Increasing roughness of the human breast cancer cell membrane through incorporation of gold nanoparticles

Abstract

Gold nanoparticles (AuNPs) have been proposed for use in the treatment of different types of cancer, including breast cancer. At present, neither the mechanisms of AuNP interaction with the plasma membrane surface and their delivery and intracellular distribution in cancer cells nor their effect on the plasma membrane so as to allow cell incorporation of larger amounts of AuNPs is known. The objective of this work was to study the interaction of bare 20 nm diameter AuNPs with the plasma membrane of human MCF-7 breast cancer cells, as well as their uptake, intracellular distribution, and induction of changes on the cell surface roughness. The dynamics of intracellular incorporation and the distribution of AuNPs were observed by confocal laser scanning microscopy. Changes in roughness were monitored in synchronized MCF-7 cells by atomic force microscopy high-resolution imaging at 6 hour intervals for 24 hours during a single cell cycle. The results show that bare AuNPs are capable of emitting fluorescence at 626 nm, without the need for a fluorescent biomarker, which allows monitoring their uptake and intracellular distribution until they reach the nucleus. These results are correlated with changes in cell roughness, which significantly increases at 12 hours of incubation with AuNPs, when compared with control cells. The obtained data provide bases to understand molecular processes of the use of AuNPs in the treatment of different diseases, mainly breast cancer.

Development of a Nanostructured Platform for Identifying HER2-Heterogeneity of Breast Cancer Cells by Surface-Enhanced Raman Scattering

“…The surface roughness values (RMS [Rq] ) were 4.83 ± 0.28 nm and 3.96 ± 0.83 nm, respectively. The process for calculating the surface roughness is reported in the work of Lara-Cruz et al [ 40 ]. At this point, we consider that the FSNP prepared in this work accomplished all requirements to be employed as substrate for identification of breast cancer cells.…”

Glycerol-3-phosphate acyltransferase 2 expression modulates cell roughness and membrane permeability: An atomic force microscopy study

“…For Atomic force microscopy (AFM) measurements, scr-MDA (control) and sh-MDA ( GPAT2 silenced) cells were plated on glass coverslips and grown in routine medium without the addition of AA for 1−2 days until 80% confluent. Then, the cells were fixed using an ethanol dehydration train at room temperature and subsequently air dried [ 18 ]. Fixation is necessary because high-resolution images of cells are poorly achieved in solution, and the enhanced AFM resolution obtained with fixed cells allows a more detailed subcellular analysis [ 12 ].…”

<p>Gold nanoparticle uptake is enhanced by estradiol in MCF-7 breast cancer cells</p>

“…Active targeting17 involves the selective molecular recognition of antigens that are expressed on the surfaces of cancer cells to localize AuNPs to malignant cells or the exploitation of the membrane properties associated with malignancy. The development of AuNPs that actively target specific cells depends on a better understanding of the many factors affecting the characteristics of bare AuNPs, the behavior of tumor cells and the responses of tumor cells to external stimuli 2,18…”

“…Similarly, the bare AuNPs used in that study emitted a fluorescent signal at 626 nm), thus allowing the distribution of these nanoparticles in the cellular interior to be monitored using confocal laser scanning microscopy (CLSM). These results helped to determine the association between changes in the plasma membrane roughness of MCF-7 cells with the incorporation and intracellular distribution of AuNPs as well as the formation of membrane pores linked to endocytosis uptake mechanisms as analyzed by AFM 18…”