Regulation of Prolactin Gene Expression by Hypothalamic Pituitary Adenylate Cyclase-Activating Polypeptide (PACAP) in the Female Rat Pituitary Gland / 대한내분비학회지

BACKGROUND: Pituitary adenylate cyclase-activating polypeptide (PACAP) plays the role of a hypophysiotropic factor, which regulates the synthesis and secretion of pituitary hormones through the hypothalamo-hypophysial portal system. No clear evidence has yet been reported regarding the regulation of prolactin (PRL) by PACAP. In the present study, we tested a hypothesis that PACAP regulates the synthetic machinery of PRL during the estrus cycle and pubertal process using intracerebroventricular (i.c.v.) injection of an antisense oligodeoxynucleotide (ODN) against type I PACAP receptor (PAC1). METHODS: An RNase protection assay (RPA) was used to determine the pattern of hypothalamic PACAP and PAC1 mRNA expressions during the estrus cycle. Antisense PAC1 ODN was administered via i.c.v. injection to the female rats in normal estrus cycle of pubertal process. Northern blot analysis was used to determine the mRNA ievel of PRL in the pituitary gland. RESULTS: 1) PACAP mRNA in the medial basal hypothalamus was significantly increased at the diestrus I, while PAC1 mRNA showed no significant change. 2) PRL mRNA level of pituitary was increased by an injection of antisense PAC1 ODN at the proestrus and estrus stages. 3) PRL mRNA level of pituitary was significantly decreased by antisense PAC1 ODN injection at stage of prepuberty and initiate puberty, while its level was increased at stage of puberty. CONCLUSION: These data suggest that PACAP suppresses PRL mRNA synthesis through the PAC1 signaling pathway in the certain estrus cycle environments. It may be also involved in the regulation of pituitary PRL gene expression during the pubertal process

The Effect of Vasoactive Intestinal Peptide on Cord Blood CD34 (+) Cells / 대한소아혈액종양학회지

PURPOSE: We investigated the expression of vasoactive intestinal peptide (VIP), VIP receptor 1 (VPAC1), VIP receptor 2 (VPAC2) genes in the human umbilical cord blood CD34 cells, and the ability of VIP to stimulate human primitive as well as monopotent hematopoietic progenitors. METHODS: We isolated RNA from umbilical cord blood CD34 cells, and then performed RT-PCR, and sequencing. The umbilical cord blood CD34 cells were cultured with the various concentrations of VIP for burst-forming unit of erythrocyte (BFU-E), colony-forming unit of granulocyte/monocyte (CFU-GM), colony-forming unit of graulocyte/erythrocyte/monocyte/megakaryocyte (CFU-GEMM), and colony-forming unit of megakaryocyte (CFU-Mk). RESULTS: The RNA coding for VPAC1 was detected in human umbilical cord blood CD34 cells. VIP significantly stimulated the growth of CFU-GEMM and CFU-Mk. CONCLUSION: The present results suggest that VIP is an important neuropeptide in the early proliferation of human primitive as well as megakaryocyte progenitors.

Vasoactive Intestinal Peptide/Pituitary Adenylate Cyclase Activating Peptide Receptor Subtypes in Neuroblastoma, Stomach Cancer / 대한소아혈액종양학회지

PURPOSE: We analyzed the expression of vasoactive intestinal peptide (VIP), pituitary adenylate cyclase activating peptide (PACAP), VIP receptor 1 (VIPR1), VIP receptor 2 (VIPR 2) and PACAP receptor (PACAPR) genes in human neuroblastoma, neuroblastoma cell line, human stomach cancer, and human stomach cancer cell lines using RT-PCR and Sourthern hybridization. The results should permit identification of potential clinical applications for VIP and PACAP. METHODS: We isolated RNA from 1 neuroblastoma cell line, 8 stomach cancer cell lines, 13 neuroblastoma, and 10 stomach cancer tumor specimens. And then we performed RT-PCR, Sourthern hybridization, and sequencing. RESULTS: We detected the RNAs coding for VIP, VIPR1, VIPR2, PACAP, and PACAPR in 1, 11, 2, 12, and 13 out of 13 neuroblastoma tumor specimens, respectively. VIP and PACAPR RNA was expressed in SKNSH. VIPR1 RNA was expressed in 4 of 8 the stomach cancer cell lines and 6 of 10 stomach cancer tumor specimens. CONCLUSION: VIP/PACAP RNA and VIP/PACAP receptors RNA were expressed in SKNSH and neuroblastoma tumor specimens. VIPR1 was expressed in stomach cancer cell lines and tumor specimens. The present results suggested that VIP/PACAP analogues could be a candidate as the growth inhibitor of neuroblastoma and stomach cancer.