Association of nutritional status and comorbidity with long-term survival among community-dwelling older males.

BACKGROUND: Estimates of survival in the older can be of benefit in various facets, particularly in medical and individual decision-making. We aim to validate the value of a combination of nutrition status evaluation and comorbidity assessment in predicting long-term survival among community-dwelling older. METHODS: The Charlson Comorbidity Index (CCI) was applied for comprehensive evaluation of comorbidities. Participants were classified into CCI score ≤ 2 and ≥ 3 subgroups. Nutritional status was assessed by using Mini Nutritional Assessment-Short Form (MNA-SF) and Geriatric Nutritional Risk Index (GNRI) evaluations. Mortality rates and survival curves over a 5-year period were compared among subgroups classified by CCI and/or MNA-SF/GNRI evaluations. RESULTS: A total of 1033 elderly male participants were enrolled in this study, with an average age of 79.44 ± 8.61 years. 108 deceased participants (10.5%) were identified during a follow-up of 5 years. Cox proportional hazards regression analysis showed that age, CCI, MNA-SF and GNRI were independent predictors of 5-year all-cause death in this cohort. Compared to those with normal nutrition status and CCI ≤ 2, the subgroup at risk of malnutrition and CCI ≥ 3 had a significantly higher 5-year all-cause mortality rate (HR = 4.671; 95% CI:2.613-8.351 for MNA-SF and HR = 7.268; 95% CI:3.401-15.530 for GNRI; P < 0.001 for both). Receiver operating characteristic curve analysis demonstrated that a combination of either MNA-SF or GNRI with CCI had significantly better performance than CCI, MNA-SF or GNRI alone in predicting all-cause death. CONCLUSION: The combination of nutritional assessment (MNA-SF or GNRI) with CCI can significantly improve the predictive accuracy of long-term mortality outcomes among community-dwelling older males.

Heat shock protein 70 is involved in polaprezinc driven cell protection against Helicobacter pylori-induced injury.

Polaprezinc (PZ) plays a role in the protection of gastric mucosa and inhibiting Helicobacter pylori (H. pylori) growth in vitro. The objective of this study was to determine the protective effects of PZ on human gastric epithelial cells (GES-1) against H. pylori-induced damage, while also examining heat shock protein 70 (HSP70) as a potential underlying factor in this protection. Our findings revealed that PZ exerted bactericidal effects against H. pylori strains. We also observed that PZ mitigated the H. pylori-induced damage to GES-1 cells by increasing cell viability, reducing LDH release, and decreasing the secretion of pro-inflammatory factors such as MCP-1 and IL-6. Co-culturing PZ with GES-1 cells significantly up-regulated the GES-1 HSP70 expression in both a time and dose-dependent manner. Pre-incubating (for 12 h) or co-culturing (for 24 h) GES-1 cells with PZ reversed the down-regulation of HSP70 in GES-1 cells caused by H. pylori infection. However, when quercetin was used to inhibit the up-regulation of HSP70 in GES-1 cells, the protective effect of PZ on GES-1 cells was significantly reduced. Based on the results of this study, PZ exhibits a protective role on GES-1 cells against H. pylori injury, as well as a direct bactericidal effect on H. pylori. HSP70 is involved in the PZ-driven host cell protection against H. pylori injury. These findings provide insight into alternative strategies for H. pylori treatment.

Transcriptomic and Functional Approaches Unveil the Role of tmRNA in Zinc Acetate Mediated Levofloxacin Sensitivity in Helicobacter pylori.

Rapid increase in resistance of Helicobacter pylori (H. pylori) has hindered antibiotics-based eradication efforts worldwide and raises the need for additional approaches. Here, we investigate the role of zinc-based compounds in inhibiting H. pylori growth and modulating antibiotic sensitivities, interrogate their downstream transcriptomic changes, and highlight the potential mechanism driving the observed effects. We showed that zinc acetate inhibited H. pylori growth and increased H. pylori sensitivity to levofloxacin. Transcriptomic profiling showed distinct gene expression patterns between zinc acetate treated groups versus controls. In particular, we independently replicated the association between zinc acetate treatment and increased ssrA expression. Knockdown of ssrA restored levofloxacin resistance to levels of the control group. In this study, we first demonstrated the role of zinc acetate in H. pylori growth and antibiotic sensitivities. Additionally, we explored the transcriptomic perturbations of zinc acetate followed by functional knockdown follow-up of differentially expressed ssrA, highlighting the role of tmRNA and trans-translation in H. pylori levofloxacin resistance. Our results provide alternative and complementary strategies for H. pylori treatment and shed light on the underlying mechanisms driving these effects. IMPORTANCE Helicobacter pylori (H. pylori) eradication plays an important role in gastric cancer prevention, but the antimicrobial resistance of H. pylori is fast becoming a growing concern. In this study, we investigated the role of zinc acetate in inhibiting H. pylori growth and modulating antibiotic sensitivities in vitro. Additionally, we explored the transcriptomic perturbations of zinc acetate followed by functional knockdown follow-up of differentially expressed ssrA, highlighting the role of tmRNA and trans-translation in H. pylori levofloxacin resistance. Our results open up a new horizon for the treatment of antibiotic-resistant H. pylori.

Higher Prevalence of Non-thyroidal-Illness Syndrome in Elderly Male Patients With Active Helicobacter pylori Infection.

Objective: It is currently unclear whether the Helicobacter pylori (H. pylori) infection leads to associated alterations in thyroid functions and thyroidal illnesses. This study aims to analyse this relationship in an elderly male cohort over a five-year period. Design: A case retrospective study. Methods: A longitudinal study was designed to collect subjects (≥65 years old) receiving both a thyroid examination and H. pylori infection status determined by 13C-urea breath test in 2013 at our unit. Subjects were followed every 1 to 2 years until December 2017 for laboratory results, visits to outpatient clinics/emergency departments etc. Blood tests and thyroid ultrasonography were performed to determine thyroid function and morphology. Results: 356 male subjects with mean age 78.5 ± 9.8 years were included. Active H. pylori infection was positive in 88 subjects (24.7%). Thyroid function tests and ultrasonography showed similar patterns between H. pylori positive and negative groups. Non-thyroidal-illness syndrome (NTIS) was diagnosed in 30/210 (14%) patients who experienced acute illnesses and hospitalization over five-year follow-up. Notably, NTIS demonstrated significantly higher prevalence in the H. pylori positive group compared to the negative group (17.1 vs. 5.6%, P = 0.001). Multivariate analysis showed that when age, APACHE II score and hemoglobin levels were adjusted, H. pylori status still has significant interrelationship with NTIS (OR = 3.497, P = 0.003). Conclusions: There is a positive association between chronic active H. pylori infection and NTIS prevalence in this elderly male cohort. Further studies are needed to elucidate the role of H. pylori infection on NTIS in elderly male patients.

Effect of Temperature on Metronidazole Resistance in Helicobacter pylori.

Efficacy of Helicobacter pylori (H. pylori) eradication therapy has declined due to rapid rises in antibiotic resistance. We investigated how increased temperature affected H. pylori (NCTC 11637) growth and its sensitivity to metronidazole in vitro. We performed transcriptomic profiling using RNA-sequencing to identify differentially expressed genes (DEGs) associated with increased temperature. Transcriptional pathways involved in temperature-driven metronidazole resistance changes were analyzed through bioinformatic and literature curation approaches. We showed that H. pylori growth was inhibited at 41°C and inhibition was more apparent with prolonged incubation. Resistance to metronidazole was also reduced-minimum inhibitory concentration for metronidazole decreased from > 256 µg/ml at 37°C to 8 µg/ml at 41°C after culturing for 3 days. RNA-sequencing results, which were highly concordant within treatment conditions, revealed more than one third of genes (583/1,552) to be differentially expressed at increased temperatures with similar proportions up and down-regulated. Quantitative real-time PCR validation for 8 out of 10 DEGs tested gave consistent direction in gene expression changes. We found enrichment for redox and oxygen radical pathways, highlighting a mechanistic pathway driving temperature-related metronidazole resistance. Independent literature review of published genes associated with metronidazole resistance revealed 46 gene candidates, 21 of which showed differential expression and 7 out of 9 DEGs associated with "redox" resistance pathways. Sanger sequencing did not detect any changes in genetic sequences for known resistance genes rdxA, frxA nor fdxB. Our findings suggest that temperature increase can inhibit the growth and reduce H. pylori resistance to metronidazole. Redox pathways are possible potential drivers in metronidazole resistance change induced by temperature. Our study provides insight into potential novel approaches in treating antibiotic resistant H. pylori.

Diagnosis of Helicobacter pylori infection in the elderly using an immunochromatographic assay-based stool antigen test.

The diagnostic value of Helicobacter pylori stool antigen (HpSA) tests in elderly subjects remains unclear. The objective of this study was to assess the diagnostic accuracy of the immunochromatographic assay-based HpSA test in a male elderly cohort and identify factors affecting the accuracy. Data for asymptomatic elderly male citizens (≥65 years old) who received health checkups at the Chinese PLA General Hospital between July 2007 and November 2018 were collected. The diagnostic accuracy of the HpSA test was determined using the 13 C-urea breath test as a reference standard. Associations between baseline comorbidities and the accuracy of the HpSA test were analyzed. In total, 316 participants were enrolled, including 193 in the pre-treatment group (77.2 ± 7.8 years old) and 123 in the post-treatment group (78.7 ± 8.3 years old). The accuracy (91.5%, 91.2%, and 91.9%) and specificity (97.6%, 98.7%, and 96.0%) were high in all participants, pre- and post-treatment groups, respectively. However, sensitivities were only 68.7%, 65.1%, and 75.0%, respectively. In the pre-treatment group, constipation was associated with decreased sensitivity (p = 0.039), while colorectal polyps were associated with increased sensitivity (p = 0.010). Multivariate analysis indicated that constipation and colorectal polyps are independent factors for the sensitivity of HpSA in the pre-treatment group. The immunochromatographic assay-based HpSA test achieved high accuracy with high specificity but suboptimal sensitivity in the elderly male cohort. Constipation and colorectal polyps were negatively and positively associated with HpSA sensitivity, respectively, in the pre-treatment group.

Lifestyle intervention for gastroesophageal reflux disease: a national multicenter survey of lifestyle factor effects on gastroesophageal reflux disease in China.

BACKGROUND: Poor habits can worsen gastroesophageal reflux disease (GERD) and reduce treatment efficacy. Few large-scale studies have examined lifestyle influences, particularly eating habits, on GERD in China, and research related to eating quickly, hyperphagia, and eating hot foods is quite limited. The aim of this study was to evaluate the relationship between GERD pathogenesis and lifestyle factors to produce useful information for the development of a clinical reference guide through a national multicenter survey in China. METHODS: Symptom and lifestyle/habit questionnaires included 19 items were designed. The questionnaire results were subjected to correlation analysis relative to GERD symptom onset. A standard proton pump inhibitor (PPI) was advised to correct patients with unhealthful lifestyle habits. RESULTS: A total of 1518 subjects (832 GERD, 686 non-GERD) enrolled from six Chinese hospitals completed symptom and lifestyle/habit questionnaires. The top lifestyle factors related to GERD were fast eating, eating beyond fullness, and preference for spicy food. Univariate analysis showed that 21 factors, including male gender, a supra-normal body mass index (BMI), smoking, drinking alcohol, fast eating, eating beyond fullness, eating very hot foods, and drinking soup, among others, were associated with GERD (p < 0.05). Logistic multivariate regression analysis revealed the following risk factors for GERD [with odds ratios (ORs)]: fast eating (4.058), eating beyond fullness (2.849), wearing girdles or corsets (2.187), eating very hot foods (1.811), high BMI (1.805), lying down soon after eating (1.544), and smoking (1.521). Adjuvant lifestyle interventions improved outcomes over medication alone (z = -8.578, p < 0.001 Mann-Whitney rank sum test). CONCLUSIONS: Lifestyle interventions can improve medication efficacy in GERD patients. Numerous habits, including fast eating, eating beyond fullness, and eating very hot foods, were associated with GERD pathogenesis. The present results may be useful as a reference for preventive education and treatment.

Expression of GCRG213p, LINE-1 endonuclease variant, significantly different in gastric complete and incomplete intestinal metaplasia.

BACKGROUND: Intestinal metaplasia (IM) of the gastric mucosa is classified as complete (Type I) and incomplete IM (Type II and III) subtypes, which showed significantly different risk for developing to gastric adenocarcinoma (GAC). GCRG213, a variant of L1-endonuclease (L1-EN), first identified in our lab, was upregulated in GAC tissue. However, the relationship between GCRG213 and IM subtypes is not clear. Our study explored the association of GCRG213 protein (GCRG213p) with IM subtypes. METHODS: Gastric cancer and/or para-tumor tissue samples were collected from 123 patients who underwent gastrectomy for intestinal type gastric adenocarcinoma. The subtypes of IM were characterized with Alcian blue-periodic acid-Schiff and High Iron Diamine-Alcian blue staining methods. Immunohistochemistry of GCRG213p was performed, and its expression in gastric adenocarcinoma and para-tumor tissue including dysplasia, IM, and normal mucosa were analyzed. RESULTS: GCRG213p was expressed in 48.94% IM, 57.14% dysplasia and 55.32% GAC, respectively. GCRG213p expression was higher in well and moderately differentiated adenocarcinoma (P = 0.037). In IM glands, GCRG213p expressed mainly in the cytoplasm of absorptive enterocytes with defined brush borders, but not in goblet cells. The expression of GCRG213p in type I IM (90.00%) was significantly higher than that in type II (36.36%) and type III (25.00%) (P < 0.001). In normal gastric mucosa, GCRG213p was exclusively positive in the cytoplasm of gastric chief cells. CONCLUSIONS: The expression of GCRG213p in complete IM was significantly higher than in incomplete IM, which implies that GCRG213p may play a role on the developing of IM to adenocarcinoma. GCRG213p was exclusively expressed in chief cells, suggesting that it might be involved in cell differentiation from the chief cells to IM.

Association of active Helicobacter pylori infection and anemia in elderly males.

BACKGROUND: The prevalence of Helicobacter pylori (H. pylori) infection increases with age. However, the relationship between H. pylori infection and anemia in the elderly population remains to be identified. The aim of this study is to explore whether H. pylori infection is associated with anemia in a male elderly cohort. METHODS: A cross-sectional study was designed using data collected from asymptomatic male senior citizens (≥ 65 years old) who received an assessment of their health status at the General Hospital of Chinese PLA from January 2015 to December 2015. H. pylori infection was confirmed by the 13C-urea breath test. Blood samples from the participants were taken to assay for hemoglobin and other erythroid-related indices - serum iron, ferritin, and C-reactive protein (CRP). Anemia was defined as hemoglobin values lower than 120.0 g/L. Charlson Comorbidity Index (CCI) was applied to establish baseline comorbidities. RESULTS: Data from 646 subjects were analyzed. The mean age of the study cohort was 79.4 ± 8.9 years. The overall prevalence of H. pylori infection was 35.3%. The prevalence of anemia in the H. pylori positive group was higher than that in the negative group (5.3% vs. 2.2%, P = .033). Among the patients who had higher CCI scores (> 2), the prevalence of anemia in the H. pylori positive and negative groups were 10.3 and 1.4%, respectively (P = .009). Compared to the H. pylori negative group, the odds ratio for anemia of the H. pylori positive group was 2.53 (P = .033). No correlation between H. pylori infection and serum iron and ferritin levels was found. The mean corpuscular volume of the H. pylori positive and negative group was 91.17 ± 3.94 fl and 91.17 ± 4.09 fl (mean ± SD), respectively (P = .986). The CRP level in the H. pylori positive group was higher than that in the H. pylori negative group (Median: 0.17 mg/dL vs. 0.10 mg/dL, P < .001). CONCLUSION: H. pylori infection seems to be associated with normocytic and normochromic anemia in elderly males, especially in those with more comorbidities. Further clinical studies are needed to verify the association.

Maximizing Specific Loss Power for Magnetic Hyperthermia by Hard-Soft Mixed Ferrites.

Maximized specific loss power and intrinsic loss power approaching theoretical limits for alternating-current (AC) magnetic-field heating of nanoparticles are reported. This is achieved by engineering the effective magnetic anisotropy barrier of nanoparticles via alloying of hard and soft ferrites. 22 nm Co0.03 Mn0.28 Fe2.7 O4 /SiO2 nanoparticles reach a specific loss power value of 3417 W g-1metal at a field of 33 kA m-1 and 380 kHz. Biocompatible Zn0.3 Fe2.7 O4 /SiO2 nanoparticles achieve specific loss power of 500 W g-1metal and intrinsic loss power of 26.8 nHm2 kg-1 at field parameters of 7 kA m-1 and 380 kHz, below the clinical safety limit. Magnetic bone cement achieves heating adequate for bone tumor hyperthermia, incorporating an ultralow dosage of just 1 wt% of nanoparticles. In cellular hyperthermia experiments, these nanoparticles demonstrate high cell death rate at low field parameters. Zn0.3 Fe2.7 O4 /SiO2 nanoparticles show cell viabilities above 97% at concentrations up to 500 µg mL-1 within 48 h, suggesting toxicity lower than that of magnetite.

Management and survival analysis of elderly patients with a cancer in the digestive system who refused to receive anticancer treatments.

Treatment and management of cancers in elderly patients require some special considerations. A better understanding of how cancers progress in those elderly patients who have not received any anticancer treatments could better help us in treating these patients and in making end-of-life decisions. Over the past years, we had encountered 57 elderly patients, aged 75 to 94 years (87.6 on average), with a cancer in the digestive system, who refused to accept anticancer treatment but who did receive the best available supportive and palliative care. Clinicopathological data of these patients were analyzed. Of these 57 cases, 49 were at an advanced or late stage, while the remaining eight were at an early stage at the time of diagnosis. The median overall survival time of all the patients was 11 months, and almost the entire cohort manifested multiple-organ impairments. The average number of malfunctioning organs per patient was 3.68. After carefully predicting, and then preventing or managing complications, only 54.4% of the patients eventually died of multiple-organ functional failure. Nearly 18% of the single organ dysfunctions were finally well-controlled. Our data provide the first statistical information on the survival time and the direct cause of death of the elderly patients with a cancer in the digestive system not treated with chemotherapy or other direct anticancer interventions, but who did receive the best available supportive and palliative cares. During their struggle with cancer, elderly patients clearly could benefit from prophylactic interventions on organ dysfunction.

[Deuterium depleted environment inhibits the growth of gastric cancer cells: in vitro study].

OBJECTIVE: To examine whether deuterium depleted environment may affect the biological features of human gastric cancer cells(SGC-7901)and explore the possible underlying mechanisms. METHODS: SGC-7901 cells were cultured in RPMI-1640 medium prepared with distilled water of different deuterium concentrations(experimental group:25ppm deuterium;control group:150ppm deuterium). Assays on cellular proliferation, cell cycle and apoptosis were conducted at different time points and comparison. The protein expression of proliferating cell nuclear antigen (PCNA) was measured using Western blot. RESULTS: In contrast to 150ppm group, the proliferation rate of SGC-7901 cells in 25ppm deuterium was decreased by 10% as indicated by the CCK-8 assay. Wound healing ability and the colony formation ability of these cells were also significantly suppressed (P<0.05). Flow cytometry analysis further revealed that exposure to 25ppm significantly increased the ratio of cancer cells at G1 phase (P<0.01) while decreased the ratio at S phase (P<0.05) compared to the 150ppm group. There was no significant difference in apoptosis between the two groups. Down-regulated expression of PCNA was also identified in cancer cells treated with 25ppm deuterium. CONCLUSIONS: Deuterium depleted environment inhibited the proliferation of gastric cancer cells, which may be attributed to the down-regulation of PCNA and cell cycle arrest at G1 phase.

Learning about the Importance of Mutation Prevention from Curable Cancers and Benign Tumors.

Some cancers can be cured by chemotherapy or radiotherapy, presumably because they are derived from those cell types that not only can die easily but also have already been equipped with mobility and adaptability, which would later allow the cancers to metastasize without the acquisition of additional mutations. From a viewpoint of biological dispersal, invasive and metastatic cells may, among other possibilities, have been initial losers in the competition for resources with other cancer cells in the same primary tumor and thus have had to look for new habitats in order to survive. If this is really the case, manipulation of their ecosystems, such as by slightly ameliorating their hardship, may prevent metastasis. Since new mutations may occur, especially during and after therapy, to drive progression of cancer cells to metastasis and therapy-resistance, preventing new mutations from occurring should be a key principle for the development of new anticancer drugs. Such new drugs should be able to kill cancer cells very quickly without leaving the surviving cells enough time to develop new mutations and select resistant or metastatic clones. This principle questions the traditional use and the future development of genotoxic drugs for cancer therapy.

[Effect of hypoxia on gastric cancer cell proliferation and LINE-1 endonuclease variant GCRG213 expression].

OBJECTIVE: To investigate the change of gastric cancer cell proliferation and the expression of gastric cancer related gene 213 (GCRG213), a long interspersed nuclear element-1 (LINE-1) endonuclease variant, during hypoxia. METHODS: Normal gastric mucosa cell GES-1 and gastric cancer cell BGC-823 were cultured in 20% or 3% oxygen concentrations, respectively. MTT test was used to analyze the proliferation of the GES-1 and BGC-823 cells. The change of GCRG213 mRNA and protein expression in GES-1 and BGC-823 cells was detected by using RT-PCR and Western blot analysis. Blast was used at the NCBI Blast server to identify GCRG213 sequence to any alignment in the GeneBank databases. RESULTS: Compared with 20% oxygen condition, 3% oxygen concentration could promote cell growth. Mean-while, the expression of GCRG213 at mRNA and protein levels was increased. GCRG213 sequence shared high homology with LINE-1 endonuclease sequence. CONCLUSION: GCRG213 is a variant of LINE-1 endonuclease. Hypoxia as in 3% oxygen condition can promote cell proliferation and lead to GCRG213 overexpression.

Comparison of global gene expression of gastric cardia and noncardia cancers from a high-risk population in china.

OBJECTIVE: To profile RNA expression in gastric cancer by anatomic subsites as an initial step in identifying molecular subtypes and providing targets for early detection and therapy. METHODS: We performed transcriptome analysis using the Affymetrix GeneChip U133A in gastric cardia adenocarcinomas (n = 62) and gastric noncardia adenocarcinomas (n = 72) and their matched normal tissues from patients in Shanxi Province, and validated selected dysregulated genes with additional RNA studies. Expression of dysregulated genes was also related to survival of cases. RESULTS: Principal Component Analysis showed that samples clustered by tumor vs. normal, anatomic location, and histopathologic features. Paired t-tests of tumor/normal tissues identified 511 genes whose expression was dysregulated (P<4.7E-07 and at least two-fold difference in magnitude) in cardia or noncardia gastric cancers, including nearly one-half (n = 239, 47%) dysregulated in both cardia and noncardia, one-fourth dysregulated in cardia only (n = 128, 25%), and about one-fourth in noncardia only (n = 144, 28%). Additional RNA studies confirmed profiling results. Expression was associated with case survival for 20 genes in cardia and 36 genes in noncardia gastric cancers. CONCLUSIONS: The dysregulated genes identified here represent a comprehensive starting point for future efforts to understand etiologic heterogeneity, develop diagnostic biomarkers for early detection, and test molecularly-targeted therapies for gastric cancer.

Expression of a LINE-1 endonuclease variant in gastric cancer: its association with clinicopathological parameters.

BACKGROUND: Long interspersed nuclear element-1 (LINE-1 or L1), the most abundant and only autonomously active family of non-LTR retrotransposons in the human genome, expressed not only in the germ lines but also in somatic tissues. It contributes to genetic instability, aging, and age-related diseases, such as cancer. Our previous study identified in human gastric adenocarcinoma an upregulated transcript GCRG213, which shared 88% homology with human L1 sequence and contained a putative conserved apurinic/apyrimidinic endonucleas1 domain. METHODS: Immunohistochemistry was carried out by using a monoclonal mouse anti-human GCRG213 protein (GCRG213p) antibody produced in our laboratory, on tissue microarray constructed with specimens from 175 gastric adenocarcinoma patients. The correlation between GCRG213p expression and patient clinicopathological parameters was evaluated. GCRG213p expression in gastric cancer cell lines were studied using Western blotting analysis. L1 promoter methylation status of gastric cancer cells was tested using methylation-specific PCR. BLASTP was used at the NCBI Blast server to identify GCRG213p sequence to any alignments in the Protein Data Bank databases. RESULTS: Most primary gastric cancer, lymph node metastases and gastric intestinal metaplasia glands showed positive GCRG213p immunoreactivity. High GCRG213p immunostaining score in the primary gastric cancer was positively correlated with tumor differentiation (well differentiated, p = 0.001), Lauren's classification (intestinal type, p < 0.05) and a late age onset of gastric adenocarcinoma (≥65 yrs; p < 0.05). GCRG213p expression has no association with other clinicopathological parameters, including survival. Western blotting analysis of GCRG213p expression in gastric cancer cells indicated that GCRG213p level was higher in gastric cancer cell lines than in human normal gastric epithelium immortalized cell line GES-1. Partial methylation of L1 in gastric cancer cells was confirmed by methylation-specific PCR. BLASTP program analysis revealed that GCRG213p peptide shared 83.0% alignment with the C-terminal region of L1 endonuclease (L1-EN). GCRG213p sequence possesses the important residues that compose the conserved features of L1-EN. CONCLUSIONS: GCRG213p could be a variant of L1-EN, a functional member of L1-EN family. Overexpression of GCRG213p is common in both primary gastric cancer and lymph node metastasis. These findings provide evidence of somatic L1 expression in gastric cancer, and its potential consequences in the form of tumor.

[Preparation and identification of monoclonal antibody against human GCRG213].

AIM: To prepare and characterize the monoclonal antibody against human GCRG213. METHODS: The HIS-GCRG213 fusion protein was expressed in E.coli. Mice were immunized with the purified HIS-GCRG213 protein. Hybridoma cell lines secreting monoclonal antibodies against GCRG213 were screened by regular cell fusion and subcloning approach. The titer and specificity of the antibody was characterized by ELISA and Western blot, respectively. The expression of GCRG213 was determined using immunohistochemistry technique on paraffin-embedded tissue sections from normal gastric mucosal tissues and advanced gastric cancer. RESULTS: The HIS-GCRG213 fusion protein with relative molecular mass of 20 800 was over expressed in E.coli. Two hybridoma cell lines which secreted monoclonal antibody specifically against human GCRG213 fusion protein were successfully obtained. The ascite titers of this monoclonal antibody reached 1:10(6);. Western blot analysis showed that the monoclonal antibody could bind to the recombinant HIS-GCRG213 protein specifically.The immunohistochemistry showed that GCRG213 were expressed higher in gastric cancer tissues than in normal ones. CONCLUSION: The monoclonal antibody against human GCRG213 with high titer and specificity has been successfully prepared, which could be utilized as a useful reagent for further studying the biological function of the GCRG213.

Tissue microarray analysis of topoisomerase IIalpha protein in gastric adenocarcinomas: histogenetic and prognostic implications.

UNLABELLED: The aim of this study was to: To investigate topoisomerase IIα (topo-IIα) expression and its correlation with clinicopathological parameters in primary gastric cancer patients. PATIENTS AND METHODS: A tissue microarray including tumor, paired non-tumoral and lymph node metastasis specimens from 210 gastric adenocarcinoma patients was built for immunohistochemical interrogation. The correlation between topo-IIα expression and patient clinicopathological parameters was evaluated by univariate and multivariate analyses. RESULTS: High topo-IIα expression was observed in 30.00% (63/210) of the primary tumors, 25.27% (23/91) of the lymph node metastases and 0.47% (1/210) of the non-tumoral gastric mucosa (p<0.001). Topo-IIα expression in the gastric adenocarcinoma was positively correlated with tumor location (gastric cardia, p<0.001), intestinal histological type (p=0.041), late age onset of gastric adenocarcinoma (≥50 years; p=0.002) and male gender (p=0.038). There was no association with other clinicopathological parameters. No correlation was observed between topo-IIα expression and survival. CONCLUSION: The prognostic value of topo-IIα in gastric adenocarcinoma remains underdetermined.

[Preparation, identification and preliminary application of the polyclonal antibody against gastric cancer-related protein GCRG224].

AIM: To prepare the polyclonal antibody against gastric cancer-related protein GCRG224. METHODS: The thioredoxin/GCRG224 fusion protein was expressed in E.coli. The polyclonal antibody against GCRG224 was obtained by immunizing a rabbit with the purified GCRG224 protein. The titer and specificity of the antibody were determined by ELISA and Western blot, respectively. The expression of GCRG224 in paraffin-embedded tissue sections from normal gastric mucosal tissues and advanced gastric cancer was determined using immunohistochemistry technique. RESULTS: The thioredoxin/GCRG224 fusion protein with relative molecular mass of 16.8 kDa was over-expressed in E.coli. The purity of the expressed product directly purified from a denaturing polyacrylamide gel was about 100%. The polyclonal antibody against GCRG224 was prepared. ELISA detection proved the titer of antiserum against GCRG224 was about 1:256,000. Western blot analysis showed that the antiserum could bind to the expressed fusion protein specifically. GCRG224 was found to have higher expression in gastric cancer tissues than in normal ones by immunohistochemistry. CONCLUSION: The successful preparation of the polyclonal antibody against GCRG224 lays a foundation for further study of the biological function and the possible role of GCRG224 in the development of gastric carcinoma.