Functional expression of the serotonin 5-HT7 receptor in human glioblastoma cell lines.
Serotonin 5-HT(7) receptors are present in astrocytes. Understanding their role in this type of cell would greatly benefit from the identification of astroglial cell lines expressing this receptor type. The aim of the present study was to assess the expression of native 5-HT(7) receptors and 5-HT(7) receptor mRNA in a number of human glioblastoma cell lines, by means of cAMP measurements, Western blot analysis and reverse transcriptase-polymerase chain reaction (RT-PCR) analysis. 5-Hydroxytryptamine (5-HT), 5-carboxamidotryptamine (5-CT), 5-methoxytryptamine (5-MeOT) and 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) induced concentration-dependent stimulations of cAMP accumulation in the human glioblastoma cell lines, U-373 MG, U-138 MG, U-87 MG, DBTRG-05MG, T98G, H4, CCF-STTG1 and Hs 683. The rank order of potency was 5-CT>5-HT=5-MeOT>>8-OH-DPAT. The effect of 5-CT was inhibited in a concentration-dependent manner by the selective 5-HT(7) receptor antagonist SB-269970 in all human glioblastoma cells. Schild analyses yielded slope factors close to unity (0.89-1.13) and pA(2) values of 8.69-9.05. Western blot analysis revealed the presence of immunoreactive bands corresponding to the human 5-HT(7) receptor in extracts of all human glioblastoma cell lines. The presence of the three splice variants of the 5-HT(7) receptor (5-HT(7(a/b/d))) was visualized by RT-PCR analysis with specific primers in all human glioblastoma cell lines. In conclusion, human glioblastoma cell lines express functional 5-HT(7) receptors and the three splice variants of the corresponding mRNA. These cell lines could serve as model systems of native 5-HT(7) receptors in glial cells to investigate their putative role in processes like release of neurotrophic factors or inflammatory cytokines.
Mahé
Cécile
C
Neuroscience Research, Novartis Institutes for BioMedical Research, Novartis Pharma AG, WSJ-386.7.44, CH-4002 Basel, Switzerland.
Bernhard
Michel
M
Bobirnac
Ionel
I
Keser
Corinna
C
Loetscher
Erika
E
Feuerbach
Dominik
D
Dev
Kumlesh K
KK
Schoeffter
Philippe
P
D008735:5-Methoxytryptamine / Q000494:pharmacology; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000494:pharmacology; D000818:Animals; D015153:Blotting, Western; D016466:CHO Cells; D045744:Cell Line, Tumor; D006224:Cricetinae; D003412:Cricetulus; D000242:Cyclic AMP / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D015972:Gene Expression Regulation, Neoplastic; D005909:Glioblastoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D006801:Humans; D020033:Protein Isoforms / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011985:Receptors, Serotonin / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012701:Serotonin / Q000031:analogs & derivatives* / Q000494:pharmacology
D020033:Protein Isoforms; D012333:RNA, Messenger; D011985:Receptors, Serotonin; C104425:serotonin 7 receptor; D012701:Serotonin; D008735:5-Methoxytryptamine; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; C047087:5-carboxamidotryptamine; D000242:Cyclic AMP