TP73L
Encyclopedia
Tumor protein p63 also known as transformation-related protein 63 is a protein
that in humans is encoded by the TP63 gene
.
TP63 also known as the p63 gene was discovered 20 years after the discovery of the p53
tumor suppressor gene and along with p73
constitutes the p53 gene family based on their structural similarity. Despite being discovered significantly later than p53, phylogenetic analysis of p53, p63 and p73, suggest that p63 was the original member of the family from which p53 and p73 evolved.
s. p63 -/- mice have several developmental defects which include the lack of limbs and other tissues, such as teeth and mammary glands, which develop as a result of interactions between mesenchyme
and epithelium
. TP63 encodes for two main isoforms by alternative promoters (TAp63 and ΔNp63). ΔNp63 is involved in multiple functions during skin development and in adult stem/progenitor cell regulation. In contrast, TAp63 has been mostly restricted to its apoptotic function and more recently as the guardian of oocyte integrity. Recently, two new functions have been attributed to TAp63 in heart development and premature aging.
, Hay–Wells syndrome, cleft lip/palate syndrome 3 (EEC3); split-hand/foot malformation 4 (SHFM4); ankyloblepharon-ectodermal defects-cleft lip/palate; ADULT syndrome (acro-dermato-ungual-lacrimal-tooth); limb-mammary syndrome; Rap-Hodgkin syndrome (RHS); and orofacial cleft 8.
has utility for differentiating prostatic adenocarcinoma
(the most common type of prostate cancer
) and benign prostatic
tissue; normal prostatic glands stain with p63 (as they have basal cell
s), while the malignant
glands in prostatic adenocarcinoma (which lacks these cells) do not.
P63 is also helpful in distinguishing poorly differentiated squamous cell carcinoma from small cell carcinoma or adenocarcinoma. P63 should be strongly stained in poorly differentiated squamous cell, but negative in small cell or adenocarcinoma.
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
that in humans is encoded by the TP63 gene
Gene
A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...
.
TP63 also known as the p63 gene was discovered 20 years after the discovery of the p53
P53
p53 , is a tumor suppressor protein that in humans is encoded by the TP53 gene. p53 is crucial in multicellular organisms, where it regulates the cell cycle and, thus, functions as a tumor suppressor that is involved in preventing cancer...
tumor suppressor gene and along with p73
P73
p73 is a protein related to the p53 tumor protein. Because of its structural resemblance to p53, it has also been considered a tumor suppressor. It is involved in cell cycle regulation, and induction of apoptosis. Like p53, p73 is characterized by the presence of different isoforms of the protein...
constitutes the p53 gene family based on their structural similarity. Despite being discovered significantly later than p53, phylogenetic analysis of p53, p63 and p73, suggest that p63 was the original member of the family from which p53 and p73 evolved.
Function
Tumor protein p63 is a member of the p53 family of transcription factorTranscription factor
In molecular biology and genetics, a transcription factor is a protein that binds to specific DNA sequences, thereby controlling the flow of genetic information from DNA to mRNA...
s. p63 -/- mice have several developmental defects which include the lack of limbs and other tissues, such as teeth and mammary glands, which develop as a result of interactions between mesenchyme
Mesenchyme
Mesenchyme, or mesenchymal connective tissue, is a type of undifferentiated loose connective tissue that is derived mostly from mesoderm, although some are derived from other germ layers; e.g. some mesenchyme is derived from neural crest cells and thus originates from the ectoderm...
and epithelium
Epithelium
Epithelium is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. Epithelial tissues line the cavities and surfaces of structures throughout the body, and also form many glands. Functions of epithelial cells include secretion, selective...
. TP63 encodes for two main isoforms by alternative promoters (TAp63 and ΔNp63). ΔNp63 is involved in multiple functions during skin development and in adult stem/progenitor cell regulation. In contrast, TAp63 has been mostly restricted to its apoptotic function and more recently as the guardian of oocyte integrity. Recently, two new functions have been attributed to TAp63 in heart development and premature aging.
Clinical significance
Mutations in the TP63 gene are associated with ectrodactyly-ectodermal dysplasia-cleft syndromeEctrodactyly-Ectodermal Dysplasia-Cleft Syndrome
Ectrodactyly–ectodermal dysplasia–cleft syndrome, or EEC, and also referred to as EEC syndrome is a rare form of ectodermal dysplasia, an autosomal dominant disorder inherited as an genetic trait. EEC is characterized by the triad of ectrodactyly, ectodermal dysplasia, and Facial Clefts...
, Hay–Wells syndrome, cleft lip/palate syndrome 3 (EEC3); split-hand/foot malformation 4 (SHFM4); ankyloblepharon-ectodermal defects-cleft lip/palate; ADULT syndrome (acro-dermato-ungual-lacrimal-tooth); limb-mammary syndrome; Rap-Hodgkin syndrome (RHS); and orofacial cleft 8.
Diagnostic utility
p63 immunostainingImmunostaining
Immunostaining is a general term in biochemistry that applies to any use of an antibody-based method to detect a specific protein in a sample. The term immunostaining was originally used to refer to the immunohistochemical staining of tissue sections, as first described by Albert Coons in 1941...
has utility for differentiating prostatic adenocarcinoma
Adenocarcinoma
Adenocarcinoma is a cancer of an epithelium that originates in glandular tissue. Epithelial tissue includes, but is not limited to, the surface layer of skin, glands and a variety of other tissue that lines the cavities and organs of the body. Epithelium can be derived embryologically from...
(the most common type of prostate cancer
Prostate cancer
Prostate cancer is a form of cancer that develops in the prostate, a gland in the male reproductive system. Most prostate cancers are slow growing; however, there are cases of aggressive prostate cancers. The cancer cells may metastasize from the prostate to other parts of the body, particularly...
) and benign prostatic
Prostate
The prostate is a compound tubuloalveolar exocrine gland of the male reproductive system in most mammals....
tissue; normal prostatic glands stain with p63 (as they have basal cell
Cell (biology)
The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos....
s), while the malignant
Malignant
Malignancy is the tendency of a medical condition, especially tumors, to become progressively worse and to potentially result in death. Malignancy in cancers is characterized by anaplasia, invasiveness, and metastasis...
glands in prostatic adenocarcinoma (which lacks these cells) do not.
P63 is also helpful in distinguishing poorly differentiated squamous cell carcinoma from small cell carcinoma or adenocarcinoma. P63 should be strongly stained in poorly differentiated squamous cell, but negative in small cell or adenocarcinoma.
Regulation
There is some evidence that the expression of p63 is regulated by the microRNA miR-203.Further reading
- Shalom-Feuerstein R, Lena AM, Zhou H, De La Forest Divonne S, Van Bokhoven H, Candi E, Melino G, Aberdam D. ΔNp63 is an ectodermal gatekeeper of epidermal morphogenesis. Cell Death Differ. 2011 May;18(5):887-96. Link