Tumor­suppressive effects of Smad­ubiquitination regulator 2 in papillary thyroid carcinoma.

Smad-ubiquitination regulator 2 (SMURF2) functions as a homolog of E6AP carboxyl terminus-type E3 ubiquitin ligase to regulate cell cycle progression and tumor growth factor expression. SMURF2 has been revealed to function as a tumor suppressor in a number of cancers; however, its function in papillary thyroid carcinoma (PTC) remains largely unknown. Therefore, the aim of the present study was to investigate the function of SMURF2 in PTC. Reverse transcription-quantitative PCR and western blotting were used to detect cellular expression of SMURF2 in vitro. After increasing or inhibiting the expression of SMURF2, MTT was used to detect the effect on tumor cell proliferation and Transwell assays were used to detect the effect on tumor cell migration and invasion. Finally, ELISA was used to detect the effects on glucose and glutamine metabolism in tumor cells and the findings revealed that SMURF2 was downregulated in PTC tissues. Moreover, SMURF2 inhibited the proliferation, invasion and migration of PTC cells, and promoted their apoptosis. Finally, SMURF2 inhibited cell glycolysis and glutaminolysis and affected metabolism in the PTC cell line, TPC-1. Thus, the findings of the present study suggest that SMURF2 may be a potential target in the treatment of PTC.

Upregulation of ubiquitin carboxy­terminal hydrolase 47 (USP47) in papillary thyroid carcinoma ex vivo and reduction of tumor cell malignant behaviors after USP47 knockdown by stabilizing SATB1 expression in vitro.

Aberrant ubiquitination contributes to cancer development, including thyroid carcinoma. The present study assessed the expression of ubiquitin carboxy-terminal hydrolase 47 (USP47) and underlying molecular events in the development of papillary thyroid carcinoma (PTC). The effects of USP47 on PTC cell invasion and migration were analyzed by Transwell assays, while. the effects of USP47 and SATB1on PTC cell gene expression and changes in tumor cell metabolism were assayed by reverse transcription-quantitative PCR, western bolt, or ELISA, respectively. The expression of USP47 mRNA and protein was upregulated in PTC tissue and associated with the PTC tumor size. Knockdown of USP47 expression in PTC cell lines (TPC-1 and K1), decreased the cell proliferation mobility and invasion capacities, whereas USP47 overexpression in these cell lines showed an inverse effect and promoted cell glycolysis and glutamine metabolism. Moreover, expression of special AT-rich sequence-binding protein-1 (SATB1) was high in PTC tissue and was associated with USP47 expression. SATB1 expression promoted tumor cell glycolysis and glutamine metabolism, while USP47 protein bound to and deubiquitinated SATB1 to increase its intracellular levels, thus promoting glycolysis and glutamine metabolism. USP47 promotion of PTC development may be due to its stabilization of SATB1 protein, suggesting that targeting the USP47/SATB1 signaling axis may serve as a therapeutic intervention for PTC.