The 5-HT2A serotoninergic receptor is expressed in the MCF-7 human breast cancer cell line and reveals a mitogenic effect of serotonin.
Serotonin (5-hydroxytryptamine, 5-HT) has been described as a mitogen in a variety of cell types and carcinomas. It exerts its mitogenic effect by interacting with a wide range of 5-HT receptor types. Certain studies suggest that some selective serotonin re-uptake inhibitors promote breast cancer in animals and humans. This study attempts to clarify the role of serotonin in promoting the growth of neoplastic mammary cells. Expression of the 5-HT(2A) serotoninergic receptor subtype in MCF-7 cells was determined by RT-PCR, Western blotting, and immunofluorescence analysis. The mitogenic effect of 5-HT on MCF-7 cells was determined by means of the MTT proliferation assay. We have demonstrated that the 5-HT(2A) receptor subtype is fully expressed in the MCF-7 human breast cancer cell line, in terms of encoding mRNA and receptor protein. Automated sequencing has confirmed that the 5-HT(2A) receptor present in this cell line is identical to the 5-HT(2A) receptor found in human platelets and in human cerebral cortex. Furthermore, this receptor was found by immunofluorescence to be on the plasma membrane. MTT proliferation assays revealed that 5-HT and DOI, a selective 5-HT(2A) receptor subtype agonist, stimulated MCF-7 cell. These results indicate that 5-HT plays a mitogenic role in neoplastic mammary cells. Our data also indicate that 5-HT exerts this positive growth effect on MCF-7 cells through, in part, the 5-HT(2A) receptor subtype, which is fully expressed in this cell line.
Department of Chemistry and Biochemistry, Université de Moncton, Moncton, NB, Canada.
Brigitte
B
Sonier
Madeleine
M
Arseneault
Carole
C
Lavigne
Rodney J
RJ
Ouellette
Cathy
C
Vaillancourt
D000662:Amphetamines / Q000494:pharmacology; D001943:Breast Neoplasms / Q000378:metabolism*; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects*; D005260:Female; D005455:Fluorescent Antibody Technique; D006801:Humans; D012333:RNA, Messenger / Q000096:biosynthesis; D044402:Receptor, Serotonin, 5-HT2A / Q000096:biosynthesis* / Q000235:genetics; D012701:Serotonin / Q000494:pharmacology / Q000502:physiology*; D058826:Serotonin 5-HT2 Receptor Agonists
D000662:Amphetamines; D012333:RNA, Messenger; D044402:Receptor, Serotonin, 5-HT2A; D058826:Serotonin 5-HT2 Receptor Agonists; D012701:Serotonin; C015952:4-iodo-2,5-dimethoxyphenylisopropylamine