Table 1.

The anti-cancer mechanisms of action of retinoids

Pathways	Cancer type	Biomarkers	References
Gene signaling pathways
RAR/RXR	Melanoma	RAR	[54]
	Gastric cancer		[49]
	Neuroblastoma		[45,53]
	Cutaneous T-cell Lymphoma	RAR	[39]
		RAR and RXR	[18]
	Prostate cancer	RAR and RXR	[21]
EGFR/MAPK	Breast cancer	MMP2 and MMP9	[46]
	Melanoma	EGFR, MAPK and MMP2	[15]
		MMP-9	[54]
	Lung cancer	EGFR	[20]
Wnt/β-catenin	Breast cancer	Cyclin D1, c-MYC and β-catenin	[8]
	Melanoma	Cyclin D1	[54]
	Colorectal cancer	MED28, cyclin D1, c-MYC, β-catenin, E-cadherin and HBP1	[66]
	Lung cancer	CTNNB1	[20]
JAK/STAT	Breast cancer	GRIM-19	[58]
	Hepatocellular carcinoma	JAK2 and STAT3	[69]
	Cutaneous T-cell lymphoma	JAK1, STAT3, STAT5, Bcl-xL and cyclin D1	[18]
Caspase	Melanoma	Caspase-3	[33]
	Lung cancer	BCL-2, survivin and BAX	[47]
MYCN	Hepatocellular carcinoma	MYCN and N-myc	[9]
	Neuroblastoma		[75]
DOK1/PPARγ	Breast cancer	DOK1 and PPARγ	[48]
Src-YAP-IL6		Src-YAP-IL6	[52]
HER2		HER2	[50]
FAK		FAK
ERK/MAPK	Colorectal cancer	ERK1, MAPK and MLCK
	Thyroid cancer	ERK2	[51]
SPHK1-S1P	Hepatocellular carcinoma	SPHK and S1P	[83]
SKP2/p27kip1	Cutaneous T-cell lymphoma	SKP2 and p27kip1	[37]
Keap1/Nrf2/ARE	Glioma	Keap1, Nrf2 and ARE	[42]
PI3K/AKT	Gastric cancer	AKT	[19]
ERK1/2		ERK1/2
PAK	Pancreatic cancer	PAK	[49]
Other mechanisms
Mitochondrial function	Breast cancer	Cardiolipins amount	[14]
	Neuroblastoma	mitochondrial stress response	[45]
	Glioma	ATP	[34]
MicroRNAs	Hepatocellular carcinoma	miR-200a-3p, miR-200c-3p and miR-141-3p	[17]
Tumor stem cells	Gastric cancer	CD44, ALDH, KLF4 and SOX2	[22]