Deficient PCNA expression and radiation sensitivity

Abstract

Wasted mice express radiosensitivity in lymphoid and nervous system tissues, displaying increased apoptosis, increased transcriptional activation, and altered gene induction in response to radiation when compared to control littermates. In order to evaluate altered gene induction linked with radiosensitivity in spinal cord tissue of the wasted mice, we isolated total RNA from the spinal cords of radiation-exposed and unexposed wasted and control mice and hybridized it to a gene expression microarray. Previous studies by our group had demonstrated that lymphoid tissues of wasted mice lack proliferating cell nuclear antigen (PCNA) expression. This protein is involved in almost every aspect of DNA replication and repair, and radiosensitivity in lymphoid tissues of wasted mouse can easily be linked to proliferating cell nuclear antigen (PCNA) deficiency. In total spinal cord tissue, however, PCNA mRNA expression was not altered in wasted mice relative to controls. Nevertheless, mRNAs for many proteins that were known to interact with PCNA were modulated in wasted spinal cords compared to the tissues from BCF1 controls.