RESUMO
We studied the expression and activation of the main effector protein kinase of phosphatidylinositol-3-kinase cascade (PI3K) Akt in conventionally normal tissues, benign and highly differentiated (with and without metastases) human thyroid tumors. There was a difference in the Akt1 amount in tumor tissue compared with normal tissue in papillary carcinomas and tissue of multinodular goiter. Akt expression both in tumor and conventionally normal tissues of follicular adenoma was significantly lower than in follicular carcinoma. The lowest level of Akt expression was observed in tissues of multinodular goiter. Total activity of all three isoforms of Akt1/2/3 was lower in tumors compared to conventionally normal tissue. Thus, Akt activity (according to Thr308 phosphorylation) is not associated with proliferative processes in the tumor tissue of the thyroid. Apoptosis level detected in these tissues was not associated with the protein kinase activity either. Possible mechanisms of signaling cascade PI3K/Akt inhibition in thyroid tumors are discussed.
Assuntos
Adenocarcinoma Folicular/genética , Adenoma/genética , Carcinoma Papilar/genética , Bócio Nodular/genética , Fosfatidilinositol 3-Quinases/genética , Proteínas Proto-Oncogênicas c-akt/genética , Neoplasias da Glândula Tireoide/genética , Adenocarcinoma Folicular/enzimologia , Adenocarcinoma Folicular/patologia , Adenocarcinoma Folicular/cirurgia , Adenoma/enzimologia , Adenoma/patologia , Adenoma/cirurgia , Apoptose , Carcinoma Papilar/enzimologia , Carcinoma Papilar/patologia , Carcinoma Papilar/cirurgia , Regulação Neoplásica da Expressão Gênica , Bócio Nodular/enzimologia , Bócio Nodular/patologia , Bócio Nodular/cirurgia , Humanos , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação , Poli(ADP-Ribose) Polimerase-1/genética , Poli(ADP-Ribose) Polimerase-1/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , Glândula Tireoide/enzimologia , Glândula Tireoide/patologia , Glândula Tireoide/cirurgia , Neoplasias da Glândula Tireoide/enzimologia , Neoplasias da Glândula Tireoide/patologia , Neoplasias da Glândula Tireoide/cirurgiaRESUMO
UNLABELLED: The study was aimed on analysis of human beta-defensin-1-4 (hBDs) mRNA expression in cultured thyroid cancer cells and evaluation of effects of recombinant hBD-2 (rec-hBD-2) on growth patterns, migration properties and expression of E-cadherin and vimentin in these cells. METHODS: The study was performed on cultured follicular thyroid cancer WRO cells, papillary thyroid cancer TPC1 cells, and anaplastic thyroid cancer KTC-2 cells. For analysis of hBD-1-4 mRNA expression in thyroid cancer cells, semiquantitative RT-PCR was used. Effects of rec-hBD-2 on cell proliferation, viability, and migration were analyzed using direct cell counting, MTT test, and scratch assay respectively. Expression of vimentin and E-cadherin was evaluated by quantitative PCR (qPCR). RESULTS: By the data of RT-PCR, all three studied thyroid cancer cell lines express hBD-1 and -4 mRNA, but not hBD-2 mRNA, while hBD-3 expression was detected in WRO and KTC-2 cells. The treatment of TPC-1, WRO, and KTC-2 cells with 100-1000 nM rec-hBD-2 resulted in significant concentration-dependent suppression of cell proliferation, viability, and migratory property. By the data of qPCR, significant up-regulation of vimentin expression was registered in KTC-2 and WRO cells treated with 500 nM rec-hBD-2. Significant down-regulation of E-cadherin expression (p < 0.05) was detected only in KTC-2 cells treated with the defensin. Also, it has been shown that TPC-1 cells treated with 500 nM rec-hBD-2 acquired more elongated morphology. CONCLUSION: The data demonstrate that hBD-2 in concentrations higher than 100 nM exerts significant concentration-dependent suppression of thyroid cancer cell growth and migration, and affects vimentin and E-cadherin expression dependent on histologic type of thyroid cancer cells.