Intellectual, scientific, conception and design of the study; acquisition, analysis and interpretation of data; technical procedures; statistical analysis; manuscript preparation, final approval.

BackgroundPapillary thyroid carcinoma (PTC) is associated with mutations of BRAFV600E and RET/PTC and high levels of expression of nuclear factor-κB (NF-κB). However, few studies have focused on the association between NF-κB expression and mutations in BRAFV600E and RET/PTC, especially regarding PTC cell proliferation and migration. The aim of this in vitro study was to investigate the effect of BRAFV600E or RET/PTC on NF-κB expression, cell proliferation and cell migration in four established PTC cell lines.Material/MethodsFour cell lines included TPC-1 (BRAFWT/WT), BCPAP (BRAFV600E/V600E), PCCL3, and PTC3-5 (RET/PTC), were grown in culture in vitro with or without suppression of NF-κB using pyrrolidine dithiocarbamate (PDTC), and cell proliferation, and cell migration were evaluated.ResultsExpression of the BRAF gene was increased in the BCPAP cell line when compared with the TPC-1 cells. Expression of the RET gene was increased in the PTC3-5 cell line when compared with the PCCL3 cells. In the BCPAP and PTC3-5 cell lines, the relative expression of NF-κB protein, including phosphorylated p100/52, phosphorylated p65, phosphorylated IKKα/β, phosphorylated IκBα, and p65 nuclear translocation were increased compared with the TPC-1 and PCCL3 cells. Proliferation and migration of BCPAP and PTC3-5 cells were increased compared with the TPC-1 and PCCL3 cells. Suppression of NF-κB reduced NF-κB protein expression and inhibited the proliferation of cells in the TPC-1, BCPAP, PCCL3 and PTC3-5 cell lines, and migration of the BCPAP and PTC3-5 cells.ConclusionsBRAFV600E and RET/PTC and the expression of NF-κB promote the proliferation and migration of papillary thyroid carcinoma cells in vitro.

Due to the lack of potential organs, hepatocellular transplantation has been considered for treating end-stage liver disease. Induced pluripotent stem cells (iPSCs) are reverted from somatic cells and are able to differentiate into hepatocytes. The present study aimed to investigate the mechanisms underlying iPSC differentiation to hepatocytes. GSE66076 was downloaded from the Gene Expression Omnibus; this database includes data from 3 undifferentiated (T0), 3 definitive endoderm (T5), and 3 early hepatocyte (T24) samples across hepatic-directed differentiation of iPSCs. Differentially expressed genes (DEGs) between T0 and T5 or T24 samples were identified using the linear models for microarray data package in Bioconductor, and enrichment analyses were performed. Using the weighted correlation network analysis package in R, clusters were identified for the merged DEGs. Cytoscape was used to construct protein-protein interaction (PPI) networks for DEGs identified to belong to significant clusters. Using the ReactomeFI plugin in Cytoscape, functional interaction (FI) networks were constructed for the common genes. A total of 433 and 1,342 DEGs were identified in the T5 and T24 samples respectively, compared with the T0 samples. Blue and turquoise clusters were identified as significant gene clusters. In the PPI network for DEGs in the blue cluster, the key node fibroblast growth factor 2 (FGF2) could interact with bone morphogenetic protein 2 (BMP2). Cyclin-dependent kinase 1 (CDK1) was demonstrated to have the highest degree (degree=71) in the PPI network for DEGs in the turquoise cluster. Enrichment analysis for the common genes, including hepatocyte nuclear factor 4α (HNF4A) and epidermal growth factor (EGF), in the FI network indicated that EGF and FGF2 were enriched in the Ras and Rap1 signaling pathways. The present results suggest that FGF2, BMP2, CDK1, HNF4A and EGF may participate in the differentiation of iPSCs into hepatocytes.