Table 2. Changes of MEG3 expression level in different mouse models.

Reference	Cancer Type	Country	Samples	Number of samples case/control	MEG3 Level	Methods	Potential function and mechanism
Chunharojrith et al., 2015 [80]	NFAs	USA	Nude mice	5/5	Down	RT-PCR	MEG3 causes cell cycle arrest at the G1 phase
Luo et al., 2015 [60]	PC	China	Nude mice	5/5(pCDNA /pCDNA-MEG3)	Down	qRT-PCR	MEG3 inhibits the expression of cell cycle regulatory protein Cyclin D1 and induced cell cycle arrest in G0/G1 phase
Yin et al., 2015 [54]	CRC	China	Nude mice	3/3	Down	qRT-PCR	The proliferation index ki-67 is significantly decreased in the MEG3-transfected tumor cells. In addition, the cleaved caspase-3 level is increased.
Zhuo et al., 2015 [34]	HCC	China	Nude mice	5/5	Down	qRT-PCR	MEG3 inhibits proliferation and induces apoptosis through the accumulation of TP53.
Liu et al., 2015 [38]	LAD	China	Nude mouse xenograft model	6/6 (pCDNA-MEG3/ empty vector + cisplatin)	Down	qRT-PCR	MEG3 overexpression increases the in vivo chemosensitivity of LAD cells to cisplatin.
Modali et al., 2015 [62]	Insulinomas	USA	Mice	7/6	Down	qRT-PCR	DNA demethylating drugs reduce mouse insulinoma cell proliferation and restore MEG3 expression.
Lu et al., 2013 [44]	NSCLC	China	Nude mice	5/5	Down	qRT-PCR	Overexpression of MEG3 could inhibit tumor growth in vivo.
Lempiäinen et al., 2013 [82]	LT	UK	PB treatment Mice	5 Pairs	Down	qRT-PCR	PB induces MEG3 expression in glutamine synthetase positive hypertrophic hepatocytes.
Gordon et al., 2010 [81]	PA	USA	Nude mice	5 Pairs	Lost	qRT-PCR	Increased expression of angiogenic genes in the brains of MEG3-null mice.
Kawakami et al., 2006 [46]	RCC	Japan	Nude mice	5 Pairs	Lost	qRT-PCR	Reintroduction of DLK1 into DLK1-null RCC cell suppresses tumor growth in nude mice.

Abbreviations: CRC; Colorectal cancer; HCC, Hepatocellular Carcinoma; LAD; lung adenocarcinoma, PA, pituitary adenomas; RCC, Renal Cell Carcinoma; LT, Liver Tumor; NSCLC, Non-small cell lung cancer.; NFAs, non-functioning pituitary adenomas.