Revealing the Effect of Photothermal Therapy on Human Breast Cancer Cells: A Combined Study from Mechanical Properties to Membrane HSP70

Abstract

Hyperthermia-induced overexpression of heat shock protein 70 (HSP70) leads to the thermoresistance of cancer cells and reduces the efficiency of photothermal therapy (PTT). In contrast, cancer cell-specific membraneassociated HSP70 has been proven to activate antitumor immune responses. The dual effect of HSP70 on cancer cells inspires us that in-depth research of membrane HSP70 (mHSP70) during PTT treatment is essential. In this work, a PTT treatment platform for human breast cancer cells (MCF-7 cells) based on a mPEG-NH 2 -modified polydopamine (PDA)-coated gold nanorod core−shell structure (GNR@PDA-PEG) is developed. Using the force-distance curve-based atomic force microscopy (FD-based AFM), we gain insight into the PTT-induced changes in the morphology, mechanical properties, and mHSP70 expression and distribution of individual MCF-7 cells with high-resolution at the single-cell level. PTT treatment causes pseudopod contraction of MCF-7 cells and generates a high level of intracellular reactive oxygen species, which severely disrupt the cytoskeleton, leading to a decrease in cellular mechanical properties. The adhesion maps, which are recorded by aptamer A8 functional probes using FD-based AFM, reveal that PTT treatment causes a significant upregulation of mHSP70 expression and it starts to exhibit a partial aggregation distribution on the MCF-7 cell surface. This work not only exemplifies that AFM can be a powerful tool for detecting changes in cancer cells during PTT treatment but also provides a better view for targeting mHSP70 for cancer therapy.

Determining the degree of chromosomal instability in breast cancer cells by atomic force microscopy

“…The morphological and mechanical properties of cells were important for maintaining the normal physiological functions of cells. 38 The morphological and mechanical properties of the three types of different malignant breast cells were quantitatively characterized by AFM (Fig. 4A).…”

Acid-Activated TAT Peptide-Modified Biomimetic Boron Nitride Nanoparticles for Enhanced Targeted Codelivery of Doxorubicin and Indocyanine Green: A Synergistic Cancer Photothermal and Chemotherapeutic Approach

“…Compared to the PBS group, there was an increase in the apoptosis rate for tumor cells and a decrease in the proliferation rate treated with the membrane-encapsulated group, which were less pronounced for the other treatment types (Figure G). Heat shock protein 70 (HSP70), a crucial protein maintaining cellular metabolic homeostasis, is released into the extracellular environment when cancer cells are exposed to high temperatures, triggering antitumor immune responses . Under irradiation, HSP70 expression was upregulated in tumor tissues in the CM-BID+L and CM-BID d T+L groups, indicating the effective application of their photothermal effect at the tumor site (Figure G).…”

Antibacterial and antibiofilm activities of zeolitic imidazolate framework-67 for dental caries prevention

“…Bacterial biofilms were established by allowing bacteria to be co-cultured with ZIF-67 for 24 hours [10] . Subsequently, the bacteria were wiped off, and the biofilms were stained with SYTO9 and propidium iodide, then observed using laser confocal microscopy to capture fluorescence images of the biofilm (Fig 2d).…”