Effect of Irradiation on Cell Transcriptome and Proteome of Rat Submandibular Salivary Glands

Abstract

Salivary glands (SGs) are irreversibly damaged by irradiation (IR) treatment in head and neck cancer patients. Here, we used an animal irradiation model to investigate and define the molecular mechanisms affecting SGs following IR, focusing on saliva proteome and global transcription profile of submandibular salivary gland (SSG) tissue.We show that saliva secretion was gradually reduced to 50% of its initial level 12 weeks post-IR. Saliva protein composition was further examined by proteomic analysis following mass spectrometry (MS) analysis that revealed proteins with reduced expression originating from SSGs and proteins with increased expression derived from the serum, both indicating salivary tissue damage. To examine alterations in mRNA expression levels microarray analysis was performed. We found significant alterations in 95 genes, including cell-cycle arrest genes, SG functional genes and a DNA repair gene.Tissue damage was seen by confocal immunofluorescence of α-amylase and c-Kit that showed an increase and decrease, respectively, in protein expression. This was coherent with real-time PCR results.This data indicates that IR damages the SSG cells' ability to produce and secrete saliva and proteins, and maintain the physiological barrier between serum and saliva. The damage does not heal due to cell-cycle arrest, which prevents tissue regeneration. Taken together, our results reveal a new insight into IR pathobiology.

Long-term Pilocarpine Treatment Improves Salivary Flow in Irradiated Mice

“…Similar to previous studies [2, 22, 23, 26, 31, 37, 39], female animals were used in this study. Nine-week-old (body weight, 30–32 g) female ICR mice were purchased from SLC Inc. (Shizuoka, Japan).…”

New and safe experimental model of radiation-induced neurovascular histological changes for microsurgical research

“…However, previous experimental models of irradiated heads and necks of rats have shown devastating local RT effects in comparison with the local effects in the inguinal region. [16][17][18][19][20] For that reason, a majority of experimental microsurgical studies in irradiated fields have been made in the inguinal region (Table 6), 3,14,[38][39][40][41][42] although without obtaining comparable results in terms of viability of the vascular anastomosis to those obtained in the cervical region. 4,[6][7][8]10,12,14,32 For all these reasons, there is a need to create a safe irradiated NV bundle model, with reproducible metrics and low local side-effects.…”

“…4,[6][7][8]10,12,14,32 For all these reasons, there is a need to create a safe irradiated NV bundle model, with reproducible metrics and low local side-effects. This model, in contrast to previous described models in which the head and neck are irradiated indiscriminately, [16][17][18][19][20] is based on selective irradiation of the left hemicervical region by means of a 2 Â 2 cm frontal field that covers the cervical NV bundle and avoids unnecessary irradiation of the surrounding vital structures.…”

“…16 However, studying the effect of RT on vascular microanastomosis causes an increase in rats' morbimortality after cervical/cranial external irradiation. [17][18][19][20] The aim of the present study is to create a new and safe rat model of RT-induced NV histological changes for microsurgical research, reducing the morbimortality described in previous models. [17][18][19][20] Animals Seventy-two adult male Sprague-Dawley rats weighing 250-300 g were obtained from Janvier Labs (Roubaix, France).…”

Network-based approaches for anticancer therapy

“…Nevertheless, some investigations have demonstrated the involvement of several genes, including HDAC1, MDM2, c-Jun, PKC-β, c-Abl and CDK1, in cellular responses to radiation (79)(80)(81). Some of these genes have been studied as potential targets for radiosensitizer development.…”