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Zhang Q.,Harvard University | Jin H.,HYK High throughput Biotechnology Institute | Wang L.,HYK High throughput Biotechnology Institute | Xin B.,HYK High throughput Biotechnology Institute | And 2 more authors.
Tumor Biology | Year: 2014

Inconsistent results are often found regarding the risk of genetic variants in lung cancer association studies. To alleviate these conflicts, we performed a large-scale meta-analysis to evaluate the effect of variants on lung cancer in East Asian population (Han Chinese, Japanese, and Korean). Forty-three genetic variants with data from at least three independent case-control studies were under investigation of which two variants (rs1800734 in hMLH1, rs2273953-rs1801173 bi-marker in P73) were first meta-analyzed in East Asians. We found that three variants in CYP1A1, GSTM1, and XRCC1 showed consistently significant associations with lung cancer in mixed analysis and stratified analysis, and several variants showed diverse effects interacting with different environmental factors in stratified analysis. Our study presents a comprehensive and systematic analysis of lung cancer association studies in East Asians and confirms the effect of three variants in lung cancer risk. Additionally, result from stratified analysis suggests the importance of inclusion of environmental factors, such as smoking and tumor histology, in the analysis. © 2014 International Society of Oncology and BioMarkers (ISOBM).

Liu S.-Y.,Guangdong Medical College | Liu S.-Y.,Shenzhen Nanshan Center for Chronic Disease Control | Zhao H.-D.,The Kangci Hospital | Wang J.-L.,The Kangci Hospital | And 9 more authors.
CNS Neuroscience and Therapeutics | Year: 2015

Aims: Alzheimer's disease (AD) is a multifactor disease that has been reported to have a close association with type 2 diabetes (T2D) where the v-akt murine thymoma viral oncogene homolog 1 (AKT1) plays an important role in the protein synthesis pathways and cell apoptosis processes. Evidence has been shown that AKT1 protein may be related to AD risk among patients with T2D. The aim of this study was to analyze the potential association between single nucleotide polymorphisms of AKT1 promoter and the risk of AD among patients with T2D. Methods: The association between AKT1 polymorphisms and AD risk in patients with T2D was assessed among 574 consecutive unrelated subjects including 112 AD patients with T2D, 231 patients with AD, and 231 healthy controls in a case-control study. The cognitive function of all subjects was assessed using MMSE. Six single nucleotide polymorphisms with minor allele frequency >0.2 (rs2498786, rs74090038, rs2494750, rs2494751, rs5811155, and rs2494752) in AKT1 promoter were analyzed by polymerase chain reaction (PCR), and the concentration of AKT1 protein in serum was tested using enzyme-linked immunosorbent assay (ELISA). Results: Overall, there was statistically significant difference in AKT1 rs2498786 polymorphism. The CC frequency of AKT1 rs2498786 polymorphism in AD with T2D group and AD control group was significantly higher than that in healthy control group (PAD+T2D vs. health < 0.0001, PAD vs. health < 0.0001). However, the difference was not found between AD with T2D group and AD control group. Compared with healthy control group, the plasma levels of AKT1 protein in AD with T2D group (PAD+T2D vs. health < 0.0001) and AD control group (PAD vs. health = 0.0003) decreased significantly. Among genotypes of AKT1 rs2498786 polymorphism, the AKT1 protein level in GG genotype was significantly higher than that in GC genotype (PGG vs. GC < 0.0001) and CC genotype (PGG vs. CC < 0.0001). Conclusion: The study suggests that AKT1 rs2498786 polymorphism in insulin signaling pathway may be associated with AD risk and different genotypes may affects levels of protein expression. However, the polymorphism is not shown to be exclusive in AD patients with T2D. © 2015 John Wiley & Sons Ltd.

Zhang Q.,Harvard University | Li H.,HYK High throughput Biotechnology Institute | Jin H.,HYK High throughput Biotechnology Institute | Tan H.,HYK High throughput Biotechnology Institute | And 4 more authors.
BMC Medical Genomics | Year: 2014

Background: The transcriptome complexity in an organism can be achieved by alternative splicing of precursor messenger RNAs. It has been revealed that alternations in mRNA splicing play an important role in a number of diseases including human cancers. Methods. In this study, we exploited whole transcriptome sequencing data from five lung adenocarcinoma tissues and their matched normal tissues to interrogate intron retention, a less studied alternative splicing form which has profound structural and functional consequence by modifying open reading frame or inserting premature stop codons. Results: Abundant intron retention events were found in both tumor and normal tissues, and 2,340 and 1,422 genes only contain tumor-specific retentions and normal-specific retentions, respectively. Combined with gene expression analysis, we showed that genes with tumor-specific retentions tend to be over-expressed in tumors, and the abundance of intron retention within genes is negatively related with gene expression, indicating the action of nonsense mediated decay. Further functional analysis demonstrated that genes with tumor-specific retentions include known lung cancer driver genes and are found enriched in pathways important in carcinogenesis. Conclusions: We hypothesize that intron retentions and consequent nonsense mediated decay may collectively counteract the over-expression of genes promoting cancer development. Identification of genes with tumor-specific retentions may also help develop targeted therapies. © 2014Zhang et al.; licensee BioMed Central Ltd.

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