Single-Cell ICP-MS in Veterinary Research: Measuring Cisplatin Uptake in Healthy and Cancerous Animal Cell Lines

Platinum derivatives have been used in cancer treatment for several decades. However, the clinical effectiveness of these drugs is significantly hindered by their toxicity, resulting from accumulation in healthy cells and by the development of resistance in specific cancer cells. Previous research has successfully explored cisplatin's mechanisms of cell transport, its antineoplastic effects, and its toxicity. Nevertheless, quantifying platinum uptake in individual cells posed a technological challenge until recent advancements. The single-cell inductively coupled plasma mass spectrometry (SC ICP-MS) method utilized in this study addresses this challenge. In our experiments, we used two murine carcinoma cell lines, C26 (colorectal carcinoma) and 4T1 (mammary carcinoma), along with a healthy epithelial cell line (MDCK) derived from a canine kidney. The cell cultures were exposed to various concentrations of cisplatin (10, 20, and 40 μM) for 24 h, followed by three washing steps and centrifugation. We monitored morphological changes in the cell cultures using an Olympus IX70 inverted phase-contrast microscope, while cell counts were measured with a Merck Scepter 3.0 cell counter. The uptake of platinum and its intercellular distribution were assessed using a PerkinElmer NexION2000 ICP-MS. Different cell lines absorbed platinum to varying degrees when exposed to the same cisplatin concentrations. Higher drug concentrations corresponded to increased amounts of platinum measured within all cell cultures. This relationship was directly proportional for several cell lines within specific concentration ranges. Notable cell death occurred in all cell line cultures when exposure exceeded a particular concentration, resulting in cell fragmentation. The SC ICP-MS technique detected this as an increase in cell number. Our findings corroborate several previous studies and highlight the applicability of the SC ICP-MS method in both human and animal cancer research.