Cancer is a complex process in which the abnormalities of many genes appear to be involved. The combinatorial patterns of gene mutations may reveal the functional relations between genes and pathways in tumorigenesis as well as identify targets for treatment. We examined the patterns of somatic mutations of cancers from Catalog of Somatic Mutations in Cancer (COSMIC), a large-scale database curated by the Wellcome Trust Sanger Institute.
View Article and Find Full Text PDFThe F box protein Skp2 is oncogenic, and its frequent amplification and overexpression correlate with the grade of malignancy of certain tumors. Conversely, depletion of Skp2 decreases cell growth and increases apoptosis. Here, we show that Skp2 counteracts the transactivation function of p53 and suppresses apoptosis mediated by DNA damage or p53 stabilization.
View Article and Find Full Text PDFBackground: Although increased capsular volume has been implicated in shoulder instability, there is a paucity of clinical evidence to quantify the size of the capsule with specific instability conditions of the shoulder.
Hypothesis: Shoulder capsular area, as measured by magnetic resonance arthrography, is increased with specific patterns of shoulder instability.
Study Design: Cross-sectional study; Level of evidence, 4.
Background: Among gynecologic cancers, ovarian cancer is the second most common and has the highest death rate. Cancer is a genetic disorder and arises due to the accumulation of somatic mutations in critical genes. An understanding of the genetic basis of ovarian cancer has implications both for early detection and for therapeutic intervention in this population of patients.
View Article and Find Full Text PDFCardio-facio-cutaneous (CFC) syndrome is a sporadic developmental disorder characterized by distinctive craniofacial features, heart defects, mental retardation and ectodermal abnormalities. We recently reported missense germline mutations in the genes MEK1 and MEK2 in patients with CFC. These mutations, including F53S and Y130C MEK1, and F57C MEK2, are the first naturally occurring mutations to be identified in these genes.
View Article and Find Full Text PDFThe eradication of brain tumor stem cells is essential for long-term brain tumor remission after treatment. In this study, we examined the therapeutic potential of an oncolytic adenovirus, Delta-24-RGD, targeted to the abnormal p16INK4/Rb pathway in brain tumor stem cells. Four brain tumor stem cell lines from surgical glioblastoma specimens expressed high levels of adenoviral receptors and allowed for efficient viral infection, replication, and oncolysis in an Rb-dependent manner.
View Article and Find Full Text PDFDuring the late stages of adenovirus infection, the 100K protein (100K) inhibits the translation of cellular messages in the cytoplasm and regulates hexon trimerization and assembly in the nucleus. However, it is not known how it switches between these two functions. Here we show that 100K is methylated on arginine residues at its C terminus during infection and that this region is necessary for binding PRMT1 methylase.
View Article and Find Full Text PDFJ Mol Med (Berl)
November 2007
Dishevelled is a key component of the Wnt signaling and planar polarity pathways. We discovered that in selective cell types, it potently activates the transcriptional activity of the tumor suppressor p53. This action, however, is not dependent on the downstream of either the Wnt or the planar polarity pathways.
View Article and Find Full Text PDFThe purpose of this study was to evaluate the use of adipose-derived stem cells (ADSCs) as a source for full-thickness cartilage repair in an animal model. Autologous ADSCs were isolated and induced with growth medium and placed in a fibrin glue scaffold and into 3-mm x 4-mm full-thickness chondral defects in rabbits with negative controls. Specimens were evaluated for early healing using immunostaining, Western blotting, reverse transcriptase polymerase chain reaction, transfection with the Lac Z gene, and quantitative assessment.
View Article and Find Full Text PDFCyclin D1 regulates G1 progression. Its transcriptional regulation is well understood. However, the mechanism underlying cyclin D1 ubiquitination and its subsequent degradation is not yet clear.
View Article and Find Full Text PDFStudy Design: A case of subacute odontoid fracture in a patient with osteopetrosis treated with posterior cervical arthrodesis using transarticular screws and interspinous wiring.
Objectives: To report the first successful cervical arthrodesis in a patient with osteopetrosis and to highlight the potential perioperative pitfalls in this rare surgical population.
Summary Of Background Data: Osteopetrosis is a group of skeletal dysplasias characterized by osteoclast dysfunction, impaired bone resorption, and poor bone remodeling.
Recent studies suggest that thousands of genes may contribute to breast cancer pathophysiologies when deregulated by genomic or epigenomic events. Here, we describe a model "system" to appraise the functional contributions of these genes to breast cancer subsets. In general, the recurrent genomic and transcriptional characteristics of 51 breast cancer cell lines mirror those of 145 primary breast tumors, although some significant differences are documented.
View Article and Find Full Text PDFp97 (also referred to as DAP5, NAT1 or eIF4G2) has been proposed to act as a repressor of protein synthesis. However, we found that p97 is abundantly expressed in proliferating cells and p97 is recruited to ribosomes following growth factor stimulation. We also report that p97 binds eIF2beta through its C-terminal domain and localizes to ribosome through its N-terminal MIF4G domain.
View Article and Find Full Text PDFThe treatment for malignant gliomas is suboptimal. Oncolytic adenoviruses hold the promise of being effective agents for the treatment of solid tumors. Importantly, the first oncolytic viral therapy has just been approved for use in combination with chemotherapy for late-stage refractory nasopharyngeal cancer by the Chinese State FDA, following a successful Phase III randomized clinical trial.
View Article and Find Full Text PDFRas family GTPases (RFGs), when in their active GTP-bound state, interact with a wide array of downstream effectors to regulate many biological functions in different cell types. How signal specificity among the closely related family members is achieved is still poorly understood. There is both promiscuity and specificity in the ability of RFGs to interact with and regulate the various effector families, as well as isoforms within those families.
View Article and Find Full Text PDFRas family GTPases (RFGs) are known to share many regulatory and effector proteins. How signaling and biological specificity is achieved is poorly understood. Using a proteomics approach, we have identified a complex comprised of Shoc2/Sur-8 and the catalytic subunit of protein phosphatase 1 (PP1c) as a highly specific M-Ras effector.
View Article and Find Full Text PDFH-Ras, N-Ras, and K-Ras proteins have distinct biological properties, despite ubiquitous expression and similar affinities for regulators and effectors. C-terminal hypervariable regions that distinguish H-Ras, N-Ras, and K-Ras proteins direct them to distinct membrane compartments, where they may encounter regulators and effectors at different local concentrations. Jura and coworkers now report that these membrane-targeting domains direct differential ubiquitination of Ras proteins and so provide a molecular mechanism to explain the sorting process and, perhaps, some of the dramatic differences in biological potency among H-Ras, N-Ras, and K-Ras proteins.
View Article and Find Full Text PDFWnt-1 was first identified as a proto-oncogene activated in mouse mammary tumors induced by mouse mammary tumor virus in 1982. Wnt-1 signal is a secreted glycoprotein that plays important roles in embryonic development and carcinogenesis. In a conditional Wnt-1 transgenic mouse tumor model, reduction of Wnt-1 signaling results in the regression of the Wnt-1 initiated primary mammary tumors and lung metastasis.
View Article and Find Full Text PDFCardio-facio-cutaneous (CFC) syndrome is a sporadic developmental disorder involving characteristic craniofacial features, cardiac defects, ectodermal abnormalities, and developmental delay. We demonstrate that heterogeneous de novo missense mutations in three genes within the mitogen-activated protein kinase (MAPK) pathway cause CFC syndrome. The majority of cases (18 out of 23) are caused by mutations in BRAF, a gene frequently mutated in cancer.
View Article and Find Full Text PDFPurpose: In this study, we sought to determine whether Delta-24 could sensitize glioma cells to the topoisomerase I inhibitor irinotecan (CPT-11) and to identify the mechanisms underlying this enhanced anticancer effect.
Experimental Design: We used human glioblastoma cell lines for the in vitro studies. The expression of topoisomerase I was determined in Western blot analyses, and topoisomerase I activity was determined by measuring the relaxation of a supercoiled DNA.
The phosphatidylinositol 3'-kinase (PI3K) pathway is activated in many human cancers. In addition to inactivation of the PTEN tumor suppressor gene, mutations or amplifications of the catalytic subunit alpha of PI3K (PIK3CA) have been reported. However, the coexistence of mutations in these two genes seems exceedingly rare.
View Article and Find Full Text PDFViruses have been engineered to replicate selectively in cancer cells, based on a number of innovative principles. Several of these viruses have entered clinical trials and have proven relatively safe, and have shown evidence of efficacy. However, further research is required to enable these agents to function systemically.
View Article and Find Full Text PDFThe EphA2 receptor tyrosine kinase is frequently overexpressed in many cancers, including 40% of breast cancers. Here, we show that EphA2 is a direct transcriptional target of the Ras-Raf-MAPK pathway and that ligand-stimulated EphA2 attenuates the growth factor-induced activation of Ras. Thus, a negative feedback loop is created that regulates Ras activity.
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