Table 2.

Chromium exposure-induced alterations of miRNAs and carcinogenesis

miRNA	Alteration	Role	Target(s)	Role in carcinogenesis	References
miR-143	Down	Tumor suppressor	IGF-IR, IRS	Suppress cell transformation and tumor angiogenesis via IGF-IR/IRS1/ERK/IL-8 pathway	[69]
miR-222	Up	Oncogene		Promote MAPK and nerve growth factor pathways	[72]
miR-494	Down	Tumor suppressor	c-Myc	Inhibit CSC-like property and carcinogenesis by targeting c-Myc	[75]
miR-3940-5p	Down	Tumor suppressor	XRCC2, BRCC3	Protective effect in Cr(VI) induced DNA damage	[76]
miR-19a-3p, miR-19b-3p and miR-142-3p	Down	N/A	See Ref	Regulate MAPK, cAMP, cGMP-PKG, and FoxO signaling pathways	[77]
miR-590-3p	Up	N/A	See Ref	Regulate MAPK, cAMP, cGMP-PKG, and FoxO signaling pathways	[77]
miR-21 and miR-155	Down	N/A	N/A	N/A	[78]