Table 3.

Function of lysosomes in subset of cells in TME

Cell subset	Function of lysosomes	Outcomes	Reference
Tumor cell	Proliferation	EGFR can be internalized from plasma membrane and degrade in lysosomes	[184, 185]
		Autophagy and macropinocytosis provide extra nutrients	[183, 187, 188]
	Invasion	Cathepsins degrade extracellular component and promote EMT	[193, 195]
	Radioresistance	Radioresistance can be achieved through autophagy, cathepsins, and tumor stem cells	[205, 206, 212, 214, 215]
	Chemoresistance	Drugs are sequestrated in lysosomes by actively transportation or passive diffusion	[220]
		Autophagy promotes or inhibits cancer cell death in different situation	[232–237]
TAMs	M2-like polarization	Autophagy, LAP, and CMA regulate M2-like polarization at most cases	[257, 259, 260]
	M1-like polarization	TLRs on lysosomal membrane regulate M1-like polarization	[262, 264, 266]
		Elevated luminal pH is correlated with M1-like polarization	[275, 276]
	Invasion promotion	TAM-derived cathepsins promote tumor invasion	[280, 283, 284]
	Chemoresistance induction	TAM-derived cathepsins protect tumor cells from drug-induced apoptosis	[279]
	Infiltration promotion	TAM-derived cathepsins promote macrophage infiltration into TME	[290, 291]
DCs	Antigen presentation	LAMP3+ DCs are able to elicit CD8+ T cell immunity. Autophagy may promote or inhibit antigen presentation	[293–296]
CAFs	Chemoresistance regulation	Autophagy in CAFs promotes or inhibits chemoresistance in different tumor	[303, 304]
	Proliferation promotion	Autophagy in CAFs provides nutrients for tumor cells	[299, 300]
	Invasion promotion	Autophagy in CAFs promotes EMT in tumor cells	[305]
	Stemness promotion	CAFs with active autophagy release HMGB1 to enhance stemness in tumor cells	[306]
T cells	CD8+ T cell immunity	Autophagy in CD8+ T cells promotes or inhibits CD8+ T cell immunity in different tumor	[309, 310]
	CD4+ T cell immunity	Autophagy in CD4+ T cells inhibits anti-tumor effects by TH9 cell	[311, 312]
	Treg inhibition	Autophagy in Treg promotes survival and stability of Treg cells	[313]