Thromboxane A2 analogue U 46619 enhances tumour cell proliferation in HeLa cells via specific receptors which are apparently distinct from TXA2 receptors on human platelets.
In this study, we have demonstrated for the first time by using U 46619, a stable analogue of thromboxane A2 (TXA2), that TXA2 exerts a cell proliferative effect on HeLa cells which is mediated by specific TXA2 receptors, inasmuch as the cell proliferation could be dose-dependently suppressed by TXA2 receptor antagonist BM 13177. The investigation of the phospholipase C pathway by U 46619 and prostaglandin H2 (PGH2) in the presence and absence of BM 13177 in cells with or without pertussis toxin pretreatment, as well as radioligand receptor binding studies, revealed that, in contrast to TXA2 receptors on human platelets, where TXA2 and PGH2 share the same receptor binding sites, HeLa cells possess distinct receptors for TXA2 and PGH2.
Nigam
S
S
Department of Gynecology, Klinikum Steglitz, Free University, Berlin, Germany.
Eskafi
S
S
Roscher
A
A
Weitzel
H
H
D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; D001665:Binding Sites; D001792:Blood Platelets / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D002455:Cell Division / Q000187:drug effects*; D006367:HeLa Cells; D006801:Humans; D011450:Prostaglandin Endoperoxides, Synthetic / Q000494:pharmacology*; D044262:Prostaglandin H2; D011463:Prostaglandins H / Q000494:pharmacology; D011869:Radioligand Assay; D017482:Receptors, Thromboxane / Q000187:drug effects* / Q000378:metabolism
D011450:Prostaglandin Endoperoxides, Synthetic; D011463:Prostaglandins H; D017482:Receptors, Thromboxane; D044262:Prostaglandin H2; D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid