VIP AND PITUITARY ADENYLATE-CYCLASE ACTIVATING POLYPEPTIDE (PACAP) HAVE AN ANTIPROLIFERATIVE EFFECT ON THE T98G HUMAN GLIOBLASTOMA CELL-LINE THROUGH INTERACTION WITH VIP2 RECEPTOR

Functional VIP/PACAP receptors were identified in the human glioblasto ma cell line T98G, based on the relative potency of VIP, PACAP and PAC AP-38 to stimulate adenylate cyclase activity, Analysis of the T98G ce lls mRNA by reverse transcription followed by a polymerase chain react ion (RT-PCR) demonstrated the expression of the mRNA coding for the VI P2 receptor subclass only. VIP, PACAP-27 and PACAP-38 were potent and efficient inhibitors of cell proliferation, assessed by the colorimetr ic MTT assay. VIP, PACAP-27 and PACAP-38 also reduced the incorporatio n of H-3-thymidine in T98G cells, but did not significantly alter the percentage of cells present at each stage of the cell cycle. Thus, VIP and PACAP, probably acting through a VIP2 receptor subtype, decreased cell proliferation.