Table 2.

MicroRNA sequences shown to interact with GAS5.

MicroRNA/Aliases	Site of Interaction with GAS5 lncRNA	Tumor or Cell Type	Effect Demonstrated	Reference
miR-221/222	Exon	Gliomas	Unknown	Zong et al., [49]
miRNA-21	Exon 5 *	Endothelial cells, ovarian carcinoma, cervical carcinoma	Reduced	Ma, et al. [36] Shen and She [86]; Wen et al. [39]
miRNA-135b	Exon	Hepatocellular carcinoma (HCC)	Sponging or translational inhibition	Yang and Jiang [87].
miRNA-196a	GAS5 promoter ** or exon	Glioma, esophageal squamous cells	Downregulation of GAS5 RNA (Wang)	Wang et al. [83]; Zhao et al. [84]
miRNA-137	Exon	Melanoma	GAS5 RNA and miRNA co-regulated	Bian et al. [43]

* It is claimed [86] that the target of miRNA-21 is the 22-nucleotide region of GAS5 (5′-ACAGGCATTAGACAGAAAGCTG-3′-OH; their Figure 1). This target lies completely within human exon 5 (the exon between SNORD77 and SNORD44); this exon (our Figure 1) harbors a putative small open reading frame. In protein-coding conventional mRNAs, microRNAs usual bind 3′-UTRs, although unconventional miRNA binding to ORFs has occasionally been observed. The authors of this 2018 publication make no comment on any proposed ORF. ** It is claimed [84] that miRNA-196a (highly expressed in glioblastoma multiforme), instead of serving as a post-transcriptional regulator, can be an epigenetic regulator and binds to a region of the GAS5 promoter which can be occupied by the transcription factor FOXO1, a TATTTT motif in the GAS5 promoter, presumably shutting down transcription of the tumor suppressor GAS5. This finding is consistent with numerous reports of short RNAs serving as epigenetic regulators at promoters [88].