12-''O''-Tetradecanoylphorbol-13-acetate (TPA), also commonly known as tetradecanoylphorbol acetate, tetradecanoyl phorbol acetate, and phorbol 12-myristate 13-acetate (PMA) is a diester of
phorbol
Phorbol is a natural, plant-derived organic compound. It is a member of the tigliane family of diterpenes. Phorbol was first isolated in 1934 as the hydrolysis product of croton oil, which is derived from the seeds of the purging croton, '' Crot ...
. It is a potent
tumor promoter Tumor promotion is a process in carcinogenesis by which various factors permit the descendants of a single initiated cell to survive and expand in number, i.e. to resist apoptosis and to undergo clonal growth. This is a step toward tumor progre ...
often employed in biomedical research to activate the
signal transduction
Signal transduction is the process by which a chemical or physical signal is transmitted through a cell as a series of molecular events, most commonly protein phosphorylation catalyzed by protein kinases, which ultimately results in a cellular ...
enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different molecule ...
protein kinase C
In cell biology, Protein kinase C, commonly abbreviated to PKC (EC 2.7.11.13), is a family of protein kinase enzymes that are involved in controlling the function of other proteins through the phosphorylation of hydroxyl groups of serine and ...
(PKC). The effects of TPA on PKC result from its similarity to one of the natural activators of classic PKC isoforms,
diacylglycerol
A diglyceride, or diacylglycerol (DAG), is a glyceride consisting of two fatty acid chains covalently bonded to a glycerol molecule through ester linkages. Two possible forms exist, 1,2-diacylglycerols and 1,3-diacylglycerols. DAGs can act as sur ...
. TPA is a
small molecule
Within the fields of molecular biology and pharmacology, a small molecule or micromolecule is a low molecular weight (≤ 1000 daltons) organic compound that may regulate a biological process, with a size on the order of 1 nm. Many drugs are ...
drug.
In
ROS biology,
superoxide
In chemistry, a superoxide is a compound that contains the superoxide ion, which has the chemical formula . The systematic name of the anion is dioxide(1−). The reactive oxygen ion superoxide is particularly important as the product of ...
was identified as the major reactive oxygen species induced by TPA/PMA but not by
ionomycin
Ionomycin is an ionophore and an antibiotic that binds calcium ions (Ca2+) in a ratio 1:1. It is produced by the bacterium '' Streptomyces conglobatus''. It binds also other divalent cations like magnesium and cadmium, but binds Ca2+ preferably.
I ...
in mouse macrophages. Thus, TPA/PMA has been routinely used as an inducer for endogenous
superoxide
In chemistry, a superoxide is a compound that contains the superoxide ion, which has the chemical formula . The systematic name of the anion is dioxide(1−). The reactive oxygen ion superoxide is particularly important as the product of ...
production.
TPA is also being studied as a
drug
A drug is any chemical substance that causes a change in an organism's physiology or psychology when consumed. Drugs are typically distinguished from food and substances that provide nutritional support. Consumption of drugs can be via inhal ...
in the treatment of
hematologic
Hematology ( always spelled haematology in British English) is the branch of medicine concerned with the study of the cause, prognosis, treatment, and prevention of diseases related to blood. It involves treating diseases that affect the produc ...
cancer
Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal bl ...
TPA has a specific use in cancer diagnostics as a B-cell specific
mitogen
A mitogen is a small bioactive protein or peptide that induces a cell to begin cell division, or enhances the rate of division (mitosis). Mitogenesis is the induction (triggering) of mitosis, typically via a mitogen. The mechanism of action of a ...
in
cytogenetic
Cytogenetics is essentially a branch of genetics, but is also a part of cell biology/cytology (a subdivision of human anatomy), that is concerned with how the chromosomes relate to cell behaviour, particularly to their behaviour during mitosis an ...
testing. To view the chromosomes, a cytogenetic test requires dividing cells. TPA is used to stimulate division of B-cells during cytogenetic diagnosis of B-cell cancers such as
chronic lymphocytic leukemia
Chronic lymphocytic leukemia (CLL) is a type of cancer in which the bone marrow makes too many lymphocytes (a type of white blood cell). Early on, there are typically no symptoms. Later, non-painful lymph node swelling, feeling tired, fever, n ...
.
TPA is also commonly used together with
ionomycin
Ionomycin is an ionophore and an antibiotic that binds calcium ions (Ca2+) in a ratio 1:1. It is produced by the bacterium '' Streptomyces conglobatus''. It binds also other divalent cations like magnesium and cadmium, but binds Ca2+ preferably.
I ...
to stimulate T-cell activation, proliferation, and cytokine production, and is used in protocols for intracellular staining of these cytokines.
TPA induces
KSHV reactivation in PEL cell cultures via stimulation of the mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) pathway. The pathway involves the activation of the early-immediate viral protein RTA that contributes to the activation of the lytic cycle.
TPA was first found in the
croton plant, a shrub found in Southeast Asia, exposure to which provokes a
poison ivy-like rash. It underwent a phase 1
clinical trial
Clinical trials are prospective biomedical or behavioral research studies on human subject research, human participants designed to answer specific questions about biomedical or behavioral interventions, including new treatments (such as novel v ...
.
References
External links
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{{DEFAULTSORT:Tetradecanoylphorbol-13-acetate, 12-O-
Diterpenes
Carcinogens
Acetate esters
Cyclopropanes
Cyclopentenes
Phorbol esters