RESUMO
Thyroid cancer is the most common type of endocrine tumor. MicroRNAs (miRNAs) play a critical role in a variety of diseases, especially cancer occurrence and progression. However, the specific mechanism by which miRNAs trigger disease states has not been fully elucidated. This study aims to investigate the role of miR-27a in thyroid cancer cells. A wound healing assay was adopted to examine cell migration. A transwell assay was applied to assess cell invasion. A thyroid cancer xenograft model was established using BALB/c nude mice. Western blot was performed to quantify iNOS expression. Tumor tissue blood vessel density was evaluated via immunohistochemistry assays. The results indicated that miR-27a downregulation inhibited thyroid cancer cell migration, while upregulation of miR-27a promoted thyroid cancer cell migration (P < 0.05). Furthermore, reduction in miR-27a expression suppressed thyroid cancer cell invasion (P < 0.05). In the nude mouse model of thyroid cancer xenograft, upregulation of miR-27 induced iNOS expression in pathological tumor tissues, whereas miR-27a inhibition resulted in the opposite effect (P < 0.05). CD105 level was also significantly increased during miR-27a upregulation, and was declined when miR-27a was inhibited (P < 0.05). In conclusion, miR-27a upregulation in thyroid cancer cells affects tumor cell migration, invasion, and angiogenesis by targeting downstream genes. Therefore, miR27a may act as a biomarker of thyroid cancer.
Assuntos
MicroRNAs/genética , Neovascularização Patológica/genética , Neoplasias da Glândula Tireoide/genética , Animais , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Endoglina/genética , Endoglina/metabolismo , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Camundongos , Camundongos Nus , Invasividade Neoplásica , Transplante de Neoplasias , Neovascularização Patológica/metabolismo , Neoplasias da Glândula Tireoide/metabolismoRESUMO
Neutron fluences were measured from 435 MeV/nucleon Nb ions stopping in a Nb target and 272 MeV/nucleon Nb ions stopping in targets of Nb and Al for neutrons above 20 MeV and at laboratory angles between 3 degrees and 80 degrees. The resultant spectra were integrated over angles to produce neutron energy distributions and over energy to produce neutron angular distributions. The total neutron yields for each system were obtained by integrating over the angular distributions. The angular distributions from all three systems are peaked forward, and the energy distributions from all three systems show an appreciable yield of neutrons with velocities greater than the beam velocity. Comparison of the total neutron yields from the two Nb + Nb systems suggests that the average neutron multiplicity decreases with decreasing projectile energy. Comparison of the total yields from the two 272 MeV/nucleon systems suggests that the total yields show the same dependence on projectile and target mass number as do total inclusive neutron cross sections. The data are compared with Boltzmann-Uehling-Uhlenbeck model calculations.
Assuntos
Alumínio , Radiação Cósmica , Modelos Teóricos , Nêutrons , Nióbio , Interações de Partículas Elementares , Partículas Elementares , Transferência de Energia , Proteção Radiológica , Análise EspectralRESUMO
Measurements of dielectron production in p + p and p + d collisions with beamkinetic energies from 1.04 to 4.88 GeV are presented. The differential cross section is presented as a function of invariant pair mass, transverse momentum, and rapidity. The shapes of the mass spectra and their evolution with beam energy provide information about the relative importance of the various dielectron production mechanisms in this energy regime. The p + d to p + p ratio of the dielectron yield is also presented as a function of invariant pair mass, transverse momentum, and rapidity. The shapes of the transverse momentum and rapidity spectra from the p + d and p + p systems are found to be similar to one another for each of the beam energies studied. The beam energy dependence of the integrated cross sections is also presented.