dimethylaminomicheliolide and Pituitary-Neoplasms

ACT001, derived from traditional herbal medicine, is a novel compound with effective anticancer activity in clinical trials. However, little is known regarding its role in pituitary adenomas. Here, we demonstrated that ACT001 suppressed cell proliferation and induced cell death of pituitary tumor cells in vitro and in vivo. ACT001 was also effective in suppressing the growth of different subtypes of human pituitary adenomas. The cytotoxic mechanism ACT001 employed was mainly related to autophagic cell death (ACD), indicated by autophagosome formation and LC3-II accumulation. In addition, ACT001-mediated inhibitory effect decreased when either ATG7 was downregulated or cells were cotreated with autophagy inhibitor 3-methyladenine (3-MA). RNA-seq analysis showed that mitogen-activated protein kinase (MAPK) pathway was a putative target of ACT001. Specifically, ACT001 treatment promoted the phosphorylation of JNK and P38 by binding to mitogen-activated protein kinase kinase 4 (MEK4). Our study indicated that ACT001-induced ACD of pituitary tumor cells via activating JNK and P38 phosphorylation by binding with MEK4, and it might be a novel and effective anticancer drug for pituitary adenomas.

Topics: Antineoplastic Agents; Apoptosis; Autophagic Cell Death; Autophagy; Cell Line, Tumor; Furans; Humans; MAP Kinase Kinase 4; MAP Kinase Signaling System; Mitogen-Activated Protein Kinases; Pituitary Neoplasms

Dopamine agonist (DA) is the first choice for the treatment of prolactinomas, and drug resistance is unavoidable during treatment due to the heterogeneity of tumors. The two prolactinoma cell lines (GH3 cells and MMQ cells) were found to have different sensitivity and responding modes to the cabergoline (CAB) and bromocriptine (BRC). In this research, we disclosed the capability of ACT001, a derivative of parthenolide analogs, to activate AMPK by increasing the intracellular reactive oxygen species (ROS) level and AMP/ATP ratio to reverse DA resistance through dual pathways in prolactinoma cells. The results indicated that ACT001 could reverse the CAB resistance in GH3 cells by inhibiting the mTOR signaling pathway, inducing cell death through autophagy, and reverse the BRC resistance in MMQ cells by activating the EGR1 signaling pathway, inducing cell death through apoptosis. Our results suggested that ACT001 is a promising therapeutic compound for treating DA-resistant prolactinomas.

Topics: AMP-Activated Protein Kinases; Antineoplastic Combined Chemotherapy Protocols; Bromocriptine; Cabergoline; Drug Resistance, Neoplasm; Drug Synergism; Early Growth Response Protein 1; Furans; Humans; Pituitary Neoplasms; Prolactinoma; TOR Serine-Threonine Kinases