Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Skip to content

Proton irradiation augments the reduction in tumor progression observed with advanced age

Metadata Updated: December 6, 2023

Proton irradiation is touted for its improved tumor targeting due to the physical advantages of ion beams for radiotherapy. Recent studies from our laboratory have shown that in addition to targeting advantages proton irradiation can inhibit angiogenic and immune factors and thereby modulate tumor progression. High-energy protons also constitute a principal component of the galactic cosmic rays to which astronauts are exposed. Increased understanding of the biological effects of proton exposure would thus contribute to both improved cancer therapy and carcinogenesis risk assessment for space travel. In addition age plays a major role in tumor incidence and is a critical consideration for estimating cancer risk. We investigated the effects of host age and proton exposure on tumor progression. Tumor lag time and growth dynamics were tracked following injection of murine Lewis lung carcinoma (LLC) cells into young (68 day) versus old (736 day) mice with or without coincident irradiation. Tumor progression was suppressed in old compared to young mice. Differences in progression were further modulated by proton irradiation (1GeV) with increased inhibition evident in old mice. Through global transcriptome analysis TGFB1 and TGFB2 were determined to be key players that contributed to the tumor dynamics observed. These findings point to older hosts providing decreased systemic tumor support which can be further inhibited by proton irradiation. Overall design: For genome-wide expression profiling of tumor tissue Mouse WG-6 BeadArray chips (Illumina San Diego CA) were used. Total RNA was amplified with the Ambion Illumina TotalPrep Amplification Kit (Ambion Austin TX) and labeled from all replicate biological samples for each condition. For tumor replicates thirty tumor samples from adolescent and thirty tumor samples from old mice for a total of 60 tumor samples were used. All replicate samples were run individually. For each age group ten tumor samples had received proton irradiation while twenty tumor samples were from unirradiated mice (as described above). Total RNA was isolated and purified using TRIzol (Invitrogen) and quantified using an Agilent Bioanalyzer. Samples were deemed suitable for amplification and hybridization if they had 28s/18s = 2:1 RIN >7. Total RNA of 500ng per sample was amplified using AmbionTotalPrep and 1.5ug of the product was loaded onto the chips. Following hybridization at 55C the chips were washed and then scanned using the Illumina iScan System. The data was checked with GenomeStudio (Illumina) for quality control. In GenomeStudio data was background subtracted and rank invariant normalization was applied. Data was imported into MultiExperiment Viewer MeV for statistical analysis. The statistically significant genes were determined using MeV by applying a one-way ANOVA analysis with standard Bonferroni correction with a FDR <0.05 that resulted in a list of significant genes. Average gene expression signals <10 were filtered out due to signal being

Access & Use Information

Public: This dataset is intended for public access and use. License: us-pd

Downloads & Resources


Metadata Created Date January 31, 2023
Metadata Updated Date December 6, 2023
Data Update Frequency irregular

Metadata Source

Harvested from NASA Data.json

Additional Metadata

Resource Type Dataset
Metadata Created Date January 31, 2023
Metadata Updated Date December 6, 2023
Publisher National Aeronautics and Space Administration
Identifier nasa_genelab_GLDS-131_8epm-qtb2
Data First Published 2021-05-21
Data Last Modified 2023-01-26
Category Earth Science
Public Access Level public
Data Update Frequency irregular
Bureau Code 026:00
Metadata Context
Metadata Catalog ID
Schema Version
Catalog Describedby
Harvest Object Id 82f6f79e-55ff-4b91-a68b-7da9f81be94d
Harvest Source Id 58f92550-7a01-4f00-b1b2-8dc953bd598f
Harvest Source Title NASA Data.json
Homepage URL
Program Code 026:005
Source Datajson Identifier True
Source Hash f892fa50d840acecca007f843bca357757cd58a40e0a579752209f7b702ccc44
Source Schema Version 1.1

Didn't find what you're looking for? Suggest a dataset here.