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Role of miR‐214 in regulation of β‐catenin and the malignant phenotype of melanoma
Author(s) -
Prabhakar Kirthana,
Rodrίguez Carlos I.,
Jayanthy Ashika S.,
Mikheil Dareen M.,
Bhasker Aishwarya Iyer,
Perera Ranjan J.,
Setaluri Vijayasaradhi
Publication year - 2019
Publication title -
molecular carcinogenesis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.254
H-Index - 97
eISSN - 1098-2744
pISSN - 0899-1987
DOI - 10.1002/mc.23089
Subject(s) - wnt signaling pathway , biology , melanoma , cancer research , catenin , microrna , gene knockdown , signal transduction , beta catenin , microbiology and biotechnology , cell culture , gene , genetics
Wnt/β‐catenin signaling plays an important role in melanocyte biology, especially in the early stages of melanocyte transformation and melanomagenesis. β‐catenin, encoded by the gene CTNNB1, is an intracellular signal transducer of Wnt signaling and activates transcription of genes important for cell proliferation and survival. Wnt/β‐catenin signaling is frequently activated in melanoma through oncogenic mutations of β‐catenin and elevated β‐catenin levels are positively correlated with melanoma aggressiveness. Molecular mechanisms that regulate β‐catenin expression in melanoma are not fully understood. MicroRNA‐214 is known to function as a tumor suppressor by targeting β‐catenin in several types of cancer cells. Here, we investigated the regulation of β‐catenin by miR‐214 and its role in melanoma. We show that β‐catenin mRNA levels are negatively correlated with miR‐214 in melanoma. However, overexpression of miR‐214 paradoxically increased β‐catenin protein levels and promoted malignant properties of melanoma cells including resistance to mitogen‐activated protein kinase inhibitors (MAPKi). RNA‐seq analysis revealed that melanoma cells predominantly express a β‐catenin mRNA isoform lacking miR‐214 target site. Using matched miRNA and mRNA‐seq and bioinformatics analysis, we identified novel miR‐214 targets, ankyrin repeat domain 6 (ANKRD6) and C‐terminal binding protein 1 (CTBP1), that are involved in negative regulation of Wnt signaling. Overexpression of miR‐214 or knockdown of the novel miR‐214 targets, ANKRD6 or CTBP1, increased melanoma cell proliferation, migration, and decreased sensitivity to MAPKi. Our data suggest that in melanoma cells β‐catenin is not regulated by miR‐214 and the functions of miR‐214 in melanoma are mediated partly by regulating proteins involved in attenuation of Wnt/β‐catenin signaling.