Table 1.

Pro- or anti-tumoral effects mediated by TLRs.

Receptor	Tumor Type	Tumor Role	Mechanism	Pathways or Molecules Involved	Ref
TLRs	Intestine, liver, skin	Protumoral	Inflammation	NF-κB, IL-1β, TNFα and IL-6	[46]
TLR2	Gastric	Protumoral	Cell survival and proliferation in gastric tumor epithelium	PI3K/Akt, ERK1/2, JNK MAPKs, NF-kb	[47]
TLR2/6	Lewis lung carcinoma	Protumoral	Inflammation, macrophage activation, metastasis	Myd88, TRIF, ECM-protein versican, IL-6, TNF-α	[48]
TLR2/4	Lung	Protumoral	ECM remodeling,	EGFR	[38]
TLR3	Breast	Protumoral	Tumor growth	β- Catenin, NF-κB	[49]
TLR4	Liver	Protumoral	Inflammation	NF-κB	[50]
TLR4	Lung	Protumoral	immunosuppression, antiapoptosis	VEGF, TGF-β, IL-8	[42]
TLR4	Colon	Protumoral	Inflammation, tumor burden	Cox-2	[51]
TLR4	Skin	Protumoral	Inflammation	Myd88	[52]
TLR7	Pancreatic	Protumoral	Stromal inflammation	NF-kB, MAPKs	[53]
TLR7, TLR8	Lung	Protumoral	Inflammation, tumor cell growth and survival, chemoresistance	NF-kB, MAPK, IRF, Bcl-2, IL-6, IL-8, CSF-2, IL-1α, IL-12, NOS-2	[44]
TLR9	Lung	Protumoral	Monocyte recruitment, antiapoptosis	MCP1	[45]
TLR2	Lung	Antitumoral	Monocytic myeloid-derived suppressor cell	JNK, TNF-α, IL-12p40, IL-12p70	[54]
TLR3	Prostate, liver	Antitumoral	Treatment with agonist stops tumor growth	Type I interferons	[55]
TLR3	Liver	Antitumoral	Induction of tumor parenchyma (hepatocytes) cell death; induction of intratumor expression of chemokines that attract NK cells or T cells to the tumor microenvironment; and activation of tumor-infiltrating NK cells that promote cytotoxic activity.	IFN-γ	[56]
TLR5	Breast, colon	Antitumoral	Immune cell activation	Dendritic cells	[37,57,58]
TLR7/8	Melanoma	Antitumoral	Immune cell activation	Dendritic cells and Natural Killer	[38,39]