Simulated Microgravity Condition Alters the Histone Gene Expression in Mda-Mb-231

Background and aim: chromatin is a collection of dna and dna-attaching proteins consisting of histones and non-histone chromosomic proteins. histones (h1, h2a, h2b, h3, h4) are the responsible proteins in packing chromatin fibers and units of the structure of nucleosome have a very important role in the formation of chromatin's structure and as a result in the gene expression regulation. the aim of this study was to investigate the effect of simulated microgravity on gene expression of histone in the breast cancer cell line (mda-mb-231).methods: after isolation and characterization of mda-mb-231, cells were exposed to simulated microgravity for 24 and 72 hours. real-time polymerase chain reaction (pcr) assay and western blot analysis were performed to evaluate the alterations of the h3f3b protein level.results: the results showed that the rate of expression of the gene h3f3b reduced to 75% in the microgravity samples compared to the control sample until the third day (p?0.05).conclusion: according to our results, microgravity can influence h3f3b gene expression. taken together, this altered gene expression may affect astronaut health.