High expression of NUCB2 promotes papillary thyroid cancer cells proliferation and invasion

Background: NUCB2, a novel multifunctional protein containing several functional domains, was newly found to play important roles in many cancers, but its role in papillary thyroid cancer (PTC) is not well investigated. Therefore, our study was performed to explore the functions of NUCB2 in PTC. Methods: NUCB2 protein level was analyzed by immunohistochemistry. Data analyses were made by performing chi-squared test. Quantitative reverse-transcription PCR, Western blot colony formation, MTT, and transwell invasion assays were performed to test the expression levels and functions of NUCB2 in PTC. Results: In PTC tissues, NUCB2 protein expression level was positively correlated with extrathyroidal extension, TNM stage, and tumor size of PTC patients. In vitro experiments demonstrated that knockdown of NUCB2 using specific shRNA for NUCB2 significantly impaired cell proliferation and invasion of PTC cell lines. In vivo, silencing ofNUCB2 inhibited the growth of tumors in mice. Conclusion: These results suggested a novel function ofNUCB2 in the process of proliferation and invasion in PTC. NUCB2 may be considered a potent prognostic factor in PTC.