A new superbase, the cyclic trimeric phosphazene base (CTPB), was prepared with high yield and purity. In the presence of alcohol, the CTPB serves as a highly efficient organocatalyst for ring-opening polymerization of the "non-polymerizable" γ-butyrolactone to offer well-defined poly(γ-butyrolactone) with high conversions (up to 98 %) at -60 °C. The produced polymers have high molecular weights (up to 22.9 kg mol ) and low polydispersity distributions (1.27-1.50). NMR analysis of initiation process and the structural analysis of resulting polymers by MALDI-TOF suggest a mechanism involving an activating initiator which leads only to linear polymers with BnO/H chain ends.
We newly genotyped 6,483 cases and 5,488 controls using the Illumina Global Screening Array (GSA), which included two studies (East-GWAS: 4,872 cases and 3,397 controls from Jiangsu province and Shanghai; North-GWAS: 1,611 cases and 2,091 controls from Shandong province, Hebei province and Tianjin). We consecutively recruited histopathologically confirmed gastric cancer cases from hospitals. Cancer-free controls were selected from individuals receiving routine physical examination at hospitals or those participating in community screening for non-communicable diseases. Demographic characteristics of all participants were displayed in Table S1. Onco-GWAS:Histopathologically confirmed gastric cancer cases were consecutively recruited from hospitals in Jiangsu province, China. The cancer-free control subjects were selected from individuals receiving routine physical examination at hospitals or those participating in community screening for non-communicable diseases in Jiangsu province. A total of 1,140 cases and 345 controls were genotyped using the Illumina OncoArray, and 708 controls were genotyped using the Illumina OmniZhongHua chips (Table S1). Detailed study design and genotype calling was provided previously. 1 NJ-GWAS and BJ-GWAS:For the NJ-GWAS and BJ-GWAS, individuals were derived from separate casecontrol studies conducted in Nanjing (565 cases and 1,162 controls) and Beijing (468 cases and 1,123 controls) (Table S1). Individuals were genotyped using the Affymetrix Genome-Wide Human SNP Array (V.6.0), which consisting ~ 900,000 markers. The details of study design and relevant data were reported previously. 2 1.4 SX-GWAS: A total of 1625 gastric cancer cases and 2100 controls were from the Shanxi Upper Gastrointestinal Cancer Genetics Project and the Linxian Nutrition Intervention Trial (Table S1). All participants were genotyped using the Illumina 660W Quad chip. The study was reported elsewhere 3 and the genotype data was downloaded from dbGap (study accession: phs00361.v1.p1). Quality control.The same protocol of quality control procedures on genotyping data was applied for all six GWAS datasets. The genotyped variants were excluded if they had a call rate of <95%, a P value for Hardy-Weinberg Equilibrium (HWE) in controls ≤1.0×10 −6 or a minor allele frequency (MAF) of <1% in controls; and samples were removed if they were with call rates of <95%, outliers (>6 s.d. from the mean) in population stratification analysis and heterozygosity analysis, or duplicated or related individuals (PI_HAT > 0.25).A total of 100,641 samples in the CKB cohort were genotyped with a customized Affymetrix Axiom® CKB array. Samples with call rate < 98% or gender discrepancy, or samples with extreme heterozygosity (F statistic S.D. score <5) were excluded. Variants with call rate <95% were excluded. Variants with call rate ≥ 95% and < 98%, or deviation from the expected frequency as observed in the 1000 Genomes project (the Phase III integrated variant set release, 504 East Asians), or deviation from Hardy-Weinberg disequil...
Over the past several years, organocatalyzed polymerization reactions have attracted considerable attention, and these efforts have led to major advances. A large number of organic compounds have been proven active for the polymerization of a large variety of monomers. In particular, phosphazene bases (PBs) are a family of extremely strong, non‐nucleophilic, and uncharged auxiliary bases, and have shown their remarkable potential as organocatalysts for the ring‐opening polymerization (ROP) of cyclic monomers. By deprotonation of weak acids or in combination with lithium cation, PBs significantly enhance the nucleophilicity of the initiator/chain‐end, thus allowing fast and usually controlled anionic polymerization. In this feature article, the recent advances in phosphazene‐catalyzed ROP of cyclic esters are summarized. This review is divided into three sections, including general features, design and synthesis, and catalytic applications. It aims to provide a critical analysis of PB‐mediated ROP systems and a useful guide for the further design of organocatalysts applied to polymer synthesis. An outlook is given at the end.
Objective Although several genome-wide association studies (GWAS) of non-cardia gastric cancer have been published, more novel association signals could be exploited by combining individual studies together, which will further elucidate the genetic susceptibility of non-cardia gastric cancer. Design We conducted a meta-analysis of two published Chinese GWAS studies (2031 non-cardia gastric cancer cases and 4970 cancer-free controls) and followed by genotyping of additional 3564 cases and 4637 controls in two stages. Results The overall meta-analysis revealed two new association signals. The first was a novel locus at 5q14.3 and marked by rs7712641 ( per-allele OR=0.84, 95% CI 0.80 to 0.88; p=1.21×10 −11 ). This single-nucleotide polymorphism (SNP) marker maps to the intron of the long non-coding RNA, lnc-POLR3G-4 (XLOC_004464), which we observed has lower expression in non-cardia gastric tumour compared with matched normal tissue (P wilcoxon signed-rank =7.20×10 −4). We also identified a new signal at the 1q22 locus, rs80142782 ( per-allele OR=0.62; 95% CI 0.56 to 0.69; p=1.71×10 ), which was independent of the previously reported SNP at the same locus, rs4072037 ( per-allele OR=0.74; 95% CI 0.69 to 0.79; p=6.28×10 −17 ). Analysis of the new SNP conditioned on the known SNP showed that the new SNP remained genome-wide significant (P conditional =3.47×10 −8). Interestingly, rs80142782 has a minor allele frequency of 0.05 in East Asians but is monomorphic in both European and African populations. Conclusion These findings add new evidence for inherited genetic susceptibility to non-cardia gastric cancer and provide further clues to its aetiology in the Han Chinese population.
Two recent genome-wide association studies reported significant associations of genetic variants at 1q22, 10q23 and 20p13 with gastric cancer (GC) risk in Chinese populations. However, these findings have not been confirmed in other independent studies. Here, we performed an independent case-control study in a Chinese population by genotyping three loci (rs4072037A>G at 1q22, rs2274223A>G at 10q23 and rs13042395C>T at 20p13) in 1681 GC cases and 1858 controls. We found that rs4072037 at 1q22 and rs2274223 at 10q23 were significantly associated with risk of GC with per allele odds ratio (OR) of 0.72 [95% confidence interval (CI): 0.63-0.81; P = 2.98 × 10(-7)] and 1.42 (95% CI: 1.27-1.58; P = 9.68 × 10(-10)), respectively. The association was more prominent for rs2274223 in female (OR = 1.86, 95% CI: 1.49-2.32) and gastric cardia adenocarcinoma (GCA) (OR = 1.71, 95% CI: 1.49-1.95). Furthermore, we combined the two single-nucleotide polymorphisms to evaluate the joint effect and found that the GC risk significantly increased with the number of risk allele increasing with a trend P value of 6.66 × 10(-16), and individuals with four risk alleles had a 3.28-fold (95% CI: 1.75-6.13) risk of GC compared with those having no risk alleles. However, no significant association was detected between rs13042395 at 20p13 and GC risk (OR = 1.04, 95% CI: 0.94-1.15; P = 0.452). In conclusion, our results indicate that genetic variants at 1q22 and 10q23 but not 20p13 may serve as candidate markers for GC susceptibility in the Chinese population.
Lung cancer is the leading cause of cancer death in the world, and aberrant expression of miRNA is a common feature during the cancer initiation and development. Our previous study showed that levels of miRNA-148a assessed by quantitative real-time polymerase chain reaction (qRT-PCR) were a good prognosis factor for non-small cell lung cancer (NSCLC) patients. In this study, we used high-throughput formalin-fixed and paraffin-embedded (FFPE) lung cancer tissue arrays and in situ hybridization (ISH) to determine the clinical significances of miRNA-148a and aimed to find novel target of miRNA-148a in lung cancer. Our results showed that there were 86 of 159 patients with low miRNA-148a expression and miRNA-148a was significantly down-regulated in primary cancer tissues when compared with their adjacent normal lung tissues. Low expression of miRNA-148a was strongly associated with high tumor grade, lymph node (LN) metastasis and a higher risk of tumor-related death in NSCLC. Lentivirus mediated overexpression of miRNA-148a inhibited migration and invasion of A549 and H1299 lung cancer cells. Furthermore, we validated Wnt1 as a direct target of miRNA-148a. Our data showed that the Wnt1 expression was negatively correlated with the expression of miRNA-148a in both primary cancer tissues and their corresponding adjacent normal lung tissues. In addition, overexpression of miRNA-148a inhibited Wnt1 protein expression in cancer cells. And knocking down of Wnt-1 by siRNA had the similar effect of miRNA-148a overexpression on cell migration and invasion in lung cancer cells. In conclusion, our results suggest that miRNA-148a inhibited cell migration and invasion through targeting Wnt1 and this might provide a new insight into the molecular mechanisms of lung cancer metastasis.
We have associated variants at 1p35.2 and 6p22.1 with gastric cancer risk, indicating a role for SPOCD1 and BTN3A2 in gastric carcinogenesis.
BackgroundHigh-mobility group box 2 (HMGB2) is implicated in tumorigenesis in various cancers. However, the clinical significance of HMGB2 signaling in human breast cancer progression remains unknown.MethodsWe investigated HMGB2 expression in 185 cases of primary breast cancer and matched normal breast tissue specimens, and explored the underlying mechanisms of altered HMGB2 expression as well as the impact of this altered expression on breast cancer growth and on aerobic glycolysis using in vitro and animal models of breast cancer.ResultsHMGB2 was more highly expressed in tumor-cell nuclei of breast cancer cells than in the adjacent normal breast tissues (P < 0.05). Higher HMGB2 expression correlated with larger tumor size (P = 0.003) and advanced tumor stage (P = 0.033). A Cox proportional hazards model revealed that HMGB2 expression was an independent prognostic factor for breast cancer after radical resection (P < 0.05). Experimentally, knockdown of HMGB2 expression by stable transfected shRNA significantly decreased the growth and glycolysis of breast cancer cells both in vitro and in mouse models. Mechanically, promotion of breast cancer progression by HMGB2 directly and significantly correlated with activation of LDHB expression and inactivation of FBP1 expression.ConclusionsThese results disclose a novel role for HMGB2 in reprogramming the metabolic process in breast cancer cells by targeting LDHB and FBP1 and provide potential prognostic predictors for breast cancer patients.
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