Plasmonic Biosensing for Label-Free Detection of Two Hallmarks of Cancer Cells: Cell-Matrix Interaction and Cell Division

Abstract

Two key features of cancer cells are sustained proliferation and invasion, which is preceded by a modification of the adhesion properties to the extracellular matrix. Currently, fluorescence-based techniques are mainly used to detect these processes, including flow cytometry and fluorescence resonance energy transfer (FRET) microscopy. We have previously described a simple, fast and label-free method based on a gold nanohole array biosensor to detect the spectral response of single cells, which is highly dependent on the actin cortex. Here we used this biosensor to study two cellular processes where configuration of the actin cortex plays an essential role: cell cycle and cell–matrix adhesion. Colorectal cancer cells were maintained in culture under different conditions to obtain cells stopped either in G0/G1 (resting cells/cells at the initial steps of cell growth) or G2 (cells undergoing division) phases of the cell cycle. Data from the nanohole array biosensor showed an ability to discriminate between both cell populations. Additionally, cancer cells were monitored with the biosensor during the first 60 min after cells were deposited onto a biosensor coated with fibronectin, an extracellular matrix protein. Spectral changes were detected in the first 20 min and increased over time as the cell–biosensor contact surface increased. Our data show that the nanohole array biosensor provides a label-free and real-time procedure to detect cells undergoing division or changes in cell–matrix interaction in both clinical and research settings.

Size-Specific Modulation of a Multienzyme Glucosome Assembly during the Cell Cycle

“…First, we treated Hs578T cells with lovastatin (40 μM), which is known to arrest cells in the G1 phase through the inhibition of 3-hydroxy-3-methylglutaryl coenzyme A reductase (Figure A). − Without the glucosome marker PFKL-mEGFP, the percentage of G1-arrested Hs578T cells increased 16.6% in the presence of lovastatin, relative to the percentage of asynchronous Hs578T cells in the G1 phase (i.e., 57.6 ± 5.4% to 74.2 ± 3.5%) (Figure B, light gray vs blue). Meanwhile, lovastatin also increased by 17.9% PFKL-mEGFP-transfected Hs578T cells in the G1 phase, relative to the percentage of asynchronous Hs578T cells expressing PFKL-mEGFP (i.e., 52.5 ± 3.2% to 70.4 ± 2.1%) (Figure C, red vs blue).…”

“…(E) Average percentages (%) of cells displaying differently sized glucosomes along with their standard deviations (±). Note that the concentrations of the cell cycle inhibitors we used for fluorescence live-cell imaging are lower, but still in the range of their concentrations being used in the literature, − ,,− , than what we used for flow cytometry in Figure .…”

Optical Processes behind Plasmonic Applications

“…Surface-plasmon-resonance biosensors based on plasmonic nanostructures have emerged as reliable tools for the detection and analysis of biological and chemical molecules [ 141 , 142 , 143 , 144 , 145 , 146 , 147 , 148 , 149 ]. The chip-based sensors typically comprise a glass substrate coated with (∼50 nm) of metal and a sensing layer.…”

A review on hybridization of plasmonic and photonic crystal biosensors for effective cancer cell diagnosis

“…25 To mitigate the effects of energy loss in layers of plasmonic biosensors, optimization of layer thickness, and advanced fabrication techniques such as atomic layer deposition or chemical vapor deposition, can be used to create high-quality layers with reduced energy loss. These factors advance plasmonic biosensor performances over conventional ones allowing (i) label-free detection, 26 (ii) real-time monitoring, 27 (iii) high re-usability, 28 and (iv) simple sample treatments. 29 The disadvantages include (i) mass transportation limitations, (ii) non-specificity of the binding surface, (iii) steric hindrance during the binding event, and (iv) data misinterpretation.…”