Differential Expression of Sialic Acid and N-acetylgalactosamine Residues on the Cell Surface of Intestinal Epithelial Cells According to Normal or Metastatic Potential

Abstract

In this study we investigated the levels of expression of sialic acid and N-acetylgalactosamine residues on the cell surface of a normal intestinal epithelium cell line, IEC-6, and in two colon adenocarcinoma cell lines with different metastatic potential, Caco-2 and HCT-116. Glycoprotein expression was estimated initially by cytochemistry with WGA and HPA lectins and biochemistry with isolated plasma membrane fractions of the cells. Fluorescence and electron microscopic analyses revealed differences in the expression profile of carbohydrates recognized by the lectins used on the cell surface of IEC-6, Caco-2, and HCT-116 cells. Lectin blotting identified a range of eight HPA-binding glycoprotein bands with molecular weights of 16-66 kD in Caco-2 cells, six glycoproteins of 16-36 kD, and three protein bands of 35, 24, and 21 kD in IEC-6 cells. A minor band of 66 kD and a major one of 50 kD for WGA-binding glycoproteins were observed in IEC-6 cells and seven glycoproteins of 18-97 kD in Caco-2 and HCT-116 cells but with a visible higher expression of these glycoproteins in the latter. Furthermore, significant quantitative difference in levels of expression of WGA- but not of HPA-binding glycoconjugates was noted, as analyzed by high-resolution scanning electron microscopy using backscattered electron images of cells incubated with gold-labeled lectins.

siRNA Knockdown of Ribosomal Protein Gene RPL19 Abrogates the Aggressive Phenotype of Human Prostate Cancer

“…The behavior of malignant epithelial cells is influenced by expression of cell-surface complex glycoconjugates, particularly sialic acids [46], [113]–[115]. To assess the potential effects of RPL19 knockdown on cell-surface oligosaccharide expression, cell-blocks were prepared from cell-lines PNT2, PC-3M parental , PC-3M scramble , and si- RPL19- PC-3M clone ST-3 .…”

Analysis of Cell Surface Carbohydrate Expression Patterns in Normal and Tumorigenic Human Breast Cell Lines Using Lectin Arrays

“…The mammalian cell surface is decorated with a dense layer of carbohydrates, which are attached to membrane glycoproteins and glycolipids . These cell surface carbohydrates are cell-type specific and participate in a wide variety of biological processes including cell adhesion, fertilization, differentiation, development, and tumor cell metastasis. − Abnormal glycosylation has been associated with many diseases, especially cancers, such as breast cancer, prostate cancer, lung cancer, and colon cancer. − Moreover, tumor-associated alterations of cell surface glycosylation play a crucial role in metastasis of carcinoma cells by altering tumor cell adhesion or motility in a manner that either promotes or inhibits invasion and metastasis. , The ability to characterize cell surface carbohydrate expression patterns is thus critical both to understanding their role in disease development as well as to provide diagnostic tools to help guide treatment.…”

“…[1][2][3][4][5] Abnormal glycosylation has been associated with many diseases, especially cancers, such as breast cancer, prostate cancer, lung cancer, and colon cancer. [6][7][8][9][10] Moreover, tumor-associated alterations of cell surface glycosyla-tion play a crucial role in metastasis of carcinoma cells by altering tumor cell adhesion or motility in a manner that either promotes or inhibits invasion and metastasis. 11,12 The ability to characterize cell surface carbohydrate expression patterns is thus critical both to understanding their role in disease development as well as to provide diagnostic tools to help guide treatment.…”

TMEM115 as an integral membrane protein of the Golgi apparatus involved in retrograde transport

“…Non-permeabilized cells were labeled with fluorescent-dye-conjugated lectins. HPA mainly stains the Golgi complex (Campadelli et al, 1993; Virtanen, 1990) with very weak staining at the cell surface (de Albuquerque Garcia Redondo et al, 2004). Therefore, for proper visualization of HPA labeling, the cells were permeabilized with 0.1% Triton-X-100 prior to staining.…”