摘要: Background: CEACAM1, formerly known as biliary glycoprotein, CD66a and C-CAM1, is a member of the CEA immunoglobulin superfamily.CEACAM1 is a putative tumor suppressor based on diminished expression in some solid neoplasms such as... 展开 Background: CEACAM1, formerly known as biliary glycoprotein, CD66a and C-CAM1, is a member of the CEA immunoglobulin superfamily.CEACAM1 is a putative tumor suppressor based on diminished expression in some solid neoplasms such as colorectal carcinoma. However, CEACAM1 is also over-expressed in some tumors such as non-small cell lung cancer. The expression pattern and role of CEACAM 1 in thyroid tissue remain unknown. Design: In the present study we investigated the expression of CEACAM1 in thyroid tissue and tumor cell lines, and its relationship to thyroid cell growth and adhesion. Since Vitamin D and its analogues, EB1089 and KH1060 are known to inhibit thyroid cancer cell growth, we examined the effect of these compounds on the expression of CEACAM 1 in thyroid cancer. Results: We found here that CEACAM1 is mainly detectable in aggressive ARO (anaplastic) and MRO (follicular) carcinoma cell lines but not in cell lines derived from the more benign forms of thyroid neoplasms. In primary human thyroid specimens, CEACAM1 was expressed in papillary carcinomas that demonstrated lymph nodal invasion as well as anaplastic carcinomas but was absent in normal unaffected tissue. Treatment with vitamin D or its analogues which arrest thyroid cancer cell progression also decreased CEACAM1 expression. Small interfering RNA (siRNA)-mediated attenuation of CEACAM1 resulted in promoted thyroid cancer cell adhesiveness and the loss of invasive growth and metastasis in vitro and in xenograffed mice. Conclusion: These findings suggest that CEACAM1 is expressed in a more aggressive group of thyroid malignancies and its functions may not be exclusively rumor suppressive, and it represents a target for Vitamin D therapy which modulates its expression and may have potential therapeutic applications. 收起