Integrating sex as an important biological variable is imperative to enhance the accuracy and reproducibility of cell-based studies, which provide basic information for subsequent preclinical and clinical study designs. Recently, international funding agencies and renowned journals have been attempting to integrate sex as a variable in every research step. To understand what progress has been made in reporting of cell sex in the articles published in AJP-Cell Physiology since the analysis in 2013, we examined the sex notation of the cells in relevant articles published in the same journal in 2018. Of the 107 articles reporting cell experiments, 53 reported the sex of the cells, 18 used both male and female cells, 23 used male cells only, and 12 used female cells only. Sex omission was more frequent when cell lines were used than when primary cells were used. In the articles describing experiments performed using rodent primary cells, more than half of the studies used only male cells. Our results showed an overall improvement in sex reporting for cells in AJP-Cell Physiology articles from 2013 (25%) to 2018 (50%). However, sex omission and male bias were often found still. Furthermore, the obtained results were rarely analyzed by sex even when both male and female cells were used in the experiments. To boost sex considerate research implementation in basic biomedical studies, cooperative efforts of the research community, funders, and publishers are urged.

Epstein-Barr virus (EBV) infects more than 90% of the global population and is associated with a variety of tumors including nasopharyngeal carcinoma, Hodgkin lymphoma, natural killer/T lymphoma, and gastric carcinoma. In EBV-associated gastric cancer (EBVaGC), highly expressed EBV BamHI A rightward transcripts (BART) miRNAs may contribute to tumorigenesis with limited viral antigens. Despite previous studies on the targets of BART miRNAs, the functions of all 44 BART miRNAs have not been fully clarified. Here, we used RNA sequencing data from the Cancer Genome Atlas to find genes with decreased expression in EBVaGC. Furthermore, we used AGS cells infected with EBV to determine whether expression was reduced by BART miRNA. We showed that the expression of Kruppel-like factor 2 (KLF2) is lower in AGS-EBV cells than in the AGS control. Using bioinformatics analysis, four BART miRNAs were selected to check whether they suppress KLF2 expression. We found that only miR-BART17-5p directly down-regulated KLF2 and promoted gastric carcinoma cell migration and anchorage-independent growth. Our data suggest that KLF2 functions as a tumor suppressor in EBVaGC and that miR-BART17-5p may be a valuable target for effective EBVaGC treatment.

Although Epstein-Barr virus (EBV) is known to encode over 40 different miRNAs of its own, the roles of most EBV miRNAs remain unknown. Disabled homolog 2 (DAB2) is a putative tumor suppressor, but its role in gastric carcinoma (GC), especially in EBV-associated GC, needs to be clarified. Our qRT-PCR and mRNA microarray results showed that DAB2 expression was down-regulated in EBV-positive GC cells compared to EBV-negative cells. Four BART miRNAs that might target DAB2 were predicted, and we found, using a luciferase reporter assay, that miR-BART1-3p directly targeted the 3'-UTR of DAB2. The miR-BART1-3p transfection decreased DAB2 expression at both mRNA and protein levels, while transfection of an inhibitor of miR-BART1-3p, miR-BART1-3p(i), increased DAB2 expression. In addition, miR-BART1-3p as well as siDAB2 increased migration and decreased apoptosis. Meanwhile, miR-BART1-3p(i) or pcDNA3.1-DAB2 transfection decreased migration and increased apoptosis in EBV-infected GC cells. Furthermore, decreased migration by miR-BART1-3p(i) was abrogated by co-transfected siDAB2, while decreased migration by miR-BART1-3p(i) was further suppressed by a co-transfected DAB2 over-expression vector. Our data suggest that miR-BART1-3p plays an important role in the tumorigenesis of EBV-associated GC by directly targeting DAB2.

In Epstein-Barr virus (EBV)-infected epithelial cancers, BamHI A rightward transcript (BART) miRNAs are highly expressed. However, only a few target genes of BART miRNAs have been investigated. Our mRNA microarray data showed that DKK1 was markedly down-regulated in EBV-associated gastric carcinoma (EBVaGC) cells. Using luciferase reporter assay we tested whether miR-BART10-3p regulates DKK1 by directly targeting the 3'-UTR of DKK1 mRNA. We observed that miR-BART10-3p transfection decreased DKK1 expression, while an LNA inhibitor of miR-BART10-3p (LNA-miR-BART10-3p(i)) increased DKK1 expression. Furthermore, miR-BART10-3p and siDKK1 promoted cell proliferation and migration. In contrast, transfecting GC cells with LNA-miR-BART10-3p(i) or DKK1 over expression vector suppressed cell proliferation and migration. Our results suggest that miR-BART10-3p may be involved in the tumor progression of EBVaGC by targeting DKK1.

is an anticancer drug commonly used to treat gastric cancer; however, continuous 5-FU chemotherapy causes drug resistance. Materials and Methods: We established five sublines of 5-FU-resistant AGS gastric cancer cells to investigate changes that may have occurred in the development of 5-FU resistance. Drug resistance to other chemotherapeutic reagents, proliferation, cell-cycle changes, and wound healing ability were assessed for each subline. Results: Retarded cell growth, G 0 /G 1 phase arrest, upregulation of p57, and down-regulation of cyclin D1 were commonly observed in all five sublines. Resistance to paclitaxel and cisplatin was also observed in most of the sublines. Conclusion: Our data support the notion that G 0 /G 1 arrest due to changes in p57 and cyclin D1 expression may confer drug resistance, while EMT seems non-essential to 5-FU resistance in AGS gastric carcinoma cells.Gastric cancer (GC) is the fifth most common cancer and causes the third-most cancer-related deaths worldwide (1). GC is associated with lifestyle factors such as Helicobacter pylori infection, unbalanced diet, alcohol consumption, and smoking (2). Radical surgery and chemotherapy are the primary methods of treatment for early GC. Patients with advanced GC who cannot undergo surgery are treated with neoadjuvant chemotherapy, radiotherapy, and moleculartargeted therapies. However, most patients diagnosed with advanced GC show poor overall prognosis even after treatment because of high metastatic potential and poor response to chemotherapy (3, 4). 5-Fluorouracil (5-FU) is an anticancer drug used for many solid tumor types including gastric and colon cancer (5, 6). 5-FU, an analog of uracil, is transported into cells by the same mechanism as uracil. 5-FU inhibits thymidylate synthase, incorporates into RNA and DNA, and induces cell death pathways in rapidly growing cancer cells (7-9). However, the response rate to 5-FU-based chemotherapy is lower than 32% in advanced GC (10). This low response rate is mainly due to 5-FU resistance caused by several factors including degradation of 5-FU by dihydropyrimidine dehydrogenase, increased deoxyuridine triphosphatase activity, and overexpression of thymidylate synthase, B-cell lymphoma 2 (BCL2), BCL-XL, and BCL2 family member MCL1 apoptosis regulator proteins (7,11).Acquisition of 5-FU resistance and subsequent chemotherapy failure is a common and problematic phenomenon in patients with cancer (12). Previous studies of 5-FU-resistant GC cells showed changes in the pathway of 5-FU metabolism, increased drug transporter protein, and resistance to apoptosis (13,14). In addition, epithelial to mesenchymal transition (EMT) was observed, similarly to other 5-FU-resistant solid tumors (15, 16). Various drug-resistant cell lines have been established to study strategies for overcoming anticancer drug resistance. However, most studies have used only one resistant cell line rather than comparing multiple cell lines derived simultaneously.In this study, we established five 5-FU-resistant GC cell subline...