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Systems-wide RNAi analysis of CASP8AP2/FLASH shows transcriptional deregulation of the replication-dependent histone genes and extensive effects on the transcriptome of colorectal cancer cells

BACKGROUND: Colorectal carcinomas (CRC) carry massive genetic and transcriptional alterations that influence multiple cellular pathways. The study of proteins whose loss-of-function (LOF) alters the growth of CRC cells can be used to further understand the cellular processes cancer cells depend upon...

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Autores principales: Hummon, Amanda B, Pitt, Jason J, Camps, Jordi, Emons, Georg, Skube, Susan B, Huppi, Konrad, Jones, Tamara L, Beissbarth, Tim, Kramer, Frank, Grade, Marian, Difilippantonio, Michael J, Ried, Thomas, Caplen, Natasha J
Formato: Online Artículo Texto
Lenguaje:English
Publicado: BioMed Central 2012
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3281783/
https://www.ncbi.nlm.nih.gov/pubmed/22216762
http://dx.doi.org/10.1186/1476-4598-11-1
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author Hummon, Amanda B
Pitt, Jason J
Camps, Jordi
Emons, Georg
Skube, Susan B
Huppi, Konrad
Jones, Tamara L
Beissbarth, Tim
Kramer, Frank
Grade, Marian
Difilippantonio, Michael J
Ried, Thomas
Caplen, Natasha J
author_facet Hummon, Amanda B
Pitt, Jason J
Camps, Jordi
Emons, Georg
Skube, Susan B
Huppi, Konrad
Jones, Tamara L
Beissbarth, Tim
Kramer, Frank
Grade, Marian
Difilippantonio, Michael J
Ried, Thomas
Caplen, Natasha J
author_sort Hummon, Amanda B
collection PubMed
description BACKGROUND: Colorectal carcinomas (CRC) carry massive genetic and transcriptional alterations that influence multiple cellular pathways. The study of proteins whose loss-of-function (LOF) alters the growth of CRC cells can be used to further understand the cellular processes cancer cells depend upon for survival. RESULTS: A small-scale RNAi screen of ~400 genes conducted in SW480 CRC cells identified several candidate genes as required for the viability of CRC cells, most prominently CASP8AP2/FLASH. To understand the function of this gene in maintaining the viability of CRC cells in an unbiased manner, we generated gene specific expression profiles following RNAi. Silencing of CASP8AP2/FLASH resulted in altered expression of over 2500 genes enriched for genes associated with cellular growth and proliferation. Loss of CASP8AP2/FLASH function was significantly associated with altered transcription of the genes encoding the replication-dependent histone proteins as a result of the expression of the non-canonical polyA variants of these transcripts. Silencing of CASP8AP2/FLASH also mediated enrichment of changes in the expression of targets of the NFκB and MYC transcription factors. These findings were confirmed by whole transcriptome analysis of CASP8AP2/FLASH silenced cells at multiple time points. Finally, we identified and validated that CASP8AP2/FLASH LOF increases the expression of neurofilament heavy polypeptide (NEFH), a protein recently linked to regulation of the AKT1/ß-catenin pathway. CONCLUSIONS: We have used unbiased RNAi based approaches to identify and characterize the function of CASP8AP2/FLASH, a protein not previously reported as required for cell survival. This study further defines the role CASP8AP2/FLASH plays in the regulating expression of the replication-dependent histones and shows that its LOF results in broad and reproducible effects on the transcriptome of colorectal cancer cells including the induction of expression of the recently described tumor suppressor gene NEFH.
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spelling pubmed-32817832012-02-18 Systems-wide RNAi analysis of CASP8AP2/FLASH shows transcriptional deregulation of the replication-dependent histone genes and extensive effects on the transcriptome of colorectal cancer cells Hummon, Amanda B Pitt, Jason J Camps, Jordi Emons, Georg Skube, Susan B Huppi, Konrad Jones, Tamara L Beissbarth, Tim Kramer, Frank Grade, Marian Difilippantonio, Michael J Ried, Thomas Caplen, Natasha J Mol Cancer Research BACKGROUND: Colorectal carcinomas (CRC) carry massive genetic and transcriptional alterations that influence multiple cellular pathways. The study of proteins whose loss-of-function (LOF) alters the growth of CRC cells can be used to further understand the cellular processes cancer cells depend upon for survival. RESULTS: A small-scale RNAi screen of ~400 genes conducted in SW480 CRC cells identified several candidate genes as required for the viability of CRC cells, most prominently CASP8AP2/FLASH. To understand the function of this gene in maintaining the viability of CRC cells in an unbiased manner, we generated gene specific expression profiles following RNAi. Silencing of CASP8AP2/FLASH resulted in altered expression of over 2500 genes enriched for genes associated with cellular growth and proliferation. Loss of CASP8AP2/FLASH function was significantly associated with altered transcription of the genes encoding the replication-dependent histone proteins as a result of the expression of the non-canonical polyA variants of these transcripts. Silencing of CASP8AP2/FLASH also mediated enrichment of changes in the expression of targets of the NFκB and MYC transcription factors. These findings were confirmed by whole transcriptome analysis of CASP8AP2/FLASH silenced cells at multiple time points. Finally, we identified and validated that CASP8AP2/FLASH LOF increases the expression of neurofilament heavy polypeptide (NEFH), a protein recently linked to regulation of the AKT1/ß-catenin pathway. CONCLUSIONS: We have used unbiased RNAi based approaches to identify and characterize the function of CASP8AP2/FLASH, a protein not previously reported as required for cell survival. This study further defines the role CASP8AP2/FLASH plays in the regulating expression of the replication-dependent histones and shows that its LOF results in broad and reproducible effects on the transcriptome of colorectal cancer cells including the induction of expression of the recently described tumor suppressor gene NEFH. BioMed Central 2012-01-04 /pmc/articles/PMC3281783/ /pubmed/22216762 http://dx.doi.org/10.1186/1476-4598-11-1 Text en Copyright ©2012 Hummon et al; licensee BioMed Central Ltd. http://creativecommons.org/licenses/by/2.0 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Research
Hummon, Amanda B
Pitt, Jason J
Camps, Jordi
Emons, Georg
Skube, Susan B
Huppi, Konrad
Jones, Tamara L
Beissbarth, Tim
Kramer, Frank
Grade, Marian
Difilippantonio, Michael J
Ried, Thomas
Caplen, Natasha J
Systems-wide RNAi analysis of CASP8AP2/FLASH shows transcriptional deregulation of the replication-dependent histone genes and extensive effects on the transcriptome of colorectal cancer cells
title Systems-wide RNAi analysis of CASP8AP2/FLASH shows transcriptional deregulation of the replication-dependent histone genes and extensive effects on the transcriptome of colorectal cancer cells
title_full Systems-wide RNAi analysis of CASP8AP2/FLASH shows transcriptional deregulation of the replication-dependent histone genes and extensive effects on the transcriptome of colorectal cancer cells
title_fullStr Systems-wide RNAi analysis of CASP8AP2/FLASH shows transcriptional deregulation of the replication-dependent histone genes and extensive effects on the transcriptome of colorectal cancer cells
title_full_unstemmed Systems-wide RNAi analysis of CASP8AP2/FLASH shows transcriptional deregulation of the replication-dependent histone genes and extensive effects on the transcriptome of colorectal cancer cells
title_short Systems-wide RNAi analysis of CASP8AP2/FLASH shows transcriptional deregulation of the replication-dependent histone genes and extensive effects on the transcriptome of colorectal cancer cells
title_sort systems-wide rnai analysis of casp8ap2/flash shows transcriptional deregulation of the replication-dependent histone genes and extensive effects on the transcriptome of colorectal cancer cells
topic Research
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3281783/
https://www.ncbi.nlm.nih.gov/pubmed/22216762
http://dx.doi.org/10.1186/1476-4598-11-1
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