Table 4.

Pathways regulated by multiple miRNAs (common to cancer and neurodegenerative diseases).

miRNA	Target genes	Expression in cancer	Expression in neurodegenerative disorders	Reference
let-7 family, miR-17-5p, miR-20a miR-106b	APP	Oncogene, over-expressed in oral cavity, esophageal, pancreatic, neuroendocrine, thyroid, and colorectal cancer	Concentrated at neuronal synapses and in AD-associated amyloid plaques	[69,70,71,72,73,74,75,76]
miR-29a/b-1 family	BACE1	Decrease of ST6GalI-mediated cancer cell migration	High expression in patients with sporadic AD	[78,79]
miR-21 miR-106b	PTEN	Tumour suppressor, mutated in sporadic and inherited tumours	Implicated in PD through activation of PINK1 and PARK7	[80,81,82]
miR-34b/c	PARK2	Tumour suppressor, mutated in glioblastoma, lung cancer and colon cancer	Reduced in PD brain samples displaying strong miR-34b/c downregulation	[67,83]

(APP: Amyloid Precursor Protein; BACE1: β-secretase 1; PTEN: Phosphatase and Tensin Homolog; PARK2: Parkin).