| 1. |
- Aguilo, Francesca, et al.
(author)
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Long noncoding RNA, polycomb, and the ghosts haunting INK4b-ARF-INK4a expression.
- 2011
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In: Cancer Research. - 0008-5472 .- 1538-7445. ; 71:16
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Journal article (peer-reviewed)abstract
- Polycomb group proteins (PcG) function as transcriptional repressors of gene expression. The important role of PcG in mediating repression of the INK4b-ARF-INK4a locus, by directly binding to the long noncoding RNA (lncRNA) transcript antisense noncoding RNA in the INK4 locus (ANRIL), was recently shown. INK4b-ARF-INK4a encodes 3 tumor-suppressor proteins, p15(INK4b), p14(ARF), and p16(INK4a), and its transcription is a key requirement for replicative or oncogene-induced senescence and constitutes an important barrier for tumor growth. ANRIL gene is transcribed in the antisense orientation of the INK4b-ARF-INK4a gene cluster, and different single-nucleotide polymorphisms are associated with increased susceptibility to several diseases. Although lncRNA-mediated regulation of INK4b-ARF-INK4a gene is not restricted to ANRIL, both polycomb repressive complex-1 (PRC1) and -2 (PRC2) interact with ANRIL to form heterochromatin surrounding the INK4b-ARF-INK4a locus, leading to its repression. This mechanism would provide an increased advantage for bypassing senescence, sustaining the requirements for the proliferation of stem and/or progenitor cell populations or inappropriately leading to oncogenesis through the aberrant saturation of the INK4b-ARF-INK4a locus by PcG complexes. In this review, we summarize recent findings on the underlying epigenetic mechanisms that link PcG function with ANRIL, which impose gene silencing to control cellular homeostasis as well as cancer development.
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| 2. |
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| 3. |
- Fang, Fang, et al.
(author)
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Risk of infection-related cancers after the loss of a child : a follow-up study in Sweden
- 2011
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In: Cancer Research. - Philadelphia, USA : American Association for Cancer Research. - 0008-5472 .- 1538-7445. ; 71:1, s. 116-22
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Journal article (peer-reviewed)abstract
- It is unknown whether severe emotional stress due to loss of a child influences the risk of cancers susceptible to immune modulation such as infection-related cancers. We conducted a historic cohort study in 1990 to 2004 on the basis of the Swedish Multi-Generation Register including 4,687,073 parents. Death of a child was identified through the Causes of Death Register. Poisson regression was used to derive the relative risks (RR) and 95% confidence intervals (CI) of infection-related cancers, comparing the incidence rates of parents who lost a child with those who never lost a child. A total of 101,306 parents (2%) had lost a child during follow-up, among whom 1,608 subsequently developed infection-related cancers. After adjustment for age, sex, calendar year, educational level, and civil status, the overall RR of 14 cancers studied was 1.07 (95% CI: 1.02-1.12). Parents who lost a child were particularly at a higher risk for cancers potentially associated with human papilloma virus (HPV) infection such as cervical cancer (RR: 1.46; 95% CI: 1.17-1.80). Higher RRs for most cancers were obtained within 5 years after child loss and excess risk for liver and stomach cancers was confined to that period. No association was observed for lymphoma and nonmelanoma skin cancer at any time point after child loss. Although potential confounding by unmeasured factors cannot be ruled out, our findings lend support to the hypothesis that severe life stressors, such as child loss, may raise the risk for several, chiefly HPV-related, cancers.
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| 4. |
- Hilvo, Mika, et al.
(author)
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Novel theranostic opportunities offered by characterization of altered membrane lipid metabolism in breast cancer progression
- 2011
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In: Cancer Research. - Philadelphia, PA, USA : American Association for Cancer Research. - 0008-5472 .- 1538-7445. ; 71:9, s. 3236-45
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Journal article (peer-reviewed)abstract
- Activation of lipid metabolism is an early event in carcinogenesis and a central hallmark of many cancers. However, the precise molecular composition of lipids in tumors remains generally poorly characterized. The aim of the present study was to analyze the global lipid profiles of breast cancer, integrate the results to protein expression, and validate the findings by functional experiments. Comprehensive lipidomics was conducted in 267 human breast tissues using ultraperformance liquid chromatography/ mass spectrometry. The products of de novo fatty acid synthesis incorporated into membrane phospholipids, such as palmitate-containing phosphatidylcholines, were increased in tumors as compared with normal breast tissues. These lipids were associated with cancer progression and patient survival, as their concentration was highest in estrogen receptor-negative and grade 3 tumors. In silico transcriptomics database was utilized in investigating the expression of lipid metabolism related genes in breast cancer, and on the basis of these results, the expression of specific proteins was studied by immunohistochemistry. Immunohistochemical analyses showed that several genes regulating lipid metabolism were highly expressed in clinical breast cancer samples and supported also the lipidomics results. Gene silencing experiments with seven genes [ACACA (acetyl-CoA carboxylase α), ELOVL1 (elongation of very long chain fatty acid-like 1), FASN (fatty acid synthase), INSIG1 (insulin-induced gene 1), SCAP (sterol regulatory element-binding protein cleavage-activating protein), SCD (stearoyl-CoA desaturase), and THRSP (thyroid hormone-responsive protein)] indicated that silencing of multiple lipid metabolism-regulating genes reduced the lipidomic profiles and viability of the breast cancer cells. Taken together, our results imply that phospholipids may have diagnostic potential as well as that modulation of their metabolism may provide therapeutic opportunities in breast cancer treatment.
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| 5. |
- Lindahl, Gabriel, et al.
(author)
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Tamoxifen, Flaxseed, and the Lignan Enterolactone Increase Stroma- and Cancer Cell-Derived IL-1Ra and Decrease Tumor Angiogenesis in Estrogen-Dependent Breast Cancer
- 2011
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In: CANCER RESEARCH. - : American Association for Cancer Research. - 0008-5472. ; 71:1, s. 51-60
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Journal article (peer-reviewed)abstract
- The proinflammatory cytokines IL-1 alpha and IL-1 beta promote tumor angiogenesis that might be counteracted by the IL-1 receptor antagonist (IL-1Ra), anakinra, a clinically approved agent. A diet with high amounts of phytoestrogens, such as flaxseed (Flax), genistein (GEN), and the mammalian lignan enterolactone (ENL), may affect breast cancer progression in a similar fashion as the antiestrogen tamoxifen. Both cancer cells and tumor stroma may be targets for cancer therapy. By using microdialysis in a model of human breast cancers in nude mice, we could perform species-specific analyses of released proteins in the microenvironment. We show that tumors treated with tamoxifen and fed Flax or ENL exhibited decreased in vivo release of IL-1 beta derived from the murine stroma and decreased microvessel density whereas dietary GEN had no effects. Cancer cell-released IL-1Ra were approximately 5 times higher than stroma-derived IL-1Ra. Tamoxifen, Flax, and ENL increased IL-1Ra levels significantly whereas GEN did not. The tumor stroma contained macrophages, which expressed the estrogen receptor. In vitro, estradiol decreased IL-1Ra released from breast cancer cells and from cultured macrophages. IL-1Ra decreased endothelial cell proliferation significantly in vitro whereas breast cancer cell proliferation was unaffected in presence of estradiol. Finally, IL-1Ra therapy of tumor-bearing mice opposed estrogen-dependent breast cancer growth and decreased angiogenesis. We conclude that the release of IL-1s both by cancer cells and the stroma, where macrophages are a key component, may offer feasible targets for antiestrogen therapy and dietary interventions against breast cancer.
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| 6. |
- Lovejoy, David B, et al.
(author)
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Antitumor Activity of Metal-Chelating Compound Dp44mT Is Mediated by Formation of a Redox-Active Copper Complex That Accumulates in Lysosomes
- 2011
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In: Cancer Research. - : American Association for Cancer Research. - 0008-5472 .- 1538-7445. ; 71:17, s. 5871-5880
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Journal article (peer-reviewed)abstract
- The metal-chelating compound Dp44mT is a di-2-pyridylketone thiosemicarbazone (DpT) which displays potent and selective antitumor activity. This compound is receiving translational attention, but its mechanism is poorly understood. Here, we report that Dp44mT targets lysosome integrity through copper binding. Studies using the lysosomotropic fluorochrome acridine orange established that the copper-Dp44mT complex (Cu[Dp44mT]) disrupted lysosomes. This targeting was confirmed with pepstatin A-BODIPY FL, which showed redistribution of cathepsin D to the cytosol with ensuing cleavage of the proapoptotic BH3 protein Bid. Redox activity of Cu[Dp44mT] caused cellular depletion of glutathione, and lysosomal damage was prevented by cotreatment with the glutathione precursor N-acetylcysteine. Copper binding was essential for the potent antitumor activity of Dp44mT, as coincubation with nontoxic copper chelators markedly attenuated its cytotoxicity. Taken together, our studies show how the lysosomal apoptotic pathway can be selectively activated in cancer cells by sequestration of redox-active copper. Our findings define a novel generalized strategy to selectively target lysosome function for chemotherapeutic intervention against cancer.
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| 7. |
- Martinsson, Tommy, 1956, et al.
(author)
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Appearance of the novel activating F1174S ALK mutation in neuroblastoma correlates with aggressive tumor progression and unresponsiveness to therapy.
- 2011
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In: Cancer research. - : American Association for Cancer Research. - 1538-7445 .- 0008-5472. ; 71:1, s. 98-105
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Journal article (peer-reviewed)abstract
- Mutations in the kinase domain of the ALK kinase have emerged recently as important players in the genetics of the childhood tumor neuroblastoma. Here, we report the appearance of a novel ALK mutation in neuroblastoma, correlating with aggressive tumor behavior. Analyses of genomic DNA from biopsy samples initially showed ALK sequence to be wild type. However, during disease progression, mutation of amino acid F1174 to a serine within the ALK kinase domain was observed, which correlated with aggressive neuroblastoma progression in the patient. We show that mutation of F1174 to serine generates a potent gain-of-function mutant, as observed in 2 independent systems. First, PC12 cell lines expressing ALK(F1174S) display ligand-independent activation of ALK and further downstream signaling activation. Second, analysis of ALK(F1174S) in Drosophila models confirms that the mutation mediates a strong, rough eye phenotype upon expression in the developing eye. Thus, we report a novel ALK(F1174S) mutation that displays ligand-independent activity in vivo, correlating with rapid and treatment-resistant tumor growth. The study also shows that initial screening in the first tumor biopsy of a patient may not be sufficient and that further molecular analysis, in particular in tumor progression and/or tumor relapse, is warranted for better understanding of the treatment of neuroblastoma patients.
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| 8. |
- Muthana, Munitta, et al.
(author)
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Use of Macrophages to Target Therapeutic Adenovirus to Human Prostate Tumors
- 2011
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In: Cancer Research. - 0008-5472 .- 1538-7445. ; 71:5, s. 1805-1815
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Journal article (peer-reviewed)abstract
- New therapies are required to target hypoxic areas of tumors as these sites are highly resistant to conventional cancer therapies. Monocytes continuously extravasate from the bloodstream into tumors where they differentiate into macrophages and accumulate in hypoxic areas, thereby opening up the possibility of using these cells as vehicles to deliver gene therapy to these otherwise inaccessible sites. We describe a new cell-based method that selectively targets an oncolytic adenovirus to hypoxic areas of prostate tumors. In this approach, macrophages were cotransduced with a hypoxia-regulated E1A/B construct and an E1A-dependent oncolytic adenovirus, whose proliferation is restricted to prostate tumor cells using prostate-specific promoter elements from the TARP, PSA, and PMSA genes. When such cotransduced cells reach an area of extreme hypoxia, the E1A/B proteins are expressed, thereby activating replication of the adenovirus. The virus is subsequently released by the host macrophage and infects neighboring tumor cells. Following systemic injection into mice bearing subcutaneous or orthotopic prostate tumors, cotransduced macrophages migrated into hypoxic tumor areas, upregulated E1A protein, and released multiple copies of adenovirus. The virus then infected neighboring cells but only proliferated and was cytotoxic in prostate tumor cells, resulting in the marked inhibition of tumor growth and reduction of pulmonary metastases. This novel delivery system employs 3 levels of tumor specificity: the natural "homing" of macrophages to hypoxic tumor areas, hypoxia-induced proliferation of the therapeutic adenovirus in host macrophages, and targeted replication of oncolytic virus in prostate tumor cells.
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| 9. |
- Shete, Sanjay, et al.
(author)
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Genome-wide high-density SNP linkage search for glioma susceptibility loci : results from the gliogene consortium
- 2011
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In: Cancer Research. - 0008-5472 .- 1538-7445. ; 71:24, s. 7568-7575
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Journal article (peer-reviewed)abstract
- Gliomas, which generally have a poor prognosis, are the most common primary malignant brain tumors in adults. Recent genome-wide association studies have shown that inherited susceptibility plays a role in the development of glioma. Although first-degree relatives of patients exhibit a two-fold increased risk of glioma, the search for susceptibility loci in familial forms of the disease has been challenging because the disease is relatively rare, fatal, and heterogeneous, making it difficult to collect sufficient biosamples from families for statistical power. To address this challenge, the Genetic Epidemiology of Glioma International Consortium (Gliogene) was formed to collect DNA samples from families with two or more cases of histologically confirmed glioma. In this study, we present results obtained from 46 U.S. families in which multipoint linkage analyses were undertaken using nonparametric (model-free) methods. After removal of high linkage disequilibrium single-nucleotide polymorphism, we obtained a maximum nonparametric linkage score (NPL) of 3.39 (P = 0.0005) at 17q12-21.32 and the Z-score of 4.20 (P = 0.000007). To replicate our findings, we genotyped 29 independent U.S. families and obtained a maximum NPL score of 1.26 (P = 0.008) and the Z-score of 1.47 (P = 0.035). Accounting for the genetic heterogeneity using the ordered subset analysis approach, the combined analyses of 75 families resulted in a maximum NPL score of 3.81 (P = 0.00001). The genomic regions we have implicated in this study may offer novel insights into glioma susceptibility, focusing future work to identify genes that cause familial glioma. Cancer Res; 71(24); 7568-75. (C) 2011 AACR.
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