Table 1. Roles and function mechanisms of lncRNAs in osteosarcoma.

LncRNA	Expression	Role of lncRNA	Function mechanism	Reference
TUG1	↑	promotes cell proliferation, inhibits apoptosis, inhibits G0/G1 cell cycle arrest	sponges miR-9-5p:downregulates POU2F1 expression	[29, 49–51, 87]
		associated with tumor size, clinical stage and post-operative chemotherapy	downregulates POU2F1 expression
		correlated with poor prognosis and disease status
		an independent prognostic indicator for overall survival
HOTAIR	↑	promotes cell proliferation, invasion and secrection of MMP2 and MMP9	—	[62, 67, 68]
MALAT1	↑	promotes cell proliferation and meatastasis	activates PI3K/AKT signaling pathway;	[53–56]
			involvement of RhoA/ROCK Pathway
			MALAT1/MIR376A/TGFA axis
			regulated by Myc-6
H19	↑	promotes cell proliferation, inhibites apoptosis	interacts with miR-141	[60, 61]
		induces osteosarcoma development	involvement of Hedgehog signaling
HULC	↑	correlated with clinical stage, and distant metastasis, but not in another study	—	[78, 79]
		correlated with shorter overall survival
SNHG12	↑	promotes cell proliferation and migration	upregulates angiomotin gene expression	[45]
MFI2	↑	promotes cell proliferation, suppresses apoptosis	upregulates FOXP4 expression	[46]
PACER	↑	promotes cell proliferation and metastasis	activates COX-2 gene in a NFκB-dependent way	[47]
BCAR4	↑	correlated with large tumor size, advanced Enneking stage, lung metastasis,	activates GLI2-dependent gene transcription	[80]
		and poor prognosis
HNF1A-AS1	↑	associated with clinical stage, distant metastasis, and poor overall survival	activates Wnt/β-catenin signaling pathway	[44]
BANCR	↑	associated with large tumor size, distant metastasis, and advanced clinical stage	—	[27, 86, 110]
		an independent predictor of poor survival
UCA1	↑	correlated with large tumor size, high tumor grade, distant metastasis,	—	[81]
		and advanced clinical stage
		an independent unfavorable prognostic factor
91H	↑	correlated with advanced clinical stage, chemotherapy after surgery,	—	[88]
		and tumor size >5 cm
		an independent prognostic factor for overall survival
ODRUL	↑	contributes to doxorubicin resistance	induces multidrug resistance-related ABCB1expression	[77]
HOTTIP	↑	correlated with advanced clinical stage, distant metastasis and poor prognosis	interacts with WDR5/MLL complex	[83, 108, 109]
		increases cisplatin resistance	activates Wnt/β-catenin signaling pathway
FOXC2-AS1	↑	influences tumor angiogenesis and metastasis	upregulates ABCB1, HIF1A and FOXC2 expression	[20]
		associated with poor chemoresponse and longer survival time
		contributes to doxorubicin resistance
LINC00161	↑	increases cisplatin-induced apoptosis	sponges endogenous miR-645	[107]
		reverses cisplatin resistance	upregulates IFIT2
ZEB1-AS1	↑	promotes cell proliferation and migration	binds and recruits p300 to the ZEB1 promoter region,	[48]
		correlated with large tumor size, progressed Enneking stage, tumor metastasis,	activates ZEB1 transcription
		worse recurrence-free and overall survival
loc285194	↓	promotes cell growth	induced by p53,interact with miR-211	[70, 71]
MEG3	↓	associated with poor overall survival	positively regulates p53 expression	[84, 85]
TUSC7	↓	promotes cell proliferation and increases colony formation in vitro	—	[43]
HIF2PUT	↓	promotes cell proliferation and migration	positively correlated with HIF-2α expression	[94]
		decreases the percentage of CD133 expressing cells
		impaires the osteosarcoma stem sphere-forming ability of the MG63 cells