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The incidence of thyroid cancer has recently experienced a rapid increase in China, and papillary thyroid carcinoma (PTC) accounts for nearly 80% of human thyroid cancers. In the present study, the differential expression of microRNAs (miRNAs) and their target genes were identified in order to analyze the potential roles of miRNAs as biomarkers and in papillary thyroid carcinogenesis. One hundred and twenty-six PTC samples were collected from patients at the China-Japan Union Hospital, China, and the gene/miRNA expression profiles were examined with Illumina BeadChips and verified by real‑time RT-PCR. Gene Ontology (GO) categories were determined, and pathway analysis was carried out using KEGG. miRNA target genes were predicted by implementing three computational analysis programs: TargetScanS, DIANA-microT and PicTar. Two hundred and forty-eight miRNAs and 3,631 genes were found to be significantly deregulated (gene, P

Cell death is one of the most important endpoints of radiosensitivity. The tumor suppressor p53 participates not only in regulation of apoptosis, but also in autophagy mechanism. In this study, H1299-P53 (with wild-type p53) and H1299-175H (with mutant 175H) were used, and the effects of p53 on radiosensitivity were analyzed.Cell models with different p53 status were established by gene engineering, and cell viability was examined by colony formation assay, and cell counting kit-8 (CCK-8), 3-Methyladenine, and Z-VAD were used to block autophagy and apoptosis, respectively. Western blot was used to detect protein expression; monodansylcadaverine (MDC) staining was used to analyze autophagy rate; DAPI/Propidium Iodide (PI) staining and flow cytometry were used to assess apoptosis and necrosis.In parental H1299, H1299-P53, and H1299-175H cells, radiosensitivity exhibited different by colony formation and CCK-8 assay (D0: 1.764 Gy, 1.407 Gy and 1.695 Gy; Dq: 2.977 Gy, 1.199 Gy and 2.312 Gy in turn). The radiosensitization of p53 was associated with the increase of MDM2 and P21 expression. The ionizing radiation (IR)-induced apoptosis was significant in H1299-P53 compared with in H1299 and H199-175H (p0.05) by flow cytometry, and the expression of cleaved-caspase3 was increased in H1299-P53 cells. While the IR-induced autophagy was significant in H1299 cells (p0.01) and decreased in H1299-P53 and H1299-175H cells (p0.01) by MDC staining, the expression of MAPLC3II and Beclin-1 increased in H1299, but not in H1299-p53 and H199-175H cells. The IR-induced cell survival was significantly increased by Z-VAD-FMK and decreased by 3MA in H1299-P53 cells; IR- induced autophagy was significantly increased by Z-VAD-FMK in H1299-P53 cells (p0.01), but not changed in H1299 cells.p53 could regulate radiosensitivity by inhibiting autophagy and activating apoptosis; autophagy provides a prosurvival mechanism, and p53 potently abrogated the IR-induced autophagy, while mutant 175H shown no effect on radiosensitivity, suggesting that individual treatment strategies should be based on p53 status in patients.

Purpose Autophagy has attracted attentions as a novel mechanism for tumor development. In this study Human ovarian carcinoma cell line SKOV3 and multidrug-resistant phenotype SKVCR cells were used and the roles of autophagy in radiation-induced cell death were analyzed. Methods and materials Cell viability was examined by colony formation and cell counting kit-8 (CCK-8) assay, 3MA and ZVAD were used to block autophagy and apoptosis, respectively. Quantitative real-time PCR was used to detect mRNA level and Western blot was used to detect protein expression, monodansylcadaverine (MDC) staining and flow cytometery were used for autophagy, apoptosis and cell cycle dynamics, respectively. Results (1) The radiosensitivity exhibited differently in SKOV3 and SKVCR cells (SKOV3: D0=3.37, SKVCR: D0= 4.18); compared with SKOV3 the constitutive expression of MAPLC3 in SKVCR was higher, but no change of Caspase-3 and cleaved Caspase-3. (2) The ionizing radiation (IR)- induced apoptosis and autophagy were significant in both cells (P Conclusion IR-induced autophagy provides a self-protective mechanism against radiotherapy in SKVCR cells, the use of autophagy inhibitor, 3MA, increases the killing effects of radiation by inhibiting autophagy and radiation- induced S phase delay, also by the increase of apoptosis, which suggests a better therapeutic strategy in drug- resistant SKVCR ovarian cancer cells.

Dan Cong,1 Mengzi He,2 Silin Chen,2 Xiaoli Liu,1 Xiaodong Liu,2 Hui Sun11Jilin Provincial Key Laboratory of Surgical Translational Medicine, Department of Thyroid and Parathyroid Surgery, People’s Republic of China–Japan Union Hospital, 2Key Laboratory of Radiobiology (Ministry of Health), School of Public Health, Jilin University, Changchun, Jilin, People’s Republic of ChinaAbstract: In the present study, we analyzed microRNA (miRNA) and gene expression profiles using 499 papillary thyroid carcinoma (PTC) samples and 58 normal thyroid tissues obtained from The Cancer Genome Atlas database. A pivotal regulatory network of 18 miRNA and 16 targets was identified. Upregulated miRNAs (miR-222, miR-221, miR-146b, miR-181a/b/d, miR-34a, and miR-424) and downregulated miRNAs (miR-9-1, miR-138, miR-363, miR-20b, miR-195, and miR-152) were identified. Among them, the upregulation of miR-424 and downregulation of miR-363, miR-195, and miR-152 were not previously identified. The genes CCNE2 (also known as cyclin E2), E2F1, RARA, CCND1 (cyclin D1), RUNX1, ITGA2, MET, CDKN1A (p21), and COL4A1 were overexpressed, and AXIN2, TRAF6, BCL2, RARB, HSP90B1, FGF7, and PDGFRA were downregulated. Among them, CCNE2, COL4A1, TRAF6, and HSP90B1 were newly identified. Based on receiver operating characteristic curves, several miRNAs (miR-222, miR-221, and miR-34a) and genes (CCND1 and MET) were ideal diagnostic indicators, with sensitivities and specificities greater than 90%. The combination of inversely expressed miRNAs and targets improved diagnostic accuracy. In a clinical feature analysis, several miRNAs (miR-34a, miR-424, miR-20b, and miR-152) and genes (CCNE2, COL4A1, TRAF6, and HSP90B1) were associated with aggressive clinical features, which have not previously been reported. Our study not only identified a pivotal miRNA regulatory network associated with PTC but also provided evidence that miRNAs and target genes can be used as biomarkers in PTC diagnosis and clinical risk evaluation.Keywords: thyroid carcinoma, miR-34a, miR-424, miR-20b, miR-152