We report the generation and analysis of functional data from multiple, diverse experiments performed on a targeted 1% of the human genome as part of the pilot phase of the ENCODE Project. These data have been further integrated and augmented by a number of evolutionary and computational analyses. Together, our results advance the collective knowledge about human genome function in several major areas. First, our studies provide convincing evidence that the genome is pervasively transcribed, such that the majority of its bases can be found in primary transcripts, including non-protein-coding transcripts, and those that extensively overlap one another. Second, systematic examination of transcriptional regulation has yielded new understanding about transcription start sites, including their relationship to specific regulatory sequences and features of chromatin accessibility and histone modification. Third, a more sophisticated view of chromatin structure has emerged, including its inter-relationship with DNA replication and transcriptional regulation. Finally, integration of these new sources of information, in particular with respect to mammalian evolution based on inter- and intra-species sequence comparisons, has yielded new mechanistic and evolutionary insights concerning the functional landscape of the human genome. Together, these studies are defining a path for pursuit of a more comprehensive characterization of human genome function.
Chronic inflammation has long been associated with increased incidence of malignancy and similarities in the regulatory mechanisms have been suggested for more than a century. Infiltration of innate immune cells, elevated activities of matrix metalloproteases and increased angiogenesis and vasculature density are a few examples of the similarities between chronic and tumour-associated inflammation. Conversely, the elimination of early malignant lesions by immune surveillance, which relies on the cytotoxic activity of tumour-infiltrating T cells or intra-epithelial lymphocytes, is thought to be rate-limiting for the risk to develop cancer. Here we show a molecular connection between the rise in tumour-associated inflammation and a lack of tumour immune surveillance. Expression of the heterodimeric cytokine interleukin (IL)-23, but not of its close relative IL-12, is increased in human tumours. Expression of these cytokines antagonistically regulates local inflammatory responses in the tumour microenvironment and infiltration of intra-epithelial lymphocytes. Whereas IL-12 promotes infiltration of cytotoxic T cells, IL-23 promotes inflammatory responses such as upregulation of the matrix metalloprotease MMP9, and increases angiogenesis but reduces CD8 T-cell infiltration. Genetic deletion or antibody-mediated elimination of IL-23 leads to increased infiltration of cytotoxic T cells into the transformed tissue, rendering a protective effect against chemically induced carcinogenesis. Finally, transplanted tumours are growth-restricted in hosts depleted for IL-23 or in IL-23-receptor-deficient mice. Although many strategies for immune therapy of cancer attempt to stimulate an immune response against solid tumours, infiltration of effector cells into the tumour tissue often appears to be a critical hurdle. We show that IL-23 is an important molecular link between tumour-promoting pro-inflammatory processes and the failure of the adaptive immune surveillance to infiltrate tumours.
Enhancing chemotherapeutic efficiency through improved drug delivery would facilitate treatment of chemoresistant cancers, such as recurrent mammary tumors and liver cancer. One way to improve drug delivery is through the use of nanodiamond (ND) therapies, which are both scalable and biocompatible. Here, we examined the efficacy of an ND-conjugated chemotherapeutic in mouse models of liver and mammary cancer. A complex (NDX) of ND and doxorubicin (Dox) overcame drug efflux and significantly increased apoptosis and tumor growth inhibition beyond conventional Dox treatment in both murine liver tumor and mammary carcinoma models. Unmodified Dox treatment represents the clinical standard for most cancer treatment regimens, and NDX had significantly decreased toxicity in vivo compared to standard Dox treatment. Thus, ND-conjugated chemotherapy represents a promising, biocompatible strategy for overcoming chemoresistance and enhancing chemotherapy efficacy and safety.
The advent of nanomedicine marks an unparalleled opportunity to advance the treatment of a variety of diseases, including cancer. The unique properties of nanoparticles, such as large surface-to volume ratio, small size, the ability to encapsulate a variety of drugs, and tunable surface chemistry, gives them many advantages over their bulk counterparts. This includes multivalent surface modification with targeting ligands, efficient navigation of the complex in vivo environment, increased intracellular trafficking, and sustained release of drug payload. These advantages make nanoparticles a mode of treatment potentially superior to conventional cancer therapies. This article highlights the most recent developments in cancer treatment using nanoparticles as drug-delivery vehicles, including promising opportunities in targeted and combination therapy.
We have identified an intergenic transcriptional activity that is located between the human HOXA1 and HOXA2 genes, shows myeloid-specific expression, and is upregulated during granulocytic differentiation. The novel gene, termed HOTAIRM1 (HOX antisense intergenic RNA myeloid 1), is transcribed antisense to the HOXA genes and originates from the same CpG island that embeds the start site of IntroductionHuman HOX gene clusters are known for the prevalence of intergenic transcription between coding genic members. 1 Similar activity has also been observed in other developmentally important or tissue-specific gene loci, such as those containing the human beta globin genes, cardiac myosin heavy chain genes, and the interleukin-4 (IL-4)/IL-13 gene cluster. [2][3][4] Extensive HOX gene cluster intergenic transcripts have been described largely as noncoding RNAs (ncRNAs), including both short microRNA (miRNA) species and long ncRNAs that are antisense to their canonical HOX neighbors. Well-defined HOX region ncRNAs include the mir-10 and mir-196 paralogs, bithoraxoid ncRNAs of the Drosophila bithorax complex, and human HOX antisense intergenic RNA (HOTAIR). [5][6][7] Intergenic regions have been proposed as locations for novel radiational and reorganizing changes that have occurred in the evolution of HOX gene clusters, which are relatively constrained in structure in the higher vertebrates. 5,8 Several recent studies have focused on expression of intergenic ncRNAs in the human HOX regions, especially the HOXA cluster, in tumor cell lines, tissues, and fibroblasts from different anatomic origins. All reported unusually active transcription within the intergenic regions, occurring in patterns coordinated with their HOX neighbors. 7,9,10 Intergenic ncRNAs in the HOXA gene cluster were usually associated with CpG islands and their expression accompanied changes in either polycomb group repressive complex binding or methylation of histones, suggesting a pattern of cis modulation of the intergenic transcripts before the activation of adjacent HOX genes. However, the HOTAIR transcript, located between HOXC11 and HOXC12, was found to function in trans to repress a distal group of homologous HOXD genes by demarcating an extended silenced domain through interaction with the polycomb group complex PRC2 histone methyltransferase 7,10,11 De novo genomic transcription mapping has revealed that intergenic ncRNA is possibly the most abundant form of transcriptional output from the genomes of humans and other higher eukaryotic organisms. 12,13 Within the human genome, the majority of intergenic ncRNA are not highly conserved at the sequence level, with long ncRNAs generally less conserved than short miRNAs. Nevertheless, their expression patterns may be conserved among tissues or along developmental axes. 14,15 More importantly, ncRNA function in gene regulation has emerged as an important mechanism in the control of many biologic processes in development and carcinogenesis. 16 In the present study, we have identified intergenic transc...
Tumor immune surveillance and cancer immunotherapies are thought to depend on the intratumoral infiltration of activated CD8(+) T cells. Intratumoral CD8(+) T cells are rare and lack activity. IL-10 is thought to contribute to the underlying immune suppressive microenvironment. Defying those expectations we demonstrate that IL-10 induces several essential mechanisms for effective antitumor immune surveillance: infiltration and activation of intratumoral tumor-specific cytotoxic CD8(+) T cells, expression of the Th1 cytokine interferon-γ (IFNγ) and granzymes in CD8(+) T cells, and intratumoral antigen presentation molecules. Consequently, tumor immune surveillance is weakened in mice deficient for IL-10 whereas transgenic overexpression of IL-10 protects mice from carcinogenesis. Treatment with pegylated IL-10 restores tumor-specific intratumoral CD8(+) T cell function and controls tumor growth.
Gene therapy holds great promise for treating diseases ranging from inherited disorders to acquired conditions and cancers. Nonetheless, because a method of gene delivery that is both effective and safe has remained elusive, these successes were limited. Functional nanodiamonds (NDs) are rapidly emerging as promising carriers for next-generation therapeutics with demonstrated potential. Here we introduce NDs as vectors for in vitro gene delivery via surface-immobilization with 800 Da polyethyleneimine (PEI800) and covalent conjugation with amine groups. We designed PEI800-modified NDs exhibiting the high transfection efficiency of high molecular weight PEI (PEI25K), but without the high cytotoxicity inherent to PEI25K. Additionally, we demonstrated that the enhanced delivery properties were exclusively mediated by the hybrid ND-PEI800 material and not exhibited by any of the materials alone. This platform approach represents an efficient avenue toward gene delivery via DNA-functionalized NDs, and serves as a rapid, scalable, and broadly applicable gene therapy strategy.
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