CD34

CD34 molecule
Identifiers
Symbol(s)	CD34;
External IDs	OMIM: 142230 MGI: 88329 Homologene: 1343
Gene Ontology Molecular Function: • protein binding • carbohydrate binding Cellular Component: • external side of plasma membrane • membrane • integral to membrane Biological Process: • cell adhesion • cell-cell adhesion • leukocyte migration
RNA expression pattern
Additional recommended knowledge Essential Laboratory Skills Guide Weighing the right way Daily Visual Balance Check More reference expression data
Orthologs
	Human	Mouse
Entrez	947	12490
Ensembl	ENSG00000174059	ENSMUSG00000016494
Uniprot	P28906	Q3TJP6
Refseq	NM_001025109 (mRNA) NP_001020280 (protein)	NM_133654 (mRNA) NP_598415 (protein)
Location	Chr 1: 206.12 - 206.15 Mb	Chr 1: 196.64 - 196.66 Mb
Pubmed search	[1]	[2]

CD34 molecule, also known as CD34, is a human gene.^[1]

CD34 is a cluster of differentiation molecule present on certain cells within the human body. It is a cell surface glycoprotein and functions as a cell-cell adhesion factor. It may also mediate the attachment of stem cells to bone marrow extracellular matrix or directly to stromal cells.

Cells expressing CD34 (CD34+ cell) are normally found in the umbilical cord and bone marrow as hematopoeitic cells, endothelial progenitor cells, endothelial cells of blood vessels but not lymphatics (except pleural lymphatics), mast cells, a sub-population dendritic cells (which are factor XIIIa negative) in the interstitium and around the adnexa of dermis of skin, as well as cells in soft tissue tomors like DFSP, GIST, PNSTs etc.

Clinical applications

CD34+ cells may be isolated from blood samples using immunomagnetic or immunofluorescent methods.

Antibodies are used to quantify and purify hematopoietic progenitor stem cells for research and for clinical bone marrow transplantation. However, counting CD34+ mononuclear cells may overestimate myeloid blasts in bone marrow smears due to hematogones and CD34+ megakaryocytes.

Cells observed as CD34+ and CD38- are of an undifferentiated, primitive form; i.e. they are pluripotential hemopoietic stem cells.

In tumors, CD34 is found in alveolar soft part sarcoma, preB-ALL (positive in 75%), AML (40%), AML-M7 (most), dermatofibrosarcoma protuberans, gastrointestinal stromal tumors, giant cell fibroblastoma, granulocytic sarcoma, Kaposi’s sarcoma, liposarcoma, malignant fibrous histiocytoma, malignant peripheral nerve sheath tumors, mengingeal hemangiopericytomas, meningiomas, neurofibromas, schwannomas, and papillary thyroid carcinoma.

A negative CD34 may exclude Ewing's sarcoma/PNET, myofibrosarcoma of the breast, and inflammatory myofibroblastic tumors of the stomach.

References

Further reading