Table 1.

Summary of the findings describing the mechanisms of radioresistance regulated by mitochondrial dysfunction and altered metabolism in cancer.

Altered cellular process	Authors	Cancer type	Mechanism of radioresistance	Ref
Redox balance	Lynam-Lennon, N. et al.	Oesophageal adenocarcinoma	Higher basal level of ROS	[15]
	Wei, Y. et al.	Non-small cell lung carcinoma	Lower radiation-induced ROS level	[19]
	Lynam-Lennon, N. et al.	Oesophageal adenocarcinoma	Maintenance of glutathione levels stable post irradiation	[21]
	Hanot, M. et al.	Tongue squamous cell carcinoma	Altered glutathione levels	[22]
	Chen, X. et al.	Oesophageal squamous cell carcinoma	Increased IDH2 expression	[24]
	Sun, J. et al.	CHO cells	MnSOD overexpression	[20]
	Hirose, K. et al.	Melanoma		[25]
	Kalen, A.L. et al.	Head-and-neck cancers		[26]
	Fisher, C.J. et al.	Pancreatic		[27]
DNA repair	Lynam-Lennon, N. et al.	Oesophageal adenocarcinoma	Increased repair of radiation-induced DNA damage	[21]
	Hyun, J. W. et al.	Leukaemia	Low OGG1 activity	[42]
	Ramdzan, Z.M. et al.	Breast, Lung, Glioblastoma, Colorectal	CUX1 overexpression	[46]
	Wang, Y. et al.	Non-small cell lung carcinoma	Downregulation of SSBP1	[54]
	Roy, K. et al.	Glioma	Methylation of the ATM promoter	[56]
	Squatrito, M. et al.	Glioblastoma	Loss of components in the ATM/Chk2/p53 pathway	[57]
	You, W.C. et al.	Glioblastoma	ATAD3A-mediated attenuation of DSB repairs	[58]
Apoptosis	He, Q. et al	Oesophageal squamous cell carcinoma	High LKB1 expression	[66]
	Wang, Z. et al.	Mouse embryonic fibroblasts	MKP1 inhibition of JNK-mediated apoptosis	[68]
	Candas, D. et al.	HER2-positive breast cancer	MKP1 overexpression	[148]
Cell cycle checkpoints	Wei, Y. et al.	Non-small cell lung carcinoma	Prolonged G2 arrest	[19]
	Cloos, C. R. et al.	Pancreatic	Supressed G2 activation increased cyclin B1 and CDK1	[77]
	Muschel, R. J., et al.	Cervical cancer	Altered Cyclin B expression	[78]
	Liu, R. et al.	Colon, Glioblastoma, Breast	Increased SIRT3 activity	[80]
Mitochondria-to-nucleus retrograde signaling	Wei, Y. et al.	Non-small cell lung carcinoma	NF-κB/ PI3K/AKT2/mTOR activation	[19]
	Cloos, C. R. et al.	Pancreatic cancer	Mitochondrial DNA depletion	[77]
Mitochondrial membrane potential	Dong, Q. et al.	Oesophageal carcinoma	Modulation of BMI-1 expression	[84]
	Li, Y.L. et al.	Head and neck cancers	Increased GDF15 expression	[85]
Mitochondrial ion channels	Huang, L. et al.	Glioma	Overexpression of mtKATP channel	[86]
	Arif, T. et al.	Breast, lung Glioblastoma	VDAC1 overexpression	[14]
Glycolysis	Pitroda, S.P. et al.	Tongue squamous cell carcinoma	STAT1 regulation of energy metabolism	[91]
	De Schutter, H. et al.	Head and neck cancers	GLUT1 overexpression	[95]
	Kunkel, M. et al.	Oral cavity squamous carcinoma		[96]
	Blatt, S. et al.	Head and neck cancers	High levels of lactate	[97]
	Sandulache, V.C. et al.			[98]
	Hao, J. et al.	Prostate	Increased LDHA	[99]
Glutamine metabolism	Li, D. et al.	Pancreatic	Non-canonical glutamine metabolism pathway	[107]
	Xiang, L. et al.	Cervical	Increased GLS2 expression	[105]
Oxidative phosphorylation	Lynam-Lennon et al.	Oesophageal adenocarcinoma	Increased ATP5B expression	[15]
	Le Bleu, V.S. et al.	Breast	Increased PGC1α	[110]
	Viale, A. et al	Pancreatic	Increased expression of OXPHOS genes	[112]
	Grasso, D. et al.	Head and neck cancer	Increased OXPHOS metabolism	[113]