Nuclear presence of adhesion-/growth-regulatory galectins in normal/malignant cells of squamous epithelial origin

Abstract

Cellular activities in the regulation of growth or adhesion/migration involve protein (lectin)-carbohydrate recognition at the cell surface. Members of the galectin family of endogenous lectins additionally bind distinct intracellular ligands. These interactions with protein targets explain the relevance of their nuclear and cytoplasmic presence. Expression profiling for galectins and accessible binding sites is a histochemical approach to link localization with cellular growth properties. Non-cross-reactive antibodies for the homodimeric (proto-type) galectins-1, -2 and -7 and the chimera-type galectin-3 (Gal-3) as well as the biotinylated lectins were tested. This analysis was performed with the FaDu squamous carcinoma cell line and long-term cultured human and porcine epidermal cells as models for malignant and normal cells of squamous cell epithelial origin. A set of antibodies was added for phenotypic cell characterization. Strong nuclear and cytoplasmic signals of galectins and the differential reactivity of labeled galectins support the notion of their individual properties. The length of the period of culture was effective in modulating marker expression. Cytochemical expression profiling is a prerequisite for the selection of distinct proteins for targeted modulation of gene expression as a step toward functional analysis.

Phosphorylation of adhesion- and growth-regulatory human galectin-3 leads to the induction of axonal branching by local membrane L1 and ERM redistribution

“…1). This suggests that exposure of neurons to Gal-3-HS complexes could resemble the situation in vivo, where the interaction of different forms of Gal-3 with ECM components may stabilize and/or arrange the lectin to engage in protein-carbohydrate and/or protein-protein binding with distinct partners (Gabius, 2006;Gabius, 2008;Smetana et al, 2006).…”

Changed Expression of E-cadherin and Galectin-9 in Oral Squamous Cell Carcinomas but Lack of Potential as Prognostic Markers

“…The precise functional role of Galectin-9 in the cytoplasm and association of cytoplasmic expression with surface expression have yet to be clarified (Kageshita et al, 2002;Irie et al, 2005). In this context, it is noteworthy that galectin can influence cell proliferation and apoptosis from the cell surface and also from intracellular sites (Smetana et al, 2006). Galectin-9 expression in tumour cells is associated with a better prognosis in cervical SCC (Liang et al, 2008), melanoma and breast carcinoma (Hirashima et al, 2004).…”

How adhesion/growth‐regulatory galectins‐1 and ‐3 attain cell specificity: Case study defining their target on neuroblastoma cells (SK‐N‐MC) and marked affinity regulation by affecting microdomain organization of the membrane

“…Due to the intracellular presence of both galectins and ganglioside GM1, e.g. in nuclei and the nuclear envelope (4,23), these results tempt to suggest a respective interaction also at sites different from the cell surface.…”