Stage-Specific Embryonic Antigen-1 (SSEA-1) Expression in Thyroid Tissues.

Area of Science:

• Oncology
• Immunohistochemistry
• Cancer Stem Cell Biology

Background:

• Stage-specific embryonic antigen-1 (SSEA-1), or CD15, is a cell surface marker found in various normal tissues and cancers.
• SSEA-1 expression has been noted in thyroid carcinomas, including papillary and medullary types.
• Its presence in normal stem cells and cancer stem-like cells suggests potential diagnostic and prognostic roles.

Purpose of the Study:

• To investigate the diagnostic and prognostic value of SSEA-1 in thyroid tumors.
• To analyze SSEA-1 expression in normal and neoplastic thyroid tissues using immunohistochemistry.
• To assess SSEA-1 as a potential surface marker in thyroid cell lines via flow cytometry.

Main Methods:

• Immunohistochemistry (IHC) on a tissue microarray of 158 thyroid tissue cores.
• Flow cytometric analysis of SSEA-1 expression in cultured thyroid cell lines.
• Correlation of SSEA-1 immunoreactivity with different thyroid tumor subtypes and aggressiveness.

Main Results:

• SSEA-1 immunoreactivity was detected in malignant thyroid follicular epithelial cancers, but absent in benign thyroid tissues.
• Anaplastic thyroid carcinoma (80%) and conventional papillary thyroid carcinoma (60.7%) showed higher SSEA-1 positivity than FVPTC (20.6%) and FCA (32.1%).
• Flow cytometry revealed SSEA-1 expression on a subpopulation of ATC and PTC cells, indicative of cancer stem-like cells, with ATC showing higher expression.

Conclusions:

• SSEA-1 expression in thyroid neoplasms is associated with more aggressive thyroid carcinomas.
• SSEA-1 serves as a marker for detecting malignant thyroid neoplasms in formalin-fixed paraffin-embedded tissues.
• SSEA-1 may be a valuable marker for identifying thyroid cancer stem-like cells.