Differential expression of transforming growth factor-beta in benign vs. papillary thyroid cancer nodules; a potential diagnostic tool?
BACKGROUND
Thyroid nodules are common, but only 5% of nodules are found to be malignant. In North America, the incidence of thyroid cancer is increasing. Fine needle aspirate (FNA) biopsy is the diagnostic test of choice. Unfortunately, up to 20% of FNAs are non-diagnostic. A specific molecular marker for thyroid cancer is desirable. Evidence suggests that cell signaling through transforming growth factor beta (TGF-β) is important in the development of thyroid cancer. We sought to compare the expression of TGF-β in malignant and benign thyroid nodules.


METHODS
From 2008-present, thyroid nodule tissue from thyroidectomy specimens was prospectively collected and stored at -80°C. RNA extraction and reverse transcription was performed on 47 samples (24 papillary thyroid cancer and 23 benign nodules). Quantitative PCR using SYBR green was performed to detect TGF-β-1 and -2. Resulting CT values were normalized against β-actin. Gene expression was calculated using the 2(-ΔC)T method.


RESULTS
A significantly greater expression of TGF-β1 (p < 0.0001) was detected in the group of malignant thyroid nodules compared to benign nodules. There was no difference in the expression of TGF-β2 (p = 0.4735) between the two groups.


CONCLUSIONS
In this study, we demonstrated that expression of TGF-β1 but not TGF-β2 is significantly increased in papillary thyroid cancer compared to benign thyroid nodules. This may serve as a potential diagnostic marker for papillary thyroid cancer.
Department of Otolaryngology - Head and Neck Surgery; 3rd Floor Dickson Building, Victoria General Site, QEII Health Sciences Centre, 5820 University Ave., Halifax, Nova Scotia, B3H 2Y9, Canada. matthew.brace@dal.ca.
Matthew D
MD
Brace
Department of Microbiology & Immunology, Department of Pathology, Department of Pediatrics, Canadian Center for Vaccinology, IWK Health Centre, Dr. Richard B. Goldbloom Research and Clinical Care Pavilion, 3rd Floor West, 5850/5980 University Avenue, PO Box 9700, Halifax, Nova Scotia, NS B3K 6R8, Canada. jun.wang@dal.ca.
Jun
J
Wang
Department of Microbiology & Immunology, Department of Pathology, Department of Pediatrics, Canadian Center for Vaccinology, IWK Health Centre, Dr. Richard B. Goldbloom Research and Clinical Care Pavilion, 3rd Floor West, 5850/5980 University Avenue, PO Box 9700, Halifax, Nova Scotia, NS B3K 6R8, Canada. Mark.Petten@dal.ca.
Mark
M
Petten
Department of Pathology; Dr. D. J. Mackenzie Building, 5788 University Avenue, Halifax, Nova Scotia, B3H 2Y9, Canada. Martin.Bullock@cdha.nshealth.ca.
Martin J
MJ
Bullock
Department of Otolaryngology - Head and Neck Surgery; 3rd Floor Dickson Building, Victoria General Site, QEII Health Sciences Centre, 5820 University Ave., Halifax, Nova Scotia, B3H 2Y9, Canada. f50_fawaz@hotmail.com.
Fawaz
F
Makki
Department of Otolaryngology - Head and Neck Surgery; 3rd Floor Dickson Building, Victoria General Site, QEII Health Sciences Centre, 5820 University Ave., Halifax, Nova Scotia, B3H 2Y9, Canada. Jonathan.Trites@cdha.nshealth.ca.
Jonathan
J
Trites
Department of Otolaryngology - Head and Neck Surgery; 3rd Floor Dickson Building, Victoria General Site, QEII Health Sciences Centre, 5820 University Ave., Halifax, Nova Scotia, B3H 2Y9, Canada. smarktaylor@eastlink.ca.
S Mark
SM
Taylor
Department of Otolaryngology - Head and Neck Surgery; 3rd Floor Dickson Building, Victoria General Site, QEII Health Sciences Centre, 5820 University Ave., Halifax, Nova Scotia, B3H 2Y9, Canada. Robert.Hart@cdha.nshealth.ca.
Robert D
RD
Hart
D000368:Aged; D044963:Biopsy, Fine-Needle; D002277:Carcinoma / Q000175:diagnosis* / Q000235:genetics / Q000378:metabolism; D002291:Carcinoma, Papillary; D003937:Diagnosis, Differential; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008297:Male; D012334:RNA, Neoplasm / Q000235:genetics*; D012189:Retrospective Studies; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000077273:Thyroid Cancer, Papillary; D013964:Thyroid Neoplasms / Q000175:diagnosis* / Q000235:genetics / Q000378:metabolism; D016606:Thyroid Nodule / Q000175:diagnosis*; D053773:Transforming Growth Factor beta1 / Q000096:biosynthesis / Q000235:genetics*
D012334:RNA, Neoplasm; D053773:Transforming Growth Factor beta1