Nanoscale Organization of Human GnRH-R on Human Bladder Cancer Cells

Abstract

Human gonadotropin-releasing hormone receptor (GnRH-R; or type I GnRH-R), which is expressed in tumor cells, has gained more and more attention as a specific target for cancer therapy. Given the clinical utility, the improved characterization of both the subcellular distribution and surface organization of GnRH-R is an important step in the development of more effective and possibly new therapeutic strategies. In the present study, the nano-organization of human GnRH-R was analyzed on fixed human bladder cancer cells (T24) by atomic force microscopy (AFM). The recognition images reveal that GnRH-Rs have a tendency to assemble in nanodomains (or clusters) that are irregularly distributed on the T24 cell surface. The locations of the GnRH-Rs were identified on the topographical images with nanometer accuracy. The obtained results enrich our understanding of the local distribution of GnRH-Rs on the bladder cancer cell membrane and demonstrate the ability of biological AFM to provide more complete and exact information at the single molecule level.

Physical interaction and assembly of Bacillus subtilis spore coat proteins CotE and CotZ studied by atomic force microscopy

“…For SMFS, the general process for functionalization of the silicon pieces with CotE was similar to a previously reported procedure (Zhang et al, 2014). In brief, the cleaned silicon pieces were moved into an argon-gas-filled desiccator and incubated with 50 lL 3-aminopropyltriethoxysilane (APTES) and 15 lL triethylamine for 2 h using a vapor-phase deposition method (Ebner et al, 2007).…”

AFM analysis of the multiple types of molecular interactions involved in rituximab lymphoma therapy on patient tumor cells and NK cells

“…Some FcRs clustered into nanodomains (denoted by the red dashed circles), while some FcRs distributed sparsely on the cell surface. Traditional methods used to investigate the distribution of FcR are based on flow cytometry [44] or fluorescence microscopy [45], which makes is impossible to understand how single molecules localize, assemble, and interact on the cell surface at the nanometer scale [6] due to the 200 nm resolution limit of optical microscopy. AFM provides exciting possibilities for mapping the distribution of single molecules on the surface of cells [46], paving the way for elucidating the highly complex activities between various molecules on the cell surface.…”

“…This technique is termed single-molecule force spectroscopy (SMFS) [4]. Recently, SMFS has been proven to be a useful method to analyze the activities of single molecules in situ on living bacteria [5] and mammalian cells [6]. However, current SMFS experiments are performed on purified biomolecules isolated from cell lines [7] or directly on cell lines [8].…”

Rapid recognition and functional analysis of membrane proteins on human cancer cells using atomic force microscopy

“…The cluster analysis was performed using the open source Fiji software according to the reference (Zhang et al, 2014). The adhesion images were first converted into binary images.…”