Fangzhou Liu1, Rong Yin2, Xinyuan Chen3, Wei Chen4, Yichun Qian5, Yanbin Zhao5, Yuan Jiang5, Dawei Ma6, Tingting Hu5, Tonghua Yu5, Yan Zhu7, Yuan Zhang8. 1. Department of Head & Neck Surgery, Jiangsu Cancer Hospital, Jiangsu Institute of Cancer Research, The Affiliated Cancer Hospital of Nanjing Medical University, Nanjing, 210009, PR China. Electronic address: liufangzhou2017@sina.com. 2. Department of Thoracic Surgery, Jiangsu Cancer Hospital, Jiangsu Institute of Cancer Research, The Affiliated Cancer Hospital of Nanjing Medical University, Nanjing, 210009, PR China. 3. Department of Head & Neck Surgery, Jiangsu Cancer Hospital, Jiangsu Institute of Cancer Research, The Affiliated Cancer Hospital of Nanjing Medical University, Nanjing, 210009, PR China; Department of Immunology, Nanjing Medical University, Nanjing, 211166, PR China. 4. Department of Head & Neck Surgery, Jiangsu Cancer Hospital, Jiangsu Institute of Cancer Research, The Affiliated Cancer Hospital of Nanjing Medical University, Nanjing, 210009, PR China; Jiangsu Provincial Clinical Laboratory Center, Nanjing, 210009, PR China. 5. Department of Head & Neck Surgery, Jiangsu Cancer Hospital, Jiangsu Institute of Cancer Research, The Affiliated Cancer Hospital of Nanjing Medical University, Nanjing, 210009, PR China. 6. Department of Pathology, Jiangsu Cancer Hospital, Jiangsu Institute of Cancer Research, The Affiliated Cancer Hospital of Nanjing Medical University, Nanjing 210009, PR China. 7. Department of Pathology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, PR China. 8. Department of Head & Neck Surgery, Jiangsu Cancer Hospital, Jiangsu Institute of Cancer Research, The Affiliated Cancer Hospital of Nanjing Medical University, Nanjing, 210009, PR China. Electronic address: yzhang1963@163.com.
Abstract
PURPOSE: microRNAs (miRNAs) play a critical role in drug resistance of multiple cancers including papillary thyroid carcinoma (PTC), indicating the potential of miRNAs as chemoresistance regulators in cancer treatment. The aim of this paper is to explore the relationship between miR-206 and chemoresistance of PTC. METHODS: qRT-PCR was conducted to examine the expression of miR-206 in PTC tissues, parental and TPC-1/euthyrox. The CCK-8 assay, EdU assay and flow cytometry were performed to test cells viability, proliferation and apoptosis, respectively. Luciferase reporter assay was used to confirm the potential target of miR-206. Western blotting analysis was performed to evaluate the expressions of related-proteins. RESULTS: miR-206 was significantly down-regulated in PTC tissues, parental and TPC-1/euthyrox. Moreover, the expression of miR-206 was exceptionally lower in TPC-1/euthyrox cells than that in TPC-1 cells. Furthermore, we found that over-expression of miR-206 could notably decrease the IC50 values both in TPC-1 and TPC-1/euthyrox cells, which indicated that miR-206 played an essential role in the euthyrox resistance in PTC. In addition, up-regulation of miR-206 inhibited the proliferation, induced apoptosis, suppressed the expressions of multidrug resistance-related proteins, including p-gp, MRP, BCRP and LRP, in euthyrox-resistant PTC cells. Besides, over-expression of miR-206 could notably promoted the expression of NIS, an intrinsic membrane protein that mediates the active transport of iodide into the thyroid and other tissues, playing a critical role in the progress. Further, miR-206 was demonstrated to be able to bind to MAP4K3 and negatively regulated the expression of MAP4K3. Besides, MAP4K3 was clearly up-regulated in PTC tissues, parental and TPC-1/euthyrox cells, and down-regulation of miR-206 attenuated the effect of si-MAP4K3 on the euthyrox sensitivity in euthyrox-resistant PTC cells. Moreover, TPC-1/euthyrox cells transfected with miR-206 mimics could significantly inhibit the expressions of p-p38, p-JNK and p-Erk, which indicated that miR-206 might play an essential role in the euthyrox resistance in PTC by negatively regulating the p38 and JNK signaling pathway. CONCLUSION: miR-206 contributed to euthyrox resistance in PTC cells through blockage p38 and JNK signaling pathway by targeting MAP4K3, providing a potential therapeutic application for the treatment of patients with euthyrox-resistant PTC in the further.
PURPOSE: microRNAs (miRNAs) play a critical role in drug resistance of multiple cancers including papillary thyroid carcinoma (PTC), indicating the potential of miRNAs as chemoresistance regulators in cancer treatment. The aim of this paper is to explore the relationship between miR-206 and chemoresistance of PTC. METHODS: qRT-PCR was conducted to examine the expression of miR-206 in PTC tissues, parental and TPC-1/euthyrox. The CCK-8 assay, EdU assay and flow cytometry were performed to test cells viability, proliferation and apoptosis, respectively. Luciferase reporter assay was used to confirm the potential target of miR-206. Western blotting analysis was performed to evaluate the expressions of related-proteins. RESULTS:miR-206 was significantly down-regulated in PTC tissues, parental and TPC-1/euthyrox. Moreover, the expression of miR-206 was exceptionally lower in TPC-1/euthyrox cells than that in TPC-1 cells. Furthermore, we found that over-expression of miR-206 could notably decrease the IC50 values both in TPC-1 and TPC-1/euthyrox cells, which indicated that miR-206 played an essential role in the euthyrox resistance in PTC. In addition, up-regulation of miR-206 inhibited the proliferation, induced apoptosis, suppressed the expressions of multidrug resistance-related proteins, including p-gp, MRP, BCRP and LRP, in euthyrox-resistant PTC cells. Besides, over-expression of miR-206 could notably promoted the expression of NIS, an intrinsic membrane protein that mediates the active transport of iodide into the thyroid and other tissues, playing a critical role in the progress. Further, miR-206 was demonstrated to be able to bind to MAP4K3 and negatively regulated the expression of MAP4K3. Besides, MAP4K3 was clearly up-regulated in PTC tissues, parental and TPC-1/euthyrox cells, and down-regulation of miR-206 attenuated the effect of si-MAP4K3 on the euthyrox sensitivity in euthyrox-resistant PTC cells. Moreover, TPC-1/euthyrox cells transfected with miR-206 mimics could significantly inhibit the expressions of p-p38, p-JNK and p-Erk, which indicated that miR-206 might play an essential role in the euthyrox resistance in PTC by negatively regulating the p38 and JNK signaling pathway. CONCLUSION:miR-206 contributed to euthyrox resistance in PTC cells through blockage p38 and JNK signaling pathway by targeting MAP4K3, providing a potential therapeutic application for the treatment of patients with euthyrox-resistant PTC in the further.