Why MUC16 mutations lead to a better prognosis: A study based on The Cancer Genome Atlas gastric cancer cohort

BACKGROUND MUC16, encoding cancer antigen 125, is a frequently mutated gene in gastric cancer. In addition, MUC16 mutations seem to result in a better prognosis in gastric cancer. However, the mechanisms that lead to a better prognosis by MUC16 mutations have not yet been clarified.AIMTo delve deeper into the underlying mechanisms that explain why MUC16 mutations signal a better prognosis in gastric cancer.METHODSWe used multi-omics data, including mRNA, simple nucleotide variation, copy number variation and methylation data from The Cancer Genome Atlas, to explore the relationship between MUC16 mutations and prognosis. Cox regression and random survival forest algorithms were applied to search for hub genes. Gene set enrichment analysis was used to elucidate the molecular mechanisms. Single-sample gene set enrichment analysis and “EpiDISH” were used to assess immune cells infiltration, and “ESTIMATE” for analysis of the tumor microenvironment.RESULTSOur study found that compared to the wild-type group, the mutation group had a better prognosis. Additional analysis indicated that the MUC16 mutations appear to activate the DNA repair and p53 pathways to act as an anti-tumor agent. We also identified a key gene, NPY1R (neuropeptide Y receptor Y1), which was significantly more highly expressed in the MUC16 mutations group than in the MUC16 wild-type group. The high expression of NPY1R predicted a poorer prognosis, which was also confirmed in a separate Gene Expression Omnibus cohort. Further susceptibility analysis revealed that NPY1R might be a potential drug target for gastric cancer. Furthermore, in the analysis of the tumor microenvironment, we found that immune cells in the mutation group exhibited higher anti-tumor effects. In addition, the tumor mutation burden and cancer stem cells index were also higher in the mutation group than in the wild-type group.CONCLUSIONWe speculated that the MUC16 mutations might activate the p53 pathway and DNA repair pathway: alternatively, the tumor microenvironment may be involved.     

人重组载脂蛋白E在大肠杆菌中的表达和纯化

用含有载脂蛋白EcDNA的PET32a原核表达载体转化大肠杆菌BL21（DE3），使之高效表达载脂蛋白E-thioredoxin融合蛋白，利用融合蛋白上的一段组氨酸序列，用镍离子亲合层析柱进行分离纯化。由于在载脂蛋白E和thioredoxin之间存在凝血酶的识别位点，用凝血酶消化后，经SephacrylS-300凝胶过滤得到人重组载脂蛋白E。用此方法可以从1L大肠杆菌培养液中纯化20-30mg高纯度的各种载脂蛋白E异构体和非自然存原突变体。方法简便，产量高，纯度达95%以上。     

Role of cytochrome epoxygenase (CYP2J2) in the pathophysiology of coronary artery disease in South Indian population

Background

The cytochrome P-450 2J2 (CYP2J2) is known to be one of the major enzymes of epoxygenase pathway of arachidonic acid in extrahepatic tissues, which produces series of regioisomeric cis-epoxyeicosatrienoic acids (EETs) such as 5,6-, 8,9-, 11,12-, and 14,15-EETs. In the present study, we analyzed the impact of a genetic variant in CYP2J2 on coronary artery disease (CAD) in the Telangana region of Indian population.

构建不同筛选特性的HBV X基因真核表达载体

目的:构建不同筛选特性的两个HBV X基因真核表达载体.方法:从质粒pEcob6中PCR扩增HBV X全基因,利用pCEP4和pcDNA3.1( )两者多克隆位点的特点,选用pGEM(R)-T Easy Vector构建中间载体pEasy-X,分别酶切后连接特异性片段构建载体pCEP4-X和pcDNA3.1( )-X.结果:从质粒pEcob6成功PCR扩增出HBV X全基因并克隆至质粒pEasy-X,酶切、PCR及测序均证实真核表达载体质粒pCEP4-X和pcDNA3.1( )-X构建成功.结论:具有不同筛选特性的两个HBVX基因真核表达载体业已成功构建.     

MiR-340经组织型纤溶酶原激活剂调控施万细胞的纤溶能力

目的:探讨microRNA-340(miR-340)对施万细胞纤溶能力的调控作用及作用的靶基因。方法:采用溶圈实验来检测miR-340对施万细胞纤溶能力的影响,用荧光素酶双报告基因系统确定miR-340与组织型纤溶酶原激活剂的靶向关系,用实时定量聚合酶链反应检测坐骨神经夹伤后组织型纤溶酶原激活剂mRNA和miR-340的表达变化。结果:miR-340能够抑制施万细胞的纤溶能力,并直接靶向作用于组织型纤溶酶原激活剂的3’UTR,坐骨神经夹伤后组织型纤溶酶原激活剂mRNA与miR-340的表达呈负相关性。结论:miR-340通过直接靶向组织型纤溶酶原激活剂的3’UTR,从而下调靶基因组织型纤溶酶原激活剂的表达抑制施万细胞的纤溶能力。     

Blood-based biomarkers for early detection of esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma(ESCC) is a common malignant tumor of the digestive system worldwide, especially in China. Due to the lack of effective early detection methods, ESCC patients often present at an advanced stage at the time of diagnosis, which seriously affects the prognosis of patients. At present,early detection of ESCC mainly depends on invasive and expensive endoscopy and histopathological biopsy. Therefore, there is an unmet need for a noninvasive method to detect ESCC in the early stages. With the emergence of a large class of non-invasive diagnostic tools, serum tumor markers have attracted much attention because of their potential for detection of early tumors. Therefore, the identification of serum tumor markers for early detection of ESCC is undoubtedly one of the most effective ways to achieve early diagnosis and treatment of ESCC.This article reviews the recent advances in the discovery of blood-based ESCC biomarkers, and discusses the origins, clinical applications, and technical challenges of clinical validation of various types of biomarkers.