Inhibition of N-linked glycosylation by tunicamycin induces E-cadherin-mediated cell–cell adhesion and inhibits cell proliferation in undifferentiated human colon cancer cells

• Published in: Cancer chemotherapy and pharmacology Vol. 68; no. 1; pp. 227 - 238
• Main Authors: de Freitas Junior, Julio Cesar Madureira, Silva, Bárbara Du Rocher D’Aguiar, de Souza, Waldemir Fernandes, de Araújo, Wallace Martins, Abdelhay, Eliana Saul Furquim Werneck, Morgado-Díaz, José Andrés
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.07.2011; Springer; Springer Nature B.V
• Subjects: Adherens Junctions - drug effects; Animals; Antineoplastic agents; Antineoplastic Agents - pharmacology; Apoptosis - drug effects; Biological and medical sciences; Caco-2 Cells; Cadherins - physiology; Calcium - metabolism; Cancer Research; Cell Adhesion - drug effects; Cell Proliferation - drug effects; Colonic Neoplasms - pathology; Colonic Neoplasms - physiopathology; Gastroenterology. Liver. Pancreas. Abdomen; Glycosylation; HCT116 Cells; Humans; Medical sciences; Medicine; Medicine & Public Health; Mice; Oncology; Original Article; Pharmacology. Drug treatments; Pharmacology/Toxicology; Polysaccharides - physiology; Stomach. Duodenum. Small intestine. Colon. Rectum. Anus; Tumors; Tunicamycin - pharmacology; glycosylation; Adherens junctions; Swainsonine; E-cadherin; Tunicamycin; Colorectal cancer; Human; Cell proliferation; Rectal disease; Cell adhesion molecule; Cell cell interaction; Glycosylation; Malignant tumor; N-glycosylation; Colonic disease; Colon cancer; Digestive diseases; Intestinal disease; Inhibitor; Junction; Inhibition; E Cadherin; Tumor cell; Cancer
• ISSN: 0344-5704; 1432-0843
• DOI: 10.1007/s00280-010-1477-8

Purpose Aberrant protein glycosylation and disassembly of E-cadherin-mediated cell–cell adhesion are characteristics of epithelial cancer. However, the relationship between these two events in colorectal cancer remains to be defined. In this study, we analyzed whether N -glycan expression is crucial for the loss of E-cadherin-mediated cell–cell adhesion in human colorectal cancer cells. Methods Differentiated Caco-2 and undifferentiated HCT-116 colon cancer cells were used as models of stable and unstable adherens junctions (AJs), respectively. Complex-type N -glycans were detected using the lectins E-PHA ( Phaseolus vulgaris E.) and L-PHA ( Phaseolus vulgaris L.). To study E-cadherin-mediated AJ assembly, we examined the effects of swainsonine, an inhibitor of α -mannosidase II, and tunicamycin, a drug that inhibits the biosynthesis of N -glycans, via western blot, immunofluorescence, differential extraction in Triton X-100, and electron microscopy. Cell proliferation and apoptosis were examined by crystal violet staining and flow cytometry, respectively. Results We observed positive labeling for E-PHA and L-PHA lectins in both cell lines; however, HCT-116 cells had increased E-cadherin-linked complex-type N -glycans. Interestingly, tunicamycin, but not swainsonine, was able to induce functional E-cadherin-mediated cell–cell adhesion in undifferentiated HCT-116 cells, as shown by the increased association of E-cadherin with the actin cytoskeleton. Moreover, in HCT-116 cells, tunicamycin also induced the formation of tight cell–cell contacts, and it inhibited cell proliferation without triggering apoptosis. Conclusions Collectively, our results demonstrate for the first time that altered N -glycan expression plays an important role in the loss of AJ stability in undifferentiated colorectal cancer cells and that this loss may be associated with the progression of colorectal cancer.