Relationship Between PTBP1 and Pancreatic Cancer Based on microRNA and Behavior During TYMS-Mediated Carcinogenesis

Area of Science:

• Molecular Biology
• Oncology
• Gene Regulation

Background:

• Polypyrimidine tract-binding protein 1 (PTBP1) is an alternative splicing factor involved in cancer metabolism.
• The role of PTBP1 and its regulating microRNAs (miRs) in pancreatic cancer progression is not fully understood.
• Pancreatic cancer is a complex disease with a poor prognosis, necessitating further research into its molecular drivers.

Purpose of the Study:

• To investigate the functional relationship between PTBP1-associated miRs and PTBP1 in pancreatic cancer.
• To identify pancreas-enriched miRs regulating PTBP1.
• To explore PTBP1 functions beyond metabolic reprogramming in pancreatic cancer.

Main Methods:

• Expression analysis of miR-216b-5p and PTBP1 in pancreatic cancer tissues.
• Luciferase reporter assays to confirm direct binding of miR-216b-5p to PTBP1 3' UTR.
• Proteomic analysis integrated with CLIP-seq data to identify PTBP1 downstream targets.
• Functional assays (e.g., cell cycle analysis) following PTBP1 and thymidylate synthase silencing.

Main Results:

• miR-216b-5p was significantly downregulated, while PTBP1 was upregulated in pancreatic cancer samples.
• miR-216b-5p directly suppresses PTBP1 expression, inhibiting cancer cell proliferation.
• Thymidylate synthase was identified as a novel PTBP1 downstream target, upregulated in pancreatic cancer and associated with poor prognosis.
• Silencing of PTBP1 and thymidylate synthase led to cell cycle arrest.

Conclusions:

• A novel regulatory axis (miR-216b-5p/PTBP1/thymidylate synthase) promotes pancreatic cancer progression.
• PTBP1 acts as a central regulator in pancreatic tumor biology, extending beyond its known metabolic roles.
• This axis represents a potential therapeutic target for pancreatic cancer treatment.