Differential gene expression analysis identified determinants of cell fate plasticity during radiation-induced regeneration in Drosophila

Abstract

Ionizing radiation (IR) is used to treat half of all cancer patients because of its ability to kill cells. IR, however, can induce stem cell-like properties in non-stem cancer cells, potentiating tumor regrowth and reduced therapeutic success. We identified previously a subpopulation of cells in Drosophila larval wing discs that exhibit IR-induced stem cell-like properties. These cells reside in the future wing hinge, are resistant to IR-induced apoptosis, and are capable of translocating, changing fate, and participating in regenerating the pouch that suffers more IR-induced apoptosis. We used here a combination of lineage tracing, FACS-sorting of cells that change fate, genome-wide RNAseq, and functional testing of 42 genes, to identify two key changes that are required cell-autonomously for IR-induced hinge-to-pouch fate change: (1) repression of hinge determinants Wg (Drosophila Wnt1) and conserved zinc-finger transcription factor Zfh2 and (2) upregulation of three ribosome biogenesis factors. Additional data indicate a role for Myc, a transcriptional activator of ribosome biogenesis genes, in the process. These results provide a molecular understanding of IR-induced cell fate plasticity that may be leveraged to improve radiation therapy.

DrosophilapVALIUM10 TRiP RNAi lines cause undesired silencing of Gateway-based transgenes

“…Strikingly, similar down-regulation of RNase H1::GFP was caused by pVALIUM10-based myc RNAi[TRiP.JF01761] but not myc RNAi[TRiP.HMS01538] or myc RNAi[GD2948] derived from pVALIUM20 and pMF3 vectors, respectively ( Figs 1D and 2E–H ). All three myc RNAi lines have been shown effective by others ( Aughey et al, 2016 ; Kim-Yip & Nystul, 2018 ; Rust et al, 2018 ; Ledru et al, 2022 ). These results indicated that the tested pVALIUM10 TRiP RNAi lines but not pVALIUM20, KK, or GD lines may cause undesirable silencing of the RNase H1::GFP transgene.…”

DrosophilapVALIUM10 TRiP RNAi lines cause undesired silencing of Gateway-based transgenes

“…Strikingly, similar downregulation of RNase H1::GFP was caused by pVALIUM10-based myc RNAi[TRiP.JF01761] but not myc RNAi[TRiP.HMS01538] or myc RNAi[GD2948] derived from pVALIUM20 and pMF3 vectors, respectively (Figures 1D and 2E-G). All three myc-RNAi lines have been shown effective by others (Aughey et al , 2016; Kim-Yip & Nystul, 2018; Ledru et al , 2022; Rust et al , 2018). These results indicated that the tested pVALIUM10 TRiP RNAi lines but not pVALIUM20, KK or GD lines may cause “non-specific” silencing of the RNAse H1::GFP transgene.…”

Cell-cell interactions that drive tumorigenesis in Drosophila

“…Hinge cells in the wing disc also show resistance to IR- and drug-inducible cell death via elevation of the STAT effector Zfh2 and Wg signalling [ 104 , 105 ]. IR-induced caspase activation provides stem cell-like properties in hinge cells by increased ribosome biogenesis for tissue regeneration [ 105 , 106 ]. These observations suggest that hinge cells are potentially cancer-stem cells (CSCs) that are involved in tumour initiation and recurrence.…”