Joyce Schroeder

Intravenous infusion studies in humans suggest that both von Willebrand factor (VWF) and factor VIII (FVIII) remain intravascular in contrast to other coagulation proteins. We explored whether infusion of VWF and FVIII by either intraperitoneal (i.p.) or subcutaneous (s.c.) injection would result in efficient absorption of these large proteins into the vascular circulation. FVIII(null) or VWF(null) mice were infused with plasma-derived or recombinant VWF and/or FVIII by i.p., s.c., or intravenous (i.v.) injection. Both VWF and FVIII were absorbed into the blood circulation after i.p. injection with a peak between 2 and 4 h at levels similar to those observed in mice infused intravenously. In contrast, neither VWF nor FVIII was detected in the plasma following s.c. injection. Although i.v. injection achieved peak plasma levels quickly, both human VWF and FVIII rapidly decreased during the first 2 h following i.v. injection. Following both i.v. and i.p. infusion of VWF, the multimeric structure of circulating VWF was similar to that observed in the infusate. These results demonstrate that both VWF and FVIII can be efficiently absorbed into the blood circulation following i.p., but not s.c. injection, indicating that i.p. administration could be an alternative route for VWF or FVIII infusion.<br><br>

Analgesic tolerance is partially mediated by enhanced glutamatergic transmission in the CNS. β-lactam antibiotics, through glutamate transporter subtype 1 (GLT-1) activation, reduce extracellular glutamate levels and attenuate tolerance to morphine analgesia in rats. Similar to opioids, nicotine has potent analgesic properties that are subject to tolerance. The purpose of this study was to evaluate the effects of ceftriaxone, a β-lactam antibiotic and GLT-1 activator on nicotine antinociception and its tolerance. Rats were pretreated for 5 days with ceftriaxone (200 mg/kg, intraperitoneally) before evaluating their analgesic response to nicotine (1.0 or 2.5 mg/kg, subcutaneously) for seven consecutive days using the tail-flick assay. Ceftriaxone-treated rats displayed an enhanced antinociceptive response to nicotine and unlike saline-injected controls, did not develop tolerance to nicotine's analgesic effects. These results suggest that GLT-1 transporter activation enhances and preserves nicotine antinociception and identify β-lactam antibiotics as potential complementary therapeutic agents for the treatment of chronic pain.<br><br>

Bernard-Soulier syndrome (BSS) is an inherited bleeding disorder caused by a defect in the platelet glycoprotein (GP) Ib-IX-V complex. The main treatment for BSS is platelet transfusion but it is often limited to severe bleeding episodes or surgical interventions due to the risk of alloimmunization. We have previously reported successful expression of human GPIbα (hGPIbα) in human megakaryocytes using a lentiviral vector (LV) encoding human GP1BA under control of the platelet-specific integrin αIIb promoter (2bIbα). In this study, we examined the efficacy of this strategy for the gene therapy of BSS using GPIbα(null) as a murine model of BSS. GPIbα(null) hematopoietic stem cells (HSC) transduced with 2bIbα LV were transplanted into lethally irradiated GPIbα(null) littermates. Therapeutic levels of hGPIbα expression were achieved that corrected the tail bleeding time and improved the macrothrombocytopenia. Sequential bone marrow (BM) transplants showed sustained expression of hGPIbα with similar phenotypic correction. Antibody response to hGPIbα was documented in 1 of 17 total recipient mice but was tolerated without any further treatment. These results demonstrate that lentivirus-mediated gene transfer can provide sustained phenotypic correction of murine BSS, indicating that this approach may be a promising strategy for gene therapy of BSS patients.<br><br>

CD44 has been the subject of extensive research for more than 3 decades because of its role in breast cancer, in addition to many physiological processes, but interestingly, conflicting data implicate CD44 in both tumor suppression and tumor promotion. CD44 has been shown to promote protumorigenic signaling and advance the metastatic cascade. On the other hand, CD44 has been shown to suppress growth and metastasis. Histopathological studies of human breast cancer have correlated CD44 expression with both favorable and unfavorable clinical outcomes. In recent years, CD44 has garnered significant attention because of its utility as a stem cell marker and has surfaced as a potential therapeutic target, necessitating a greater understanding of CD44 in breast cancer. In this review, we attempt to unify the literature implicating CD44 in both tumor promotion and suppression, and explain its dualistic nature.<br><br>

Dynamic states of cancer cells moving under shear flow in an antibody-functionalized microchannel are investigated experimentally and theoretically. The cell motion is analyzed with the aid of a simplified physical model featuring a receptor-coated rigid sphere moving above a solid surface with immobilized ligands. The motion of the sphere is described by the Langevin equation accounting for the hydrodynamic loadings, gravitational force, receptor-ligand bindings, and thermal fluctuations; the receptor-ligand bonds are modeled as linear springs. Depending on the applied shear flow rate, three dynamic states of cell motion have been identified: (i) free motion, (ii) rolling adhesion, and (iii) firm adhesion. Of particular interest is the fraction of captured circulating tumor cells, defined as the capture ratio, via specific receptor-ligand bonds. The cell capture ratio decreases with increasing shear flow rate with a characteristic rate. Based on both experimental and theoretical results, the characteristic flow rate increases monotonically with increasing either cell-receptor or surface-ligand density within certain ranges. Utilizing it as a scaling parameter, flow-rate dependent capture ratios for various cell-surface combinations collapse onto a single curve described by an exponential formula.<br><br>

A unique flow field pattern in a bio-functional microchannel is utilized to significantly enhance the performance of a microsystem developed for selectively isolating circulating tumor cells from cell suspensions. For high performance of such systems, disposal of maximum non-target species is just as important as retention of maximum target species; unfortunately, most studies ignore or fail to report this aspect. Therefore, sensitivity and specificity are introduced as quantitative criteria to evaluate the system performance enabling a direct comparison among systems employing different techniques. The newly proposed fluidic scheme combines a slow flow field, for maximum target-cell attachment, followed by a faster flow field, for maximum detachment of non-target cells. Suspensions of homogeneous or binary mixtures of circulating breast tumor cells, with varying relative concentrations, were driven through antibody-functionalized microchannels. Either EpCAM or cadherin-11 transmembrane receptors were targeted to selectively capture target cells from the suspensions. Cadherin-11-expressing MDA-MB-231 cancer cells were used as target cells, while BT-20 cells were used as non-target cells as they do not express cadherin-11. The attachment and detachment of these two cell lines are characterized, and a two-step attachment/detachment flow field pattern is implemented to enhance the system performance in capturing target cells from binary mixtures. While the system sensitivity remains high, above 0.95, the specificity increases from about 0.85 to 0.95 solely due to the second detachment step even for a 1 : 1000 relative concentration of the target cells.<br><br>

Conjugated linoleic acid (CLA) is a class of commercially available fatty acids that have been associated with anticancer properties in rodent models of chemical carcinogenesis. We conducted a pilot study to examine the antitumor effect of dietary CLA in a polyoma virus-middle T antigen (PyMT) mouse model of invasive breast cancer. Virgin 4-week-old PyMT mice were administered a mixed-isomer CLA diet (1% wt/wt) or control AIN-93G diet for 4 weeks (N = 6 and 5, respectively) and tumor burden was assessed at 8 weeks of age. Thoracic mammary glands were prepared as whole mounts with other glands being formalin fixed and paraffin embedded for histology and immunohistochemistry (IHC). Total RNA was prepared for microarray and real-time reverse transcription-polymerase chain reaction analysis. Western blots were performed for protein expression analysis. Tumor incidence was significantly increased in CLA-treated animals compared with controls (P = 0.009) and occurred with extensive lobular-alveolar expansion and loss of mammary adipose tissue. More than 100 genes were downregulated > or = 2-fold in the CLA-treated group compared with controls, including adipose-specific markers, as wells as cytoskeletal and adhesion-related genes. This was supported by dramatic decreases in the epithelial adherens E-cadherin and beta-catenin as demonstrated by IHC. Taken together, these results suggest that dietary CLA affects the mammary stromal environment, leading to tumor progression and cellular expansion in the PyMT mouse model. Further studies of the potential for cancer promotion are needed, especially because mixed-isomer CLA formulations are sold commercially as a nutritional supplement.<br><br>

This study examines whether differing types of victimization and coping strategies influence the type of social reactions experienced by 173 current victims of intimate partner violence (IPV). Results of path analyses showed that psychological and sexual IPV victimization were related to positive social reactions, whereas physical, psychological, and sexual IPV victimization were related to negative social reactions. Indirect relationships between victimization and social reactions differed by types of coping strategies (social support, problem solving, and avoidance) examined. Implications are discussed regarding the development of interventions with women's support networks and the augmentation of services to help victims modify their coping strategies.<br><br>

Alteration of protein trafficking and localization is associated with several diseases, including cystic fibrosis, breast cancer, colorectal cancer, leukemia and diabetes. Specifically, aberrant nuclear localization of the epidermal growth factor receptor (EGFR), a receptor tyrosine kinase, is a poor prognostic indicator in several epithelial carcinomas. It is now appreciated that in addition to signaling from the plasma membrane, EGFR also trafficks to the nucleus, and can directly bind the promoter regions of genes encoding cyclin D1 (CCND1) and B-Myb (MYBL2). We have previously established that loss of MUC1 in an EGFR-dependent transgenic mouse model of breast cancer correlates with the loss of cyclin D1 expression. Here, we provide evidence for a novel regulatory function of MUC1 in the trafficking and nuclear activity of EGFR. We found that MUC1 and EGFR interact in the nucleus of breast cancer cells, which promotes the accumulation of chromatin-bound EGFR. Additionally, the presence of MUC1 results in significant colocalization of EGFR and phosphorylated RNA polymerase II, indicating that MUC1 influences the association of EGFR with transcriptionally active promoter regions. Importantly, we found that the loss of MUC1 expression resulted in a decrease in the interaction between EGFR and the CCND1 promoter, which translated to a significant decrease in cyclin D1 protein expression. This data offers insights into a novel regulatory mechanism of EGFR nuclear function and could have important implications for evaluating nuclear localization in cancer.<br><br>

Cell penetrating peptides (CPPs) are 9-35mer cationic and/or amphipathic peptides that are rapidly internalized across cell membranes. Importantly, they can be linked to a variety of cargo, including anti-cancer therapeutics, making CPPs an efficient, effective and non-toxic mechanism for drug delivery. In this review, we discuss a number of CPP conjugated therapies (CTTs) that are either patented are in the progress of patenting, and show strong promise for clinical efficacy. The CTTs discussed here target a number of different processes specific to cancer progression, including proliferation, survival and migration. In addition, many of these CTTs also increase sensitivity to current anti-cancer therapy modalities, including radiation and other DNA damaging chemotherapies, thereby decreasing the toxic dosage required for effective treatment. Mechanistically, these CTTs function in a dominant-negative manner by blocking tumor-specific protein-protein interactions with the CPP-conjugated peptide or protein. The treatment of both cell lines and mouse models demonstrates that this method of molecular targeting results in equal if not greater efficacy than current standards of care, including DNA damaging agents and topoisomerase inhibitors. For the treatment of invasive carcinoma, these CTTs have significant clinical potential to deliver highly targeted therapies without sacrificing the patient's quality of life.<br><br>

EGFR, a critical regulator of oncogenic signaling during cancer progression, is capable of integrating multireceptor signaling pathways that promote metastasis. EGFR is subject to regulatory cues from the extracellular matrix (ECM), of which hyaluronan (HA) is a major component. In mammary tumors, HA is deposited in the ECM where it functions in biomechanical support and modulates intracellular signaling. We utilized a 3D collagen system in which HA is either polymerized in collagen matrix or provided soluble in the media (sHA). Here we report that collagen-embedded HA (eHA) inhibits EGFR activation, filopodia formation and cell spreading on a collagen matrix. These findings demonstrate a novel role for eHA as a protective molecule when encountered in the collagen matrix during cancer progression.<br><br>

Background. Encapsulating peritoneal sclerosis (EPS) is a severe complication of long-term peritoneal dialysis (PD) characterized by the development of an extensive fibrosis of the visceral peritoneum that may eventually lead to intestinal constriction. Its cause remains elusive. Nephrogenic systemic fibrosis (NSF), a disabling disease that can follow gadolinium-based contrast injection during magnetic resonance imaging, is characterized by systemic fibrosis of the skin, joints, liver, heart and vessels. Affected tissues are infiltrated by CD34+ and CD68+ fibroblasts. In the present study, we tested the hypothesis that EPS could have been triggered by a previous gadolinium injection. Methods. We performed histopathological analysis of the peritoneal membrane of two EPS and two control patients all exposed to long-term PD, including immunostaining with CD34 and CD68. The presence of gadolinium and other metals was also assessed by conventional and energy-filtered transmission electron microscopy. RESULTS: Numerous CD34+ and CD68+ cells were found in both the EPS and control patients within the vascular endothelium and in macrophages, respectively, but not in interstitial fibrocytes, as it could be expected in NSF. No trace of gadolinium deposits could be found in the four peritoneal samples; dispersed tiny iron inclusions were evidenced in the connective tissue of both EPS patients. CONCLUSIONS: These findings argue against the implication of gadolinium in the development of EPS in long-term PD patients.<br><br>