title: Elements in support of the 'non-identity' of the PGRMC1 protein with the σ2 receptor.
abstract: σ2 Receptor subtype is overexpressed in a variety of human tumors, with σ2 agonists showing antiproliferative effects towards tumor cells through multiple pathways that depend both on the tumor cell type and on the molecule type. Therefore, σ2 receptor is an intriguing target for tumor diagnosis and treatment despite the fact that that it has not yet been cloned. One of the last attempts to characterize σ2 receptors led to identify it as the progesterone receptor membrane component 1 (PGRMC1). Although still controversial, such identity appears to have been accepted. We the aim of contributing to solve this controversy, in this work we stably silenced or overexpressed PGRMC1 protein in human MCF7 adenocarcinoma cells. Western blotting analyses were performed to quantify the presence of PGRMC1 protein on each of the three MCF7 cell lines variants, while scatchard analyses with radioligand were performed in order to determine the expression of the σ2 receptors. In order to correlate the antiproliferative effect of σ2 receptor agonist with PGRMC1 density, some σ2 ligands were administered to each of the three MCF7 cells variants. The results suggested that PGRMC1 and σ2 receptors are two different molecular entities.
authors.affiliation: Dipartimento Farmacia-Scienze del Farmaco, Università degli Studi di Bari ALDO MORO, Via Orabona 4, I-70125 Bari, Italy.
authors.forename: Carmen
authors.initials: C
authors.lastname: Abate
authors.affiliation: Dipartimento Farmacia-Scienze del Farmaco, Università degli Studi di Bari ALDO MORO, Via Orabona 4, I-70125 Bari, Italy. Electronic address: mauro.niso@uniba.it.
authors.forename: Mauro
authors.initials: M
authors.lastname: Niso
authors.affiliation: Dipartimento di Scienze, Università della Basilicata, I-85100 Potenza, Italy.
authors.forename: Vittoria
authors.initials: V
authors.lastname: Infantino
authors.affiliation: Dipartimento di Bioscienze, Biotecnologie e Biofarmaceutica, Università degli Studi di Bari ALDO MORO, Via Orabona 4, I-70125 Bari, Italy.
authors.forename: Alessio
authors.initials: A
authors.lastname: Menga
authors.affiliation: Dipartimento Farmacia-Scienze del Farmaco, Università degli Studi di Bari ALDO MORO, Via Orabona 4, I-70125 Bari, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Berardi
mesh_terms: D000818:Animals; D002470:Cell Survival / Q000187:drug effects; D020868:Gene Silencing; D006168:Guinea Pigs; D006801:Humans; D061986:MCF-7 Cells; D008565:Membrane Proteins / Q000187:drug effects / Q000378:metabolism*; D011869:Radioligand Assay; D051381:Rats; D011980:Receptors, Progesterone / Q000187:drug effects / Q000378:metabolism*; D017480:Receptors, sigma / Q000187:drug effects / Q000378:metabolism*; D014162:Transfection
chemical_list: D008565:Membrane Proteins; C115296:PGRMC1 protein, human; D011980:Receptors, Progesterone; D017480:Receptors, sigma
keywords: PGRMC1 protein; σ(2) receptor; σ(2) receptor agonists