Short-term and bystander effects of radiation on murine submandibular glands

Many patients treated for head and neck cancers experience salivary gland hypofunction due to radiation damage. Understanding the mechanisms of cellular damage induced by radiation treatment is important in order to design methods of radioprotection. In addition, it is crucial to recognize the indirect effects of IR and the systemic responses that may alter saliva secretion. In this study, radiation was delivered to murine submandibular glands (SMG) bilaterally, using a 137 Cs gamma ray irradiator, or unilaterally, using a small animal radiation research platform (SARRP). Analysis at 3, 24 and 48 hours showed dynamic changes in mRNA levels and protein abundance in SMG irradiated bilaterally. Unilateral irradiation using the SARRP caused similar changes in the irradiated SMG, as well as significant off-target, bystander effects in the non-irradiated contralateral SMG. Summary statement Rapid changes in gene expression occur in irradiated salivary glands within hours of irradiation, and in non-irradiated contralateral glands, due to bystander effects.