American Association for Cancer Research
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Figure S10 from miR-146a Exerts Differential Effects on Melanoma Growth and Metastatization

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journal contribution
posted on 2023-09-21, 18:40 authored by Monica Raimo, Francesca Orso, Elena Grassi, Daniela Cimino, Elisa Penna, Cristiano De Pittà, Michael B. Stadler, Luca Primo, Enzo Calautti, Pietro Quaglino, Paolo Provero, Daniela Taverna

miR-146a affects LFNG, ROCK1, ITGAV and NUMB expression in melanoma cells.


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Malignant melanoma is the most aggressive form of skin cancer; therefore, it is crucial to disclose its underlying molecular mechanisms. MicroRNAs (miRNAs) are small endogenous noncoding RNAs able to posttranscriptionally downregulate the expression of direct target genes. Using a melanoma progression model, miR-146a was identified as a key double-acting player in melanoma malignancy. In fact, miR-146a is able to enhance tumor growth, while it suppresses dissemination. It was determined that miR-146a coordinated melanoma cell growth by its direct targets lunatic fringe (LFNG) and NUMB, which operate on the NOTCH/PTEN/Akt pathway; while inhibition of metastasis formation was linked to decreased expression of ITGAV and ROCK1. Relevantly, miR-146a expression correlated with melanoma recurrence and was enriched in both patient-derived melanoma and cutaneous metastasis specimens, while its direct targets were depleted. However, miR-146a levels drop in circulating tumor cells (CTCs), suggesting the necessity for miR-146a expression to fluctuate during tumor progression in order to favor tumor growth and allow dissemination. This study reconciles the contradictory biologic functions of miR-146a in melanoma progression and unravels distinct molecular mechanisms that need to be considered for therapeutic interventions.Implications: miR-146a controls melanoma progression in a dual way, promoting growth and inhibiting dissemination; however, it is poorly expressed in CTCs, resulting in overall tumor spreading and distant-site colonization. Mol Cancer Res; 14(6); 548–62. ©2016 AACR.