PACAP has opposing roles ranging from activation to inhibition of tumor growth and PACAP agonists/antagonists could be used in tumor therapy. In this study, the effect of PACAP stimulation on signaling pathways was investigated in MCF-7 human adenocarcinoma breast cancer cells. Results showed that MCF-7 cells express VPAC1 and VPAC2, but not PAC1, receptors. In addition, PACAP increased the phosphorylation levels of STAT1, Src and Raf within seconds, confirming their involvement in early stages of PACAP signaling whereas maximal phosphorylation of AKT, ERK and p38 was reached 10 to 20 min later. Moreover, selective inhibition of Src or PI3K resulted in a significant decrease in the phosphorylation of ERK and AKT, but not p38, demonstrating that PACAP signaling follows Src/Raf/ERK and PI3K/AKT pathways. On the other hand, selective inhibition of PLC or PKA resulted in a significant decrease in the phosphorylation of p38, but not AKT or ERK, indicating that PACAP signaling also follows the PLC and PKA/cAMP pathways. Furthermore, PACAP induced ROS through H₂O₂ production whereas pretreatment with NAC inhibitor decreased AKT and ERK phosphorylation, but not p38. Selective NOX2 inhibition affected Src/Raf/Erk and PI3K/Akt pathways, without affecting the p38/PLC/PKA pathway whereas other inhibitors (ML171, VAS2870) had no effect on PACAP induced ROS generation. On the other hand, PACAP induced calcium release, which was decreased by pretreatment with PLC inhibitor. Finally, PACAP stimulation promoted apoptosis by increasing Bax and decreasing Bcl2 expression. In conclusion, we demonstrated that PACAP signaling in MCF-7 cells follows the Src/Raf/ERK and PI3K/AKT pathways and is VPAC1 dependent in a ROS dependent manner, whereas it follows PLC and PKA/cAMP pathways and is VPAC2 dependent through p38 MAP kinase activation involving calcium.

PACAP具有从激活到抑制肿瘤生长的相反作用，PACAP激动剂/拮抗剂可用于肿瘤治疗。在这项研究中，在MCF-7人腺癌乳腺癌细胞中研究了PACAP刺激对信号通路的影响。结果显示MCF-7细胞表达VPAC1和VPAC2受体，但不表达PAC1受体。此外，PACAP可在数秒内增加STAT1，Src和Raf的磷酸化水平，从而证实它们参与了PACAP信号传导的早期阶段，而AKT，ERK和p38的最大磷酸化则在10至20分钟后达到。此外，对Src或PI3K的选择性抑制导致ERK和AKT的磷酸化显着降低，但p38却没有，表明PACAP信号传导遵循Src / Raf / ERK和PI3K / AKT途径。另一方面，对PLC或PKA的选择性抑制导致p38的磷酸化显着降低，但AKT或ERK却没有，这表明PACAP信号也遵循PLC和PKA / cAMP途径。此外，PACAP通过产生H 2 O 2诱导了ROS，而用NAC抑制剂预处理降低了AKT和ERK的磷酸化，但没有降低p38。选择性的NOX2抑制影响Src / Raf / Erk和PI3K / Akt途径，而不影响p38 / PLC / PKA途径，而其他抑制剂（ML171，VAS2870）对PACAP诱导的ROS生成没有影响。另一方面，PACAP诱导钙释放，通过用PLC抑制剂预处理可降低钙释放。最后，PACAP刺激通过增加Bax和减少Bcl2表达来促进细胞凋亡。综上所述，