Overview of methodological quality of systematic reviews about gastric cancer risk and protective factors

An analysis of the evidence underpinning the national comprehensive cancer network practice guidelines

OBJECTIVE

This study assesses the quality and completeness of systematic reviews (SRs) included by the National Comprehensive Cancer Network (NCCN) cancer screening clinical practice guidelines (CPGs).

METHODS

We evaluated SRs according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) and AMSTAR-2 (A Measurement Tool to Assess systematic Reviews).

RESULTS

Seven NCCN CPGs were included with 109 SRs. The mean PRISMA percent completeness of included SRs was 71 % (range 0.1-1.0). The mean AMSTAR-2 percent completeness was 56 % (range 0.05-0.99). Of the 70 SRs assessed via AMSTAR-2, 42 (60 %) received a "critically low" rating, 11 (15.7 %) received "low" ratings, and 17 (24.3 %) received "moderate". None of the SRs received a "high" rating.

CONCLUSION

Lack of adherence to AMSTAR-2 and PRISMA reporting standards among the SRs included is prevalent. We suggest improved reporting of SR inclusion criteria and evaluation to bolster the reporting quality of SRs underpinning CPG recommendations.

Methodological quality was critically low in 9/10 systematic reviews in advanced cancer patients-A methodological study

OBJECTIVE

To assess the methodological quality and the consideration of heterogeneity in systematic reviews (SRs).

STUDY DESIGN AND SETTING

We conducted a methodological study (CRD42019134904) and searched three databases from January 2010 to July 2019. Interventional SRs with a statistically significant meta-analysis of at least four randomized controlled trials in advanced cancer patients were included. A MeaSurement Tool to Assess Systematic Reviews (AMSTAR) 2 was used to evaluate the SRs' methodological quality. The consideration of heterogeneity was categorized in clinical or/and methodological heterogeneity and not explored.

RESULTS

From 6234 identified references, 261 SRs were included. Most SRs had a critically low quality (230, 88.1%). The majority of them (209, 80.1%) was classified as critically low because of non-registration (222, 85.1%) combined with the non-reporting of excluded full-texts and missing justifications for exclusion (218, 83.5%). Heterogeneity in trial results was not explored at all in 51 (19.5%) SRs whereas clinical heterogeneity was considered in 117 (44.8%), methodological heterogeneity in 13 (5.0%), and both clinical and methodological heterogeneity in 80 (30.7%) SRs.

CONCLUSION

The consideration of these findings in trainings for review authors and peer reviewers could improve the awareness of quality criteria and the quality of future SRs.

TRIAL REGISTRATION

PROSPERO-ID: CRD42019134904.

Processed meat intake and chronic disease morbidity and mortality: An overview of systematic reviews and meta-analyses

Despite the nutritional value of meat, a large volume of reviews and meta-analyses suggests that processed meat intake is associated with an increased risk of chronic diseases. However, assessments of the quality of these published reviews internal validity are generally lacking. We systematically reviewed and assessed the quality alongside summarizing the results of previously published systematic reviews and meta-analyses that examined the association between processed meat intake and cancers, type II diabetes (T2D), and cardiovascular diseases (CVD). Reviews and meta-analyses published until May 2018 were identified through a systematic literature search in the databases MEDLINE and EMBASE, and reference lists of included reviews. The quality of the systematic reviews and meta-analyses was assessed using A Measurement Tool to Assess Systematic Reviews (AMSTAR). All eligible reviews had to comply with two quality requirements: providing sufficient information on quality assessment of the primary studies and a comprehensive search. The results were summarized for T2D, CVD, and each of the different cancer types. The certainty in the estimates of the individual outcomes was rated using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) method. In total, 22 systematic reviews were eligible and thus included in this review. More than 100 reviews were excluded because quality assessment of the primary studies had not been performed. The AMSTAR score of the included reviews ranged from 5 to 8 indicating moderate quality. Overall, the quality assessments of primary studies of the reviews are generally lacking; the scientific quality of the systematic reviews reporting positive associations between processed meat intake and risk of various cancers, T2D and CVD is moderate, and the results from case-control studies suggest more often a positive association than the results from cohort studies. The overall certainty in the evidence was very low across all individual outcomes, due to serious risk of bias and imprecision.

Association between TIM-3 polymorphisms and cancer risk: a meta-analysis

BACKGROUND

Single nucleotide polymorphisms (SNPs) of T-cell immunoglobulin- and mucin-domain-containing molecule 3 (TIM-3) were reported to individually associate with cancer risk. To further verify its correlation with human cancers, we evaluated the association of TIM-3 polymorphisms and the risk of cancer.

METHODS

Data were collected from electronic databases. Two reviewers independently selected studies, extracted data and assessed quality of the studies. Data were meta-analyzed using the STATA 13.0 software. Crude odd ratio (OR) and 95% confidence interval was used to estimate the association between TIM-3 polymorphism and cancer susceptibility.

RESULTS

All eligible case-control studies included a total of 4,852 participants (2,229 cases and 2,623 controls). The meta-analysis showed that TIM-3 SNPs (-1516G/T, -574G/T, +4259T/G, and haplotypes) were significantly associated with an increased risk of susceptibility toward all cancers. The subgroup analyses based on cancer types showed that TIM-3 -1516G/T SNP was only associated with an increased risk in developing cancers in the digestive system or in hospital-based populations. Moreover, the TIM-3 -574G/T SNP was associated with an increased cancer risk in the digestive system or other systems, while TIM-3 +4259T/G SNP was only associated with an increased cancer risk in hospital-based populations. Among the four haplotypes observed (GGT, TGT, GGG, and GTT), The GGG haplotype showed an increase in the odds of cancer by 2.614-fold (OR 2.614; 95% CI: 1.756-3.893) compared with the GGT haplotype.

CONCLUSIONS

TIM-3 SNPs (-1516G/T, -574G/T, +4259T/G and the four haplotypes) were associated with an increased risk of developing human cancers.

DPP-4 inhibitors for the treatment of type 2 diabetes: a methodology overview of systematic reviews

AIMS

To evaluate the methodological quality of systematic reviews (SRs), and summarize evidence of important outcomes from dipeptidyl peptidase-4 inhibitors (DPP4-I) in treating type 2 diabetes mellitus (T2DM).

METHODS

We included SRs of DPP4-I for the treatment of T2DM until January, 2018 by searching the Cochrane Library, PubMed, EMBASE and three Chinese databases. We evaluated the methodological qualities with the AMSTAR (Assessing the Methodological Quality of Systematic Reviews) tool and the GRADE (The Grading of Recommendations Assessment, Development and Evaluation) approach.

RESULTS

Sixty-three SRs (a total of 2,603,140 participants) receiving DPP4-I for the treatment of T2DM were included. The results of AMSTAR showed that the lowest quality was "a list of studies (included and excluded) item" with only one (1.6%) study provided, followed by the "providing a priori design" item with only four (6.3%) studies conforming to this item, the next were "the status of publication (gray literature) used as an inclusion criterion item", with only 18 (28.9%) studies conforming to these items. Only seven (11.1%) studies scored more than nine points in AMSTAR, indicating high methodological quality. For GRADE, of the 128 outcomes, high quality evidence was provided in only 28 (21.9%), moderate in 70 (54.7%), low in 27 (21.1%), and very low in three (2.3%).

CONCLUSIONS

The methodological quality of SRs of DPP4-I for type 2 diabetes mellitus is not high and there are common areas for improvement. Furthermore, the quality of evidence level is moderate and more high quality evidence is needed.

Methodological quality of meta-analyses of single-case experimental studies

BACKGROUND

Methodological rigor is a fundamental factor in the validity and credibility of the results of a meta-analysis.

AIM

Following an increasing interest in single-case experimental design (SCED) meta-analyses, the current study investigates the methodological quality of SCED meta-analyses.

METHODS AND PROCEDURES

We assessed the methodological quality of 178 SCED meta-analyses published between 1985 and 2015 through the modified Revised-Assessment of Multiple Systematic Reviews (R-AMSTAR) checklist.

OUTCOMES AND RESULTS

The main finding of the current review is that the methodological quality of the SCED meta-analyses has increased over time, but is still low according to the R-AMSTAR checklist. A remarkable percentage of the studies (93.80% of the included SCED meta-analyses) did not even reach the midpoint score (22, on a scale of 0-44). The mean and median methodological quality scores were 15.57 and 16, respectively. Relatively high scores were observed for "providing the characteristics of the included studies" and "doing comprehensive literature search". The key areas of deficiency were "reporting an assessment of the likelihood of publication bias" and "using the methods appropriately to combine the findings of studies".

CONCLUSIONS AND IMPLICATIONS

Although the results of the current review reveal that the methodological quality of the SCED meta-analyses has increased over time, still more efforts are needed to improve their methodological quality.

MiR-122-5p inhibits cell migration and invasion in gastric cancer by down-regulating DUSP4

OBJECTIVE

To explore the relationship between miR-122-5p and DUSP4 and their effects on gastric cancer (GC) cell mobility and invasiveness.

METHODS

Abnormally expressed miRNAs and mRNAs were analyzed using microarrays. The miR-122-5p and DUSP4 mRNA expression levels in GC tissues and cells were determined by RT-qPCR. The target relationship between miR-122-5p and DUSP4 was validated by dual luciferase reporter assay. GC cell mobility and invasiveness were respectively observed by wound healing assay and transwell invasion assay. Western blot and immunohistochemistry were used for detection of the expressions of DUSP4 protein and MMP2 and MMP9 proteins related to cell invasion and migration. The migration and invasion abilities of gastric cancer cells in vivo were evaluated according to the number of lung metastatic nodules in mice.

RESULTS

The expression of miR-122-5p in GC tissues and cells was significantly down-regulated, whereas DUSP4 expression was up-regulated. Bioinformatics prediction strategies and dual luciferase reporter assay verified the binding sites of miR-122-5p on 3'UTR of DUSP4 and the target relationship between miR-122-5p and DUSP4. Overexpression of miR-122-5p and knockdown of DUSP4 in BGC-823 cells observantly suppressed GC cell mobility and invasiveness, whereas downregulation of miR-122-5p expression promoted cell metastasis. MiR-122-5p inhibited GC cell mobility and invasiveness and pulmonary tumor metastasis via downregulation of DUSP4.

CONCLUSION

MiR-122-5p restrained migration and invasion abilities of GC cells by repressing DUSP4.

MicroRNA-28 promotes cell proliferation and invasion in gastric cancer via the PTEN/PI3K/AKT signalling pathway

Gastric cancer is the fourth most common malignant disease and second leading cause of cancer‑associated mortalities worldwide. Previous studies revealed aberrantly expressed microRNAs (miRNAs) in various types of human cancer; these miRNAs play important roles in tumourigenesis and tumour development. miRNAs present a considerable potential for novel therapeutic approaches for treating human cancer. Therefore, the investigation of novel miRNAs involved in gastric cancer progression provides an opportunity to improve the prognosis of patients with gastric cancer. miRNA‑28 (miR‑28) has been investigated with regards to its expression and biological functions in many types of human cancer. However, previous studies have not discussed the expression patterns, roles and associated molecular mechanisms of miR‑28 in gastric cancer. In the present study, miR‑28 expression was identified to be upregulated in gastric cancer tissues and cell lines. miR‑28 inhibition functionally inhibited cell proliferation and invasion in gastric cancer in vitro. Using bioinformatics analysis, luciferase reporter assay, reverse transcription‑quantitative polymerase chain reaction and western blot analysis, phosphatase and tensin homolog (PTEN) was mechanically identified as a direct target of miR‑28 in gastric cancer. PTEN was downregulated in gastric cancer and negatively correlated with miR‑28 levels. Inhibition of PTEN restored the biological effects of miR‑28 downregulation on the proliferation and invasion of gastric cancer cells. Notably, the downregulation of miR‑28 results in the regulation of the phosphatidylinositol 3‑kinase/protein kinase B signaling pathway in gastric cancer. These results suggested that miR‑28 may be targeted for the development of novel treatments for gastric cancer in the future.

MicroRNA-197 inhibits gastric cancer progression by directly targeting metadherin

Gastric cancer is the fifth most frequent malignancy and the fourth most common cause of cancer‑associated mortality worldwide. MicroRNAs (miRNAs) are a group of small RNAs that regulate several cellular processes. In particular, a large number of miRNAs are involved in gastric cancer formation and progression. Thus, miRNAs may be considered as effective diagnostic biomarkers and therapeutic methods for gastric cancer. The aim of the current study was to detect miRNA (miR)‑197 expression in gastric cancer and to investigate its biological role and associated mechanism in gastric cancer. In the present study, miR‑197 expression was demonstrated to be considerably downregulated in gastric cancer tissues and cell lines. Its low expression level was associated with tumour size, invasive depth, tumour‑node‑metastasis staging and lymph node metastasis. High expression of miR‑197 inhibited tumour cell proliferation and invasion in vitro. Subsequently, metadherin (MTDH) was identified as a direct target gene of miR‑197 in gastric cancer, and this was confirmed by bioinformatics analysis, Dual‑luciferase reporter assay, reverse transcription quantitative polymerase chain reaction and western blot analysis. MTDH expression was upregulated in gastric cancer and was inversely correlated with miR‑197 expression levels. In addition, MTDH overexpression prevented the proliferation and inhibited invasion induced by miR‑197 overexpression. In addition, miR‑197 was demonstrated to regulate the phosphatase and tensin homolog (PTEN)/AKT signalling pathway in gastric cancer. The results of the present study suggested that miR‑197 serves a tumour‑suppressing role in human gastric carcinogenesis and progression by regulating the MTDH/PTEN/AKT signalling pathway. The miR‑197/MTDH axis may provide a novel effective therapeutic target for patients with gastric cancer.

Reduction of miR‑132‑3p contributes to gastric cancer proliferation by targeting MUC13

Abnormal expression of epidermal growth factor receptor (EGFR) signaling and microRNAs (miRNAs) has been widely seen in gastric cancer. The present study focused on the miRNAs that regulate human epidermal growth factor receptor (HER) activation through mucin 13 (MUC13). The protein level of MUC13 was demonstrated to be significantly increased in gastric cancer tissues compared with normal tissues by western blot analysis and immunohistochemistry. TargetScan bioinformatic predictions indicated that miRNA (miR)‑212‑3p and miR‑132‑3p may bind to the 3'‑untranslated region of MUC13. Further investigation revealed that miR‑132‑3p was significantly decreased in gastric cancer tissues compared with normal tissues, whereas miR‑212‑3p expression was unaffected. Luciferase assays and western blot confirmed MUC13 as a target gene of miR‑132‑3p. Inhibition of miR‑132‑3p enhanced gastric cancer cell migration through activation of HER2, extracellular signal‑regulated kinase (ERK) and Akt serine/threonine kinase (Akt) signaling, which was a similar effect to that of MUC13 overexpression. In summary, reduction of miR‑132‑3p may contribute to gastric cancer proliferation by targeting MUC13.

Tim-3 Up-regulation in Patients with Gastric Cancer and Peptic Ulcer Disease

Background:

T-cell immunoglobulin and mucin domain protein-3 (Tim-3), an inhibitory immunoregulatory receptor, has been recently implicated in tumor biology and tumor-associated immune suppression. In the present study, expression of Tim-3 was evaluated in gastric cancer (GC) and peptic ulcer disease (PUD) at both mRNA and protein levels.

Methods:

A total of 133 gastric tissue biopsies, comprising 43 from GC cases, 48 from PUD and 42 from non-ulcer dyspepsia (NUD) serving as controls were collected. Additionally, non-neoplastic adjacent tissue biopsies were also obtained from 6 patients with GC. Infection with Helicobacter pylori was determined by the rapid urease test for all participants and H&E staining was conducted for GC and PUD patients. Tim-3 relative mRNA expression was determined by SYBR Green based Real-Time PCR using β-actin as a reference gene. Tim-3 protein expression was also studied by immunohistochemistry in 7 GC, 7 PUD and 10 NUD tissue samples.

Results:

Tim-3 was expressed at higher levels in GC (p=0.030) and PUD (p=0.022) cases compared to he NUD group. Among paired samples obtained from gastric cancer patients, tumor tissues showed elevated Tim-3 expression (p=0.019) in comparison with adjacent non-neoplastic biopsies. Tim-3 mRNA findings were supported by detection of more Tim-3 protein in cancerous (p=0.002) and ulcerative (p=0.01) tissues than in controls. Tim-3 was similarly expressed in H. pylori positive and negative cases.

Conclusion:

Higher Tim-3 expression in patients with gastric cancer and peptic ulcer implies that it might be involved in immune regulation and establishment of these gastrointestinal diseases. Targeted immunotherapy by blocking of inhibitory receptors like Tim-3 could be a promising approach for gastric cancer treatment.

Preventive effect of Actinidia valvata Dunn extract on N-methyl-N'-nitro-N-nitrosoguanidine-induced gastrointestinal cancer in rats

PURPOSE

This study was conducted to assess the preventive effect of Actinidia valvata Dunn (AVD) extract on an animal model of gastrointestinal carcinogenesis on the basis of changes in tumor incidence, cell proliferation, and apoptosis.

MATERIALS AND METHODS

Seventy-five male Wistar rats were divided into five different treatment groups with 15 rats in each group. Group I was given normal feed, whereas Groups II to IV were treated with 10% sodium chloride in the first six weeks and 100 ug/mL of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in drinking water for 24 weeks. Group II was then given normal feed, whereas Group III was given AVD extract (0.24 g/kg/day) for 12 weeks. Group IV was given AVD extract from the first week to the 36th week, whereas Group V was treated with AVD extract alone for 36 weeks. All rats were sacrificed at the end of the 36-week experiment and assessed for the presence of gastrointestinal tumors. The occurrence of cancer was evaluated by histology. Bax, Bcl-2, Caspase-3, and cyclinD1 were determined by immunohistochemical staining and Western blotting.

RESULTS

The incidences of gastric cancer were 0% in Group I, 73.3% in Group II, 33.3% in Group III, 26.7% in Group IV, and 0% in Group V. Bcl-2 and cyclinD1 expression was decreased in AVD extract treated groups, whereas Bax and Caspase-3 expression was increased. Comparison with group II revealed significant differences (p<0.01).

CONCLUSIONS

AVD extract exhibits an obvious preventive effect on gastrointestinal carcinogenesis induced by MNNG in rats through the regulation of cell proliferation and apoptosis.

Prevention and Early Detection of Occupational Cancers - a View of Information Technology Solutions

Thousands of people die each year from cancer due to occupational causes. To reduce cancer in workers, preventive strategies should be used in the high-risk workplace. The effective prevention of occupational cancer requires knowledge of carcinogen agents. Like other areas of healthcare industry, occupational health has been affected by information technology solutions to improve prevention, early detection, treatment and finally the efficiency and cost effectiveness of the healthcare system. Information technology solutions are thus an important issue in the healthcare field. Information about occupational cancer in information systems is important for policy makers, managers, physicians, patients and researchers; because examples that include high quality data about occupational cancer patients and occupational cancer causes are able to determine the worker groups which require special attention. As a result exposed workers who are vulnerable can undergo screening and be considered for preventive interventions.

AA-PMe, a novel asiatic acid derivative, induces apoptosis and suppresses proliferation, migration, and invasion of gastric cancer cells

Asiatic acid (AA; 2α,3β,23-trihydroxyurs-12-ene-28-oic acid) is widely used for medicinal purposes in many Asian countries due to its various bioactivities. A series of AA derivatives has been synthesized in attempts to improve its therapeutic potencies. Herein we investigated the anti-tumor activities of N-(2α,3β,23-acetoxyurs-12-en-28-oyl)-l-proline methyl ester (AA-PMe), a novel AA derivative. AA-PMe exhibited a stronger anti-cancer activity than its parent compound AA. AA-PMe inhibited the proliferation of SGC7901 and HGC27 human gastric cancer cells in a dose-dependent manner but had no significant toxicity in human gastric mucosa epithelial cells (GES-1). AA-PMe induced cell cycle arrest in G₀/G₁ phase and blocked G₁-S transition, which correlated well with marked decreases in levels of cyclin D1, cyclin-dependent kinase CKD4, and phosphorylated retinoblastoma protein, and increase in cyclin-dependent kinase inhibitor P15. Further, AA-PMe induced apoptosis of human gastric cancer cells by affecting Bcl-2, Bax, c-Myc, and caspase-3. Moreover, AA-PMe suppressed the migration and invasion of human gastric cancer cells (SGC7901 and HGC27) cells by downregulating the expression of MMP-2 and MMP-9. Overall, this study investigated the potential anti-cancer activities of AA-PMe including inducing apoptosis and suppressing proliferation, migration and invasion of gastric cancer cells, as well as the underlying mechanisms, suggesting that AA-PMe is a promising anti-cancer drug candidate in gastric cancer therapy.

Stomach cancer mortality among workers exposed to asbestos: a meta-analysis

BACKGROUND

The relationship between asbestos and stomach cancer is not well understood because of small number of cases. This study aimed to determine the incidence and mortality of stomach cancer among workers exposed to asbestos based on a systematic review and meta-analysis approach.

METHODS

Relevant English electronic databases were systematically searched for published studies characterizing the risk of developing stomach cancer as a result of asbestos exposure. Standardized mortality rate (SMR) for stomach cancer with its 95% confidence interval (CI) was pooled using a fixed-/random-effect model in STATA.

RESULTS

A total of 32 independent studies were included for the analysis. The overall SMR for stomach cancer was 1.19 (95% CI 1.06-1.34), with a moderate degree of heterogeneity across the studies (I(2) = 37.6%, P = 0.011). Being male, exposure to crocidolite, miners, studies conducted in Europe and Oceania, and long study follow-up (≥ 25 years) all contribute to significantly higher SMR. Significant publication bias was observed.

CONCLUSION

Elevated risk of stomach cancer mortality was evidenced among workers exposed to crocidolite, especially male miners.

Preventive effect of rebamipide on N-methyl-N'-nitro-N-nitrosoguanidine-induced gastric carcinogenesis in rats

Chemoprevention strategies against gastric cancer (GC) need to be explored in light of the fact that stomach cancer still occurs in the absence of Helicobacter pylori (HP) infection and following HP eradication. We evaluated the effect of rebamipide on N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced carcinogenesis in SD rats. Thirty-nine male rats were divided into four groups based on whether or not they were treated with rebamipide and/or MNNG: Control, Rebamipide, Control-M, and Rebamipide-M groups. From 8 weeks of age, rats in the Control-M and Rebamipide-M groups received MNNG in drinking water for 30 weeks. The Rebamipide and Rebamipide-M groups were administered 5mg/kg/day of rebamipide. At 50 weeks, cancerous lesions were not observed in either the Control or Rebamipide groups. Nine rats in the Control-M group had developed GC, while four rats in the Rebamipide-M group had developed GC. The incidence of cancer in the Rebamipide-M group was significantly less than in the Control-M group (p<0.05), with a trend toward a lower incidence of invasive carcinoma in the Rebamipide-M group. Carcinomatous invasion into the muscularis propria was not observed in the Rebamipide-M group. In conclusion, the present study demonstrates that rebamipide suppresses. MNNG-induced carcinogenesis and may also inhibit progression of cancer in rats.

Expression of the EGF family in gastric cancer: downregulation of HER4 and its activating ligand NRG4

Gastric cancer is a major cause of cancer-related deaths in both men and women. The epidermal growth factor receptors are EGFR, HER2, HER3 and HER4. Of the four epidermal growth factor receptors, EGFR and HER2 are well-known oncogenes involved in gastric cancer. Little, however, is known about the role played by HER3 and HER4 in this disease. We obtained paired samples from the tumor and the adjacent normal tissue from the same patient undergoing surgery for gastric cancer. Using RT-qPCR, we quantified the mRNA expression of the four receptors including the HER4 splicing isoforms and all the ligands activating these receptors. Using immunohistochemistry, the protein expression of HER4 was also quantified. We found that HER2 mRNA expression was upregulated in the tumor tissue compared to the matched normal tissue (p = 0.0520). All ligands with affinity for EGFR were upregulated, whereas the expression of EGFR was unchanged. Interestingly, we found the mRNA expression of HER4 (p = 0.0002) and its ligand NRG4 (p = 0.0009) to be downregulated in the tumor tissue compared to the matched normal tissue. HER4 downregulation was demonstrated for all the alternatively spliced isoforms of this receptor. These results support the involvement of EGFR and HER2 in gastric cancer and suggest an interesting association of reduced HER4 expression with development of gastric cancer.

Risk of malignancy associated with a maternal family history of cancer

This study was conducted in order to obtain a screening and early detection reference for children whose mothers had been diagnosed with cancer. Data for 276 mother-child pairs with malignant tumors were analyzed. The distribution of cancers in affected families was generally similar to that of the general Chinese population, and correspondingly breast cancer was the most common malignancy amongst daughters whose mother had cancer (32.7%). The most prevalent cancer amongst sons with affected mothers was gastric cancer, rather than lung cancer. Daughters were more likely to have the same kind of malignant tumor as their mother (P<0.05), and were more likely to develop breast cancer than any other malignant disease if their mother had a breast tumor (P<0.0001). Likewise, if the mother was diagnosed with breast or gynecological cancer, the daughter was more likely to be diagnosed with breast or gynecological cancer than any other cancer (P<0.01). Daughters and sons developed malignant diseases 11 and 6.5 years earlier than their mothers, respectively (P<0.0001).Women with a mother who suffered cancer should be screened for malignancy from 40 years of age especially for breast, lung, and gynecological cancers. For men with affected mothers, screening should start when they are 45 years old focusing particularly on lung and digestive system cancers.

Characteristics of 240 Chinese father-child pairs with malignant disease

To obtain a screening and early detection reference for individuals who have a family history of cancer on the paternal side, we collected and analyzed data from 240 pairs in which both fathers and their children were diagnosed with cancer. Disease categories of fathers and sons were similar to that of the general population of China, whereas daughters were different from general female population with high incidence of breast cancer and gynecological cancer. Sons were more likely than daughters to have the same type of cancer, or to have cancer in the same organ system as their fathers (P <0.0001). Sons and daughters developed malignant diseases 11 and 16 years earlier than their fathers, respectively (P < 0.0001 for both sons and daughters). Daughters developed malignant diseases 5 years earlier than sons (P < 0.0001). Men with a family history of malignant tumors on the paternal side should be screened for malignancies from the age of 45 years, or 11 years earlier than the age of their fathers< diagnosis, and women should be screened from the age of 40 years, or 16 years earlier than the age at which their fathers were diagnosed with cancer. Lung cancer should be investigated in both men and women, whilst screening should focus on cancer of the digestive system in men and on breast and gynecological cancer (ovary, uterine and cervical cancer) in women.

Generation of monoclonal antibody MS17-57 targeting secreted alkaline phosphatase ectopically expressed on the surface of gastrointestinal cancer cells

Background

Therapeutic antibody development is one of the fastest growing areas of the pharmaceutical industry. Generating high-quality monoclonal antibodies against a given therapeutic target is crucial for successful drug development. However, due to immune tolerance, making it difficult to generate antibodies using conventional approaches.

Methodology/Findings

Mixed four human gastric cancer (GC) cell lines were used as the immunogen in A/J mice; sixteen highly positive hybridoma colonies were selected via fluorescence-activated cell sorting-high throughput screening (FACS-HTS) using a total of 20,000 colonies in sixty-seven 96-well plates against live cells (mixed human GC cells versus human PBMC controls). MS17-57 and control commercial Alkaline Phosphatase (ALP) mAbs were used to confirm the target antigens (Ags), which were identified as ALPs expressed on the GC cell surface through a combination of western blot, immunoprecipitation and mass spectrometry (MS).

MS identified the Ags recognized by MS17-57 to be two variants of a secreted ALP, PALP and IALP (Placental and intestinal ALP). These proteins belong to a hydrolase enzyme family responsible for removing phosphate groups from many types of molecules. Immunofluorescence staining using MS17-57 demonstrated higher staining of gastrointestinal (GI) cancer tissues compared to normal GI tissues (P<0.03), and confirmed binding of MS17-57 to be restricted to a functional epitope expressed on the cancer cell surface. Proliferation assays using the PALP/IALP-expressing GC cell lines demonstrated that MS17-57 inhibited cell growth by 32±8%. Transwell cell migration assays documented that MS17-57 can inhibit PALP/IALP-expressing GI cancer cell migration by 25±5%. MS17-57 mAb inhibited tumor growth in nude mice.

Conclusions

Our findings indicate that PALP and IALP can be ectopically expressed on extracellular matrix of GI cancers, and that MS17-57 directed against PALP/IALP can inhibit GI cancer cells growth and migration invitro and invivo. This investigation provides an example of identification of cancer biomarkers representing promising therapeutic targets using mAb generated through a novel HTS technology.

Histopathological changes in rabbit gastric mucosa after chronic exposure to pickled vegetables: an experimental study

Gastric cancer (GC) is very common in Iran. Daily consumption of pickled vegetables is a routine dietary habit in most areas of Iran. Because pickled vegetables have been associated with GC it can be of importance to study the relationship between the two. We have therefore studied the histo-morphological effects of pickled vegetables on the Rabbit gastric mucosa. Forty and twenty healthy male rabbits were respectively allocated in the experimental and control groups. The rabbits were fed freely with pickled (experimental group) and fresh vegetables (control group) for 1 yr. The gastric mucosa of rabbits was examined and the results were compared. In addition to all the rabbits of the control group, 14 rabbits (35%) of the experimental group had normal gastric mucosa. The rest showed abnormal changes including atypia-so called indefinite for dysplasia-in 10 (25%), low-grade dysplasia in 14 (35%), and high-grade dysplasia in 2 (5%). The analysis showed significant difference between results of the 2 groups (P < 0.001). Daily consumption of pickled vegetables can produce atypical and dysplastic changes in the gastric mucosa. Such preneoplastic changes can potentially transform to gastric carcinoma. This process could be prevented by reduction or cessation of daily pickled food consumption.

Seroepidemiology of Helicobacter pylori infection in a Mennonite community in Durango State, Mexico

BACKGROUND

The epidemiology of Helicobacter pylori infection among Mennonites (an ethnic group of German descent living in rural communities in Mexico) has not been previously studied.

MATERIALS AND METHODS

The prevalence of anti-H. pylori IgG antibodies was examined in 152 Mennonite individuals in Durango State, Mexico, using enzyme-linked immunoassays. Seroprevalence association with sociodemographic, clinical, and behavioral characteristics of the Mennonite community was also investigated.

RESULTS

In total, 77 (50.7%) of the 152 Mennonite participants (mean age, 38.4 ± 15.5 years) had H. pylori IgG antibodies, 35 (45.4%) of whom had H. pylori IgG antibody levels higher than 100 U/mL. Males and females had comparable seroprevalence rates of H. pylori and H. pylori IgG antibody levels. On the other hand, seroprevalence of H. pylori increased significantly with age and was significantly higher among women with history of deliveries and abortions than among those with no such obstetric characteristics. Logistic regression analysis of behavioral characteristics showed that H. pylori infection was associated with a low frequency of eating at restaurants and at fast food outlets (up to 10 times/year) (OR = 2.77; 95% CI: 1.28-5.98; p = .009), and eating meat (up to 3 days/week) (OR = 2.84; 95% CI: 1.36-5.91; p = .005).

CONCLUSIONS

This is the first report on the seroprevalence of H. pylori among Mennonites, factors contributing to such infection, and the association of H. pylori infection with abortions and low frequencies of eating out of home and meat. Further research should be conducted on this topic.