X-rays Induce Dose-dependent and Cell Cycle-independent Accumulation of p21sdi1/WAF1

Cell cycle arrest at the G1 checkpoint is governed by a function ofwild-typep53. We assessed the behavior of the sdi1 gene, which codes for a 21kDa potent inhibitor of cdk/cyclins, after X-irradiation. X-irradiation induced sdi1 mRNA accumulation and G1 arrest only in cells possessing wild-type p53. Elevation of p21sdi1/WAF1 was preceded by p53 accumulation, which occurred despite p53 mRNA constancy in normal cells growing in the log phase. The quantity of accumulated p53 and p21sdi1/WAF1 was radiation dose dependent. A decrease in the S phase cell population in normal cells observed after irradiation reached a minimum at less-than-maximum levels of p53 and p21sdi1/WAF1 Furthermore, an accumulation of p53 and p21sdi1/WAF1 was also observed when cells were synchronized in the G0, G1 and S phase and X-irradiated. These results indicated that an X-ray induced p53 and p21sdi1/WAF1 accumulation mechanism exists throughout the cell cycle, and that the signal strength induced by X-irradiation is dose-dependent.This publication is based on research performed at the Radiation Effects Research Foundation (RERF), Hiroshima and Nagasaki, Japan and is supported in part by Grants-in-Aid (S7-l) for Cancer Research from the Ministry of Health and Welfare

In Situ Molecular Analysis of Plant Tissues by Live Single-Cell Mass Spectrometry

We report the development of a rapid, direct molecular analysis of live, single plant cells viewed under a video microscope in their natural environment. A nanoelectrospray tip was used to extract the contents of a single leaf, stem, or petal cell from <i>Pelargonium zonale</i>, and the samples were analyzed on an Orbitrap mass spectrometer by nanoelectrospray ionization. Around a thousand <i>m</i>/<i>z</i> peaks belonging to metabolites and other compounds in each sample were obtained and processed by using statistical tools to find the cell specific molecular peaks. Hybrid high-resolution mass spectrometry analysis was performed to confirm the structure of specific metabolites from the analyzed samples. This method is useful for identifying specific molecules in live single cells from plant tissue and will allow different cell types and stages from different sites in the plant to be compared with morphological observations

In Situ Molecular Analysis of Plant Tissues by Live Single-Cell Mass Spectrometry

We report the development of a rapid, direct molecular analysis of live, single plant cells viewed under a video microscope in their natural environment. A nanoelectrospray tip was used to extract the contents of a single leaf, stem, or petal cell from <i>Pelargonium zonale</i>, and the samples were analyzed on an Orbitrap mass spectrometer by nanoelectrospray ionization. Around a thousand <i>m</i>/<i>z</i> peaks belonging to metabolites and other compounds in each sample were obtained and processed by using statistical tools to find the cell specific molecular peaks. Hybrid high-resolution mass spectrometry analysis was performed to confirm the structure of specific metabolites from the analyzed samples. This method is useful for identifying specific molecules in live single cells from plant tissue and will allow different cell types and stages from different sites in the plant to be compared with morphological observations

Additional file 1 of ΔNp63α transcriptionally represses p53 target genes involved in the radiation-induced DNA damage response

Supplementary Material 1. Table S1. List of primer and siRNA sequences. Table S2. List of primary and secondary antibodies. Figs. S1-S7

No increase in translocated chromosomal aberrations, an indicator of ionizing radiation exposure, in childhood thyroid cancer in Fukushima Prefecture

Abstract To investigate the effects of radiation exposure due to the Fukushima nuclear power plant accident, following the disaster Fukushima Prefecture launched thyroid ultrasound examinations of residents who were generally younger than 18 years at the time of the earthquake. As the rate of pediatric thyroid cancer was higher than expected, we conducted biological dose assessment based on the frequency of translocated chromosome (Tr) aberrations using peripheral blood lymphocytes. Tr formation frequency was compared among the thyroid cancer (n = 38, median age 18 years, age range 12–26 years), thyroid-related disease (n = 30, median age 21 years, age range 15–28 years), and healthy controls (n = 31, median age 22 years, age range 20–23 years) groups. Tr aberration frequency was initially significantly higher in the thyroid cancer than in the other two groups; however, differences among the groups disappeared after adjusting for history of CT scan, as 92%, 67%, and 28% of those in the thyroid cancer, thyroid-related disease, and control groups, respectively, had undergone CT previously. Therefore, the significant difference in the initial number of Tr formations is presumably due to radiation exposure from CT. Accordingly, the effects of medical exposure on the chromosomes of children and adolescents should be noted