Hsa-miRNA-31 regulates epithelial cell barrier function by inhibiting TNFSF15 expression

Ulcerative colitis (UC) is characterized by epithelial barrier disruption and alterations in immune regulation but with the etiology unknown. MicroRNA-31 is the most consistent differentially expressed miRNA in ulcerative colitis tissue. The aim of this project is to study the important roles of miRNA-31 in regulation of intestinal epithelial barrier function. We found that expression of miRNA-31 is proportional to the proliferation of Caco2-BBE cells and overexpression of miRNA-31 can increase its trans-epithelial resistance (TER) by decreasing the transepithelial permeability. miRNA-31 can directly bind to the 3-UTR of TNFSF15, thereafter negatively regulating its expression in Caco2-BBE cells. BrdU and TUNEL analysis demonstrated that transfection of miRNA-31 stimulates proliferation or apoptosis-resistance. Taken together, these results revealed a novel mecha-nism underlying the regulation of epithelial barrier function by miRNA-31 during its regulation on proliferation of epithelial cells.

Characterization of Complete Genome Sequences of a Porcine Endogenous Retrovirus Isolated From China Bama Minipig Reveals an Evolutionary Time Earlier Than That of Isolates From European Minipigs

BACKGROUND

A porcine endogenous retroviruses (PERV) isolate, PERV-A-BM, was isolated from a Guangxi Bama minipig in China.

METHODS

To understand its genetic variation and evolution, the complete PERV-A-BM genome sequences were determined and compared with isolates from different Sus scrofa breeds and porcine cell lines. A total of 69 nucleotide substitutions were found in the full-length genome, including 26 non-synonymous mutations.

RESULTS

Phylogenetic trees based on the complete genome sequence as well as the gag, pol, and env gene sequences from 21 PERV isolates demonstrated that the PERV-A-BM was closely related to the EF133960 isolate from Chinese Wuzhishan miniature pigs inbred in Hainan, China, and distantly related to strains isolated from European-born pigs.

CONCLUSIONS

The estimation of age in the proviral PERV-A-BM integrating into the host genome reveals that the age of PERV-A-BM is at least 8.3 × 10(6) years, an evolutionary time earlier than that of isolates from European-born pigs.

First-line erlotinib versus gemcitabine/cisplatin in patients with advanced EGFR mutation-positive non-small-cell lung cancer: analyses from the phase III, randomized, open-label, ENSURE study

BACKGROUND

The phase III, randomized, open-label ENSURE study (NCT01342965) evaluated first-line erlotinib versus gemcitabine/cisplatin (GP) in patients from China, Malaysia and the Philippines with epidermal growth factor receptor (EGFR) mutation-positive non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

Patients ≥18 years old with histologically/cytologically confirmed stage IIIB/IV EGFR mutation-positive NSCLC and Eastern Cooperative Oncology Group performance status 0-2 were randomized 1:1 to receive erlotinib (oral; 150 mg once daily until progression/unacceptable toxicity) or GP [G 1250 mg/m(2) i.v. days 1 and 8 (3-weekly cycle); P 75 mg/m(2) i.v. day 1, (3-weekly cycle) for up to four cycles]. Primary end point: investigator-assessed progression-free survival (PFS). Other end points include objective response rate (ORR), overall survival (OS), and safety.

RESULTS

A total of 217 patients were randomized: 110 to erlotinib and 107 to GP. Investigator-assessed median PFS was 11.0 months versus 5.5 months, erlotinib versus GP, respectively [hazard ratio (HR), 0.34, 95% confidence interval (CI) 0.22-0.51; log-rank P < 0.0001]. Independent Review Committee-assessed median PFS was consistent (HR, 0.42). Median OS was 26.3 versus 25.5 months, erlotinib versus GP, respectively (HR, 0.91, 95% CI 0.63-1.31; log-rank P = .607). ORR was 62.7% for erlotinib and 33.6% for GP. Treatment-related serious adverse events (AEs) occurred in 2.7% versus 10.6% of erlotinib and GP patients, respectively. The most common grade ≥3 AEs were rash (6.4%) with erlotinib, and neutropenia (25.0%), leukopenia (14.4%), and anemia (12.5%) with GP.

CONCLUSION

These analyses demonstrate that first-line erlotinib provides a statistically significant improvement in PFS versus GP in Asian patients with EGFR mutation-positive NSCLC (NCT01342965).

Reciprocal positive regulation between Cx26 and PI3K/Akt pathway confers acquired gefitinib resistance in NSCLC cells via GJIC-independent induction of EMT

Gefitinib efficiency in non-small-cell lung cancer (NSCLC) therapy is limited due to development of drug resistance. The molecular mechanisms of gefitinib resistance remain still unclear. In this study, we first found that connexin 26 (Cx26) is the predominant Cx isoform expressed in various NSCLC cell lines. Then, two gefitinib-resistant (GR) NSCLC cell lines, HCC827 GR and PC9 GR, from their parental cells were established. In these GR cells, the results showed that gefitinib resistance correlated with changes in cellular EMT phenotypes and upregulation of Cx26. Cx26 was detected to be accumulated in the cytoplasm and failed to establish functional gap-junctional intercellular communication (GJIC) either in GR cells or their parental cells. Ectopic expression of GJIC-deficient chimeric Cx26 was sufficient to induce EMT and gefitinib insensitivity in HCC827 and PC9 cells, while knockdown of Cx26 reversed EMT and gefitinib resistance in their GR cells both in vitro and in vivo. Furthermore, Cx26 overexpression could activate PI3K/Akt signaling in these cells. Cx26-mediated EMT and gefitinib resistance were significantly blocked by inhibition of PI3K/Akt pathway. Specifically, inhibition of the constitutive activation of PI3K/Akt pathway substantially suppressed Cx26 expression, and Cx26 was confirmed to functionally interplay with PI3K/Akt signaling to promote EMT and gefitinib resistance in NSCLC cells. In conclusion, the reciprocal positive regulation between Cx26 and PI3K/Akt signaling contributes to acquired gefitinib resistance in NSCLC cells by promoting EMT via a GJIC-independent manner.

Epidemiological study of influenza B in Shanghai during the 2009-2014 seasons: implications for influenza vaccination strategy

A new quadrivalent influenza vaccine has been available for influenza B, which can pose a significant global health burden. Shanghai has the highest GDP and largest metropolitan population in China. To understand the impact of influenza B in Shanghai in terms of age-related incidence and relative prevalence compared with other subtypes, we conducted this retrospective epidemiological study of influenza B in the 2009-2014 seasons. A total of 71 354 outpatients with influenza-like illness were included, and both lineages of influenza B and subtypes of influenza A were identified using real-time RT-PCR. The antigenic characteristics of influenza B isolates were analysed by sequencing and reciprocal haemagglutinin inhibition assay. On average, 33.45% of influenza strains were influenza B, and 40.20% of strains isolated from children were influenza B. The incidence of influenza B was highest (12.52 per 100 people with influenza-like illness) in children ages 6-17 years and usually peaked in this age group at the early stage of an influenza B epidemic. Overall, both matched and mismatched influenza B strains co-circulated in Shanghai annually, and 44.57% of the circulating influenza B belonged to the opposite lineage of the vaccine strains. We concluded that influenza B has caused a substantial impact in Shanghai and that school-aged children play a key role in the transmission of influenza B. Hence, it may be beneficial to prioritize influenza vaccination for school-aged children to mitigate the outbreaks of influenza B.

Decreased expression of SIRT6 promotes tumor cell growth correlates closely with poor prognosis of ovarian cancer

INTRODUCTION

Cancer is a group of diseases characterized by uncontrolled growth and spread of abnormal cells. If the spread is not con-trolled, it can result in death. Sirtunins belong to a protein family and it is present in all organisms. SIRT6 is downregulated in tumor and acts as tumor suppressor. These sirtunin proteins are linked to repair DNA and metabolism.

MATERIAL AND METHODS

To measure the role of SIRT6 in tumor cell, 20 mice were used and European Collection of Cell Cultures (ECACC) cell lines were used for the analysis. A histopathological technique showed the level of tumor cells.

RESULTS

A recent study provided exceptional insight into the mechanism of SIRT6-related chromatin regulation. According to the histopathology of cancer, SIRT1 localizes to the promoters of several aberrantly silenced tumor suppressor genes whose DNA is hypermethylated. SIRT1 has a role associated with the epigenetic hallmarks of cancer.

CONCLUSION

The link between SIRT6 and cancer provide new insight into the therapeutic potential of small molecule activators or specific targets of SIRT6 for the prevention and treatment of cancer. Further investigation into the specific mechanism of SIRT6 is required to realize this potential.

Association study of UGT1A9 promoter polymorphisms with DILI based on systematically regional variation screen in Chinese population

Drug-induced liver injury (DILI) is caused by unpredictable adverse drug reaction due mainly to the accumulation of hepatotoxic compounds in the liver resulting in significant damage. Drug-metabolizing enzymes have been prime targets for molecular studies relevant to DILI. The gene UGT1A9 mainly expresses in the liver and has an important role in drug metabolism. The Han Chinese has a very long and complex demographic history, and the population stratification arising from the interplay of different geographic areas may influence the polymorphism pattern. We selected 260 healthy subjects in three different geographic areas (including Xian, Shanghai and Liuzhou) for systemic screening and analysis of single-nucleotide polymorphisms (SNPs) in the promoter region of UGT1A9. Eight SNPs were identified and no regional disparity exists among the three populations. Based on these results, 213 DILI patients from all over the Chinese mainland were further recruited to investigate possible association between UGT1A9 and DILI. We observed statistically significant associations between SNP rs2741045 and DILI at both allele and genotype levels (allele: P=0.032; genotype: P=0.029; after Bonferroni correction). Also, multivariate interaction analysis discovered the interaction between rs2741045 and age associated with DILI significantly. This is the first such screening study to investigate the association between UGT1A9 promoter polymorphisms and DILI in the Chinese population and it could provide the basis for further study of DILI mechanisms.