Alterations of microRNAs throughout the malignant evolution of cutaneous squamous cell carcinoma: the role of miR-497 in epithelial to mesenchymal transition of keratinocytes

Abstract

Skin carcinogenesis is known to be a multi-step process with several stages along its malignant evolution. We hypothesized that transformation of normal epidermis to cutaneous squamous cell carcinoma (cSCC) is causally linked to alterations in microRNAs (miRNA) expression. For this end we decided to evaluate their alterations in the pathologic states ending in cSCC. Total RNA was extracted from formalin fixed paraffin embedded biopsies of five stages along the malignant evolution of keratinocytes towards cSCC: Normal epidermis, solar elastosis, actinic keratosis KIN1-2, advanced actinic keratosis KIN3 and well-differentiated cSCC. Next-generation small RNA sequencing was performed. We found that 18 miRNAs are overexpressed and 28 miRNAs are underexpressed in cSCC compared to normal epidermis. miR-424, miR-320, miR-222 and miR-15a showed the highest fold change among the overexpressed miRNAs. And miR-100, miR-101 and miR-497 showed the highest fold change among the underexpressed miRNAs. Heat map of hierarchical clustering analysis of significantly changed miRNAs and principle component analysis disclosed that the most prominent change in miRNAs expression occurred in the switch from 'early' stages; normal epidermis, solar elastosis and early actinic keratosis to the 'late' stages of epidermal carcinogenesis; late actinic keratosis and cSCC. We found several miRNAs with 'stage specific' alterations while others display a clear 'gradual', either progressive increase or decrease in expression along the malignant evolution of keratinocytes. The observed alterations focused in miRNAs involved in the regulation of AKT/mTOR or in those involved in epithelial to mesenchymal transition. We chose to concentrate on the evaluation of the molecular role of miR-497. We found that it induces reversion of epithelial to mesenchymal transition. We proved that SERPINE-1 is its biochemical target. The present study allows us to further study the pathways that are regulated by miRNAs along the malignant evolution of keratinocytes towards cSCC.

A Review of the Literature of Surgical and Nonsurgical Treatments of Invasive Squamous Cells Carcinoma

“…Moreover novel agents, such as herbacetin and wool hydrolysates, are currently under investigation. miRNA represents a potential biomarker along the malignant evolution of keratinocytes towards cSCC and further studies on this interesting and promising field are warranted [ 62 , 63 ].…”

Melatonin Attenuates Endothelial-to-Mesenchymal Transition of Glomerular Endothelial Cells via Regulating miR-497/ROCK in Diabetic Nephropathy

“…MiR-497 is a newly identified miRNA that inhibits epithelial-to-mesenchymal transition of cancer cells, keratinocytes, and alveolar epithelial cells [23,24,34]. A TargetScan analysis revealed that both ROCK1 and ROCK2 are potential targets of miR-497.…”

“…ROCK1 and ROCK2 reportedly have a post-transcriptional regulation mechanism [22], and miR-497 inhibits epithelial-to-mesenchymal transition [23,24]. Hence, we analyzed the relationship between miR-497 and ROCK1/ROCK2.…”

The role of LINC00094/miR‐224‐5p (miR‐497‐5p)/Endophilin‐1 axis in Memantine mediated protective effects on blood‐brain barrier in AD microenvironment

“…When LINC00094 was knocked down in ECs, microarray results showed that miR-224-5p and miR-497-5p were two of the up-regulated miRNAs. 20 MiR-497-5p is one of the members of the miR-15/107 family, 21,22 and the expression profile of miR-497-5p in vascular diseases has been extensive studied. It has been shown that miR-224-5p plays a critical role in multiple biological processes.…”

“…19 Precious study has shown that miR-224-5p acted as a protective role in inner ear damage via targeting Ptx3. 20 MiR-497-5p is one of the members of the miR-15/107 family, 21,22 and the expression profile of miR-497-5p in vascular diseases has been extensive studied. Multiple studies shown that miR-497-5p is overexpressed and participates in regulating ECs function and neuroprotection.…”