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Published on: January 5, 2015
A fluorescent oxaliplatin derivative for investigation of oxaliplatin resistance using imaging techniques
Ganna V Kalayda1, Maximilian Kullmann2, Mathea Sophia Galanski3
1Department of Clinical Pharmacy, Pharma Centre Bonn, Institute of Pharmacy, University of Bonn, An der Immenburg 4, 53121, Bonn, Germany. akalayda@uni-bonn.de.
Abstract:
Oxaliplatin is the backbone of chemotherapy for advanced colorectal cancer and undergoes clinical trials for treatment of other tumour entities. However, acquired resistance is a major hurdle. Confocal microscopy is a useful tool to get an insight into the mechanisms of resistance but it requires fluorescent compounds. This work describes the synthesis of the novel oxaliplatin derivative (CFDA-oxPt) featuring 5(6)-carboxyfluorescein diacetate and evaluation of its applicability for the investigation of oxaliplatin resistance using imaging techniques. CFDA-oxPt was somewhat less cytotoxic than oxaliplatin in sensitive colorectal cancer cells, with EC50 values of 26 and 5.8 µM, respectively. Nevertheless, the potency of the novel complex was significantly decreased to the EC50 of 711.2 µM in oxaliplatin-resistant cells, as was the case for oxaliplatin (EC50 = 81 µM). After incubation, both nuclear and cytosolic localisation was observed. Over time CFDA-oxPt concentrated near the cell membrane and in the vesicular structures, in contrast to the platinum-free label, which was rapidly excreted. These findings suggest that CFDA-oxPt can be used to study oxaliplatin resistance and open the route to new fluorophore-tethered oxaliplatin derivatives.
Insights
Researchers developed a novel fluorescent oxaliplatin derivative (CFDA-oxPt) to study chemotherapy resistance in colorectal cancer. This tool helps visualize how cancer cells become resistant to oxaliplatin, aiding in developing new treatment strategies.
Area of Science:
- Oncology
- Chemical Biology
- Medical Imaging
Background:
- Oxaliplatin is a critical chemotherapy agent for advanced colorectal cancer.
- Acquired resistance to oxaliplatin significantly limits its clinical efficacy.
- Confocal microscopy requires fluorescent probes to visualize drug mechanisms, including resistance.
Purpose of the Study:
- To synthesize a novel fluorescent oxaliplatin derivative, CFDA-oxPt.
- To evaluate CFDA-oxPt's utility in studying oxaliplatin resistance mechanisms using imaging techniques.
- To explore the potential of fluorophore-tethered oxaliplatin derivatives for cancer research.
Main Methods:
- Synthesis of the novel oxaliplatin derivative, CFDA-oxPt, incorporating 5(6)-carboxyfluorescein diacetate.
- Cytotoxicity assays were performed on both oxaliplatin-sensitive and -resistant colorectal cancer cells.
- Confocal microscopy was used to track the intracellular localization and dynamics of CFDA-oxPt.
Main Results:
- CFDA-oxPt exhibited reduced cytotoxicity compared to oxaliplatin in sensitive cells (EC50: 26 µM vs 5.8 µM).
- The potency of CFDA-oxPt was significantly diminished in resistant cells (EC50: 711.2 µM vs 81 µM for oxaliplatin).
- Intracellular localization included nuclear, cytosolic, and cell membrane/vesicular structures, with sustained presence unlike a platinum-free control.
Conclusions:
- CFDA-oxPt is a viable tool for investigating oxaliplatin resistance in cancer cells.
- The fluorescent properties of CFDA-oxPt allow for real-time imaging of drug uptake and localization.
- This study paves the way for developing new fluorescently labeled oxaliplatin analogs for enhanced drug resistance research.
