Cisplatin Protein Binding Partners and Their Relevance for Platinum Drug Sensitivity

Area of Science:

• Oncology
• Molecular Biology
• Biochemistry

Background:

• Cisplatin is a vital chemotherapy drug for solid tumors, but intrinsic or acquired resistance limits its efficacy.
• The intracellular fate and binding partners of cisplatin beyond genomic DNA are not fully understood.
• Understanding these interactions is crucial for overcoming treatment resistance.

Purpose of the Study:

• To identify cytosolic protein binding partners of cisplatin in ovarian and colorectal cancer cells.
• To evaluate the role of these binding partners in cellular sensitivity to cisplatin and oxaliplatin.
• To explore novel therapeutic strategies for overcoming cisplatin resistance.

Main Methods:

• Utilized a fluorescent cisplatin analog (BODIPY-cisplatin) for detection.
• Employed two-dimensional gel electrophoresis and mass spectrometry to identify protein binding partners.
• Investigated the functional relevance through pharmacological inhibition and siRNA-mediated knockdown of identified proteins.

Main Results:

• Identified specific protein binding partners including vimentin (ovarian cancer), growth factor receptor-bound protein 2 (colorectal cancer), and glutathione-S-transferase π (both).
• Silencing glutathione-S-transferase π sensitized intrinsically resistant colorectal cancer cells to cisplatin.
• Inhibiting vimentin sensitized ovarian cancer cells to cisplatin.

Conclusions:

• Glutathione-S-transferase π is implicated in colorectal cancer cell resistance to cisplatin.
• Vimentin is a potential therapeutic target for enhancing chemosensitivity in ovarian cancer.
• These findings offer new avenues for improving cisplatin-based cancer therapies.