Thyroid neoplasm is the most commonly encountered neoplastic disorder in endocrine clinics. Thyroid scan, ultrasonography, and fine needle aspiration cytology (FNAC) are used as diagnostic tools to differentiate a malignant nodule from a benign lesion. There are certain limitations and pitfalls in FNAC, especially in the diagnosing of follicular
tumors. The lack of characteristic findings or a specific
tumor marker are the most common problems in the preoperative diagnosis of thyroid follicular
carcinoma. Although serum
thyroglobulin level has been used as a
tumor marker for post-operative, well-differentiated
thyroid cancer, the assay cannot be used for preoperative diagnosis of
thyroid carcinoma. In this study, various thyroid tissues and
cancer cell lines including
CGTH W-1,
CGTH W-3, RO 82 W-1, SW 579 cell lines were used for the investigation of
tumor markers. Specific spots were identified in the area near the 60 kDa molecular mass
protein and isoelectric point (pI) 5.9 of the
CGTH W-1 cell line. These spots could not be found in the papillary or
anaplastic thyroid cancer cell lines. Another spot with a molecular weight of about 9.8 kDa with a low pI of 4.8 was present in the
CGTH W-1 and RO 82 W-1 cell lines. This spot appeared to be a
tumor marker of follicular
cancer cells. This spot could not be found in the papillary and anaplastic
cancer cell lines and other benign thyroid tissues. Specific
proteins that were identified in this study may be useful as
tumor markers for
follicular thyroid carcinoma.