Quantitation of thyroid peroxidase mRNA in peripheral blood for early detection of thyroid papillary carcinoma.
We applied quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) to detect tissue-specific mRNAs in circulating cancer cells for the diagnosis of early-stage cancer. By Northern blotting, the thyroid peroxidase gene (TPO) was strictly expressed in the thyroid. We also used RT-PCR to examine TPO and thyroid stimulating hormone receptor (TSHR) mRNAs in peripheral blood in 33 thyroid papillary carcinoma patients at stages I (23 cases), II (8 cases) and III (3 cases), 49 noncancer patients with benign thyroid diseases, and 20 healthy volunteers. TPO mRNA was detected in 14 of 23 (61%) cases of stage I carcinoma but only 2 of 49 cases with benign thyroid disease. TPO mRNA was not detected in 20 healthy volunteers. By real-time quantitative RT-PCR, the estimated number of thyrocytes in the circulation ranged from 0.24 and 2700 cells per milliliter of whole blood in 7 of 9 patients at stages I and II, and thyrocyte number did not correlate with tumor size or serum thyroglobulin level. Our results might suggest that detection and quantification of tissue-specific mRNAs (e.g., TPO) in peripheral blood could serve as a means to identify potential tumor markers at early stages of cancer.
Ishikawa
Tomoyoshi
T
Department of Biochemistry and Molecular Oncology, University of Tsukuba, Ibaraki, Japan.
Miwa
Masanao
M
Uchida
Kazuhiko
K
D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor; D015152:Blotting, Northern; D015139:Blotting, Southern; D002291:Carcinoma, Papillary / Q000097:blood* / Q000175:diagnosis* / Q000201:enzymology; D002648:Child; D006801:Humans; D007453:Iodide Peroxidase / Q000097:blood*; D008875:Middle Aged; D009362:Neoplasm Metastasis; D012333:RNA, Messenger / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013964:Thyroid Neoplasms / Q000097:blood* / Q000175:diagnosis* / Q000201:enzymology
D014408:Biomarkers, Tumor; D012333:RNA, Messenger; D007453:Iodide Peroxidase