Table 1.

MicroRNAs associated with sensitivity to CDK4/6 inhibition.

miRNA	Tumor Type	CDK4/6 Inhibitor	miRNA Expression	Mechanism of Action	Biological Sample	Detection Method	References
miR-126	Lumina, HER2+ breast cancer	Ribociclib	Upregulation	Downregulation of genes associated with cell cycle, especially M phase and glycolysis	Breast cancer cell lines	MicroRNA assay	[43]
miR-326	HER2+ breast cancer	Ribociclib	Upregulation	Negative correlation with multidrug resistance-associated protein (MRP-1)	Breast cancer cell lines	miRNA assay	[43]
miR-3613-3p	TNBC	Palbociclib	Upregulation	Downregulation of SMAD2 and EZH2	Fresh frozen tissue, breast cancer cell lines	miRNA assay, qRT-PCR	[40]
miR-29b-3p	Luminal, HER2+ BC	Palbociclib	C-myc upregulation	Negative regulation of CDK6	FFPE, breast cancer cell lines	miRNA assay, tissue microarrays for IHC	[41]
miR-497	NPM-ALK (+) ALCL	Palbociclib	Downregulation via MIR497HG promoter hypermethylation	Negative regulation of cell cycle genes, including CDK6	NPM-ALK ALCL cell lines, tumor tissue	qRT-PCR	[42]
miR-17-92	Atypical teratoid rhabdoid tumors	Palbociclib	SMARCB mediated upregulation	Downregulation of cyclin D1	ATRT cell lines, tumor tissue	qRT-PCR, miRNA assay, tissue microarrays for IHC	[47]
	Proneural GBM	Palbociclib, Ribociclib	E2F-mediated upregulation	Downregulation through E2F transcription factors	Glioblastoma stem cell (GSC) lines	qRT-PCR	[44]