Desmoglein 1–dependent suppression of EGFR signaling promotes epidermal differentiation and morphogenesis

Dsg1 (desmoglein 1) is a member of the cadherin family of Ca2+-dependent cell adhesion molecules that is first expressed in the epidermis as keratinocytes transit out of the basal layer and becomes concentrated in the uppermost cell layers of this stratified epithelium. In this study, we show that Dsg1 is not only required for maintaining epidermal tissue integrity in the superficial layers but also supports keratinocyte differentiation and suprabasal morphogenesis. Dsg1 lacking N-terminal ectodomain residues required for adhesion remained capable of promoting keratinocyte differentiation. Moreover, this capability did not depend on cytodomain interactions with the armadillo protein plakoglobin or coexpression of its companion suprabasal cadherin, Dsc1 (desmocollin 1). Instead, Dsg1 was required for suppression of epidermal growth factor receptor–Erk1/2 (extracellular signal-regulated kinase 1/2) signaling, thereby facilitating keratinocyte progression through a terminal differentiation program. In addition to serving as a rigid anchor between adjacent cells, this study implicates desmosomal cadherins as key components of a signaling axis governing epithelial morphogenesis

Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P < 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely

Wilms' tumor growth is suppressed by antiangiogenic pigment epithelium–derived factor in a xenograft model

Background/Purpose: Pigment epithelium–derived factor (PEDF), a potent endogenous inhibitor of angiogenesis, is highly expressed in the kidney. The authors postulated that systemic administration of PEDF would decrease Wilms' tumor growth in a xenograft model, and increased renal vascularity would result in a mouse null for PEDF. Methods: Tumors were induced in athymic mice using human anaplastic Wilms' tumor cells. Purified PEDF protein or vehicle was administered for 7 days beginning 2 to 3 weeks after inoculation. Tumors were stained with anti-PEDF and anti–Factor VIII antibodies. Mitoses and microvascular density (MVD) were counted per high-power field (hpf). PEDF-null mice were generated on a SV129/C57Bl6 background. Wild-type and null kidneys were assessed for MVD. Results: Mean tumor weight in the 2-week group was 60% less than controls (P <.05). The MVD and mitotic count in treated tumors were significantly less than controls (P <.05). PEDF stained strongly in normal kidneys but was minimal to absent in Wilms' tumor. PEDF-null kidneys had increased MVD compared with wild-type (P <.05). Conclusions: PEDF is expressed strongly in normal murine kidney, and loss of its angioinhibitory activity may contribute to pathologic angiogenesis in Wilms' tumor. Systemic PEDF suppresses WT growth by targeting both the tumor cells and its associated vasculature. J Pediatr Surg 38:336-342. Copyright 2003, Elsevier Science (USA). All rights reserved

Pigment epithelium-derived factor targets endothelial and epithelial cells in Wilms\u27 tumor.

PURPOSE: Loss of pigment epithelium-derived factor (PEDF), a potent inhibitor of angiogenesis, has been linked to progression of angiogenesis-dependent diseases. We postulated that decreased levels of endogenous PEDF in the kidney creates a tumor permissive environment for Wilms\u27 tumor. METHODS: Fresh and frozen Wilms\u27 tumor (n = 28), adjacent (n = 3), and normal kidney (n = 8) were immunostained and graded. The Wilms\u27 tumor cells (SK-NEP-1), renal epithelial cells (NRK-52), and fresh tumor samples were grown in culture. Condition media were collected and analyzed by an in vitro angiogenesis assay and Western blot. The SK-NEP-1 cells were treated with PEDF and cell viability assessed. RESULTS: Wilms\u27 tumors expressed less PEDF than normal and adjacent kidney. Pigment epithelium-derived factor protein secretion was abundant in NRK-52 cells but significantly decreased in Wilms\u27 tumor. Pigment epithelium-derived factor acted as blockade to angiogenesis and it had a dose-dependent cytotoxic effect on Wilms\u27 tumor epithelial cells. CONCLUSION: Renal tubular epithelial cells are a rich source of PEDF in the normal kidney. Reduced levels of PEDF in Wilms\u27 tumor remove a critical endogenous renal barrier to angiogenesis and tumor cell survival. Therapeutic replacement of PEDF may prove to be an effective strategy to combat Wilms\u27 tumor progression

Pigment Epithelium-Derived Factor (PEDF) Inhibits Wnt/β-catenin Signaling in the LiverSummary

Background & Aims: Pigment epithelium-derived factor (PEDF) is a secretory protein that inhibits multiple tumor types. PEDF inhibits the Wnt coreceptor, low-density lipoprotein receptor-related protein 6 (LRP6), in the eye, but whether the tumor-suppressive properties of PEDF occur in organs such as the liver is unknown. Methods: Wnt-dependent regulation of PEDF was assessed in the absence and presence of the Wnt coreceptor LRP6. Whole genome expression analysis was performed on PEDF knockout (KO) and control livers (7 months). Interrogation of Wnt/β-catenin signaling was performed in whole livers and human hepatocellular carcinoma (HCC) cell lines after RNA interference of PEDF and restoration of a PEDF-derived peptide. Western diet feeding for 6 to 8 months was used to evaluate whether the absence of PEDF was permissive for HCC formation (n = 12/group). Results: PEDF levels increased in response to canonical Wnt3a in an LRP6-dependent manner but were suppressed by noncanonical Wnt5a protein in an LRP6-independent manner. Gene set enrichment analysis (GSEA) of PEDF KO livers revealed induction of pathways associated with experimental and human HCC and a transcriptional profile characterized by Wnt/β-catenin activation. Enhanced Wnt/β-catenin signaling occurred in KO livers, and PEDF delivery in vivo reduced LRP6 activation. In human HCC cells, RNA interference of PEDF led to increased levels of activated LRP6 and β-catenin, and a PEDF 34-mer peptide decreased LRP6 activation and β-catenin signaling, and reduced Wnt target genes. PEDF KO mice fed a Western diet developed sporadic well-differentiated HCC. Human HCC specimens demonstrated decreased PEDF staining compared with hepatocytes. Conclusions: PEDF is an endogenous inhibitor of Wnt/β-catenin signaling in the liver. Keywords: Extracellular Matrix, PEDF, Wnt/β-Cateni

Alternatively spliced human tissue factor promotes tumor growth and angiogenesis in a pancreatic cancer tumor model

Tissue Factor (TF) expression is observed in many types of cancer, associated with more aggressive disease, and thrombosis. Alternatively-spliced human tissue factor (asHTF) has recently been identified in which exon 5 is deleted. asHTF is soluble due to the substitution of the transmembrane and cytoplasmic domains of exon 6 with a unique COOH-terminal domain. We examine the expression and function of asHTF and full-length Tissue Factor ( FLTF) in six human pancreatic cancer cells. Further, we transfected asHTF, FLTF, and control expression vectors into a non-expressing, human pancreatic cancer line (MiaPaCa-2). We studied the procoagulant activity of asHTF and flTF and the effect on tumor growth in mice. asHTF is expressed in 5 of 6 human pancreatic cancer cell lines, but not in normal human fibroblasts, nor the MiaPaCa-2 line. flTF conferred procoagulant activity, but asHTF did not. Transfected cells were injected subcutaneously in athymic mice. Interestingly, compared with control transfection, flTF expression was associated with reduced tumor growth (mean 7 mg vs 85 mg), while asHTF-expression was associated with enhanced tumor growth (mean 389 mg vs. 85 mg). asHTF expression resulted in increased mitotic index and microvascular density. These data suggests that asHTF expression promotes tumor growth, and is associated with increased tumor cell proliferation and angiogenesis in vivo. Our results raise a new perspective on the understanding of the relationship between TF expression and cancer growth, by showing a dissociation of the procoagulant activity of flTF and the cancer-promoting activity of asHTF

Gene transfer of pigment epithelium-derived factor suppresses tumor growth and angiogenesis in a hepatoblastoma xenograft model.

Normal hepatocytes express pigment epithelium-derived factor (PEDF), an endogenous antiangiogenic factor. We hypothesized that decreased PEDF expression may be one mechanism driving hepatoblastoma growth, and in vivo gene transfer of PEDF could suppress neovascularization and limit tumor growth. PEDF functional activity was determined in vitro using endothelial cell migration assays and in vivo using a subcutaneous tumor model. HUH-6 human hepatoblastoma tumors were treated with hybrid adenoviral/adeno-associated viral expression vectors for PEDF (Hyb-PEDF, n = 4) or beta-galactosidase (Hyb-betagal, n = 4) daily for 4 d. Mitotic figures, microvascular density (MVD), PEDF, and VEGF expression were assessed. Hyb-PEDF treatment inhibited in vivo tumor growth (p \u3c 0.008) and decreased MVD (p \u3c 0.001), the number of mitotic figures (p \u3c 0.001), and VEGF expression when compared with Hyb-betagal-treated tumors. HUH-6 expression of PEDF was dramatically reduced when cultured under hypoxic conditions and also when grown in vivo, and the addition of neutralizing anti-PEDF antibody increased the already high baseline angiogenic activity of the HUH-6 cell secretions in vitro (p \u3c 0.04). PEDF is an important endogenous regulator of the liver vasculature. Augmenting intra-tumoral PEDF levels inhibits tumor growth by reducing angiogenesis and VEGF expression. Potent inhibitors of angiogenesis, such as PEDF, may be an effective alternative treatment for children with hepatoblastoma