Effect of β4 integrin knockdown by RNA interference in anaplastic thyroid carcinoma

Background: Integrin α6β4 is a known tumor antigen; however, its function in different subtypes of thyroid cancer is not known. This study reports that α6β4 expression is selectively up-regulated in anaplastic thyroid cancer (ATC) cells, the most malignant subtype of human thyroid cancer. Materials and Methods: To assess the contribution of α6β4 in ATC progression, cell proliferation, motility and soft agar assay were performed in vitro and a xenograft tumor growth assay was performed in vivo. Results: Knockdown of β4 integrin subunit expression by shRNA in ATC cells reduced the proliferation, migration, and anchorage-independent growth of ATC cells in vitro and xenograft tumor growth in vivo. Conclusion: These data suggest that integrin α6β4 contributes to the development of aggressive forms of thyroid cancer with poor prognostic potential, such as ATC, and thus may be a novel therapeutic target for the treatment for this subtype of thyroid cancer.