Programmed cell death 4 overexpression enhances sensitivity to cisplatin via the JNK/c-Jun signaling pathway in...

Area of Science:

• Oncology
• Molecular Biology
• Cell Biology

Background:

• Bladder cancer (BCa) remains a significant health concern.
• Understanding the molecular mechanisms regulating BCa progression is crucial for developing effective therapies.
• Programmed cell death 4 (PDCD4) is implicated in tumor suppression, but its role in BCa requires further elucidation.

Purpose of the Study:

• To investigate the effect of PDCD4 on BCa cell proliferation, apoptosis, and cisplatin sensitivity.
• To explore the involvement of the Jun N-terminal kinase (JNK)/c-Jun pathway in PDCD4-mediated effects in BCa.
• To determine PDCD4's influence on epithelial-to-mesenchymal transition (EMT) in BCa cells.

Main Methods:

• Transfection of human BCa cells with PDCD4-expressing plasmids.
• Assessment of cell viability, invasion, migration, and apoptosis using various assays (e.g., flow cytometry, Transwell).
• Analysis of EMT markers via immunofluorescence and protein expression of JNK/c-Jun pathway components using western blotting.

Main Results:

• PDCD4 overexpression significantly inhibited BCa cell proliferation, invasion, and tumor growth while enhancing apoptosis, particularly when treated with cisplatin.
• PDCD4 upregulated epithelial markers and downregulated mesenchymal markers, indicating a reversal of EMT.
• Overexpression of PDCD4 led to reduced levels of phosphorylated JNK (p-JNK) and phosphorylated c-Jun (p-c-Jun).

Conclusions:

• PDCD4 enhances the sensitivity of human BCa cells to cisplatin, partly by regulating the JNK/c-Jun pathway.
• PDCD4 reverses EMT in BCa cells, suggesting a role in inhibiting metastasis.
• PDCD4 is a crucial protein in modulating BCa development and progression, offering potential therapeutic insights.