Single cell ICP-MS combined with HCS to reveal the mechanism of cisplatin chemotherapy resistance

Cisplatin is a chemotherapeutic drug approved by the FDA for clinical treatment of cancer in 1978. The therapeutic mechanism of cisplatin drugs is to kill the rapidly proliferating cancer cells by binding to form Pt-DNA complexes, which interfere with DNA replication synthesis, and belongs to cell cycle non-specific drugs. Many cancer patients are initially sensitive to platinum-based therapies, but after a period of time, patients often show resistance to cisplatin treatment, leading to cancer recurrence. Therefore, cells must repair DNA damage after chemotherapy, otherwise DNA replication is blocked and can lead to cell death. The research on the resistance mechanism of cisplatin is also a hot spot in the research of anticancer drugs. The three main molecular mechanisms currently include accelerated DNA repair, accelerated cytoplasmic inactivation, and changes in cellular uptake capacity. Among them, the change in the ability of cells to take up drugs is mainly reflected in the decreased ability of cells to ingest cisplatin and the acceleration of cisplatin transport.

Single cell ICP-MS NexIon2000

1. Single cell level cisplatin uptake study [1]

The uptake of intracellular cisplatin is associated with tumor burden, which means that a decrease in the tumor's response to cisplatin results in a decrease in intracellular cisplatin content. Therefore, analysis of the intake and distribution of cisplatin at a single cell level is of great importance in assessing the effectiveness of treatment. Excessive cisplatin entering the cell increases the frequency of DNA damage and cell death. Understanding the mechanism of single cell levels and cell subpopulations on cisplatin will provide a scientific basis for the development of new therapies to improve tumor resistance to cisplatin and reduce tumor recurrence.

Single-cell inductively coupled plasma mass spectrometry (SC-ICP-MS) is a single-particle inductively coupled plasma mass spectrometry technique that measures the discrete signals generated by individual cells (or individual nanoparticles) as they enter the plasma. Metal elements are evaluated and quantified. The metal components in each cell are ionized, producing a stream of ions, and the detector quickly measures the signal acquisition at a rate of 100,000 data points per second, allowing the metal content in a single cell to be quantified to ag (ag) per cell s level. The amount of information obtained by SC-ICP-MS is more comprehensive than the traditional method of measuring intracellular cisplatin intake.

Real-time detection of cisplatin intake in two ovarian cancer cell lines A2780 (cisplatin-sensitive) and A2780/CP70 (cisplatin-resistant) revealed that cisplatin was resistant to resistance compared to the A2780 sensitive cell line. The level of A2780/CP70 cell line was decreased; however, the cellular difference in cisplatin intake was not due to differences in cell cycle, as serum starved cells did not alter the overall intake of cisplatin. The intracellular difference in cisplatin intake is due to other undetermined factors.

High content imaging system Operetta CLS

2. Single-cell horizontal centromeric amplification study (Centrosome Amplification)

"Triple-Negative Breast Cancers" (TNBC) refers to a special type of breast that is negative for both estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor (HER2). cancer. "Three-negative" breast cancer accounts for about 10-20% of all breast cancers, but because of its lack of endocrine and anti-HER2 treatment targets, the current treatment is still based on traditional surgical resection, chemotherapy and radiotherapy. Platinum chemotherapy is currently the standard treatment for advanced breast cancer treatment. [2] Cisplatin has been reported to cause centrosome amplification by uncoupling DNA replication cycle and centromeric replication regulation, thereby inhibiting tumor cell proliferation.