APOBEC‐mediated DNA alterations: A possible new mechanism of carcinogenesis in EBV‐positive gastric cancer

AbstractMechanisms of viral oncogenesis are diverse and include the off-target activity of enzymes expressed by the infected cells, which evolved to target viral genomes for controlling their infection. Among these enzymes, the single-strand DNA editing capability of APOBECs represent a well-conserved viral infection response that can also cause untoward mutations in host DNA. Here we show, after evaluating somatic single-nucleotide variations and transcriptome data in 240 gastric cancer samples, a positive correlation between APOBEC3s mRNA-expression and the APOBEC-mutation signature, both increased in EBV+ tumors. The correlation was reinforced by the observation of APOBEC-mutations preferentially occuring in transcriptionally-active loci. The EBV-infection and APOBEC3 mutation-signature axis was confirmed in a validation cohort of 112 gastric cancer patients. Our findings suggest that APOBEC3 upregulation in EBV+ cancer may boost the mutation load, providing further clues to the mechanisms of EBV-induced gastric carcinogenesis. After further validation, this EBV-APOBEC axis may prove to be a secondary driving force in the mutational evolution of EBV+ gastric tumors, whose consequences in terms of prognosis and treatment implications should be vetted.

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Long non-coding RNA AK096174 promotes cell proliferation and invasion in gastric cancer by regulating WDR66 expression

Bioscience Reports ◽

10.1042/bsr20180277 ◽

2018 ◽

Vol 38 (4) ◽

Cited By ~ 5

Author(s):

Yeqian Zhang ◽

Site Yu ◽

Zizhen Zhang ◽

Gang Zhao ◽

Jia Xu

Keyword(s):

Gastric Cancer ◽

Overall Survival ◽

Poor Prognosis ◽

Positive Impact ◽

Non Coding Rna ◽

Mechanistic Investigation ◽

Mechanism Of Carcinogenesis ◽

Long Non Coding Rna ◽

Proliferation And Invasion ◽

Translational Level

Gastric cancer (GC) is one of the major causes of cancer deaths worldwide; however, the mechanism of carcinogenesis is complex and poorly understood. Long non-coding RNA (lncRNA) has been reported to be involved in the development of multiple cancers. Here, we identified a novel lncRNA, AK096174, which was up-regulated and associated with tumorigenesis, tumor size, metastasis, and poor prognosis in GC. Our data showed that AK096174 was highly expressed in the GC tissues and cell lines (SGC-7901, AGS, BGC-823, MGC-803), and patients with higher AK096174 expression had a poorer prognosis and shorter overall survival (OS). AK096174 knockdown inhibited the proliferation, migration, and invasiveness in SGC-7901 and BGC-823 cells, whereas AK096174 overexpression had the promoting effects. Furthermore, mechanistic investigation showed that AK096174 positively correlated with the expression of WD repeat-containing protein 66 (WDR66) gene at the translational level. Knockdown of WRD66 attenuated the positive impact of AK096174 in GC cells. The findings of the present study establish a function for AK096174 in GC progression and suggest it may serve as a potential target for GC therapy in the future.

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Ultrastructural Cytochemical Study of Human Gastric Cancer: Observation of AKP ase,ACP ase,G6P ase,TPP ase and CO ase

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100158819 ◽

1990 ◽

Vol 48 (3) ◽

pp. 254-255

Author(s):

Dong Yuming ◽

Yang Guanglin ◽

Du Wei Dong ◽

Xu Ai Liam

Keyword(s):

Gastric Cancer ◽

Gastric Epithelium ◽

Human Gastric Cancer ◽

Electron Microscopic ◽

Cytochemical Study ◽

Electron Microscopic Cytochemistry ◽

Cytochemical Reaction ◽

Set Up ◽

Cancer Tissues ◽

Cytochemical Technique

The activities and distributions of AKPase ,ACPase,G6Pase,TPPase and COase in human normal gastric mucosa and gastric cancer tissues were studied histochemically at light microscopic level. These enzymes are the marker enzymes of cell membrane lysosome endoplasmic reticulum, Golgi apparatus and mitochondrion objectively. On the basis of the research we set up a special ultrastructural cytochemical technique and first researched into gastric cancer domesticly. Ultrastructural cytochemistry is also called electron microscopic cytochemistry. This new technique possesses both the sensitivity of cytochemical reaction andi the high resolution of electron microscope. It is characterized by direct observation,exact localization and the combination morphology with function.The distributions of AKPase,ACPase,G6Pase,TPPase and COase in 14 cases of gastric cancer and 1 case of gastric Denign lesion were studied ultrastructurally. The results showed: 1. normal gastric epithelium had no AKPase reaction. The reaction of ACPase,G6Pase,TPPase and Coase were found in the corresponding organella, which were consistent with their function.

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Ultrastructural Localization Study of Carcinoembryonic Antigen (CEA) in Gastric Cancer: Immunoelectron Microscopic Observation

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100158807 ◽

1990 ◽

Vol 48 (3) ◽

pp. 252-253

Author(s):

Dong Yuming ◽

Yang Guanglin ◽

Wu Jifeng ◽

Chen Xiaolin

Keyword(s):

Gastric Cancer ◽

Intestinal Metaplasia ◽

Cancer Cells ◽

Microscopic Observation ◽

Biological Significance ◽

Ultrastructural Localization ◽

Mucinous Carcinoma ◽

Surface Glycoprotein ◽

Tubular Adenocarcinoma ◽

Pap Method

On the basis of light microscopic observation, the ultrastructural localization of CEA in gastric cancer was studied by immunoelectron microscopic technique. The distribution of CEA in gastric cancer and its biological significance and the mechanism of abnormal distribution of CEA were further discussed.Among 104 surgically resected specimens of gastric cancer with PAP method at light microscopic level, the incidence of CEA(+) was 85.58%. All of mucinous carcinoma exhibited CEA(+). In tubular adenocarcinoma the incidence of CEA(+) showed a tendency to rising with the increase of degree of differentiation. In normal epithelia and intestinal metaplasia CEA was faintly present and was found only in the luminal surface. The CEA staining patterns in cancer cells were of three types--- cytoplasmic, membranous and weak reactive type. The ultrastructural localization of CEA in 14 cases of gastric cancer was studied by immunoelectron microscopic technique.There was a little or no CEA in the microvilli of normal epithelia. In intestinal metaplasia CEA was found on the microvilli of absorptive cells and among the mucus particles of goblet cells. In gastric cancer CEA was also distributed on the lateral and basal surface or even over the entire surface of cancer cells and lost their polarity completely. Many studies had proved that the alterations in surface glycoprotein were characteristic changes of tumor cells. The antigenic determinant of CEA was glycoprotein, so the alterations of tumor-associated surface glycoprotein opened up a new way for the diagnosis of tumors.

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