Expression of AIM2 is correlated with increased inflammation in chronic hepatitis B patients.

BACKGROUND: The absent in melanoma 2 (AIM2), a cytosolic dsDNA inflammasome, can be activated by viral DNA to trigger caspase-1. Its role in immunopathology of chronic hepatitis B and C virus (HBV, HCV) infection is still largely unclear. In this study, the expression AIM2, and its downstream cytokines, caspase-1, IL-18 and IL-1ß, in liver tissue of patients with chronic hepatitis B and C (CHB, CHC) were investigated. METHODS: A total of 70 patients diagnosed with chronic hepatitis were enrolled, including 47 patients with CHB and 23 patients with CHC. A liver biopsy was taken from each patient, and immunohistochemistry was used to detect the expression of AIM2 and inflammatory factors caspase-1, IL-18, and IL-1ß in the biopsy specimens. The relationship between AIM2 expression and these inflammatory factors was analyzed. RESULTS: The expression of AIM2 in CHB patients (89.4 %) was significantly higher than in CHC patients (8.7 %), and among the CHB patients, the expression of AIM2 was significantly higher in the high HBV replication group (HBV DNA ≥ 1 × 10(5)copies/mL) than in the low HBV replication group (HBV DNA < 1 × 10(5)copies/mL). The expression of AIM2 was also correlated with HBV-associated inflammatory activity in CHB patients statistically. Additionally, AIM2 levels were positively correlated with the expression of caspase-1, IL-1ß and IL-18 in CHB patients, which implied that the AIM2 expression is directly correlated with the inflammatory activity associated with CHB. CONCLUSIONS: AIM2 upregulation may be a component of HBV immunopathology. The underlying mechanism and possible signal pathway warrant further study.

Genetic polymorphisms of NAMPT related with susceptibility to esophageal squamous cell carcinoma.

BACKGROUND: Nicotinamide phosphoribosyl transferase (Nampt) plays a crucial role in tumorigenesis. The present study examines whether genetic polymorphisms of NAMPT are related to the risk of developing esophageal squamous cell carcinoma (ESCC). METHODS: A total of 810 subjects were enrolled in this study, including 405 ESCC patients and 405 healthy controls. Using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), genotypes at rs61330082, rs2505568 and rs9034 of NAMPT were identified. Haplotypes were constructed using PHASE software. Multivariate logistic regression models were used to evaluate the potentiating effects of the genotypes, alleles and haplotypes on the development of ESCC. RESULTS: The presence of genotypes CT and TT and allele T at rs61330082 was less frequent in ESCC cases than in controls (48.89% vs. 53.33%, P < 0.01, 95% CI: 0.33-0.68; 18.52% vs. 30.37%, P < 0.01, 95% CI: 0.22-0.50; 42.96% vs. 57.04%, P < 0.01, 95% CI: 0.38-0.61; respectively). No statistically significant differences existed in the distributions of genotypes or alleles at rs2505568 or rs9034 between ESCC cases and controls. Of five haplotypes constructed, haplotypes CTC, CTT and CAC were higher in ESCC cases (P < 0.01, OR = 1.57, 95% CI: 1.16-2.12; P = 0.04, OR = 1.72, 95% CI: 1.03-2.85; P < 0.01, OR = 3.39, 95% CI: 1.99-5.75; respectively) than in controls. CONCLUSION: Genetic polymorphisms of NAMPT, specifically genotype CC and allele C at rs61330082 as well as haplotypes CTC, CTT and CAC, were significantly correlated with ESCC susceptibility.

Equivocal association of RAD51 polymorphisms with risk of esophageal squamous cell carcinoma in a Chinese population.

AIM: To study the contribution of genetic variation in RAD51 to risk of esophageal squamous cell carcinoma (ESCC). METHODS: Three single nucleotide polymorphisms (SNPs) in RAD51 (rs1801320, rs4144242 and rs4417527) were genotyped in 316 ESCC patients and 316 healthy controls in Anyang area of China using PCR- RFLP (polymerase chain reaction-restriction fragment length polymorphism). Demographic variables between cases and controls were statistically compared by T test and Chi-square test. Hardy-Weinberg equilibrium was evaluated by the Chi-square test. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to measure any association with ESCC. Haplotype frequencies were estimated by Phase 2.1. RESULT: The genotype frequencies of rs1801320, rs4144242 and rs4417527 in patients with ESCC demonstrated no significant differences from those in control group (P>0.05). When the haplotypes of these three SNPs were constructed and their relationships with ESCC risk investigated, however, CGG was observed to increase the risk (P=0.020, OR=2. 289). CONCLUSIONS: There was no association between the three SNPs of RAD51 and ESCC susceptibility in our Chinese population. However, the CGG haplotype might be a risk factor.

Shotgun proteomic analysis of microdissected postmortem human pituitary using complementary two-dimensional liquid chromatography coupled with tandem mass spectrometer.

The pituitary is responsible for multiple homeostatic functions including metabolism, growth and reproduction. Proteome analysis offers an efficient approach for a comprehensive analysis of pituitary protein expression. The pituitary is usually acquired from postmortem specimens, which may potentially affect the proteome profile by proteolysis. The aim of this study was to determine whether the postmortem pituitary could be used in proteomic analysis combining with Laser capture microdissection (LCM). Digested peptides from LCM captured prolactin (PRL) cells were separated by two dimensional-nanoscale liquid chromatography (2D-nanoLC/MS) and characterized by tandem mass spectrometry (MS). All MS/MS spectrums were searched by SEQUEST and a proteome of 1660 proteins was identified. Category analysis of the proteome revealed an extensive unbiased access to cell component proteins with diverse functional characteristics. The results demonstrated the ability of using 2D-nanoLC/MS to perform sensitive proteomic analysis on limited protein quantities through microdissection. Detailed comparisons between the proteome in question and the one derived from the prolactinoma controls at peptide and protein levels indicated that the two proteomes had similar characters. Overall, our results revealed for the first time the possibility of use of postmortem human pituitary for proteomic research which is important for further studies on disease biomarker identification and molecular mechanisms of prolactinoma tumorigenesis.

Effects of selected genetic polymorphisms in xeroderma pigmentosum complementary group D on gastric cancer.

DNA repair capacity (DRC) can be altered based on sequence variations in DNA repair genes, which may result in cancer susceptibility. The current study was to evaluate the association between genetic polymorphisms, including associated haplotypes of xeroderma pigmentosum complementary group D (XPD), and individual susceptibility to gastric cancer. Two-hundred-eight patients with gastric cancer and 339 healthy controls were enrolled in this study. Their genomic DNA was extracted from peripheral blood leukocytes. The genotypes at exon 6, 10 and 23 were identified by polymerase chain reaction (PCR). Unconditional logistic regression model was used to analyze the effects of the polymorphisms, including the corresponding haplotypes, on the susceptibility to develop gastric cancer. The proportion of genotypes GA or AA at exon 10 in cases was showed to be significantly higher than that in controls (P < 0.01, P < 0.01, respectively). The risk of genotype GA or AA carriers to develop gastric cancer was simultaneously much higher (OR = 3.38, 95% CI 2.30-4.95; OR = 6.13, 95% CI 2.45-15.31, respectively). The allele A at exon 10 was also observed to manifest a substantially higher frequency in cases compared to controls (P < 0.01), which might indicate an increased tendency to gastric cancer (OR = 2.40, 95% CI 1.81-3.17). No significant differences were found in the distribution of genotypes at exon 6 or 23 between the two groups (P = 0.23, P = 0.52; P = 0.44, P = 0.56, respectively). By haplotype analysis, haplotype AAA could individually increase incidence of gastric cancer (P < 0.01, OR = 3.39, 95% CI 2.21-5.21). In contrast, haplotypes CGA and AGA were showed a decline in gastric cancer susceptibility (OR = 0.67, 95% CI 0.46-0.97; OR = 0.58, 95% CI 0.41-0.83, respectively). The rest of haplotypes made no statistically significant difference between cases and controls. Taken together, this study demonstrates that the genetic variation at exon 10 and haplotype AAA may be contributing factors in developing gastric cancer.

Proteomic analysis of prolactinoma cells by immuno-laser capture microdissection combined with online two-dimensional nano-scale liquid chromatography/mass spectrometry.

BACKGROUND: Pituitary adenomas, the third most common intracranial tumor, comprise nearly 16.7% of intracranial neoplasm and 25%-44% of pituitary adenomas are prolactinomas. Prolactinoma represents a complex heterogeneous mixture of cells including prolactin (PRL), endothelial cells, fibroblasts, and other stromal cells, making it difficult to dissect the molecular and cellular mechanisms of prolactin cells in pituitary tumorigenesis through high-throughout-omics analysis. Our newly developed immuno-laser capture microdissection (LCM) method would permit rapid and reliable procurement of prolactin cells from this heterogeneous tissue. Thus, prolactin cell specific molecular events involved in pituitary tumorigenesis and cell signaling can be approached by proteomic analysis. RESULTS: Proteins from immuno-LCM captured prolactin cells were digested; resulting peptides were separated by two dimensional-nanoscale liquid chromatography (2D-nanoLC/MS) and characterized by tandem mass spectrometry. All MS/MS spectrums were analyzed by SEQUEST against the human International Protein Index database and a specific prolactinoma proteome consisting of 2243 proteins was identified. This collection of identified proteins by far represents the largest and the most comprehensive database of proteome for prolactinoma. Category analysis of the proteome revealed a widely unbiased access to various proteins with diverse functional characteristics. CONCLUSIONS: This manuscript described a more comprehensive proteomic profile of prolactinomas compared to other previous published reports. Thanks to the application of immuno-LCM combined with online two-dimensional nano-scale liquid chromatography here permitted identification of more proteins and, to our best knowledge, generated the largest prolactinoma proteome. This enlarged proteome would contribute significantly to further understanding of prolactinoma tumorigenesis which is crucial to the management of prolactinomas.

Association of cytotoxic T lymphocyte-associated antigen-4 gene haplotype with the susceptibility to gastric cancer.

Cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) was widely accepted as a pivotal molecule in downregulating T-cell mediated immune responses. In this study we investigated the polymorphisms which would impact the CTLA-4 gene expression and function to assess the association with the risk of gastric cancer. 205 gastric cancer patients and 262 healthy controls were included in the case-control study. PCR and restriction fragment length polymorphism (RFLP) methods were performed to identify the +49A/G and promoter -1661A/G polymorphisms. The promoter -1772T/C polymorphism was detected by PCR amplification refractory mutation system (ARMS) technique. A significant difference was observed between case and control groups. The frequency of +49A/G polymorphism AG and -1661A/G polymorphism GG genotype were significantly higher in patients than in controls (OR = 2.15, OR = 1.88, respectively). No significant difference was found in the allelic frequency of -1772T/C polymorphism between cases and controls (P = 0.478). By the haplotype analysis, logistic regression showed the frequency of haplotype A (GAT) and D (AGT) in the case group revealed significant difference compared with in control group (OR = 2.00, P < 0.001; OR = 1.62, P = 0.043, respectively). Our findings implied the genetic variations within CTLA-4 gene would be a critical risk factor to the susceptibility of gastric cancer.

[Correlation of XPD gene with susceptibility to gastric cancer].

BACKGROUND AND OBJECTIVE: Mutations in DNA repair system are related to carcinogenesis. This study was to evaluate the correlations of polymorphisms and haplotypes of XPD gene with individual susceptibility to gastric cancer. METHODS: Genomic DNA were extracted from peripheral blood leukocytes of 207 gastric cancer patients and 212 healthy controls. Genotypes at codon 312 and codon 751 polymorphic sites were identified by amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) or polymerase chain reaction-restriction fragment length polymorphism (PCR-PFLP), respectively. RESULTS: At codon 312, the frequency of GA or AA genotype was higher in the gastric cancer patients than in the healthy controls (P<0.01, OR=3.41, 95% CI: 2.06-4.79; P<0.01, OR=3.47, 95% CI: 1.39-8.68). No significant difference was found in the distribution of the polymorphism at codon 751 between the two groups (P>0.05). By the haplotype AA (codon 312A-codon 751A) analysis, the frequency of heterozygote (-/AA) or homozygote (AA/AA) was higher in the patients than in the controls (P<0.01,OR=2.81, 95% CI:1.82-4.34;P=0.02,OR=3.92, 95% CI:1.31-11.70, respectively). Whereas there were no significant differences of the other three haplotypes between the patients and the controls (P>0.05). CONCLUSIONS: The polymorphism of XPD at codon 312 might contribute to the etiology of gastric cancer. The haplotype AA (codon 312A-codon 751A) would be a critical risk factor of the susceptibility to gastric cancer.