Purpose: Despite the frequency of abortions, one-third of medical schools in the US and Canada did not include coverage of that topic, according to a survey conducted in 2002-2005. The purpose of this project was to develop, implement, and evaluate a module for second year medical students related to the ethics of abortion.
Methods: The module was designed as Independent Learning Time (ILT).
The intricate life cycle of Trypanosoma brucei requires extensive regulation of gene expression levels of the mtRNAs for adaptation. Post-transcriptional gene regulatory programs, including unencoded mtRNA 3' tail additions, potentially play major roles in this adaptation process. Intriguingly, T.
View Article and Find Full Text PDFA rate-limiting aspect of transgenic mouse models of mammary adenocarcinoma is that primary tumor burden in mammary tissue typically defines study end-points. Thus, studies focused on elucidating mechanisms of late-stage de novo metastasis are compromised, as are studies examining efficacy of anti-cancer therapies targeting mediators of metastasis in the adjuvant setting. Numerous murine mammary cancer models have been developed via targeted expression of dominant oncoproteins to mammary epithelial cells yielding models variably mimicking histopathologic and transcriptome-defined breast cancer subtypes common in women.
View Article and Find Full Text PDFUntil now, the Food and Drug Administration (FDA)-approved iron supplement ferumoxytol and other iron oxide nanoparticles have been used for treating iron deficiency, as contrast agents for magnetic resonance imaging and as drug carriers. Here, we show an intrinsic therapeutic effect of ferumoxytol on the growth of early mammary cancers, and lung cancer metastases in liver and lungs. In vitro, adenocarcinoma cells co-incubated with ferumoxytol and macrophages showed increased caspase-3 activity.
View Article and Find Full Text PDFTrypanosoma cruzi parasites causing Chagas disease are passed between mammals by the triatomine bug vector. Within the insect, T. cruzi epimastigote-stage cells replicate and progress through the increasingly nutrient-restricted digestive tract, differentiating into infectious, nonreplicative metacyclic trypomastigotes.
View Article and Find Full Text PDFLimited transendothelial permeability across tumor microvessels represents a significant bottleneck in the development of tumor-specific diagnostic agents and theranostic drugs. Here, we show an approach to increase transendothelial permeability of macromolecular and nanoparticle-based contrast agents via inhibition of the type I TGF-β receptor, activin-like kinase 5 (Alk5), in tumors. Alk5 inhibition significantly increased tumor contrast agent delivery and enhancement on imaging studies, while healthy organs remained relatively unaffected.
View Article and Find Full Text PDFMetastasis is the most devastating aspect of cancer, however we know very little about the mechanisms of local invasion, the earliest step of metastasis. During tumor growth CD11b+ Gr1+ cells, known also as MDSCs, have been shown to promote tumor progression by a wide spectrum of effects that suppress the anti-tumor immune response. In addition to immunosuppression, CD11b+ Gr1+ cells promote metastasis by mechanisms that are currently unknown.
View Article and Find Full Text PDFBone Morphogenetic Proteins (BMPs) are secreted cytokines that are part of the Transforming Growth Factor β (TGFβ) superfamily. BMPs have been shown to be highly expressed in human breast cancers, and loss of BMP signaling in mammary carcinomas has been shown to accelerate metastases. Interestingly, other work has indicated that stimulation of dermal fibroblasts with BMP can enhance secretion of pro-tumorigenic factors.
View Article and Find Full Text PDFTGF-β receptors (TGF-βRs) inhibit growth of many cell types. Loss of TGF-βRs or its signaling components have been found in several human malignancies. The expression and the role of TGF-βRs in regulating anaplastic meningioma growth has not been studied.
View Article and Find Full Text PDFUnlabelled: Tumor microenvironment constitutes a reservoir for proteins released from tumor cells and the host, which can contribute significantly to tumor growth and invasion. This study aims to apply a method of combining in vivo microdialysis and proteomics to identify proteins in mammary tumor interstitial fluids, a major component of tumor microenvironment. In vivo microdialysis was performed in polyomavirus middle T antigen (PyVmT) transgenic mouse mammary tumors and age-matched control wild-type mammary glands.
View Article and Find Full Text PDFIn the past century, gradual but sustained advances in our understanding of the molecular mechanisms involved in the growth and invasive properties of cancer cells have led to better management of tumors. However, many tumors still escape regulation and progress to advanced disease. Until recently, there has not been an organized and sustained focus on the "normal" cells in the vicinity of tumors.
View Article and Find Full Text PDFBackground: Hedgehog (Hh) signaling from the urogenital sinus (UGS) epithelium to the surrounding mesenchyme plays a critical role in regulating ductal formation and growth during prostate development. The primary cilium, a feature of most interphase vertebrate cell types, serves as a required localization domain for Hh signaling transducing proteins.
Results: Immunostaining revealed the presence of primary cilia in mesenchymal cells of the developing prostate.
Differentiation
January 2010
Stromal-epithelial signaling is a critical regulator of normal prostate development and has been speculated to play an equally important role in the development and progression of prostate cancer. Sonic hedgehog (Shh) and bone morphogenetic proteins (BMP-4, BMP-7), expressed by the urogenital sinus epithelium and mesenchyme, exert reciprocal and coordinate effects on outgrowth of nascent prostate ducts. Over-expression of Shh in the LNCaP xenograft was shown previously to accelerate tumor growth by a paracrine mechanism.
View Article and Find Full Text PDFBidirectional signaling between the urogenital sinus epithelium and mesenchyme is an essential element of prostate development that regulates ductal morphogenesis, growth, and differentiation. Comparable interactions between the epithelium and stroma in the adult prostate appear to regulate normal growth homeostasis. Alterations in the stromal-epithelial dialogue that recapitulate features of the mesenchymal-epithelial interactions of development may play a critical role in the development of benign prostatic hyperplasia and in the progression of prostate cancer.
View Article and Find Full Text PDFMesenchymal expression of the BMP antagonist NOGGIN during prostate development plays a critical role in pre-natal ventral prostate development and opposes BMP4-mediated inhibition of cell proliferation during postnatal ductal development. Morphologic examination of newborn Noggin-/- male fetuses revealed genitourinary anomalies including cryptorchidism, incomplete separation of the hindgut from the urogenital sinus (UGS), absence of the ventral mesenchymal pad, and a complete loss of ventral prostate (VP) budding. Examination of lobe-specific marker expression in the E14 Noggin-/- UGS rescued by transplantation under the renal capsule of a male nude mouse confirmed a complete loss of VP determination.
View Article and Find Full Text PDFAlterations of the Wnt/beta-catenin signaling pathway are positively associated with the development and progression of human cancer, including carcinoma of the prostate. To determine the role of activated Wnt/beta-catenin signaling in mouse prostate carcinogenesis, we created a mouse prostate tumor model using probasin-Cre-mediated deletion of Apc. Prostate tumors induced by the deletion of Apc have elevated levels of beta-catenin protein and are highly proliferative.
View Article and Find Full Text PDFPurpose: Several recent reports highlighted the role of hedgehog signaling in prostate cancer. However, the relative contributions of autocrine and paracrine hedgehog signaling to tumor growth and progression are unclear. Efforts to model autocrine signaling for drug development have been hampered by conflicting reports of the presence or absence of autocrine signaling in established human prostate cancer cell lines.
View Article and Find Full Text PDFPurpose: Recent discoveries highlight the importance of the hedgehog signaling pathway in prostate growth regulation. We reviewed the role of hedgehog signaling in prostate development, adult prostate homeostasis and prostate cancer.
Materials And Methods: A comprehensive review of all relevant literature was done.
Background: Stromal-epithelial signaling plays an important role in prostate development and cancer progression. Study of these interactions will be facilitated by the use of suitable prostate cell lines in appropriate model systems.
Methods: We have isolated an immortalized prostate mesenchymal cell line from the mouse E16 urogenital sinus (UGS).
During fetal prostate development, Sonic hedgehog (Shh) expression by the urogenital sinus epithelium activates Gli-1 expression in the adjacent mesenchyme and promotes outgrowth of the nascent ducts. Shh signaling is down-regulated at the conclusion of prostate ductal development. However, a survey of adult human prostate tissues reveals substantial levels of Shh signaling in normal, hyperplasic, and malignant prostate tissue.
View Article and Find Full Text PDFDuring pathological bone loss, factors that are both stimulatory and inhibitory for osteoclast differentiation are over-expressed. Despite the presence of inhibitory factors, osteoclast differentiation is significantly enhanced to bring about bone loss. To examine the hypothesis that stimulatory growth factors overcome the effects of inhibitory factors, we have examined the ability of IGF-I, IGF-II, IL-6, LIF, and TNF-alpha to overcome osteoclast differentiation inhibition by GM-CSF in vitro.
View Article and Find Full Text PDFWe have examined highly purified osteoclasts that were generated in vitro from murine co-culture of marrow precursors with stromal support cells and have found evidence of activation of the MEK/ERK and AKT/NFkappaB survival pathways. Many mature marrow-derived osteoclasts survived for at least 48 h in culture whether or not they are maintained with stromal cells. Moreover, supplementing purified osteoclasts with RANKL and/or M-CSF had no impact on their survival pattern.
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