Publications by authors named "Haskell K"

Autoimmune diseases such as rheumatoid arthritis are caused by immune system recognition of self-proteins and subsequent production of effector T cells that recognize and attack healthy tissue. Therapies for these diseases typically utilize broad immune suppression, which can be effective, but which also come with an elevated risk of susceptibility to infection and cancer. T cell recognition of antigens is driven by binding of T cell receptors to peptides displayed on major histocompatibility complex proteins (MHCs) on the cell surface of antigen-presenting cells.

View Article and Find Full Text PDF

RNA interference (RNAi) offers the potential to treat disease at the earliest onset by selectively turning off the expression of target genes, such as intracellular oncogenes that drive cancer growth. However, the development of RNAi therapeutics as anti-cancer drugs has been limited by both a lack of efficient and target cell-specific delivery systems and the necessity to overcome numerous intracellular barriers, including serum/lysosomal instability, cell membrane impermeability, and limited endosomal escape. Here, we combine two technologies to achieve posttranscriptional gene silencing in tumor cells: Centyrins, alternative scaffold proteins binding plasma membrane receptors for targeted delivery, and small interfering RNAs (siRNAs), chemically modified for high metabolic stability and potency.

View Article and Find Full Text PDF

The frequent use of antibiotics contributes to antibiotic resistance in bacteria, resulting in an increase in infections that are difficult to treat. Livestock are commonly administered antibiotics in their feed, but there is current interest in raising animals that are only administered antibiotics during active infections. Staphylococcus aureus (SA) is a common pathogen of both humans and livestock raised for human consumption.

View Article and Find Full Text PDF

Myotonic dystrophy Type 1 (DM1) is a rare genetic disease caused by the expansion of CTG trinucleotide repeats ((CTG)exp) in the 3' untranslated region of the DMPK gene. The repeat transcripts sequester the RNA binding protein Muscleblind-like protein 1 (MBNL1) and hamper its normal function in pre-mRNA splicing. Overexpressing exogenous MBNL1 in the DM1 mouse model has been shown to rescue the splicing defects and reverse myotonia.

View Article and Find Full Text PDF

Staphylococcus aureus (SA) is a commensal bacterium and opportunistic pathogen commonly associated with humans and is capable of causing serious disease and death including sepsis, pneumonia, and meningitis. Methicillin-resistant SA (MRSA) isolates are typically resistant to many available antibiotics with the common exception of vancomycin. The presence of vancomycin resistance in some SA isolates combined with the current heavy use of vancomycin to treat MRSA infections indicates that MRSA may achieve broad resistance to vancomycin in the near future.

View Article and Find Full Text PDF

Studies have shown an increased head circumference and the absence of the head tilt reflex as possible risk factors for autism spectrum disorder, allowing for early detection at 12 months in typically developing population of infants. Our aim was to develop a screening tool to identify infants prior to 12 months at risk for autism spectrum disorder and developmental learning delay, not affected by literacy or primary parental language, and provide immediate determination of risk for autism spectrum disorder. An abrupt head circumference acceleration and the absence of head tilt reflex by 9 months were used to identify infants at risk for autism spectrum disorder.

View Article and Find Full Text PDF

Transgenic mice with Tie2- green fluorescent protein (GFP) are used as a model to study the kinetic distribution of the Cy5-siRNA delivered by lipid nanoparticles (LNP) into the liver. After the mouse is injected with the LNP, it undergoes a procedure of intra-vital multi-photon microscopy imaging over a period of two hours, during which the process for the nanoparticle to diffuse into the hepatocytes from the vasculature system is monitored. Since the images are obtained in-vivo, the quantification of Cy5 kinetics suffers from the moving field of view (FOV).

View Article and Find Full Text PDF

49, XXXXY is a rare aneuploidy and variant of Klinefelter syndrome, occurring in 1 per 80,000-100,000 live births. We present a cohort of 40 affected males, focusing on musculoskeletal problems. Subjects were participants in an annual 49er family support group meeting.

View Article and Find Full Text PDF

The PI3K-Akt pathway is dysregulated in the majority of solid tumors. Pharmacological inhibition of Akt is a promising strategy for treating tumors resistant to growth factor receptor antagonists due to mutations in PI3K or PTEN. We have developed allosteric, isozyme-specific inhibitors of Akt activity and activation, as well as ex vivo kinase assays to measure inhibition of individual Akt isozymes in tissues.

View Article and Find Full Text PDF

Exercise is a mechanism for maintenance of body weight in humans. Morbidly obese human patients have been shown to possess single nucleotide polymorphisms in the melanocortin-4 receptor (MC4R). MC4R knockout mice have been well characterized as a genetic model that possesses phenotypic metabolic disorders, including obesity, hyperphagia, hyperinsulinemia, and hyperleptinemia, similar to those observed in humans possessing dysfunctional hMC4Rs.

View Article and Find Full Text PDF

Background: Dysregulated PI3K/Akt signaling occurs commonly in breast cancers and is due to HER2 amplification, PI3K mutation or PTEN inactivation. The objective of this study was to determine the role of Akt activation in breast cancer as a function of mechanism of activation and whether inhibition of Akt signaling is a feasible approach to therapy.

Methodology/principal Findings: A selective allosteric inhibitor of Akt kinase was used to interrogate a panel of breast cancer cell lines characterized for genetic lesions that activate PI3K/Akt signaling: HER2 amplification or PI3K or PTEN mutations in order to determine the biochemical and biologic consequences of inhibition of this pathway.

View Article and Find Full Text PDF

A series of naphthyridine and naphthyridinone allosteric dual inhibitors of Akt1 and 2 have been developed. These compounds have been optimized to have potent dual activity against the activated kinase as well as the activation of Akt in cells. One molecule in particular, compound 17, has potent inhibitory activity against Akt1 and 2 in vivo in a mouse lung and efficacy in a tumor xenograft model.

View Article and Find Full Text PDF

Recent studies indicate that dysregulation of the Akt/PKB family of serine/threonine kinases is a prominent feature of many human cancers. The Akt/PKB family is composed of three members termed Akt1/PKBalpha, Akt2/PKBbeta, and Akt3/PKBgamma. It is currently not known to what extent there is functional overlap between these family members.

View Article and Find Full Text PDF

We developed a high-throughput HTRF (homogeneous time-resolved fluorescence) assay for Akt kinase activity and screened approx. 270000 compounds for their ability to inhibit the three isoforms of Akt. Two Akt inhibitors were identified that exhibited isoenzyme specificity.

View Article and Find Full Text PDF

Currently, there is no therapy for men with androgen-refractory prostate cancer that substantially extends survival. This report characterizes by in vitro and in vivo techniques a new chemotherapeutic that is composed of desacetyl-vinblastine covalently linked to a peptide that contains a peptide bond that can be hydrolyzed by prostate-specific antigen (PSA). This compound (referred to as vinblastine-conjugate) is minimally toxic to cells in culture which do not express PSA.

View Article and Find Full Text PDF

We covalently linked doxorubicin with a peptide that is hydrolyzable by prostate-specific antigen. In the presence of prostate tumor cells secreting prostate-specific antigen, the peptide moiety of this conjugate, L-377,202, was hydrolyzed, resulting in the release of leucine-doxorubicin and doxorubicin, which are both very cytotoxic to cancer cells. However, L-377,202 was much less cytotoxic than conventional doxorubicin to cells in culture that do not secrete prostate-specific antigen.

View Article and Find Full Text PDF

Electron cryomicroscopy and icosahedral reconstruction are used to obtain the three-dimensional structure of the 1250-A-diameter herpesvirus B-capsid. The centers and orientations of particles in focal pairs of 400-kV, spot-scan micrographs are determined and iteratively refined by common-lines-based local and global refinement procedures. We describe the rationale behind choosing shared-memory multiprocessor computers for executing the global refinement, which is the most computationally intensive step in the reconstruction procedure.

View Article and Find Full Text PDF

The retinoblastoma gene product, pRB, regulates cell proliferation by binding to and inhibiting the activity of key growth promoting proteins. Several cellular proteins have been shown to bind directly to pRB and the genes encoding a number of them have been isolated. The protein product of one of these genes is the transcription factor E2F.

View Article and Find Full Text PDF

Human papillomaviruses (HPVs) are the etiologic agents responsible for benign epithelial proliferative disorders including genital warts and are a contributory factor in the pathogenesis of cervical cancer. HPVs demonstrate strict species and cell-type specificity, which is manifested by the inability of these viruses to induce disease in any species other than humans. The natural history of HPV infection in humans is closely mimicked by cottontail rabbit papillomavirus (CRPV) infection in domestic laboratory rabbits.

View Article and Find Full Text PDF

Binding of the human papillomavirus type 16 (HPV-16) E7 oncoprotein to the retinoblastoma protein (pRb) is thought to be involved in the cellular transformation mediated by HPV-16. Here we show that the E7 protein of the cottontail rabbit papillomavirus (CRPV) binds to the same C-terminal portion of human pRb as HPV-16 E7, and that both the CRPV and HPV-16 E7 proteins bind specifically through similar domains to rabbit pRb. Furthermore, a single amino acid substitution which reduces the binding of HPV-16 E7 to human pRb also abolishes binding of CRPV E7 to both human and rabbit pRb.

View Article and Find Full Text PDF

The E7 transforming protein of human papilloma virus-16 binds to the retinoblastoma gene product (pRb) through a nine-amino-acid segment of E7 (21-29). This segment of E7 is homologous to the pRb-binding domains of the simian virus 40 large T and adenovirus E1A transforming proteins. Each of these viral transforming proteins bind to the same region of pRb.

View Article and Find Full Text PDF

A variety of signal transduction pathways contribute to the regulation of transcription in mammalian cells. Several of these pathways ultimately rely upon the interaction of transcription factors with genetic sequences termed response elements in the promoter regions of some genes. The biochemical mechanisms that control the levels and state of activation of transcription factors are poorly understood.

View Article and Find Full Text PDF

To evaluate ras-mediated signal transduction, an alkaline phosphatase gene (SEAP) was placed under the control of the ras-inducible phorbol ester response element (TRE) in murine fibroblasts (TRE-SEAP cells). The Kirsten ras gene was placed under the control of the glucocorticoid-inducible mouse mammary tumor virus promoter and introduced into the TRE-SEAP cells. Dexamethasone increased ras expression in the TRE-SEAP cells carrying the Kirsten ras gene and stimulated SEAP activity 25-fold.

View Article and Find Full Text PDF

The beta 2-adrenergic receptor from mouse 3T3-L1 cells is up-regulated through genetic mechanisms by glucocorticoids and butyrate. To study the genetic regulation of these receptors, we sequenced a 5 kb region of genomic DNA from 3T3-L1 cells, containing the beta-adrenergic receptor gene and approx. 1.

View Article and Find Full Text PDF