Quaternized chitosan promotes the antiproliferative effect of vemurafenib in melanoma cells by increasing cell permeability

Abstract

BackgroundAs one of the most invasive cutaneous carcinomas among all types of skin cancer, malignant melanoma remains a severe challenge in oncology and plastic surgery. Selective small-molecule inhibitors of V600E-mutant B-Raf (vemurafenib, for instance) have demonstrated satisfactory therapeutic efficacy in melanoma patients. However, acquired resistance during the period of drug administration has limited their clinical application.Materials and methodsIn the present study, human melanoma cells with the B-RafV600E mutation were treated with the indicated concentrations of vemurafenib, quaternized chitosan, or a combination of vemurafenib and quaternized chitosan. Cell proliferation and viability were evaluated using cell counting kit-8 assay and DAPI staining, and the IC50 values for vemurafenib in melanoma cells were also determined. Cell apoptosis was evaluated by Live/Dead cell staining using confocal laser scanning microscopy and Annexin V-FITC Apoptosis detection using flow cytometry, respectively. The leakage of ATP and K+ into the cell supernatants was measured to evaluate cell permeability. Furthermore, the surface charge variation of melanoma cells after drug treatment was determined by measuring the zeta potential of the cell membrane to clarify the electrostatic interaction between quaternized chitosan and the cells.ResultsOur results indicated that the addition of quaternized chitosan could promote the antiproliferative effect of vemurafenib in melanoma cells and could also promote the cell apoptosis of melanoma cells treated with vemurafenib. In addition, quaternized chitosan could increase cell permeability at early stages of co-culture, thus contributing to the improvement in intracellular drug uptake. Meanwhile, the majority of the negative surface charge of the cells was counteracted by the quaternized chitosan, indicating that the surface charge of melanoma cells was disturbed after the addition of quaternized chitosan.ConclusionThis study indicated that disturbance of the surface charge of the cell membrane by quaternized chitosan is an important mechanism involved in changes in cell permeability, which promote the antiproliferative effect of vemurafenib in melanoma cells. Our preliminarily investigation provides new insights into the improvement of clinical melanoma therapy in the future.

Biomedical Applications of Quaternized Chitosan

“…Interestingly, polycationic QCh made electrostatic interactions with negatively charged cancerous cells that disturbed their cytoplasmic integrity. The investigation concluded that QCh upset the surface charges on melanoma cell, which may be an important parameter to change cell permeability [ 86 ]. Wongwanakul et al (2017) examined cell proliferation and cell differentiation properties of QCh on the intestinal barrier through CaCo-2 cell lines in vitro model.…”

Dual-Purpose Magnesium-Incorporated Titanium Nanotubes for Combating Bacterial Infection and Ameliorating Osteolysis to Realize Better Osseointegration

“…Moreover, the effects of various specimens on cell apoptosis and cell cycle were determined using flow cytometry (BD LSRFortessa, BD Biosciences, Franklin Lakes, NJ, USA) as described in a previously reported method. 47 For cell apoptosis analysis, cells at a density of 5.0 × 10 5 per well were cocultured with the specimens for 48 h. Then, cells were collected after trypsinization and washed twice with phosphate buffer solution (PBS). Subsequently, cells were suspended in 500 μL of 1× binding buffer.…”