A useful marker of FB21 mAb for the diagnosis of follicular carcinoma of thyroid and the regulation of sialylation

Yoshihiro Nozawa 1, Hirofumi Ami 2, Toshihiko Fukushima 2, Osamu Suzuki 1, Masafumi Abe 1

1 Department of Pathology, 2 Second Department of Surgery, Fukushima Medical University School of Medicine, Fukushima, Japan

AIM. FB21 mAb was reported a useful marker for the diagnosis of follicular carcinoma of thyroid [Pathology International, 1999;49:403-407]. We have investigated the sialylation and its regulation using immunohistochemical and RT-PCR methods. METHODS. Reactivity of FB21 and LN-1(anti-CDw75) mAbs, which recognizes sialic acid-dependent carbohydrate epitopes, were examined in paraffin sections (4 cases of normal thyroid tissue, 4 cases of follicular adenoma, and 4 cases of follicular carcinoma) using immunohistochemical method. The expression of alpha 2-6 sialyltransferase and UDP-GlcNAc 2-epimerase mRNA were tested by RT-PCR. RESULTS. FB21 mAb reacted with 3 of 4 cases of follicular carcinoma with microfollicular pattern, and not with normal thyroid and follicular adenoma. Non-neoplastic and neoplastic thyroid tissues were negative or rare cell positive for LN-1 mAb. Alpha 2-6 sialyltransferase mRNA was detected by RT-PCR in normal thyroid, follicular adenoma, and follicular carcinoma. UDP-GlcNAc 2-epimerase mRNA was also detected less in carcinoma than in normal thyroid tissue and adenoma. CONCLUSION. Our data suggests that FB21 is a useful marker to distinguish follicular carcinoma from follicular adenoma and the regulation of sialylation in follicular carcinoma is different from that in hematopoietic cell lines.

For more information, contact

Paper presented at the International Symposium on Predictive Oncology and Intervention Strategies; Paris, France; February 9 - 12, 2002; in the section on Diagnostic Markers.