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. It is a potent tumor promoter often employed in biomedical research to activate the signal transductionenzymeprotein kinase C (PKC).[1][2][3] The effects of TPA on PKC result from its similarity to one of the natural activators of classic PKC isoforms, diacylglycerol. TPA is a small molecule drug.
In ROS biology, superoxide was identified as the major reactive oxygen species induced by TPA/PMA but not by ionomycin in mouse macrophages.[4] Thus, TPA/PMA has been routinely used as an inducer for endogenous superoxide production.[5]
TPA has a specific use in cancer diagnostics as a B-cell specific mitogen in cytogenetic testing. Cells must be divided in a cytogenic test to view the chromosomes. TPA is used to stimulate division of B-cells during cytogenetic diagnosis of B-cell cancers such as chronic lymphocytic leukemia.[6]
TPA is also commonly used together with ionomycin to stimulate T-cell activation, proliferation, and cytokine production, and is used in protocols for intracellular staining of these cytokines.[7]
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.[8]
^Blumberg (1988). "Protein kinase C as the receptor for the phorbol ester tumor promoters: sixth Rhoads memorial award lecture". Cancer Research. 48 (1): 1–8. PMID3275491.
^Cohen, Adina; Brodie, Chaya; Sarid, Ronit (April 2006). "An essential role of ERK signalling in TPA-induced reactivation of Kaposi's sarcoma-associated herpesvirus". The Journal of General Virology. 87 (Pt 4): 795–802. CiteSeerX10.1.1.321.5484. doi:10.1099/vir.0.81619-0. PMID16528027.