P62 sustains a protumorigenic gene signature in melanoma opposing mRNA-dependent decay [UACC62_3days]
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ABSTRACT: 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.
Project description: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.
Project description: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.
Project description: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.
Project description:p62/SQSTM1 was identified as a modulator of metastatic genes selectively enriched in melanoma in autophagy independent manner. iTRAQ quantitative proteomic approach was performed in melanoma cell lines (SK-Mel-103 and UACC-62) deficient for p62 to identify downstream effectors of p62. Similar studies were performed for ATG5, a core component of autophagy, as a reference for autophagy-associated changes in protein abundance. Additionally, melanoma cells were subjected to affinity purification (AP-MS) to identify the interactors of p62. Overall, these studies underscore a novel unexpected role of p62 regulating the stability of prometastatic factors via the interaction with RNA Binding Proteins, thus leading to the inhibition of protein translation.
Project description:p62/SQSTM1 was identified as a modulator of metastatic genes selectively enriched in melanoma in autophagy independent manner. iTRAQ quantitative proteomic approach was performed in melanoma cell lines (SK-Mel-103 and UACC-62) deficient for p62 to identify downstream effectors of p62. Similar studies were performed for ATG5, a core component of autophagy, as a reference for autophagy-associated changes in protein abundance. Additionally, melanoma cells were subjected to affinity purification (AP-MS) to identify the interactors of p62. Overall, these studies underscore a novel unexpected role of p62 regulating the stability of prometastatic factors via the interaction with RNA Binding Proteins, thus leading to the inhibition of protein translation.
Project description:These are the results of the iCLIP experiment for p62/SQSTM1 in Human Huh-7 cells treated with DMSO. We used iCLIP method to identify the RNA targets of p62 and nucleotide positions of the p62 interaction on RNA. We used 2 replicates and 2 different antibodies against endogenous p62 to enrich protein/RNA complexes. cDNAs were tagged with iCLIP composite barcodes (e.g. NNNTTGTNN) which contain 4 sample-encoding bases (e.g. TTGT) and and 5 random bases (noted with N in NNNTTGTNN example) which serve as unique molecular identifiers to post-filter PCR duplicates. These composite barcodes are found in the read headers (after last colon ':' character) of submitted fastq files.
Project description:Chromosomal instability (CIN) generates micronuclei, aberrant extranuclear structures that catalyze the acquisition of complex chromosomal rearrangements present in cancer. Micronuclei are characterized by persistent DNA damage and catastrophic nuclear envelope collapse, exposing DNA to the cytoplasm and driving a pro-inflammatory, pro-metastatic environment. Here, we identify the autophagic receptor p62/SQSTM1 as a regulator of micronuclei. p62 modulates micronuclear stability, influencing chromosome fragmentation and rearrangements, via exerting local spatial control on peri-micronuclear ESCRT-mediated repair activity. We demonstrate that proximity of micronuclei to mitochondria leads to oxidation-driven homo-oligomerization of p62, which triggers autophagic degradation of ESCRT components, thereby limiting their repair activity. Notably, we find that p62 levels correlate with increased chromothripsis across human cancer cell lines and with increased CIN in colorectal tumors. Thus, our study identifies p62 as a novel regulator of micronuclei and indicates that it may serve as a prognostic marker of tumors with high CIN.
Project description:The purpose of this study is to identify the differential transcriptome profiles in WT, hepatic Atg5 KO, TSC1 KO, Atg5/TSC1 DKO, Atg5/TSC1/p62 TKO and Atg5/TSC1/Nrf2 TKO mouse livers. Hepatic mRNA from 2-month-old mice from 5 different mouse strains were extracted and performed for Nextseq analysis in quadruplicates.