title: Molecular galactose-galectin association in neuroblastoma cells: An unconventional tool for qualitative/quantitative screening.
abstract: Galectin decorates the cell membrane and forms an extracellular molecular association with galactoside units. Here, galactoside probes have been used to study galectin expression in neuroblastoma cells. The hypothesis behind this investigation has been that the molecular mechanisms by which glycans modulate neural metastatic cells involve a protein-carbohydrate association, galectin-galactose.
  
  
  
  Preliminary screening to validate the hypothesis has been performed with galactose moieties anchored to beads. The molecular association has been studied by FACS. In vitro experiments reveal the molecular binding preferences of the metastatic neuroblastoma cells. Ex vivo, the galactose probes discriminate healthy tissues. The unconventional assay in microfluidics used in this study displayed results analogous to the above (GI-LI-N cell capture efficiency overcomes IMR-32).
  
  
  
  At the point of equilibrium of shear and binding forces, the capture yield inside the chamber was measured to 60 ± 4.4% in GI-LI-N versus 40 ± 2.1% in IMR-32. Staining of the fished cells and subsequent conjugation with red beads bearing the galactose also have evidenced that microfluidics can be used to study and quantify the molecular association of galectin-galactose. Most importantly, a crucial insight for obtaining single-cell qualitative/quantitative glycome analysis has been achieved. Finally, the specificity of the assay performed in microfluidics is demonstrated by comparing GI-LI-N fishing efficiency in galactose and fucose environments. The residual adhesion to fucose confirmed the existence of receptors for this glycan and that its eventual unspecific binding (i.e. due to electrostatic interactions) is insignificant compared with the molecular binding.
  
  
  
  Identification and understanding of this mechanism of discrimination can be relevant for diagnostic monitoring and for producing probes tailored to interfere with galectin activities associated with the malignant phenotype. Besides, the given strategy has implications for the rational design of galectin-specific ligands.
authors.affiliation: Laboratorio di Oncologia, Unità di Terapie Sperimentali, Istituto G Gaslini, Via G. Gaslini 5, 16147, Genova, Italy.
authors.forename: Fabio
authors.initials: F
authors.lastname: Pastorino
authors.affiliation: Laboratorio di Oncologia, Unità di Terapie Sperimentali, Istituto G Gaslini, Via G. Gaslini 5, 16147, Genova, Italy.
authors.forename: Mirco
authors.initials: M
authors.lastname: Ponzoni
authors.affiliation: Department of Mechanical Engineering, Northwestern Polytechnical University, 127 West Youyi Road, Xi'an Shaanxi, 710072, P.R. China.|University of Naples Federico II, Piazzale Tecchio 80, 80125 Napoli, Italy.
authors.forename: Giuseppina
authors.initials: G
authors.lastname: Simone
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D005690:Galactose / Q000378:metabolism*; D037161:Galectins / Q000378:metabolism*; D006801:Humans; D056656:Lab-On-A-Chip Devices; D051379:Mice; D009447:Neuroblastoma / Q000378:metabolism / Q000473:pathology*; D011485:Protein Binding
chemical_list: D037161:Galectins; D005690:Galactose
keywords: Galactose; Galectin; Neuroblastoma; Single cell; Unconventional technology