p62 sustains a protumorigenic gene signature in melanoma opposing mRNA-dependent decay [UACC62_3days]

Metastasis is a common cancer hallmark which however, may be acquired by tumor-type specific mechanisms. Here we identify p62/SQSTM1 as a modulator of metastatic genes selectively enriched in melanoma. Loss- and gain-of-function analyses of p62 effectors revealed FERMT2 as an indicator of poor patient prognosis. Analyses in tumor cells, clinical biopsies and genetically-engineered mice (to compare p62 vs. ATG5) demonstrated that known p62 roles in autophagy and stress responses were not essential in melanomas. Instead, a genome-wide transcriptomic/proteomic/interactomic approach demonstrated that p62 controls FERMT2 and yet additional pro-metastatic genes by modulating transcript stability. This function of p62 was exerted by recruiting RNA-binding proteins, here exemplified by IGF2BP1. These data illustrate how genetically altered cancers can coordinately fuel pro-metastatic signatures. Two-condition experiment: shp62 vs. shControl. Biological replicates: 3 control replicates, 3 transfected replicates. 2 cell lines: SK-Mel-103, UACC62. 2 exposure times: 3 days, 6 days. This dataset includes cell line UACC62 at day 3.