell line and to realize the relationship between the cytogenetic abnormality and the pathogenetic mechanism in LSCC. METHODS: The fresh resulted samples of LSCC were analyzed with an improved primary cell culture for chromosome preparation and G-banding technique. Hep-2 cell line was analyzed by high resolution banding technique. Molecular cytogenetics analysis was made by chromosome 6 painting probe. RESULTS: Four primary LSCC succeeded in primary cell culture and obtained metaphases, one was tetraploid, the other three were triploid. The chromosome mode of Hep-2 cell line was from 68 to 75 and fifteen marker chromosomes were found. The most structural abnormalities of chromosome in primary LSCC and HEP-2 cell line were unbalance translocation, terminal deletion and isochromosome. The complicate aberration in chromosome 6 was common in LSCC and Hep-2. CONCLUSION: 6q-, I(5p), 17p-, 5q- are considered as characteristic chomosome changs in LSCC. Fluorescence in situ hybridization (FISH) may enhance the ability of detecting complicated chromosome rearrangements and marker chromosomes, which could provide more value data to verify the chromosome characteristic aberration in LSCC.

[The role of insulin-like growth factor-2 gene differentially methylated regions in TCDD-induced malformation].

OBJECTIVE: To study the effects of 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD) on the development of fetal rats and to explore the relationship between TCDD-induced abnormal development in rats and the expression and the methylation of insulin-like growth factor 2 gene (Igf2). METHODS: A single dose of 10 microg/kg TCDD was given to gestation day (GD) 10 pregnant rats by gavage. On GD20, the fetuses were taken out and examined. The crown-rump length, the body weight and the placental weight were measured. The expression of Igf2 in liver was detected by real-time quantitative reverse transcription (RT-PCR) and Western blot. The methylation of Igf2 differentially methylated regions (DMRs) in liver was analyzed by a methylation-sensitive restriction enzyme Hpa II PCR assay and a bisulfite-modified DNA sequencing procedure. RESULTS: In the treatment group, 12.2% of the fetuses were either dead or absorbed, and 11.6% of them were malformed. For the live fetuses, their crown-rump length, body weight and placental weight were significantly lower than those of the control group. The relative amount of Igf2 mRNA in the treated livers and the control livers was 0.77 +/- 0.11 and 0.27+/- 0.15, respectively. The number was significantly higher in the treatment group than in the control group (P < 0.01). Western blot also showed a remarkable up regulation of Igf2 protein in liver after treatment. The two groups showed no difference in the methylation status of Igf2 DMR1 in liver. The DMR2 Igf2 was significantly hypomethylated in the treated livers than in the control livers. CONCLUSION: Exposure to TCDD in pregnancy can lead fetal rats to death, absorption, malformation and intrauterine growth retardation (IUGR). The TCDD led abnormal development in rats may be associated with the hypomethylated DMR2 of Igf2 and the up regulation of Igf2 in liver.

[Non-invasive prenatal genetic diagnosis using multiple displacement amplification].

OBJECTIVE: To investigate the feasibility of multiple displacement amplification (MDA) to apply in the non-invasive prenatal genetic diagnosis of Duchenne muscular dystrophy (DMD). METHODS: Maternal blood was obtained from 20 pregnant women at 7 to 25 weeks of gestation. After the discontinuous density gradient centrifugation with Percoll, the fetal nucleated red blood cells (NRBCs) were stained with Kleihauer test. All positive NRBCs were collected by micromanipulator and then performed with MDA. Sex and short tandern repeat (STR) analysis were determind from a small aliquot of the reaction. The origin of NRBCs was verified and prenatal diagnosis of DMD was made at the same time. RESULTS: The product length of MDA was >15 kb, while primer extension preamplification (PEP) is only about 1 kb. We completed non-invasive prenatal genetic diagnosis of 6 fetus at high risk of DMD using MDA. The results were all coincident with amniotic fluid control. CONCLUSION: The MDA method which provides a highly uniform representation across the genome, representing the entire genome with minimal amplification bias, shows good application prospects.

Novel partners of S100A8 identified in laryngeal cancer cell lines.

OBJECTIVE: To explore mechanism of S100A8 in the oncogenesis and development of laryngeal cancer. METHODS: Proteins interacting with S100A8 were isolated from laryngeal cancer cell lines Hep-2 by immunoprecipitation assay with anti-S100A8 antibody. The target bands were cut out and identified by maxtrix assisted laser desorption/ionization time of flight (MALDI-TOF). The peptide mass fingerprinting data of the proteins identified were analyzed based on the Mascot database. The NF-kappa B binding sites of the proteins were predicted by P-Match software. The binding ability of one of the proteins to S100A8 was confirmed by co-immunoprecipitation and immunocytochemistry methods. RESULTS: Four proteins interacting with S100A8 were obtained, which were hypothetical protein LOC80154, MHC class I HLA-B, similar to T-box 1 isoform C and sarcolemmal associated protein 1. The four genes were predicted to have NF-kappa B binding sites. MHC class I HLA-B, which is one of targets in NF-kappa B pathway, was first confirmed to have the binding ability to S100A8. CONCLUSION: The novel partners of S100A8 identified in the study might be involved in NF-kappa B pathway. The binding ability of MHC class I HLA-B to S100A8 implies that S100A8 might function as a new member with other proteins including HLA-B in NF-kappa B pathway. These findings provide a new clue to further study on the molecular mechanism of S100A8 in the genesis of laryngeal carcinomas.

[Proteomic analysis of the ankle joint bone, ankle joint tissue and spinal cord of clubfoot-like deformity in rat fetuses].

OBJECTIVE: To explore the etiology of idiopathic talipes equinovarus (ITEV) in all-trans retinoic acid (ATRA) induced clubfoot-like deformity in rat fetuses with two-dimensional gel electrophoresis (2-DE) and mass spectrometry (MS). METHODS: Clubfoot-like deformity model in rat fetuses was induced with ATRA (135 mg/kg) in gestation day (GD10) pregnant Wistar rats. 2-DE was applied to separate the total proteins of ankle joint tissue, ankle joint bone and spinal cord of the animal models. The Coomassie Brilliant Blue staining gels were analyzed by 2-DE software PDQuest 7.1.0. Selected differential protein spots were identified with peptide mass fingerprinting based on matrix-assisted laser adsorption/ionization time-of-flight mass spectrometry and database searching. xiap, tnnt1 and col2 alpha 1, three genes of the differential proteins, were identified furthermore. Apoptosis study was made in terminal deoxynucleotidyl transferase nick end labeling. RESULTS: There were many differential expressed proteins in the clubfoot-like deformity model. Out of the differentially expressed proteins,16 protein spots were identified to be differentially expressed in the clubfoot-like deformity model with MS. Three of the 16 protein spots, xiap, tnnt1 and col2 alpha 1 were confirmed to be significantly down-regulated by the RT-PCR, and Xiap was further confirmed to be significantly down-regulated with immunohistochemistry. Another randomly selected gene, ngfr, did not express differently in ATRA-induced clubfoot-like deformity in rat fetuses. The rates of the apoptosis in the spinal, bone of the clubfoot-like deformity fetuses was 5.4 and 10 times of those of the normal fetuses respectively. CONCLUSION: The results suggest that there are certain differently expressed proteins in ankle joint tissue, ankle joint bone and spinal cord of the ATRA-induced clubfoot-like deformity in rat fetuses, and Xiap, sTnT, and Col2 alpha 1 show a significant correlation with ITEV. Ngfr is not correlation with ITEV. Apoptosis plays a key role in the development of ITEV and related to the decreased expression of the Xiap.

[Analysis of association between COL9A1 gene and idiopathic congenital talipes equinovarus].

Genotypes of 2 SNPs(rs592121 and rs1135056) within COL9A1 gene in 84 ICTEV nuclear pedigrees were analyzed by restriction fragment length polymorphism and DNA sequencing. Analysis of association between SNP locus and ICTEV was performed using ETDT software. Haplotypes and their frequencies in 84 nuclear pedigrees were established and analyzed by TRANSMIT software. RT-PCR was used to detect the expressions of COL9A1 mRNA in 25 patients with ICTEV. The results showed that rs592121 and rs1135056 loci within COL9A1 gene existed transmission disequilibrium in 84 nuclear pedigrees (P<0.05). Expression of COL9A1 on mRNA levels showed significantly higher in patients with ICTEV than in normal person (t=4.7500, P<0.05) . These results indicate that COL9A1 gene may be important suscept-ble genes of ICTEV.

[Detection of fetal nucleated red blood cells in the maternal circulation by Kleihauer test].

Maternal blood was obtained from 18 pregnant women at 7 to 25 weeks of gestation. After Percoll discontinuous density gradient centifugation, the fetal nucleated red blood cells (NRBCs) were stained with Kleihauer test. Positive fetal cells appeared with an intense red cytoplasmic staining while maternal cells with adult haemoglobin were colourless. Individual positive NRBC was collected by micromanipulator and whole genome amplification was then performed to determine sex and STR status. This allowed the simultaneous verification of the fetal origin of NRBC and prenatal diagnosis of genetic diseases. The non-invasive prenatal genetic diagnosis of 9 fetuses at high risk of Duchenne muscular dystrophy (DMD) was completed successfully. The Kleihauer test is a rapid, simple and direct chemical staining method to select fetal cells and can be applied in prenatal diagnosis.

[Effect of B-RAF-specific RNA interference on gastric cancer BGC823 cell line].

To investigate the influence of B-RAF-specific RNA interference on the proliferation and apoptosis of gastric cancer BGC823 cell line. B-RAF-siRNA and scramble-siRNA were synthesized and transfected into BGC823 cells by TransMessenger. The expression of B-RAF gene and Bcl-2 gene in BGC823 cells was detected by RT-PCR and the level of apoptosis was evaluated in transfected cells by flow cytometry. Results showed that TransMessenger could effectively transfect B-RAF-siRNA and scramble-siRNA into BGC823 cells. B-RAF-siRNA significantly inhibited the expression of B-RAF gene and Bcl-2 gene in BGC823 cells by more than 90% to 100%. B-RAF-siRNA inhibited BGC823 cell prolifera-tion and induced apoptosis (P < 0.01). In conclusion, B-RAF-siRNA can effectively inhibit the expression of B-RAF gene and Bcl-2 gene, induce cell apoptosis and inhibit the proliferation of gastric cancer BGC823 cells.