X-irradiation and bystander effects induce similar changes of transcript profiles in most functional pathways in human melanoma cells

Bystander Effects Induced by Medium From Irradiated Cells: Similar Transcriptome Responses in Irradiated and Bystander K562 Cells

“…Total ribonucleic acid was isolated from approximately 3 Â 10 6 cells with RNeasy Mini Kits (Qiagen, Valencia, CA), and synthesis of complementary DNA and biotinylated complementary ribonucleic acid, hybridization, and staining were performed by use of materials and methods from Affymetrix as described previously (33). Raw fluorescence data were normalized and expression values calculated by robust multi-array analysis by use of the RMAexpress program (34, http://rmaexpress.bmbolstad.com/).…”

“…In an independent series of experiments, time course changes in the level of selected transcripts representing different functional pathways were followed by qRT-PCR performed on three replicate samples by use of a Chromo4 System with DNA Engine (Bio-Rad, Hercules, CA) as previously described (33), and primers are shown in Table E1. Transcript level changes were calculated by ''relative quantification normalized to a reference gene'' (Bio-Rad RT-PCR Applications Guide) with ribosomal protein gene RPL41 as reference.…”

Intercellular Communication in Response to Radiation Induced Stress: Bystander Effects in Vitro and in Vivo and Their Possible Clinical Implications

“…Closing these connections by lindane, an inhibitor of gap junction, lead to the inhibition of bystander effect, evidenced as the reduced expression of TP53, CDKN1A (p21) and CDC2 genes (Azzam et al, 1998), or increased survival of clonogens (Bishayee et al, 1999). Several studies have demonstrated that the radiation-induced bystander effect triggers apoptosis (Prise et al, 1998, Morthersill and Seymour, 2001, Przybyszewski et al, 2004 and increase of micronucleus frequency, DNA double-strand breaks (DSBs) measured as histone H2AX phosphorylation (Sokolov et al, 2007, Burdak-Rothkam et al, 2007, accumulation of p53 (Tartier et al, 2007) andATM andATR proteins (Burdak-Rothkam et al, 2008), epigenetic changes, such as DNA hypomethylation, as well as the expression of other genes (Chaudry, 2006, Iwakawa et al, 2008, Rzeszowska-Wolny et al, 2009b. Many of these experiments showed that higher doses of radiation, including those used in conventional radiotherapy, also induce bystander effects in non-irradiated cells.…”

Cell death pathways in directly irradiated cells and cells exposed to medium from irradiated cells

“…Studies have shown very similar changes in the transcriptome of both directly irradiated and bystander cells (Rzeszowska-Wolny et al 2009;Herok et al 2010) while Ghandhi et al (2010) showed that gene clusters for irradiated cells were enriched for signal transduction, cell cycle/cell death and inflammation / immunity processes whereas gene clusters for bystander cells were enriched for cell communication / motility, signal transduction and inflammation processes. Mitochondrial damage, including mitochondrial DNA (mtDNA) damage and altered mitochondrial function, has been shown to be similar in directly irradiated cells and cells exposed to irradiated cell conditioned media (ICCM) (Murphy et al 2005;Nugent et al 2007;Nugent et al 2010).…”