The pituitary tumor-transforming gene (PTTG1) is a recently discovered oncogene implicated in the malignant progression of a number of neoplasms. It has been shown to drive both endocrine and non-endocrine malignancies, but has not yet been studied in the context of renal cell carcinoma (RCC). Clear cell RCC (ccRCC) is cytogenetically characterized by deletion of chromosome 3p, harboring the von-Hippel Lindau tumor suppressor gene, and amplification of chromosome 5q. The significance of copy number gain of chromosome 5 is not clear, but is presumed to be the location of oncogenes that influence ccRCC development or progression. The PTTG1 oncogene maps to chromosome 5q, and here we show that PTTG1 is amplified in clear cell RCC, is overexpressed in tumor tissue relative to adjacent normal kidney, and expression is associated with high grade, high stage, and poor prognosis. Furthermore, we establish a functional role for PTTG1 in ccRCC tumorigenesis and progression. PTTG1 ablation reduces both the tumorigenic ability of ccRCC cells in vitro and in vivo and the invasive ability of these cells in vitro. An analysis of genes whose transcription is regulated by PTTG1 was supportive of an association with invasive and metastatic disease. PTTG1-dependent expression of the Rho-GEF ECT2, another proto-oncogene, is observed in a number of ccRCC cell lines, and ECT2 expression correlates with PTTG1 expression, high stage, high grade, and poor prognosis ccRCC. As GEF's have been promoted as potential drug targets for targeted cancer therapeutics, the relationship between the PTTG1 and ECT2 oncogenes may be able to be exploited for the treatment of this disease.
Expression of the PTTG1 oncogene is associated with aggressive clear cell renal cell carcinoma.
Specimen part, Cell lineView Samples
Systematic somatic mutation screening of 4000 genes in human clear cell renal cell carcinoma. Information on corresponding somatic mutations in each sample can be found at http://www.sanger.ac.uk/genetics/CGP/Studies/.
Systematic sequencing of renal carcinoma reveals inactivation of histone modifying genes.
No sample metadata fieldsView Samples
The new official nomenclature subdivides human monocytes into three subsets, classical (CD14++CD16-), intermediate (CD14++CD16+) and nonclassical (CD14+CD16+). Here, we comprehensively define relationships and unique characteristics of the three human monocyte subsets using microarray and flow cytometry analysis. Our analysis revealed that the intermediate and nonclassical monocyte subsets were most closely related. For the intermediate subset, majority of genes and surface markers were expressed at an intermediary level between the classical and nonclassical subset. There features therefore indicate a close and direct lineage relationship between the intermediate and nonclassical subset. From gene expression profiles, we define unique characteristics for each monocyte subset. Classical monocytes were functionally versatile, due to the expression of a wide range of sensing receptors and several members of the AP-1 transcription factor family. The intermediate subset was distinguished by high expression of MHC class II associated genes. The nonclassical subset were most highly differentiated and defined by genes involved in cytoskeleton rearrangement that explains their highly motile patrolling behavior in vivo. Additionally, we identify unique surface markers, CLEC4D, IL-13RA1 for classical, GFRA2, CLEC10A for intermediate and GPR44 for nonclassical. Our study hence defines the fundamental features of monocyte subsets necessary for future research on monocyte heterogeneity.
Gene expression profiling reveals the defining features of the classical, intermediate, and nonclassical human monocyte subsets.
Specimen part, SubjectView Samples
Fusion of the EWS gene to FLI1 produces a fusion oncoprotein that drives an aberrant gene expression program responsible for the development of Ewing sarcoma. We used a homogenous proximity assay to screen for compounds that disrupt the binding of EWS-FLI1 to its cognate DNA targets. A number of DNA-binding chemotherapeutic agents were found to non-specifically disrupt protein binding to DNA. In contrast, actinomycin D was found to preferentially disrupt EWS-FLI1 binding by comparison to p53 binding to their respective cognate DNA targets in vitro. In cell-based assays, low concentrations of actinomycin preferentially blocked EWS-FLI1 binding to chromatin, and disrupted EWS-FLI1-mediated gene expression. Higher concentrations of actinomycin globally repressed transcription. These results demonstrate that actinomycin preferentially disrupts EWS-FLI1 binding to DNA at selected concentrations. Although the window between this preferential effect and global suppression is too narrow to exploit in a therapeutic manner, these results suggest that base-preferences may be exploited to find DNA-binding compounds that preferentially disrupt subclasses of transcription factors.
Differential disruption of EWS-FLI1 binding by DNA-binding agents.
Cell line, TreatmentView Samples
Gene Expression Profiling of Breast Cancer Patients with Brain Metastases Brain metastases confer the worst prognosis of breast cancer as no therapy exists that prevents or eliminates the cancer from spreading to the brain. We developed a new computational modeling method to derive specific downstream signaling pathways that reveal unknown target-disease connections and new mechanisms for specific cancer subtypes. The model enables us to reposition drugs based on available gene expression data of patients. We applied this model to repurpose known or shelved drugs for brain, lung, and bone metastases of breast cancer with the hypothesis that cancer subtypes have their own specific signaling mechanisms. To test the hypothesis, we addressed the specific CSBs for each metastasis that satisfy that (1) CSB proteins are activated by the maximal number of enriched signaling pathways specific to this metastasis, and (2) CSB proteins involve in the most differential expressed coding-genes specific to the specific breast cancer metastasis. The identified signaling networks for the three types of metastases contain 31, 15, and 18 proteins, respectively, and are used to reposition 15, 9, and 2 drug candidates for the brain, lung, and bone metastases of breast cancer. We performed in vitro and in vivo preclinical experiments as well as analysis on patient tumor specimens to evaluate the targets and repositioned drugs. Two known drugs, Sunitinib (FDA approved for renal cell carcinoma and imatinib-resistant gastrointestinal stromal tumor) and Dasatinib (FDA approved for chronic myelogenous leukemia (CML) after imatinib treatment and Philadelphia chromosome-positive acute lymphoblastic leukemia), were shown to prohibit the metastatic colonization in brain.
Novel modeling of cancer cell signaling pathways enables systematic drug repositioning for distinct breast cancer metastases.
Brain development requires a massive increase in brain lipogenesis and accretion of the essential omega-3 fatty acid docosahexaenoic acid (DHA). Brain acquisition of DHA is primarily mediated by the transporter Major Facilitator Superfamily Domain containing 2a (Mfsd2a) expressed in the endothelium of the blood-brain barrier. Mfsd2a transports DHA and other polyunsaturated fatty acids esterified to lysophosphatidylcholine (LPC-DHA). However, the function of Mfsd2a and DHA in brain development is incompletely understood. Using vascular endothelial-specific (2aECKO) and inducible vascular endothelial-specific (2aiECKO) deletion of Mfsd2a in mice, we found Mfsd2a to be uniquely required postnatally at the blood-brain barrier for normal brain growth and DHA accretion, with DHA deficiency preceding the onset of microcephaly. Gene expression profiling analysis of these DHA deficient brains indicated that Srebp-1 and Srebp-2 pathways were highly elevated.
The lysolipid transporter Mfsd2a regulates lipogenesis in the developing brain.
Specimen partView Samples
Gene regulation at the maternal-embryonic transition in the pre-implantation mouse embryo is not well understood. We knock down Ccna2 to establish proof-of-concept that antisense morpholino oligonucleotides can be used to target specific genes. We applied this strategy to study Oct4 and discovered that Oct4 is required prior to blastocyst development. Specifically, gene expression is altered as early as the 2-cell stage in Oct4-knockdown embryos.
A novel and critical role for Oct4 as a regulator of the maternal-embryonic transition.
No sample metadata fieldsView Samples