RESUMEN
After the 2011 Fukushima Dai-ichi Nuclear Power Station (FDNPS) accident, wild populations of animals and plants living in the evacuation zone received additional ionizing radiation of both internal and external radiation doses. Morphological abnormalities of pine and fir trees near the FDNPS were reported. In order to evaluate dose-effect relationships, it is necessary to quantify the radiation doses to trees and plants. In this study, the internal and external dose rates to Japanese cedar and plants collected at three sites in Okuma, approximately 4 km southwest of FDNPS were estimated applying the ERICA Assessment Tool. The activity concentrations of 134Cs and 137Cs in soils, cedar trunks, and plants were determined. The total dose rates to cedar ranged from 2.2 ± 1.2 to 6.1 ± 2.2 µGy h-1. These rates were within the derived consideration reference levels (DCRLs) reported by ICRP 108 as 4-40 µGy h-1 for pine trees. The highest estimate for plants was 7.1 ± 2.7 µGy h-1, much smaller than the DCRLs reported for grasses and herbs (40-400 µGy h-1). On average, the internal radiation dose rates to cedars at the two sites accounted for 5% and 29% of the external dose rates, respectively, while the value in another site was only 0.4% for cedar. This was attributed to differences in the crown area between the three sites. The trunk diameter of cedars shows a positive correlation with the ratio of internal to external radiation dose rates. It indicates that the total dose rate to cedars is easily estimated with the soil radiocaesium inventory and trunk diameter. The internal radiation dose rate to the plant varied depending on the plant species. This variation was considerably large in plants due to the presence of two species, including Solidago altissima and Artemisia indica var. maximowiczii.
Asunto(s)
Cryptomeria , Accidente Nuclear de Fukushima , Monitoreo de Radiación , Contaminantes Radiactivos del Suelo , Animales , Radioisótopos de Cesio/análisis , Japón , Plantas de Energía Nuclear , Dosis de Radiación , Contaminantes Radiactivos del Suelo/análisisRESUMEN
Anaplastic lymphoma kinase (ALK) is known to be an important therapeutic target in various types of cancer. NVPTAE684, a wellknown inhibitor of ALK, was revealed to exert antitumor effects in several different malignancies. However, the molecular mechanisms responsible for these antitumor effects in cancer cells, including pancreatic adenocarcinoma cells, remain unknown. In the present study, NVPTAE684 was investigated for its antitumor effects towards pancreatic adenocarcinoma cells. MTT assay, western blot analysis, flow cytometry, caspase3/7 activity assay and Trypan blue exclusion assay were used and it was revealed that NVPTAE684 suppressed the proliferation of seven human pancreatic adenocarcinoma cell lines (AsPC1, Panc1, MIA PaCa2, Capan1, CFPAC1, Colo357 and BxPC3), and significantly increased G2/M arrest and apoptotic cell death. Furthermore, NVPTAE684 inhibited the phosphorylation of ALK at Y1604, as well as that of downstream mediators such as AKT (S473) and ERK1/2 (Y202/T204). Notably, knocking down ALK with siRNAs also decreased proliferation and promoted G2/M arrest and apoptosis. Furthermore, inhibition of ALK with NVPTAE684 or siRNA synergistically enhanced gemcitabineinduced cell death by inducing apoptosis. In conclusion, the findings of the present study indicated that NVPTAE684 exerted its antitumor effects by inducing G2/M arrest and apoptosis via the inhibition of the ALK signaling pathway, and suggests its potential use as an antitumor agent against pancreatic adenocarcinoma.