Distribution of the cadherin-catenin complex in normal human thyroid epithelium and a thyroid carcinoma cell line

✍ Scribed by Shih-Horng Huang; Jiahn-Chun Wu; King-Jen Chang; Koung-Yi Liaw; Seu-Mei Wang

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 355 KB
• Volume: 70
• Category: Article
• ISSN: 0730-2312
• DOI: 10.1002/(sici)1097-4644(19980901)70:3<330::aid-jcb6>3.0.co;2-o

✦ Synopsis

E-cadherin is the major cell-cell adhesion molecule expressed by epithelial cells. Cadherins form a complex with three cytoplasmic proteins, ␣-, ␤-, and ␥-catenin, and the interaction between them is crucial for anchoring the actin cytoskeleton to the intercellular adherens junctions. The invasive behavior of cancer cells has been attributed to a dysfunction of these molecules. In this study, we examined the distribution of the cadherin-catenin complex in a Chinese human thyroid cancer cell line, CGTH W-2, compared with that in normal human thyroid epithelial cells. In the normal cells, using immunofluorescence staining, E-cadherin and ␣-, ␤-, and ␥-catenin were found to be localized at the intercellular junction and appeared as 135, 102, 90, and 80 kD proteins on Western blots. In CGTH W-2 cells, no E-cadherin and ␥-catenin immunoreactivity was detected by immunofluorescence or Western blotting; ␣and ␤-catenin were detected as 102 and 90 kD proteins on blots but gave a diffuse cytoplasmic immunofluorescence staining pattern in most cells, while ␤-catenin was also distributed throughout the cytoplasm in most cells but was found at the cell junction in some, where it colocalized with ␣-actinin. The present data indicate that the loss of cell adhesiveness in these cancer cells may be due to incomplete assembly of the cadherin-catenin complex at the cell junction. However, this defect did not affect the linkage of actin bundles to vinculin-enriched intercellular junctions.