BTG1 expression in thyroid carcinoma: diagnostic indicator and prognostic marker

Area of Science:

• Oncology
• Molecular Biology
• Genetics

Background:

• Thyroid carcinoma is a significant global health concern.
• Understanding the molecular mechanisms underlying thyroid cancer progression is crucial for developing effective therapeutic strategies.
• B cell translocation gene 1 (BTG1) is a potential tumor suppressor gene, but its role in thyroid carcinoma remains unclear.

Purpose of the Study:

• To investigate the expression and functional role of BTG1 in thyroid carcinoma.
• To determine the correlation between BTG1 expression levels and clinicopathological features and prognosis of thyroid cancer patients.
• To elucidate the in vitro effects of BTG1 overexpression on thyroid cancer cell behavior.

Main Methods:

• Immunohistochemistry and western blotting were used to assess BTG1 expression in thyroid cancer tissues and adjacent normal tissues.
• A human thyroid cancer cell line (FTC-133) was stably transfected with a lentivirus to overexpress BTG1 (LeBTG1 cells).
• In vitro assays including MTT, flow cytometry, and Matrigel invasion assays were performed to evaluate cell viability, proliferation, apoptosis, cell cycle distribution, migration, and invasion.

Main Results:

• BTG1 protein expression was significantly lower in thyroid cancer tissues compared to normal tissues (36.1% vs. 80.0% for IHC, P<0.05).
• Reduced BTG1 expression correlated with lymph node metastasis, advanced clinical stage, poor pathological differentiation, and decreased 10-year survival rates (30.2% vs. 66.7%, P<0.05).
• In vitro, BTG1 overexpression in FTC-133 cells led to reduced cell survival, increased apoptosis, G0/G1 cell cycle arrest, and impaired migration and invasion, accompanied by decreased expression of cyclin D1, Bcl-2, and MMP-9.

Conclusions:

• BTG1 expression is significantly downregulated in thyroid carcinoma.
• BTG1 acts as a negative regulator of thyroid cancer progression by inhibiting cell proliferation, survival, and metastasis.
• BTG1 serves as a potential prognostic biomarker for thyroid cancer.