Targeting DNA repair mechanisms in aggresive neuroblastoma

Sammanfattning: Neuroblastoma is a tumour derived from cells of the nervous system and is the most common solid tumour in childhood. MYCN amplified and 11q-deleted neuroblastoma, two high-risk neuroblastoma were investigated in this study. RAD51 gene family includes six central genes for the dsDNA breaks repair by homologous recombination, which has been reported as important in varying types of cancer. The study aims to investigate if the dysregulation of this gene family could be involved in the unstable genome of 11q-deleted neuroblastoma, and to better understand the link between both high-risk tumours. The RAD51 family genes’ expression level was measured by RT-qPCR in samples of 11q-deleted and MYCN-amplified neuroblastoma that were treated with a UVC treatment and were recovered during varying hours. R2 database and DAVID were used to study the RAD51 family’s expression levels, associated event-free survivability, and altered pathways. RAD51 family is highly dysregulated in these tumours, four genes of six were found to be altered in high-risk neuroblastoma. Four of six genes presented altered expression levels in 11q-loss, and three of six in the MYCN-amplified case after the UVC treatment. The event-free survival probability analysis shown that the levels of expressions associated with high-risk neuroblastoma coincide with those that represent a poor life expectancy. Altered pathways were different in each type of tumour. 11q-deletion neuroblastoma’s pathways were associated with the nervous system development, and MYCN-amplified was related to the immune system. This study suggests that 11q-loss neuroblastoma presents a greater RAD51 family dysregulation compared with MYCN-amplified one, which could explain why its genome is unstable.