Comparative Efficacy of AZD9496 and Fulvestrant on the Growth of Pituitary Adenoma via Blocking JAK2/STAT5B Pathway

Area of Science:

• Endocrinology
• Oncology
• Molecular Biology

Background:

• Pituitary adenomas are common tumors, with gonadotropin-type adenomas representing a significant subset.
• Estrogen receptor 1 (ESR1) expression is implicated in pituitary adenoma development and progression.
• Understanding ESR1's role is crucial for identifying novel therapeutic targets.

Purpose of the Study:

• To investigate the expression of ESR1 in gonadotropin-type pituitary adenomas.
• To analyze the association between ESR1 expression and patient survival.
• To evaluate the therapeutic potential of estrogen receptor (ER) inhibitors in pituitary adenoma models.

Main Methods:

• Analysis of 158 pituitary adenoma tissue specimens for ESR1 expression.
• Transcriptome sequencing of 79 adenoma cases to identify ESR1-related genes.
• KEGG pathway analysis to determine enriched pathways and key genes.
• In vitro and in vivo studies using pituitary models to assess ER inhibitors (AZD9496, fulvestrant).
• Investigation of the mechanism of action of ER inhibitors on the JAK2/STAT5B pathway.

Main Results:

• Low ESR1 expression correlated with longer progression-free survival (PFS) in pituitary adenoma patients.
• The ErbB signaling pathway was identified as the main enriched pathway.
• STAT5B was identified as a key ESR1-related gene, positively correlated with ESR1 expression.
• AZD9496 demonstrated potent inhibitory effects on pituitary adenoma cell growth, comparable to fulvestrant.
• Both AZD9496 and fulvestrant effectively inhibited the JAK2/STAT5B pathway in vitro and in vivo.

Conclusions:

• ESR1 expression is a prognostic marker in pituitary adenoma.
• The JAK2/STAT5B pathway is a critical target for ER inhibitors in pituitary adenoma.
• AZD9496 shows significant therapeutic potential for pituitary adenoma treatment, warranting further clinical investigation.