CD Markers
CD9
Copyright: 2002-2024, PathologyOutlines.com, Inc.
PubMed Search: CD9[title]
CD9
Author: Nat Pernick, M.D.
Last author update: 1 August 2013
Last staff update: 15 March 2022
Copyright: 2002-2024, PathologyOutlines.com, Inc.
PubMed Search: CD9[title]
Table of Contents
Definition / general | Pathophysiology | Clinical features | Diagrams / tables | Uses by pathologists | Microscopic (histologic) images | Positive staining - normal | Positive staining - disease | Negative stainingCite this page: Pernick N. CD9. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/cdmarkerscd9.html. Accessed December 18th, 2024.
Definition / general
- Cell surface protein that mediates adhesion, migration, signal transduction
- Also called tetraspanin CD9, motility related protein 1 (MRP1) [note: MRP is multidrug resistance associated protein]
- Antibodies are used to purge bone marrow in acute lymphoblastic leukemia prior to peripheral stem cell bone marrow transplant (Am J Pediatr Hematol Oncol 1993;15:162)
Pathophysiology
- Member of transmembrane 4 superfamily (tetraspanin family); tetraspanins have 4 hydrophobic domains, organize multimolecular complexes in plasma membrane; each tetraspanin associates specifically with integrins and other tetraspanins, forming primary complexes and leading to molecular network of interactions, the "tetraspanin web"
- Regulates cell motility, development, activation, growth and adhesion (Blood 2011;117:1840), differentiation (OMIM #143030), fertilization (oocyte CD9 is required for sperm-egg fusion)
- Regulates paranodal junction formation (between neurons and glia)
- Required for microparticle release from coated-platelets (Platelets 2009;20:361); triggers platelet activation and aggregation
- Supports myotube maintenance and promotes muscle cell fusion
- Downregulation in ovarian carcinoma may promote tumor dissemination (Cancer Res 2005;65:2617)
- May suppress metastasis in small cell lung cancer by promoting apoptosis via calretinin expression (Cancer Res 2010;70:8025, FEBS Open Bio 2013;3:225)
- May mediate invasion by upregulating MMP9 (PLoS One 2013;8:e67766)
Clinical features
- Favorable prognostic marker for gallbladder carcinoma (World J Surg Oncol 2012;10:92), gastric GIST (Cancer Sci 2011;102:883), malignant mesothelioma (Oncol Rep 2013;29:21), oral squamous cell carcinoma (Oral Oncol 2010;46:166)
- Poor prognosis factor in gastric carcinoma (Pathol Res Pract 2010;206:607)
Diagrams / tables
Images hosted on other servers:
Structure
Uses by pathologists
- No significant clinical use by pathologists
Microscopic (histologic) images
Images hosted on other servers:
Normal tissue:
Cerebrum
Cervical squamous epithelium (fig A)
Various tumors:
Cervical carcinoma
CNS nonneuroepithelial tumors
Gallbladder: well differentiated adenocarcinoma
Mesothelioma
Skin: basal and
squamous cell
carcinoma and
actinic keratosis
Small cell lung cancer
Positive staining - normal
- Pre B cells, B cell subset, activated T cells, basophils, eosinophils (Am J Respir Cell Mol Biol 2012;46:188), macrophages, megakaryocytes, plasma cells, plasma cell precursors in germinal centers (Biochem Biophys Res Commun 2013;431:41), platelets
- Brain, cardiac muscle, GI system, kidney (glomeruli, tubules and collective ducts), liver, lymphatic epithelium, ovarian surface epithelium, peripheral nerve, skin, spleen, thyroid, tonsil
Positive staining - disease
- Pre-B ALL, acute promyelocytic leukemia, astrocytoma (J Histochem Cytochem 2002;50:1195), mast cell disease
- Vascular tumors: angiosarcoma, juvenile nasopharyngeal angiofibroma, Kaposi sarcoma (Mod Pathol 2003;16:1028)
Negative staining
- Red blood cells, renal collecting duct carcinomas (almost all)
