Mechanisms of different response to ionizing irradiation in isogenic head and neck cancer cell lines

Radiation Oncology

Table 2 Basal gene expression of genes involved in DNA damage signaling pathway in non-irradiated isogenic radioresistant FaDu-RR and radiosensitive 2A3 cells compared to non-irradiated parental FaDu cells

Gene^a	FaDu-RR^b	P value^c	2A3^d	P value^c	DNA damage signaling pathways
APEX1			2.11	0.002	BER
ATM			2.08	0.003	ATM/ATR signaling, DSB repair, apoptosis, cell cycle
BARD1			1.66	0.004	ATM/ATR signaling, other DNA repair genes, apoptosis
BBC3			−1.99	0.03	apoptosis
BLM	− 2.60	0.0003	−3.35	0.00003	DSB repair
CHEK1			1.96	0.001	ATM/ATR signaling, DSB repair, cell cycle
CIB1			−3.69	0.00003	other DNA repair genes, apoptosis
DDB2			1.78	0.02	NER
ERCC2	−2.35	0.005			NER
FANCD2	−1.74	0.05	1.78	0.0010	ATM/ATR signaling, other DNA repair genes
FEN1			1.79	0.001	BER
GADD45A	−2.19	0.04	3.30	0.02	other DNA repair genes
H2AFX	−1.92	0.009	1.61	0.03	ATM/ATR signaling, DSB repair
HUS1	−2.10	0.03			ATM/ATR signaling, DSB repair
MBD4	−1.54	0.0008			BER
MLH1			2.13	0.01	DSB repair, mismatch repair
MSH3			1.77	0.0006	mismatch repair
OGG1			1.70	0.005	NER, BER
PCNA	−1.57	0.04			NER, BER, mismatch repair
PMS1			1.90	0.003	mismatch repair
PNKP			−1.60	0.009	NER
PPM1D			1.82	0.04	cell cycle
PRKDC			1.89	0.02	DSB repair, apoptosis
RAD1			2.10	0.0004	ATM/ATR signaling, other DNA repair genes
RAD17			1.96	0.003	ATM/ATR signaling, other DNA repair genes
RAD18			1.82	0.004	other DNA repair genes
RBBP8			2.27	0.001	ATM/ATR signaling, other DNA repair genes
REV1			1.61	0.0007	other DNA repair genes
RNF168	−1.69	0.04	−2.13	0.0001	ATM/ATR signaling, other DNA repair genes
SUMO1			−2.60	0.00002	other DNA repair genes
TOPBP1	−1.68	0.01			ATM/ATR signaling, other DNA repair genes
UNG			2.20	0.005	BER
XRCC2	−2.47	0.04	2.01	0.03	DSB repair
XRCC3	−1.96	0.02			other DNA repair genes

^a Gene symbol according to HUGO Gene Nomenclature Committee; ^b Fold regulation in gene expression in radioresistant FaDu cells in comparison to parental FaDu cells. Positive fold regulation values indicate gene over-expression, negative fold regulation values indicate gene under-expression; ^c The P values are calculated based on a Student’s t-test of the replicate 2^{(− ΔΔ CT)} values for each gene in the parental FaDu cells and radioresistant FaDu-RR or radiosensitive 2A3 cells, and differences in gene expression were considered significant for P values less than 0.05; ^d Fold regulation in gene expression in radiosensitive 2A3 cells in comparison to parental FaDu cells. BER base excision repair, DSB double-strand break, NER nucleotide excision repair

ISSN: 1748-717X