Changes in Radiation Sensitivity of Human Osteosarcoma Cells after p53 Introduction

Abstract
Human osteosarcoma SAOS‐2 cells, which have a deletion in p53 gene, were transfected with plasmid pMSVneop53 containing human p53 cDNA and neomycin‐resistance gene. Three clones (SAOS‐MC10, SAOS‐MC11 and SAOS‐MC43) among 60 clones expressed p53 mRNA. No p53 protein was observed in SAOS‐MC10, while SAOS‐MC11 and SAOS‐MC43 produced p53 protein. The molecular weight of p53 protein in SAOS‐MC43 was lower than that in SAOS‐MC11. SAOS‐MC11 and SAOS‐MC43 were more sensitive and more resistant, respectively, to ionizing radiation than the parental SAOS‐2. We suggest that exogenous p53 protein might be one of the factors determining cellular radiosensitivity.