Platelet-derived growth factor subunit B is a protein that in humans is encoded by the PDGFB gene. [5] [6]
The protein encoded by this gene is a member of the platelet-derived growth factor family. The four members of this family are mitogenic factors for cells of mesenchymal origin and are characterized by a motif of eight cysteines. This gene product can exist either as a homodimer (PDGF-BB) or as a heterodimer with the platelet-derived growth factor alpha (PDGFA) polypeptide (PDGF-AB), where the dimers are connected by disulfide bonds.
Mutations in this gene are associated with meningioma. Reciprocal translocations between chromosomes 22 and 17, at sites where the PDGFB and COL1A1 genes are respectively located or, alternatively, an abnormal small supernumerary ring chromosome merge these two genes to form a COL1A-PDGFB fusion gene. This fusion gene greatly overproduces PDGFB and is considered responsible for causing the development and/or progression of three closely related fibroblastic and myofibroblastic tumors of the skin: giant cell fibroblastoma, dermatofibrosarcoma protuberans, and dermatofibrosarcoma protuberans, sarcomatous. [7]
Two splice variants have been identified for the PDGFB gene. [8]
Platelet-derived growth factor (PDGF) is one among numerous growth factors that regulate cell growth and division. In particular, PDGF plays a significant role in blood vessel formation, the growth of blood vessels from already-existing blood vessel tissue, mitogenesis, i.e. proliferation, of mesenchymal cells such as fibroblasts, osteoblasts, tenocytes, vascular smooth muscle cells and mesenchymal stem cells as well as chemotaxis, the directed migration, of mesenchymal cells. Platelet-derived growth factor is a dimeric glycoprotein that can be composed of two A subunits (PDGF-AA), two B subunits (PDGF-BB), or one of each (PDGF-AB).
Dermatofibrosarcoma protuberans (DFSP) is a rare locally aggressive malignant cutaneous soft-tissue sarcoma. DFSP develops in the connective tissue cells in the middle layer of the skin (dermis). Estimates of the overall occurrence of DFSP in the United States are 0.8 to 4.5 cases per million persons per year. In the United States, DFSP accounts for between 1 and 6 percent of all soft tissue sarcomas and 18 percent of all cutaneous soft tissue sarcomas. In the Surveillance, Epidemiology and End Results (SEER) tumor registry from 1992 through 2004, DFSP was second only to Kaposi sarcoma.
The nuclear receptor 4A3 (NR4A3) also known as neuron-derived orphan receptor 1 (NOR1) is a protein that in humans is encoded by the NR4A3 gene. NR4A3 is a member of the nuclear receptor family of intracellular transcription factors.
Platelet-derived growth factor receptor beta is a protein that in humans is encoded by the PDGFRB gene. Mutations in PDGFRB are mainly associated with the clonal eosinophilia class of malignancies.
Platelet-derived growth factor subunit A is a protein that in humans is encoded by the PDGFA gene.
Platelet glycoprotein Ib alpha chain also known as glycoprotein Ib (platelet), alpha polypeptide or CD42b, is a protein that in humans is encoded by the GP1BA gene.
TYMP is a gene that encodes for the enzyme thymidine phosphorylase. The TYMP gene is also known as ECGF1 and MNGIE due to its role in MNGIE syndrome.
Proto-oncogene tyrosine-protein kinase Yes is a non-receptor tyrosine kinase that in humans is encoded by the YES1 gene.
Calpastatin is a protein that in humans is encoded by the CAST gene.
Glycoprotein Ib (platelet), beta polypeptide (GP1BB) also known as CD42c, is a protein that in humans is encoded by the GP1BB gene.
Platelet-derived growth factor C, also known as PDGF-C, is a 345-amino acid protein that in humans is encoded by the PDGFC gene. Platelet-derived growth factors are important in connective tissue growth, survival and function, and consist of disulphide-linked dimers involving two polypeptide chains, PDGF-A and PDGF-B. PDGF-C is a member of the PDGF/VEGF family of growth factors with a unique two-domain structure and expression pattern. PDGF-C was not previously identified with PDGF-A and PDGF-B, possibly because it may be that it is synthesized and secreted as a latent growth factor, requiring proteolytic removal of the N-terminal CUB domain for receptor binding and activation.
Platelet-derived growth factor D is a protein that in humans is encoded by the PDGFD gene.
Giant cell fibroblastoma (GCF) is a rare type of soft-tissue tumor marked by painless nodules in the dermis and subcutaneous tissue. These tumors may come back after surgery, but they do not spread to other parts of the body. They occur mostly in boys. GCF tumor tissues consist of bland spindle-shaped or stellate-shaped cells interspersed among multinucleated giant cells.
SH2B adapter protein 3 (SH2B3), also known as lymphocyte adapter protein (LNK), is a protein that in humans is encoded by the SH2B3 gene on chromosome 12.
28 kDa heat- and acid-stable phosphoprotein is a protein that in humans is encoded by the PDAP1 gene.
PDGFRA, i.e. platelet-derived growth factor receptor A, also termed PDGFRα, i.e. platelet-derived growth factor receptor α, or CD140a i.e. Cluster of Differentiation 140a, is a receptor located on the surface of a wide range of cell types. This receptor binds to certain isoforms of platelet-derived growth factors (PDGFs) and thereby becomes active in stimulating cell signaling pathways that elicit responses such as cellular growth and differentiation. The receptor is critical for the development of certain tissues and organs during embryogenesis and for the maintenance of these tissues and organs, particularly hematologic tissues, throughout life. Mutations in the gene which codes for PDGFRA, i.e. the PDGFRA gene, are associated with an array of clinically significant neoplasms, notably ones of the clonal hypereosinophilia class of malignancies, as well as gastrointestinal stromal tumors (GISTs).
Eukaryotic translation initiation factor 3, subunit M (eIF3m) also known as PCI domain containing 1 (PCID1), is a protein that in humans is encoded by the EIF3M gene.
Lipofibromatosis (LPF) is an extremely rare soft tissue tumor which was first clearly described in 2000 by Fetsch et al as a strictly pediatric, locally invasive, and often recurrent tumor. It is nonetheless a non-metastasizing, i.e. benign, tumor. While even the more recent literature has sometimes regarded LPF as a strictly childhood disorder, rare cases of LPF has been diagnosed in adults. The diagnosis of lipofibromatosis should not be automatically discarded because of an individual's age.
Fibroblastic and myofibroblastic tumors (FMTs) develop from the mesenchymal stem cells which differentiate into fibroblasts and/or the myocytes/myoblasts that differentiate into muscle cells. FMTs are a heterogeneous group of soft tissue neoplasms. The World Health Organization (2020) defined tumors as being FMTs based on their morphology and, more importantly, newly discovered abnormalities in the expression levels of key gene products made by these tumors' neoplastic cells. Histopathologically, FMTs consist of neoplastic connective tissue cells which have differented into cells that have microscopic appearances resembling fibroblasts and/or myofibroblasts. The fibroblastic cells are characterized as spindle-shaped cells with inconspicuous nucleoli that express vimentin, an intracellular protein typically found in mesenchymal cells, and CD34, a cell surface membrane glycoprotein. Myofibroblastic cells are plumper with more abundant cytoplasm and more prominent nucleoli; they express smooth muscle marker proteins such as smooth muscle actins, desmin, and caldesmon. The World Health organization further classified FMTs into four tumor forms based on their varying levels of aggressiveness: benign, intermediate, intermediate, and malignant.
Dermatofibrosarcoma protuberans, fibrosarcomatous (DFSP-FS), also termed fibrosarcomatous dermatofibrosarcoma protuberans, is a rare type of tumor located in the dermis. DFSP-FS tumors have been viewed as: 1) a more aggressive form of the dermatofibrosarcoma protuberans (DFSP) tumors because they have areas that resemble and tend to behave like malignant fibrosarcomas or 2) as a distinctly different tumor than DFSP. DFSP-FS tumors are related to DFSP. For example, surgically removed DFSP tumors often recur with newly developed fibrobosarcoma-like areas. Nonetheless, the World Health Organization (WHO), 2020, classified DFSP and DFSP-FS as different tumors with DFSP being in the category of benign and DFSP-FS in the category of rarely metastasizing fibroblastic and myofibroblastic tumors. This article follows the WHO classification: the 5-15% of DFSP tumors that have any areas of fibrosarcomatous microscopic histopathology are here considered DFSP-FS rather than DFSP tumors.