Persistent colonization of the gastric mucosa by Helicobacter pylori (Hp) elicits chronic inflammation and aberrant epithelial cell proliferation, which increases the risk of gastric cancer. We examined the ability of microRNAs to modulate gastric cell proliferation in response to persistent Hp infection and found that epigenetic silencing of miR-210 plays a key role in gastric disease progression. Importantly, DNA methylation of the miR-210 gene was increased in Hp-positive human gastric biopsies as compared to Hp-negative controls. Moreover silencing of miR-210 in gastric epithelial cells promoted proliferation. We identified STMN1 and DIMT1 as miR-210 target genes and demonstrated that inhibition of miR-210 expression augmented cell proliferation by activating STMN1 and DIMT1. Together, our results highlight inflammation-induced epigenetic silencing of miR-210 as a mechanism of induction of chronic gastric diseases, including cancer, during Hp infection.
Epigenetic silencing of miR-210 increases the proliferation of gastric epithelium during chronic Helicobacter pylori infection.
Cell line
View SamplesCells located at the invasive front and in the tumor mass of mouse cervical squamous cell carcinomas were isolated by laser microdissection from hematoxylin-stained HPV/E2 sections. 7 months old HPV/E2 mice treated with oestrogen develop invasive cervical squamous cell carcinomas. This model recapitulates human invasive cervical neoplasias.
Inflammatory Cytokines Induce Podoplanin Expression at the Tumor Invasive Front.
Specimen part
View SamplesOsteosarcoma (OS) is the malignant bone tumor with a high tendency to metastasize to the lung, where the molecular mechanisms are unclear. The mouse OS cell line LM8 has been isolated originally from the Dunn OS cell line by in vivo selection as a subline with a high metastatic potential to the lung.
Stable knockdown of S100A4 suppresses cell migration and metastasis of osteosarcoma.
Cell line
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Classification of Epstein-Barr virus-positive gastric cancers by definition of DNA methylation epigenotypes.
Specimen part, Cell line
View SamplesAberrant promoter methylation is known to be deeply involved in human gastric carcinogenesis, while association of Epstein-Barr virus (EBV) to the aberrant methylation has not been fully clarified. We analyzed promoter methylation in clinical gastric cancer cases using illumina's Infinium beadarray, and hierarchical clustering analysis classified gastric cancer into three subgroups: low and high methylation epigenotypes in EBV-negative cases, and markedly higher methylation epigenotype that was completely matched to EBV-positive cases. Three epigenotypes were characterized by three groups of genes: genes methylated specifically in the EBV-positive epigenotype (EBV(+)-markers, e.g. CXXC4, TIMP2, PLXND1), genes methylated both in EBV-positive and high epigenotypes (High-markers, e.g. COL9A2, EYA1, ZNF365), and genes methylated all in EBV-positive, high and low epigenotypes of gastric cancer (Common-markers, e.g. AMPH, SORCS3, AJAP1). Polycomb repressive complex (PRC)-target genes in ES cells were significantly enriched in High- and Common-markers (P=2x10-15 and 2x10-34, respectively), but not in EBV(+)-markers (P=0.2), suggesting a different cause for EBV(+)-marker methylation. Recombinant EBV was infected to low epigenotype gastric cancer cell, MKN7. In all the three independently established clones, DNA methylation was induced in High- and EBV(+)-markers after 18 weeks, demonstrating that EBV-positive epigenotype should involve methylation of Common-, High-, and EBV(+)-markers simultaneously. The de novo methylated genes were overlapped well among the three clones, and the methylation caused gene repression. In summary, gastric cancer was classified into three DNA methylation epigenotypes, EBV-positive gastric cancer showed markedly high methylation epigenotype expanding to non-PRC target genes, and EBV infection per se could induce the EBV-positive epigenotype.
Classification of Epstein-Barr virus-positive gastric cancers by definition of DNA methylation epigenotypes.
Specimen part, Cell line
View SamplesCancer cells express different sets of receptor type tyrosine kinases. These receptor kinases may be activated through autocrine or paracrine mechanisms. Fibroblasts may modify the biologic properties of surrounding cancer cells through paracrine mechansms.
The role of HGF/MET and FGF/FGFR in fibroblast-derived growth stimulation and lapatinib-resistance of esophageal squamous cell carcinoma.
Specimen part, Cell line
View SamplesLoss or reduction in function of tumor suppressor genes contributes to tumorigenesis. We identified a novel homozygous deletion of DACH1 in gliomas.
Homozygously deleted gene DACH1 regulates tumor-initiating activity of glioma cells.
Specimen part, Cell line
View SamplesSharpin (Shank-associated RH domain-interacting protein, also known as SIPL1) is a multifunctional molecule that participates in various biological settings, including nuclear factor-B signaling activation and tumor suppressor gene inhibition. Sharpin is upregulated in various types of cancers, including hepatocellular carcinoma (HCC), and is implicated in tumor progression. However, the exact roles of Sharpin in tumorigenesis and tumor progression remain largely unknown. Here, we report novel mechanisms of HCC progression through Sharpin overexpression. Sharpin was upregulated in human HCC tissues. Increased Sharpin expression enhanced hepatoma cell invasion, whereas decrease in Sharpin expression by RNA interference inhibited invasion. Microarray analysis identified that versican, a chondroitin sulfate proteoglycan that plays crucial roles in tumor progression and invasion, was also upregulated in stably Sharpin-expressing cells. Versican expression increased in the majority of HCC tissues and knocking down of versican greatly attenuated hepatoma cell invasion. Sharpin expression resulted in a significant induction of versican transcription synergistically with Wnt/-catenin pathway activation. Furthermore, Sharpin overexpressing cells had high tumorigenic properties in vivo. These results demonstrate that Sharpin promotes versican expression synergistically with the Wnt/-catenin pathway, potentially contributing to HCC development. A Sharpin/versican axis could be an attractive therapeutic target for this currently untreatable cancer.
Sharpin promotes hepatocellular carcinoma progression via transactivation of Versican expression.
Specimen part
View SamplesIn order to clarify the downstream target genes of SPAG4, we performed knockdown of SPAG4 using siRNA both under normoxia and hypoxia.
Sperm-associated antigen 4, a novel hypoxia-inducible factor 1 target, regulates cytokinesis, and its expression correlates with the prognosis of renal cell carcinoma.
Cell line
View SamplesOvarian clear cell carcinoma (CCC) is generally associated with chemoresistance and poor clinical outcome, even with early diagnosis; whereas high-grade serous carcinomas (SCs) and endometrioid carcinomas (ECs) are commonly chemosensitive at advanced stages. Although an integrated genomic analysis of SC has been performed, conclusive views on copy number and expression profiles for CCC are still limited. In this study, we performed single nucleotide polymorphism arrays in 57 (31 CCCs, 14 SCs, and 12 ECs) and expression microarrays in 55 epithelial ovarian cancers (25 CCCs, 16 SCs, and 14 ECs), and then evaluated PIK3CA mutations and ARID1A expression in CCCs. SNP array analysis classified 13% of CCCs into a cluster with high frequency and focal range of copy number alterations (CNAs), significantly lower than for SCs (93%, P < 0.01) and ECs (50%, P = 0.017). The ratio of whole-arm to all CNAs was higher in CCCs (46.9%) than SCs (21.7%) (P < 0.0001). SCs with loss of heterozygosity (LOH) of BRCA1 (85%) also had LOH of NF1 and TP53, and LOH of BRCA2 (62%) coexisted with LOH of RB1 and TP53. Microarray analysis classified CCCs into three clusters. One cluster (CCC-2, n = 10) showed more favorable prognosis than the others (CCC-1and CCC-3) (P = 0.041). Coexistent alterations of PIK3CA and ARID1A were more common in CCC-1 and CCC-3 (7/11, 64%) than in CCC-2 (0/10, 0%) (P < 0.01). Being in cluster CCC-2 was an independent favorable prognostic factor in CCC. In conclusion, CCC was characterized by a high ratio of whole-arm CNAs; whereas CNAs in SC were mainly focal, but preferentially caused LOH of well-known tumor suppressor genes. As such, expression profiles might be useful for sub-classification of CCC, and might provide useful information on prognosis.
Correction: Integrated Copy Number and Expression Analysis Identifies Profiles of Whole-Arm Chromosomal Alterations and Subgroups with Favorable Outcome in Ovarian Clear Cell Carcinomas.
Age
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