ESTAT3 Inhibitor AG-490 Inhibits the Growth of Prostate Cancer by miR-503-5p Both In Vivo and In Vitro

Area of Science:

• Oncology
• Molecular Biology
• Pharmacology

Background:

• Prostate cancer remains a significant health concern with ongoing research into novel therapeutic targets.
• Signal transducer and activator of transcription 3 (STAT3) is frequently implicated in cancer progression and proliferation.
• Identifying effective inhibitors of STAT3 signaling is crucial for developing new prostate cancer treatments.

Purpose of the Study:

• To investigate the inhibitory effects of the STAT3 inhibitor AG-490 on prostate cancer cell proliferation.
• To elucidate the underlying molecular mechanisms, including the role of miR-503-5p, in AG-490's anti-cancer activity.

Main Methods:

• In vitro studies utilized PC3 and DU145 prostate cancer cell lines treated with AG-490.
• In vivo efficacy was assessed using a prostate cancer xenograft mouse model (BALB/c nude mice).
• Molecular analyses included gene expression (miR-503-5p, PDCD4, TIMP-3, PTEN), Western blotting, and immunohistochemistry.

Main Results:

• AG-490 treatment significantly reduced proliferation and invasion of PC3 and DU145 cells.
• AG-490 led to decreased expression of miR-503-5p and increased expression of its target genes (PDCD4, TIMP-3, PTEN).
• In vivo, AG-490 inhibited tumor growth, reduced STAT3 and proliferation markers (Ki67, Bcl-2, MMP-2), and increased apoptosis.

Conclusions:

• AG-490 inhibits prostate cancer cell growth and tumor progression through a mechanism dependent on miR-503-5p and STAT3 inhibition.
• The findings suggest that AG-490 holds promise as a novel therapeutic agent for prostate cancer treatment.