28 research outputs found

    Escaping Antiangiogenic Therapy: Strategies Employed by Cancer Cells

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    Tumor angiogenesis is widely recognized as one of the “hallmarks of cancer”. Consequently, during the last decades the development and testing of commercial angiogenic inhibitors has been a central focus for both basic and clinical cancer research. While antiangiogenic drugs are now incorporated into standard clinical practice, as with all cancer therapies, tumors can eventually become resistant by employing a variety of strategies to receive nutrients and oxygen in the event of therapeutic assault. Herein, we concentrate and review in detail three of the principal mechanisms of antiangiogenic therapy escape: (1) upregulation of compensatory/alternative pathways for angiogenesis; (2) vasculogenic mimicry; and (3) vessel co-option. We suggest that an understanding of how a cancer cell adapts to antiangiogenic therapy may also parallel the mechanisms employed in the bourgeoning tumor and isolated metastatic cells delivering responsible for residual disease. Finally, we speculate on strategies to adapt antiangiogenic therapy for future clinical uses

    Noncoding Genomics in Gastric Cancer and the Gastric Precancerous Cascade: Pathogenesis and Biomarkers

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    Gastric cancer is the fifth most common cancer and the third leading cause of cancer-related death, whose patterns vary among geographical regions and ethnicities. It is a multifactorial disease, and its development depends on infection by Helicobacter pylori (H. pylori) and Epstein-Barr virus (EBV), host genetic factors, and environmental factors. The heterogeneity of the disease has begun to be unraveled by a comprehensive mutational evaluation of primary tumors. The low-abundance of mutations suggests that other mechanisms participate in the evolution of the disease, such as those found through analyses of noncoding genomics. Noncoding genomics includes single nucleotide polymorphisms (SNPs), regulation of gene expression through DNA methylation of promoter sites, miRNAs, other noncoding RNAs in regulatory regions, and other topics. These processes and molecules ultimately control gene expression. Potential biomarkers are appearing from analyses of noncoding genomics. This review focuses on noncoding genomics and potential biomarkers in the context of gastric cancer and the gastric precancerous cascade

    Noncoding Genomics in Gastric Cancer and the Gastric Precancerous Cascade: Pathogenesis and Biomarkers

    No full text
    Gastric cancer is the fifth most common cancer and the third leading cause of cancer-related death, whose patterns vary among geographical regions and ethnicities. It is a multifactorial disease, and its development depends on infection by Helicobacter pylori (H. pylori) and Epstein-Barr virus (EBV), host genetic factors, and environmental factors. The heterogeneity of the disease has begun to be unraveled by a comprehensive mutational evaluation of primary tumors. The low-abundance of mutations suggests that other mechanisms participate in the evolution of the disease, such as those found through analyses of noncoding genomics. Noncoding genomics includes single nucleotide polymorphisms (SNPs), regulation of gene expression through DNA methylation of promoter sites, miRNAs, other noncoding RNAs in regulatory regions, and other topics. These processes and molecules ultimately control gene expression. Potential biomarkers are appearing from analyses of noncoding genomics. This review focuses on noncoding genomics and potential biomarkers in the context of gastric cancer and the gastric precancerous cascade

    Arsenic may be a carcinogenic determinant of a subset of gallbladder cancer: A pilot study

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    Gallbladder cancer (GBC) is one of the deadliest malignancy and treatment options are deplorably limited. Better strategies of prevention are urgently needed but knowledge on risk factors remains scarce. Recent data suggested that arsenic (As) may be involved in GBC carcinogenesis but the question remains debated. To date, there are no data on As measurement in GBC samples. This pilot study aimed to measure As concentrations in tissue samples from patients with GBC compared to non-cancerous gallbladder (NCGB). Included patients underwent chole-cystectomy at Hospital Clinico Universidad de Chile, Santiago in Chile, a country with high As exposure, between 2001 and 2020. Tissue samples were preserved in formalin-fixed, paraffin-embedded blocks. Selected samples were retrieved, processed and submitted to inductively coupled plasma mass spectrometry (ICP-MS) to determine As concentrations. A total of 77 patients were included, including 35 GBC and 42 NCGB. The two groups were comparable, except for age (68 vs. 49 years, p < 0.001). Measured in 11 GBC and 38 NCGB, total As was detected in 5 GBC (14%) compared to 0 NCGB samples (p < 0.001). GBC group also showed higher median values of As compared to NCGB (p < 0.001). This pilot study provided a proof-of-concept to measure As concentrations in gallbladder samples and showed higher level of As in GBC samples compared to NCGB, paving the way for future studies aiming to investigate the impact of As on GBC, which may contribute to the prevention of this deadly disease

    Loss of Expression of Reprimo, a p53-induced Cell Cycle Arrest Gene, Correlates with Invasive Stage of Tumor Progression and p73 Expression in Gastric Cancer

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    Artículo de publicación ISIReprimo (RPRM), a downstream effector of p53-induced cell cycle arrest at G2/M, has been proposed as a putative tumor suppressor gene (TSG) and as a potential biomarker for non-invasive detection of gastric cancer (GC). The aim of this study was to evaluate the epigenetic silencing of RPRM gene by promoter methylation and its tumor suppressor function in GC cell lines. Furthermore, clinical significance of RPRM protein product and its association with p53/p73 tumor suppressor protein family was explored. Epigenetic silencing of RPRM gene by promoter methylation was evaluated in four GC cell lines. Protein expression of RPRM was evaluated in 20 tumor and non-tumor matched cases. The clinical significance of RPRM association with p53/p73 tumor suppressor protein family was assessed in 114 GC cases. Tumor suppressor function was examined through functional assays. RPRM gene expression was negatively correlated with promoter methylation (Spearman rank r = -1; p = 0.042). RPRM overexpression inhibited colony formation and anchorage-independent growth. In clinical samples, RPRM gene protein expression was detected in 75% (15/20) of non-tumor adjacent mucosa, but only in 25% (5/20) of gastric tumor tissues (p = 0.001). Clinicopathological correlations of loss of RPRM expression were significantly associated with invasive stage of GC (stage I to II-IV, p = 0.02) and a positive association between RPRM and p73 gene protein product expression was found (p<0.0001 and kappa value = 0.363). In conclusion, epigenetic silencing of RPRM gene by promoter methylation is associated with loss of RPRM expression. Functional assays suggest that RPRM behaves as a TSG. Loss of expression of RPRM gene protein product is associated with the invasive stage of GC. Positive association between RPRM and p73 expression suggest that other members of the p53 gene family may participate in the regulation of RPRM expression.CONICYT-FONDECYT from the Government of Chile 1111014 CONICYT-FONDAP from the Government of Chile 1513001

    Additional file 4: Figure S4. of MicroRNA-335-5p is a potential suppressor of metastasis and invasion in gastric cancer

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    Transfection efficiency of human gastric cancer AGS and Hs 746T cell lines treated with miR-335 mimics/inhibitor. Increased or decreased expression of miR-335 in AGS and Hs 746T transfected with NC/miR-335 mimic or with NC/miR-335 inhibitor. Expression of miR-335 was normalized to RNU6B. Data were transformed to logarithmic values (log 2) (PPTX 51 kb
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