Overexpression of long noncoding RNA SLC26A4-AS1 inhibits the epithelial-mesenchymal transition via the MAPK pathway in papillary thyroid carcinoma.

Papillary thyroid carcinoma (PTC) is recognized as one of the most prevalent types of thyroid cancer with poor prognosis. Long noncoding RNA (lncRNA) has undergone an intensive study for their involvement in tumor treatment. This study intends to unravel the association of lncRNA SLC26A4-AS1 with PTC. Initially, PTC-related expression profiling data (GSE33630) was utilized to screen differentially expressed lncRNAs in PTC and the underlying mechanisms involved with the mitogen-activated protein kinase (MAPK) pathway. Moreover, PTC tumor tissues and paracancerous tissues were arranged to determine expressions of TP53, SLC26A4-AS1, and genes related to epithelial-mesenchymal transition (EMT) and the MAPK pathway. Furthermore, SLC26A4-AS1 was overexpressed or underexpressed and JNK was underexpressed through cell transfection to examine the effect of SLC26A4-AS1 on PTC via MAPK pathway. Besides, tumor formation in nude mice was used to verify the fore experiment. LncRNA SLC26A4-AS1 regulating TP53 had the potential to participate in PTC by regulating the MAPK pathway. SLC26A4-AS1 was expressed poorly in PTC. Notably, SLC26A4-AS1 elevated E-cadherin expression while it reduced that of ERK and Vimentin. In addition, the overexpression of SLC26A4-AS1 inactivated the MAPK pathway by promoting TP53 and decreased cell migration, proliferation, and invasion. In addition to all these effects, the overexpression of SLC26A4-AS1 promoted apoptosis of TPC-1 cells. Additionally, the overexpression of lncRNA SLC26A4-AS1 reduced xenograft tumor volume in nude mice. Furthermore, the effect of SLC26A4-AS1 overexpression was found to be promoted after the MAPK pathway inactivation. Taken together, the overexpression of lncRNA SLC26A4-AS1 coffered anti-oncogenic effects on PTC through the inactivation of the MAPK pathway.

microRNA-599 promotes apoptosis and represses proliferation and epithelial-mesenchymal transition of papillary thyroid carcinoma cells via downregulation of Hey2-depentent Notch signaling pathway.

Although papillary thyroid carcinoma (PTC) has a favorable prognosis after surgical or medical treatment, its survival rate is still very low. Therefore, finding more reliable therapy methods to limit PTC is a necessity. Compelling evidence has implicated the role of microRNAs (miRNAs or miRs) in PTC. This study aims at investigating the possible effect of microRNA-599 (miR-599) on proliferation, apoptosis, and epithelial-mesenchymal transition (EMT) of PTC cells by targeting Hey2 gene. Differentially expressed genes/miRNAs associated with PTC were screened based on microarray analysis. Then, the expression of the candidate gene, as well as, the regulatory miRNA were detected in PTC cells, the related signaling pathway was verified. Afterward, the relationship between the miR and the candidate gene was verified by dual-luciferase reporter gene assay. Subsequently, the effects of overexpressed miR and silenced candidate gene on cell proliferation, cell apoptosis, EMT, migration, and invasion were detected. In PTC tissues and cells, miR-599 was downregulated while Hey2 expressed highly. Hey2 is a target gene of miR-559. In addition, the expression of Bax and E-cadherin was elevated while that of Hey2, Notch1, Delta-like1, Hes1, N1ICD, Jagged1, Snail, Slug, N-cadherin and Vimentin, and Bcl-2 was reduced in cells treated with upregulated miR-599 or downregulated Hey2. Moreover, miR-599 overexpression or Hey2 silencing inhibited cell proliferation, migration, invasion, along with EMT but promoted apoptosis. This study verified that miR-599 promotes apoptosis and represses proliferation, EMT of PTC cells through inactivating the Notch signaling pathway by downregulating Hey2, which has great clinical significance for PTC treatment.

[The management of thyroid well-differentiated carcinoma invading the upper aerodigestive tract].

OBJECTIVE: To investigate the management and prognosis of thyroid well-differentiated carcinoma invading the upper aerodigestive tract. METHODS: A retrospective analysis of the management was performed done 62 patients with thyroid well-differentiated carcinoma invading the upper aerodigestive tract. The main method of surgery was shaving excision, and the other means including partial thyrochondrectomy, total laryngectomy, sleeve tracheal resection, sternocleidomastoid myoperiosteal flap and myodermal flap reconstruction, or simply palliative excision. Some patients received postoperative radioactive isotope therapy and radiotherapy. All patients were followed-up for 2 to 15 years with an average of 6.5 years. RESULTS: The best curative effect was proved in the patients with local invasion, with the lumen uninvolved and their locoregional control rate was 100.0% (17/17). And the second choice was in patients with more extensive involvement of the upper aerodigestive tract structures. For them, extensive surgical management was done attempting to remove all gross disease followed by reconstruction, their locoregional control rate was 87.5% (7/8). And the third place was designated to patients with local invasion for which shaving excision was performed even though minor residual disease was left, their locoregional control rate was 55.6% (5/9). The poorest result went to simple palliative excision. For 17 patients with minor residual tumor, the locoregional control rate of those who were given postoperative radioactive isotope therapy was significantly higher than those without. CONCLUSION: According to the limits and degree of invasion in the upper aerodigestive tract by thyroid well-differentiated carcinoma, different ways of surgery is indicated. For patients with residual disease, radioactive isotope therapy should be used to improve the result and life quality. Advanced lesions should be given postoperative radio therapy.