垂体腺苷酸环化酶激活多肽促进胰腺癌细胞的生长

Pitutary Adenylate Cyclase-Activating Polypeptide Stimulating Growth of Pancreas Carcinoma Cell

目的:观察垂体腺苷酸环化酶激活多肽(pituitaryadenylatecyclaseactivatingpolypeptide,PACAP)对人胰腺癌细胞株ASPC-1的生长调控作用,探讨PACAP受体后信息传导途径,并确定神经鞘磷脂(sphingomyolin)是否作为第二信使参与此过程。方法:将ASPC-1细胞培养、传代,分别加入不同浓度的PACAP1-38(10-12～10-6mol/L)于细胞中。应用MTT法观察细胞增殖程度,薄层层析法测定细胞神经鞘磷脂,放免法测定细胞内cAMP含量,Fura-2/AM测定犤Ca2+犦i。结果:PACAP1-38促进ASPC-1的生长,促进ASPC-1细胞cAMP、Ca2+的生成,且呈剂量依赖性;PACAP6-38拮抗PACAP1-38的上述作用。结论:PACAP1-38促进ASPC-1的增殖;PACAP受体后信息传递途径,一是通过腺苷酸环化酶途径,另一是钙-钙调素途径,神经鞘磷脂作为第二信使也参与此过程。

Objectives: To investigate the growth modulation of pituitary adenylate cyclase activating polypeptide (PACAP) on human pancreas carcinoma cell strain ASPC 1; by measuring the concentrations of intracellular cyclic adenosine monophosphate (cAMP), free calcium and sphingomyelin (SM), find the pathways of postreceptor signal transduction. Methods: ASPC 1 cells were cultivated,then were treated with the PACAP1 38 alone or and PACAP6 38. Proliferation and viability of the cells were determined by 3 (4,5 dimethylthiazal 2 yl) 2,5 diphenylterazolium bromide colorimetry(MTT)method. Intracellular adenosine monophosphate levels was determined by radioimmunoassay. Intracellular Ca2+ level was measured using a F 2000 flurorescence spectrophotometer. The amount of SM in the cells were determined with thin layer chromotograph. Results: PACAP1 38 stimulated the proliferation of human pancreatic cancer cells ASPC 1 which were dose dependent. This stimulating effect was abolished by the specific PACAP receptor antagonist,PACAP6 38. PACAP strongly increased formation of intracellular cAMP and cytosolic Ca2+ in a dose dependent manner. PACAP6 38 inhibited this effect of PACAP1 38. Conclusions: PACAP1 38 can stimulate the proliferation of human pancreatic cancer cell strain ASPC 1. The growth promoting effect of PACAP1 38 were mediated by the corresponding receptors. Its post receptor messenger transduction are mediated by Ca2+ calmodin pathway and activating adenosine cyclinase pathway. SM participates in this process as a second messenger.