The protein expression and clinical significance of coiled-coil domain containing 67 and B cell lymphoma/leukemia-2 in papillary thyroid carcinoma

Abstract

Objective To investigate the protein expression of coiled-coil domain containing 67 (CCDC67) and B cell lymphoma/leukemia-2 (bcl-2) in papillary thyroid carcinoma (PTC) and adjacent normal tissues so as to explore their clinical significance in the pathogenesis of PTC. Methods CCDC67 and bcl-2 protein expression was detected by immunohistochemistry in 57 cases of PTC. The apoptosis index (AI) was measured by TdT-mediated dUTP nick end labeling (TUNEL) method. Results The expression rate of CCDC67 protein in PTC tissue was lower than that of non-cancerous adjacent tissues (96.49% vs. 43.86%, P=0.000). The expression rate of CCDC67 protein was related to tumor size, TNM stage, pathological grade and lymph node metastasis of PTC (χ2=3.944, 4.711, 6.068, 7.143; P=0.047, 0.030, 0.014, 0.008). The expression rate of bcl-2 protein in PTC tissue was higher than that of non-cancerous adjacent tissues (57.89% vs. 15.79%, P=0.000), and correlated with the TNM stage, pathological grade and lymph node metastasis (χ2=8.757, 4.765, 8.449; P=0.003, 0.029, 0.004) of PTC. The expression levels of CCDC67 and bcl-2 proteins displayed a negative correlation (r=0.400, P=0.003). The AI in CCDC67 protein positive group was higher than that in CCDC67 protein negative group (t=12.812, P=0.000). Conclusion CCDC67 gene represented as a tumor suppressor gene, playing an important role in PTC via regulation of tumor cell apoptosis. The expressions of CCDC67 and bcl-2 protein may be used as clinical biological indicators to evaluate the prognosis of PTC. Key words: Thyroid carcinoma; Coiled-coil domain containing 67; B-cell leukemia/lymphoma-2