Significance and alterations of p14ARF gene of CDKN2A locus in gastric cancer

AIM:To investigate the significance and changes of p14^ARF gene in gastric cancer.METHODS:The tumors and gastric tissues neighboring carcinoma from 48 patients with gastric cancer were studied. The homozygous deletions, mutations, methylation of the CpG islands, and mRNA expression of p14^ARF gene were assessed by PCR, PCR-SSCP, PCR based methylation assay, and RT-PCR.RESULTS:①The homozygous deletion rate of p14^ARF was 31.3% (15/48), and no homozygous deletions were examined in all the gastric tissues neighboring tumor. ②There were no point mutations of p14^ARF in 33 gastric cancers without homozygous deletion and in the matched gastric tissues adjacent to tumor. ③Methylation rate of the CpG islands of p14^ARF was significantly higher in gastric cancers(47.9%, 23/48) than that in gastric tissues neighboring cancer (4.2%, 2/48)(P＜0.01).④ No expression of p14^ARF mRNA was detected in 45.8%(22/48) of gastric cancers. Moreover, the negative rate (100%, 3/3) of p14^ARF mRNA of gastric cancers with the combined methylation of exons 1β and 2 was significantly higher than that (15%, 3/20) of the sole methylation of exon2(P＜0.05). CONCLUSION:p14^ARF gene is frequently inactivated by homozygous deletion and methylation of the 5' CpG islands in gastric cancer, which may play an important role in the development of gastric cancer.     

Relationship between the point mutation of ABCB4 gene and intrahepatic cholestasis of pregnancy

AIM:To investigate the relationship between the point mutation of ABCB4 gene and intrahepatic cholestasis of pregnancy (ICP). METHODS:Using the method of polymerase chain reaction single strand conformation polymorphism (PCR-SSCP), the point mutation of the ABCB4 gene exon 6 and exon 14 in 31 women with ICP were detected. The PCR products of suspected cases with the point mutation were further DNA sequenced so as to determine its mutation characters. RESULTS:The target band of ABCB4 gene exon 6 and exon 14 was found in all blood samples from 31 cases with ICP. No ABCB4 gene exon 6 and exon 14 deletion and point mutation were detected by PCR and PCR-SSCP, respectively. To check the finding, 7 cases amongst the 31 ICP cases were selected randomly for DNA sequencing. No point mutation of ABCB4 gene exon 6 and exon 14 were detected also. CONCLUSION:The finding suggests that there may be no relationship between the two mutation hot spots and the ICP pathogenesis. Further investigation of other mutation hot spots of ABCB4 gene and enlargement sample size are needed to testify the relationship between the point mutation of ABCB4 gene and the pathogenesis of ICP.     

Mechanism of DMD with gene defect and change of protein structure

AIM: To examine the relationship between the gene defect, change of protein hydrophobicity, spacial structure change and clinical phenotypes of Duchenne muscular dystrophy（DMD）,and to explore the molecular pathogenesis of DMD. METHODS: The gene sequences of 59 cases of DMD/BMD patients with deletion from mutation were analyzed. The relationship between the protein hydrophobicity, 3D-spacial structure and clinical phenotypes was examined by biological informatic technology. RESULTS: 50 cases of frameshift mutation were all DMD. In other 5 cases with codon mutation that involved the 3rd hydrophobic region, 4 cases were diagnosed as DMD and the rest one was BMD. The exon 3 deletion leaded to the intortion of dystrophin N-terminal, which in turn affected the combination of dystrophin and troponin resulting in the DMD pathopoiesis. CONCLUSION: The severity of clinical phenotypes of muscular dystrophy diseases is related to whether the deletion destroys the reading frame, involves the 3rd hydrophobic region or changes the protein special structure. The biological informatic technology provides a new potential research methodology for studying the pathogenesis of DMD.     

Screening of CYP21 gene P459H mutation by PCR-ACRS

AIM:To investigate the frequency of P459H (CCC→CAC) in exon 10 of CYP21 gene among normal population. METHODS:The exons 3-10 of CYP21 gene were amplified with polymerase chain reaction (PCR). The PCR round products were digested by restriction enzyme Pst I to confirm that CYP21 gene was specifically amplified. PCR-based amplification-created restriction site (PCR-ACRS) was performed using the first round PCR products as template. After the second PCR products were digested by restriction enzyme Fsp I, 10% polyacrylamide gel electrophoresis was used to screen the frequency of P459H in exon 10. RESULTS:The codon 459 in exon 10 of CYP21 gene was all CCC among 100 normal cases tested. CONCLUSION:P459H (CCC →CAC) of CYP21 gene might be a novel point mutation causing CAH. Furthermore, PCR-ACRS was a fast and safe method for gene mutation screening.     

Relationship between RUNX3 gene 364 locus C→T mutation and gastric cancer in Chinese

AIM: To study the frequency difference of RUNX3 gene 364 locus C→T mutation between normal people(controls) and gastric cancer (GC) patients, and mutation in gastric mucosa of subjects with H.pylori infection. METHODS: Genomic DNA was extracted from peripheral blood and gastric mucosal biopsy specimens of normal people and GC patients in lower or higher prevalence region. Gene mutation was analyzed by PCR-RFLP. RESULTS: The frequency of RUNX3 T/T genotype was no significant difference between controls and GC in lower (χ2=0.57, P>0.05) or higher prevalence region (χ2=0.16, P>0.05). A higher mutation rate in mucosal tissue infected with H.pylori was not discovered. CONCLUSION: RUNX3 gene C364T mutation may be not a genetic susceptibility to GC in Chinese. The mutation is impossibly involved in the pathway of H.pylori infection resulting in gastric carcinoma.     

Relationship between mutated k-ras and biological behavior of colorectal cancer

AIM: To investigate mutations of oncogene k-ras in colorectal cancer tissues and the relationship between mutations of k-ras and biological behavior of colorectal carcinoma. METHODS: The specimens of 123 patients with colorectal cancer were collected. Real-time fluorescence quantitative PCR were performed to detect k-ras mutations at codon 12 and codon 13 of exon 1, and the results were analyzed with the corresponding clinical pathological data. RESULTS: Among 123 colorectal cancer cases, point mutations were detected in 53 cases (40.8%), point mutations at codon 12 were found in 42 (34.1%) cases, and 11(8.9%) cases at codon 13. No closely relationship between mutations of k-ras and tumor size, location, invasive depth and differentiation extent was observed. The rate of k-ras mutation in the cases with more invaded lymph nodes was higher than that in the cases without invaded lymph nodes (P<0.05), and the rate of k-ras gene mutation in the cases with hepatic metastases was higher than that in no hepatic metastases (P<0.05). The rate of k-ras gene mutation was higher in TNM staging Ⅲ/Ⅳ than that in Ⅰ/Ⅱ(P<0.05). CONCLUSION: Mutation of oncogene k-ras plays an important role in the carcinogenesis and development of colorectal cancer, and it is closely associated with invaded lymph notes and hepatic metastases, suggesting that mutation of k-ras indicates a poor prognosis.     

Differential expression of Golgi mannosidaseⅡ in different differentiated gastric carcinoma cell lines and tissues

AIM: To explore the role of Golgi mannosidase Ⅱ(GMⅡ) in the development of gastric carcinoma by analysis of the relationship between differential expression of GMⅡ and differentiation of gastric carcinoma cell lines and tissues. METHODS: Thirty cases of human normal gastric tissues and 38 cases of gastric adenocarcinoma tissues were selected. Three different differentiated gastric carcinoma cell lines (MKN-28, SGC-7901 and BGC-823) and a normal gastric epithelial cell line GES-1 were cultured in vitro. The mRNA levels of GMⅡ were detected by RT-PCR, and the protein expression was detected by immunohistochemistry and Western blotting. RESULTS: GMⅡ was mainly distributed in cytoplasm. The positive rates of GMⅡ in 30 cases of human normal gastric tissues, 8 cases of well-differentiated, 18 cases of moderately-differentiated and 12 cases of poorly-differentiated gastric cancer tissues were 53% (16/30), 63% (5/8), 83% (15/18) and 100% (12/12), respectively. The expression of GMⅡ was gradually increased in normal gastric epithelial cell line and in well, moderately and poorly-differentiated gastric cancer cell lines by cell-attached coverslip. Compared with normal gastric epithelial cell line, 3 gastric carcinoma cell lines showed the higher expression of GMⅡ at mRNA and protein levels (P<0.05). Furthermore, GMⅡ expression in poorly-differentiated gastric carcinoma cell line BGC823 was the highest, and the lowest expression of GMⅡ was the well-differentiated cell line MKN-28. Compared with normal gastric epithelial tissues, gastric carcinoma tissues showed the higher expression of GMⅡ at mRNA and protein levels (P<0.05), and the highest was the poorly-differentiated carcinoma tissues. The expression of GMⅡ at mRNA and protein levels in normal gastric tissues was the lowest. CONCLUSION: GMⅡ is involved in the development and progression of gastric cancer. The expression of GMⅡ is highly related to the poorly-differentiated gastric cancer.     

One novel mutation and copy number variation of NF1 gene in Chinese patients with type 1 neurofibromatosis

AIM: To investigate the mutations and the copy number variation of neurofibromatosis 1(NF1) gene in 2 sporadic patients with type 1 neurofibromatosis in China. METHODS: All coding exons and exon-intron boundaries of NF1 were amplified by PCR. The PCR products were sequenced. The DNA samples from 50 normal subjects were also sequenced for control. Multiplex ligation-dependent probe amplification (MLPA) was also employed to detect the copy number variation of NF1 gene in these patients. Long range PCR was used for the identification of the breakpoint in the large deletion of the gene. RESULTS: The novel mutation, c. 6345_6346 ins G (p. Leu2116Alafs*4), was detected in patient S736. This mutation was absent in her parents and the controls, indicating a de novo mutation. It caused open reading frame shifting, introducing a premature stop codon and resulting in the truncation of the 721 amino acids at the C terminus of the wild-type protein. This truncation cut off part of the armadillo (ARM)-type fold domain in the wild-type protein. A 1.3~1.9 Mb deletion of the gene was also detected in the other patient S743. The deletion spanned the whole NF1 gene and part of the flanking regions in both ends, but the breaking point was still unknown. CONCLUSION: We have identified a novel mutation of NF1, c.6345_6346 ins G (p.Leu2116Alafs*4). We also first report the copy number variation of NF1 gene in Chinese patients. The investigation will be helpful for the molecular diagnosis and understanding the pathogenesis of the disease.     

Expression of Glypican-3 gene and its regulating mechanism in hepatocellular carcinoma

AIM:To investigate the expression of Glypican-3 gene and its regulating mechanism in hepatocellular carcinoma. METHODS:The expression of GPC3 mRNA and its gene mutation in 48 hepatocellular carcinoma tissues, 39 paracarcinomatous tissues and 31 normal liver tissues were detected by using RT-PCR and PCR-SSCP. The expressions of GPC3 protein, P53 and PCNA protein were detected by using immunohistochemistry S-P. RESULTS:The positive expressive rate of GPC3 mRNA was 77.1% in hepatocellular carcinoma tissue. No expression of GPC3 mRNA in paracarcinomatous tissues and normal liver tissues was observed. No gene mutation of GPC3 in hepatocellular carcinoma tissue was found. No correlation was found between GPC3 and P53 (r=-0.12574, P>0.05). The mean index of proliferating cell nuclear antigen(PCNA) in positive and negative GPC3 expression were (46.32±27.54)% and (39.83±21.47)%, respectively (P>0.05). CONCLUSION:The high expression of GPC3 mRNA in hepatocellular carcinoma is independent to the gene mutation, and to the expression of P53 and PCNA protein.     

Detection of EML4-ALK fusion gene and analysis of its clinical features in NSCLC patients with EGFR mutation

AIM: To detect the frequency of EML4-ALK fusion gene in non-small-cell lung cancer (NSCLC) patients who had epidermal growth factor receptor (EGFR) mutation, and to analyze the relationship between EML4-ALK fusion gene and clinical features. METHODS: One hundred and two Chinese patients with NSCLC were selected on the basis of one or more of the following characteristics: female, never/light smoking history and adenocarcinoma histology. The EML4-ALK fusion gene was identified by single-tube multiplex RT-PCR. In EML4-ALK-positive samples, exon 18 to 21 EGFR mutations and exon 1 and 2 KRAS (Kirsten rat sarcoma) mutations were detected by DNA direct sequencing after PCR amplification. RESULTS: Eight specimens (7.8%) were identified with EML4-ALK fusion genes from 102 NSCLC tissues. Of all positive cases, 7 were variant 1 (V1) and 1 was variant 2 (V2). In 8 EML4-ALK-positive samples, exon 18 to 21 EGFR and exon 1 and 2 KRAS were wild-types. Among 8 EML4-ALK-positive cases, 5 cases (5/8, 62.5%) were younger than the mean age. Six cases (6/8, 75%) were female and 7 cases (7/8, 87.5%) were non-smokers. Five cases (5/8, 62.5%) had adenocarcinoma histology. CONCLUSION: EML4-ALK fusion gene defines a new molecular subset of NSCLC with distinct characteristics. The EML4-ALK fusion gene is mutually exclusive to EGFR and KRAS mutations.     

Establishment of a method to quantitatively detect FLT3 internal tandem duplication in acute myeloid leukemia with denaturing high-performance liquid chromatography

AIM: To establish a relatively-quantitative method to detect the internal tandem duplication (ITD) mutation of Fms-like tyrosine kinase 3( FLT3 )gene in acute myeloid leukemia (AML) patients using denaturing high-performance liquid chromatography (DHPLC).METHODS: According to the fact that much more FLT3 -ITD mutations are located in exon 14, we designed the primers, and use the method of polymerase chain reaction (PCR) to specifically amplify FLT3 -ITD mutation gene in 121 cases of AML, and relatively quantified the situation of mutant allelic gene of FLT3- ITD by the method of DHPLC.The effectiveness of DHPLC was verified by the method of capillary electrophoresis (CE).The sequenced results from PCR amplified products of 121 samples were compared.RESULTS: A characteristic of elution peak was detected by DHPLC with 10.7% overall positive rate (13/121) and varied in the proportion of mutant alleles,with a single duplicated insert fragment from 21 bp to 87 bp.The median range of mutant alleles was 34.5% (11.4%-80.2%).No significant difference of the positive rates and mutation proportions between the results with DHPLC and the results with CE method was observed.The results of FLT3 -ITD mutant gene of 121 samples were consistent with the results using sequencing method.CONCLUSION: A relatively-quantitative method to analyze AML patients with FLT3 -ITD mutation by DHPLC is successfully established.     

An unusual and novel heterozygous TCIRG1 mutation causes infantile malignant osteopetrosis

AIM: To investigate the underlying genetic changes of a Chinese patient with infantile malignant osteopetrosis (IMO). IMO is a monogenic disease, mostly caused by mutations of TCIRG1 and CLCN7 genes. The former is believed a homozygous gene and only cause the disease in homozygous or compound heterozygous status. However, it has been reported that heterozygous mutations also cause the disease in 6 non-Chinese cases. METHODS: Genomic DNA was extracted from peripheral blood of the patient and his parents. All exons and splice sites of TCIRG1 and CLCN7 genes were amplified by PCR followed by Sanger sequencing. Mutation detection in the 2 genes was also investigated in the parents. Haplotypes were constructed by variations obtained in mutation detection and microsatillites flanking TCIRG1 gene in the family by Cyrillic. Chromosomal microarray analysis (CMA) was performed to detect copy number variations (CNV) of the patient and his mother. RESULTS: A novel mutation c.449_452delAGAG (p.Gln149Glnfs16) was detected in the patient. This mutation truncated 666 amino acids at the C terminal of the V-ATPase 116 kD isoform a3 protein. It wiped out the entire ATPase V0 complex and was predicted to result in total loss of protein function. This mutation was also detected in the patient's father. No pathogenic mutation was detected in CLCN7 gene. CMA did not reveal any CNV involving TCIRG1 or CLCN7 gene. CONCLUSION: We reported a novel heterozygous mutation of TCIRG1 gene causing IMO. This represents the first IMO case in China caused by heterozygous TCIRG1 gene mutation.     

DNA ploidy analysis and the expression of TIMP-2 and E-cadherin in gastric carcinoma

AIM:To investigate DNA ploidy and the expression of TIMP-2 and E-cadherin in gastric carcinoma in order to understand its molecular basis and probable mechanism of invasion and metastasis. METHODS:Immunohistochemical methods were used to detect the expression for TIMP-2 and E-cadherin in 99 cases of gastric carcinoma, 16 cases of adjacent noncancerous mucosa, 16 cases of distant metastases and 25 cases of metastatic lymph nodes. Flow cytometry DNA ploidy and S-phase fraction (SPF) analysis was performed on 47 cases of gastric cancer, 6 cases of adjacent noncancerous mucosa and 4 cases of distant metastasis cancer with the use of formalin-fixed paraffin embedded specimens. RESULTS:The expression of TIMP-2 was significantly correlated with Borrmann’s classification, LN metastasis and the depth of invasion. The expression of E-cadherin was significantly correlated with tumor cell differentiation, Lauren’s classification, Borrmann’s classification, LN metastasis and the depth of invasion. There was a positive relationship between DNA aneuploid rate and differentiation and LN metastasis. There was a positive relationship between SPF that is higher than 15% and tumor size, differentiation and LN metastasis. And there was a significantly difference between carcinoma and noncarcinoma when the expression of E-cadherin, DNA aneuploid rate and SPF were analyzed. There was no correlation between TIMP-2 and E-cadherin. There was a positive relationship between DNA ploidy or SPF and the expression of E-cadherin. CONCLUSION:As the development of tumor progression and heterogeneity, the abnormal expression of TIMP-2 or E-cadherin or the rate of DNA aneupoid or higher SPF gradually correspondingly increases, suggesting that they play a crucial role in gastric carcinoma progression. Furthermore, each factor influences one another and further accelerates the process of tumor progression.     

Interaction of polymorphisms of ICAM-1 gene K469E and MCP-1 gene -2518A/G in invasion and metastasis of gastric carcinoma

AIM: To investigate the interaction of polymorphisms of intercellular adhesion molecule-1 (ICAM-1) gene K469E and monocyte chemoattractant protein-1 (MCP-1) gene -2518A/G in the invasion and metastasis of gastric carcinoma. METHODS: Based on TNM classification, 4 500 patients with confirmed gastric carcinoma from the First Affiliated Hospital of Xinxiang Medical University in China from December 2009 to November 2014 were divided into stageⅠ group, stage Ⅱgroup, stage Ⅲ group, stage Ⅳ group, and stage 0 group, with 900 cases in each group. No significant difference among the 5 groups in age, gender, ethnicity, birthplace and living habit was observed. The genetic polymorphisms of ICAM-1 gene K469E and MCP-1 gene -2518A/G were analyzed by the technique of polymorphism-polymerase chain reaction (PCR) in peripheral blood leukocytes of above-mentioned cases. RESULTS: Statistical tests showed signi-ficant differences in the frequencies of K469E (EE) and -2518A/G (GG) among each group (P<0.01). The risk of the invasion and metastasis of gastric carcinoma significantly increased in subjects with K469E (EE) genotype and in those with -2518A/G (GG) genotype. Combined analysis of the polymorphisms showed that distribution frequency of K469E (EE)/-2518A/G (GG) in stage Ⅰ group, stage Ⅱ group, stage Ⅲ group, stage Ⅳ group and stage 0 group was 39.22%, 53.22%, 59.22, 65.44% and 12.11%, respectively (P<0.01). The people who carried with K469E (EE)/-2518A/G (GG) had a high risk of the invasion and metastasis of gastric carcinoma, and statistical analysis suggested a positive interaction in a super-multiplicative model between K469E (EE) and -2518A/G (GG) in increasing the risk of the invasion and metastasis of gastric carcinoma. CONCLUSION: ICAM-1 gene K469E (EE) and MCP-1 gene -2518A/G (GG) are the risk factors in the invasion and metastasis of gastric carcinoma, and significant interactions between genetic polymorphisms of K469E and -2518A/G added the risk of the invasion and metastasis of gastric carcinoma.     

Regulatory effect of siRNA interference targeting BMI-1 gene on proliferation of bladder cancer EJ cells

AIM: To investigate whether siRNA-mediated BMI-1 gene silencing inhibits the proliferation of EJ cells by detecting the expression of BMI-1, p16^INK4a and p14^ARF genes at mRNA and protein levels in bladder cancer EJ cells and normal bladder transitional epithelium cells. METHODS: The protein expression and localization of BMI-1, p16^INK4a and p14^ARF in EJ cells were determined by cellular immunofluorescence. An siRNA targeting BMI-1 gene was synthesized and transfected into bladder carcinoma EJ cells by liposomes. The mRNA expression of BMI-1, p16^INK4a and p14^ARF was detected by real-time PCR and the protein levels were measured by Western blotting in bladder cancer EJ cells and normal bladder transitional epithelium cells. Cell survival was analyzed by CCK-8 assay. Cell apoptosis were examined by flow cytometry. RESULTS: The mRNA and protein expression of BMI-1 in EJ cells was higher than that in bladder transitional epithelium cells. However, the expression of p16^INK4a and p14^ARF were opposite.While BMI-1 gene in EJ cells was silenced by siRNA, the mRNA and protein expression of BMI-1 were declined whereas the expression of p16^INK4a and p14^ARF was increased. The viability of the EJ cells was decreased and the apoptotic cells were increased when BMI-1 gene was silenced. CONCLUSION: The expression of BMI-1 is inversely correlated with the expression of p16^INK4a and p14^ARF in bladder transitional cell carcinoma EJ cells. The siRNA-mediated BMI-1 gene silencing in bladder cancer EJ cells inhibits the cell growth and up-regulates the expression of p16^INK4a and p14^ARF in vitro.     

Dickkopf-1 silencing inhibits invasion and epithelial-mesenchymal transition in gastric carcinoma cells by down-regulating β-catenin

AIM: To explore the expression of Dickkopf-1 (DKK1) in human gastric carcinoma cells, and the influences of DKK1 gene silencing on cell invasion. METHODS: The levels of DKK1 in the human gastric mucosa cell line GES-1 and gastric carcinoma cell lines MKN-45 and SGC-7901 were detected by real-time PCR and Western blot. DKK1 gene was silenced by RNA interference, which was verified by real-time PCR, Western blot and ELISA. The cell invasion ability was determined by Transwell assay, and the cell proliferation was inhibited by mitomycin C. The levels of E-cadherin, N-cadherin, vimentin and β-catenin were determined by real-time PCR and Western blot. RESULTS: The expression of DKK1 was significantly higher in MKN-45 cells and SGC-7901 cells than that in GES-1 cells, indicating that DKK1 expression was obviously increased in gastric carcinoma cells. After successful silencing of DKK1 gene in the MKN-45 cells and SGC-7901 cells, the cell invasion ability was markedly decreased in a time-dependent pattern with increased expression of E-cadherin and decreased expression of N-cadherin and vimentin, indicating that DKK1 silencing dramatically inhibited gastric carcinoma cell invasion and epithelial-mesenchymal transition (EMT). The introduction of exogenous recombinant DKK1 (rDKK1) demonstrated the promoting effect of DKK1 on gastric carcinoma cell invasion and EMT. In addition, the inhibitory effects of DKK1 silencing on gastric carcinoma cell invasion and EMT were fulfilled by down-regulating β-catenin. CONCLUSION: The expression of DKK1 is significantly increased in human gastric carcinoma cells. Silencing of DKK1 markedly inhibits gastric carcinoma cell invasion and EMT by down-regulating β-catenin.     

Relationships between lncRNA HOTAIR/H19 SNPs and genetic susceptibility to gastric carcinoma/EBV-related gastric carcinoma

AIM To investigate the potential associations between the single nucleotide polymorphisms （SNPs） of long noncoding RNA （lncRNA） H19/HOTAIR and the susceptibility to gastric carcinoma, especially to Epstein-Barr virus （EBV）-associated gastric carcinoma （EBVaGC）. METHODS Peripheral blood samples from 65 cases of EBV-negative gastric carcinoma （EBVnGC）, 50 cases of EBVaGC and 115 cases of healthy people were collected. A total of 4 TagSNPs, H19 rs3024270 and rs3741219, as well as HOTAIR rs4759314 and rs874945, were selected. The Taq-Man MGB allele typing kit was used to detect the genotype of each SNP locus, and the experimental results were statistically analyzed. RESULTS （1） There were significant differences of both genotypic and allelic frequencies at H19 rs3024270 locus between gastric carcinoma group and control group （P<0.05）. Individuals carrying the G allele at H19 rs3024270 locus had significantly low risk of gastric carcinoma （P<0.01）, indicating that the G allele was protective. （2） People with the GG genotype at HOTAIR rs4759314 locus had significantly high risk of gastric carcinoma （P<0.05）. Carrying the G allele increased the risk of gastric carcinoma, which indicated that the risk gene for gastric carcinoma might be the G allele. （3） No significant difference of the genotypic and allelic frequencies at H19 rs3741219 and HOTAIR rs874945 loci between gastric carcinoma group and control group was observed （P>0.05）.（4） The G allele frequency at HOTAIR rs4759314 locus in EBVaGC group was significantly higher than that in EBVnGC group. However, no difference of the other 3 SNPs was found between EBVaGC group and EBVnGC group （P>0.05）. CONCLUSION The SNPs at H19 rs3024270 and HOTAIR rs4759314 loci are related to the risk of gastric carcinoma, but not significantly related to the risk of EBVaGC.     

Level and clinical significance of RNA oxidative damage in human gastric cancer and para-carcinoma tissues

AIM: To investigate the RNA oxidative damage in human gastric cancer tissue and para-carcinoma tissue for exploring the role of RNA oxidation in the occurrence of gastric cancer. METHODS: Immunohistochemical observation and LC-MS/MS analysis were performed in 61 cases of gastric carcinoma. The position and concentration of 8-oxoguanosine (8-oxoGsn) were detected, respectively. RESULTS: The results of immunohistochemical observation showed that 8-oxoGsn was obviously up-regulated in the gastric cancer. The positive staining mainly accumulated in the cytoplasm of the tumor cells. The results of mass spectrometry showed that the level of 8-oxoGsn in the gastric cancer tissues was higher than that in the para-carcinoma tissues (P<0.05). CONCLUSION: 8-oxoGsn is up-regulated in gastric cancer. RNA oxidative damage may play important roles in the occurrence of gastric cancer.