Background: Thyroid cancer (TC) is the most common type of endocrine malignancy tumor and the incidence of it is increasing over years. Conventional surgery, radiotherapy and chemotherapy are difficult to improve the significant effects of it due to aggression and metastasis of poorly differentiated thyroid cancer (PDTC) and anaplastic thyroid cancer (ATC), which are regarded as the most malignant type of TC. Glucose-regulated protein (GRP78) is the key molecule of tumor growth, apoptosis and metastasis. However, the underlying mechanisms of GRP78 on TC still require discussion. This study aimed to explore the role of GRP78 and its potential mechanism in TC.Results: GRP78 expression was increased in TC tissues when compared with adjacent normal tissues. Besides, down-regulation of GRP78 significantly inhibited the metastatic and proliferative ability of ATC cells in in vitro studies. In addition, tunicamycin-induced ER stress up-regulated the expression of GRP78, PERK and XBP1 as well as reversed the metastatic ability of GRP78 in ATC cells. Bioinformatics and statistical analysis of gene ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways for RNA-sequencing data from si-GRP78 and si-control showed that GRP78 might regulate the ability of metastasis through extracellular matrix (ECM) remodeling in ATC cells, as well as the expression of ECM components such as COL1A1 and MMP13 were shown to be highly relevant to ATC. The analysis of GEPIA database confirmed high genomic amplification of MMP13 and COL1A1 in TC tissues and showed correlation with TNM stage. Further western blotting analysis showed that MMP13 might be the target of GRP78 in ATC cells and ER stress could activate the expression of MMP13 that was suppressed by the GRP78 depletion.Conclusions: GRP78 acts as an important regulator of metastasis under ER stress. In addition, the function of GRP7 might be mediated by ECM remodeling in ATC cells, implicating it as a therapeutic target in TC.

Background Thyroid cancer(TC)is the most common type of endocrine malignant tumor and the incidence is increasing by years. Conventional surgery, radiotherapy and chemotherapy are difficult to improve significantly effects due to the aggression and metastasis of poorly differentiated thyroid cancer (PDTC) and anaplastic thyroid cancer (ATC) which are the most malignant type of thyroid cancer. Glucose-regulated protein (GRP78) as the key molecule is related to tumor growth, apoptosis and metastasis. However, the mechanisms responsible for the effects of TC on GRP78 still need to be discussed. Therefore, the purpose of this study was to explore the presence of GRP78 and the potential mechanism of TC. Results GRP78 expression is increased in thyroid carcinoma tissues in comparison with the adjacent normal tissues. Besides, down-regulation of GRP78 significantly inhibited the metastatic and proliferative potential of ATC cells in vitro studies. In addition, tunicomycin (TM)-induced ER stress could up-regulate the expression of GRP78, PERK and XBP1 as well as reverse metastatic ability of GRP78 in TC cells. Bioinformatics and statistical analysis of gene ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways for RNA-seq data from si-GRP78 and si-control showed GRP78 may regulate the ability of metastasis through the ECM remodeling in ATC cells, as well as the expression of ECM components such as COL1A1 and MMP13 were illustrated to be highly relevant to ATC. The analysis of GEPIA database confirmed that high genomic amplification of MMP13 and COL1A1 in TC tissues and were correlated with TNM stage. A further western blot analysis showed MMP13 may be the target of GRP78 in ATC cells and ER stress could activate the expression of MMP13 which was suppressed by depletion of GRP78. Conclusions GRP78 is an important regulator of metastasis under the ER stress. In addition, GRP78’s functions might be mediated by ECM remodeling in ATC cells, which implicates GRP78 as a therapeutic target in thyroid cancer.

Background: Thyroid cancer (TC) is the most common type of endocrine malignancy and its incidence is increasing over years. Conventional surgery, radiotherapy and chemotherapy are difficult to improve the significant effects of it due to aggression and metastasis of poorly differentiated thyroid cancer (PDTC) and anaplastic thyroid cancer (ATC), and these are regarded as the most malignant types of TC. Glucose-regulated protein (GRP78) is the key molecule of tumor growth, apoptosis and metastasis. However, the underlying mechanisms of GRP78 in TC still require discussion. This study aimed to explore the role of GRP78 and its potential mechanism in TC.Results: GRP78 expression was increased in TC tissues when compared with adjacent normal tissues. Besides, down-regulation of GRP78 significantly inhibited the metastatic and proliferative ability of ATC cells in in vitro studies. In addition, tunicamycin-induced ER stress up-regulated the expression of GRP78, PERK and XBP1 as well as reversed the metastatic ability of GRP78 in ATC cells. Bioinformatics and statistical analysis of gene ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways for RNA-sequencing data with regard to si-GRP78 and si-control showed that GRP78 might regulate the ability of metastasis through extracellular matrix (ECM) remodeling in ATC cells, as well as the expression of ECM components such as COL1A1 and MMP13, which were highly relevant to ATC cells. The analysis of GEPIA database confirmed that high genomic amplification of MMP13 and COL1A1 in TC tissues showed correlation with TNM stage. Further western blotting analysis showed that MMP13 might be the target of GRP78 in ATC cells and ER stress could activate the expression of MMP13 that is suppressed by GRP78 depletion.Conclusions: GRP78 acts as an important regulator of metastasis under ER stress. In addition, the function of GRP78 might be mediated by ECM remodeling in ATC cells, implicating it as a therapeutic target in TC.