title: Deep sequencing and in silico analyses identify MYB-regulated gene networks and signaling pathways in pancreatic cancer.
abstract: We have recently demonstrated that the transcription factor MYB can modulate several cancer-associated phenotypes in pancreatic cancer. In order to understand the molecular basis of these MYB-associated changes, we conducted deep-sequencing of transcriptome of MYB-overexpressing and -silenced pancreatic cancer cells, followed by in silico pathway analysis. We identified significant modulation of 774 genes upon MYB-silencing (p < 0.05) that were assigned to 25 gene networks by in silico analysis. Further analyses placed genes in our RNA sequencing-generated dataset to several canonical signalling pathways, such as cell-cycle control, DNA-damage and -repair responses, p53 and HIF1α. Importantly, we observed downregulation of the pancreatic adenocarcinoma signaling pathway in MYB-silenced pancreatic cancer cells exhibiting suppression of EGFR and NF-κB. Decreased expression of EGFR and RELA was validated by both qPCR and immunoblotting and they were both shown to be under direct transcriptional control of MYB. These observations were further confirmed in a converse approach wherein MYB was overexpressed ectopically in a MYB-null pancreatic cancer cell line. Our findings thus suggest that MYB potentially regulates growth and genomic stability of pancreatic cancer cells via targeting complex gene networks and signaling pathways. Further in-depth functional studies are warranted to fully understand MYB signaling in pancreatic cancer.
authors.affiliation: Department of Oncologic Sciences, Mitchell Cancer Institute, University of South Alabama, Mobile, AL 36604, USA.
authors.forename: Shafquat
authors.initials: S
authors.lastname: Azim
authors.affiliation: Department of Oncologic Sciences, Mitchell Cancer Institute, University of South Alabama, Mobile, AL 36604, USA.
authors.forename: Haseeb
authors.initials: H
authors.lastname: Zubair
authors.affiliation: Department of Oncologic Sciences, Mitchell Cancer Institute, University of South Alabama, Mobile, AL 36604, USA.
authors.forename: Sanjeev K
authors.initials: SK
authors.lastname: Srivastava
authors.affiliation: Department of Oncologic Sciences, Mitchell Cancer Institute, University of South Alabama, Mobile, AL 36604, USA.
authors.forename: Arun
authors.initials: A
authors.lastname: Bhardwaj
authors.affiliation: Molecular and Computational Biology, School of Biological Sciences, Dornsife College of Letters, Arts and Sciences, University of Southern California, Los Angeles, CA 90089, USA.
authors.forename: Asif
authors.initials: A
authors.lastname: Zubair
authors.affiliation: Department of Oncologic Sciences, Mitchell Cancer Institute, University of South Alabama, Mobile, AL 36604, USA.
authors.forename: Aamir
authors.initials: A
authors.lastname: Ahmad
authors.affiliation: Department of Oncologic Sciences, Mitchell Cancer Institute, University of South Alabama, Mobile, AL 36604, USA.|Department of Biochemistry and Molecular Biology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA.
authors.forename: Seema
authors.initials: S
authors.lastname: Singh
authors.affiliation: Department of Interdisciplinary Clinical Oncology, Mitchell Cancer Institute, University of South Alabama, Mobile, AL 36604, USA.
authors.forename: Moh'd
authors.initials: M
authors.lastname: Khushman
authors.affiliation: Department of Oncologic Sciences, Mitchell Cancer Institute, University of South Alabama, Mobile, AL 36604, USA.|Department of Biochemistry and Molecular Biology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA.
authors.forename: Ajay P
authors.initials: AP
authors.lastname: Singh
mesh_terms: D045744:Cell Line, Tumor; D015536:Down-Regulation; D066246:ErbB Receptors / Q000235:genetics / Q000378:metabolism; D053263:Gene Regulatory Networks / Q000235:genetics*; D042822:Genomic Instability; D059014:High-Throughput Nucleotide Sequencing; D006801:Humans; D010190:Pancreatic Neoplasms / Q000378:metabolism / Q000473:pathology; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D020598:Proto-Oncogene Proteins c-myb / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000378:metabolism; D017422:Sequence Analysis, DNA; D015398:Signal Transduction / Q000235:genetics*; D051996:Transcription Factor RelA / Q000235:genetics / Q000378:metabolism; D015854:Up-Regulation
chemical_list: D020598:Proto-Oncogene Proteins c-myb; C498143:RELA protein, human; D034741:RNA, Small Interfering; D051996:Transcription Factor RelA; D066246:ErbB Receptors