title: Overexpression of HPV16 E6* Alters β-Integrin and Mitochondrial Dysfunction Pathways in Cervical Cancer Cells.
abstract: BACKGROUND
  High-risk human papillomaviruses (HPV) cause nearly all cases of cervical cancer, as well as many types of oral and anogenital cancer. Alternative splicing increases the capacity of the HPV genome to encode the proteins necessary for successful completion of its infectious life cycle. However, the roles of these splice variants, including E6*, the smaller splice isoform of the E6 oncogene, in carcinogenesis are not clear.
  
  
  METHODS
  SiHa (HPV16(+)) and C33A (HPV(-)) cells were transfected with the E6* plasmid, and tandem mass tag-labeled protein levels were quantified by mass spectrometry. Proteomic analyses identified pathways affected by E6* in both HPV(+) and HPV(-) cells, and pathways were validated using in vitro methods.
  
  
  RESULTS
  A total of 4,300 proteins were identified and quantified in lysates of SiHa and C33A cells with and without HPV16 E6* expression. SiHa and C33A cells expressing E6* underwent changes in protein expression affecting integrin signaling and mitochondrial dysfunction pathways, respectively. Subsequent experiments were performed to validate selected E6*-mediated alterations in protein levels.
  
  
  CONCLUSIONS
  E6* modifies the expression of proteins involved in mitochondrial dysfunction and oxidative phosphorylation in C33A cells, and β-integrin signaling in SiHa cells.
authors.affiliation: Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA, U.S.A. Center for Health Disparities and Molecular Medicine, Loma Linda University School of Medicine, Loma Linda, CA, U.S.A.
authors.forename: Whitney
authors.initials: W
authors.lastname: Evans
authors.affiliation: Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA, U.S.A. Center for Health Disparities and Molecular Medicine, Loma Linda University School of Medicine, Loma Linda, CA, U.S.A.
authors.forename: Maria
authors.initials: M
authors.lastname: Filippova
authors.affiliation: Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA, U.S.A. Center for Health Disparities and Molecular Medicine, Loma Linda University School of Medicine, Loma Linda, CA, U.S.A.
authors.forename: Valery
authors.initials: V
authors.lastname: Filippov
authors.affiliation: Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA, U.S.A. Center for Health Disparities and Molecular Medicine, Loma Linda University School of Medicine, Loma Linda, CA, U.S.A.
authors.forename: Svetlana
authors.initials: S
authors.lastname: Bashkirova
authors.affiliation: Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA, U.S.A. Center for Health Disparities and Molecular Medicine, Loma Linda University School of Medicine, Loma Linda, CA, U.S.A.
authors.forename: Guangyu
authors.initials: G
authors.lastname: Zhang
authors.affiliation: Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA, U.S.A. Center for Health Disparities and Molecular Medicine, Loma Linda University School of Medicine, Loma Linda, CA, U.S.A. Department of Surgery, Loma Linda University School of Medicine, and Surgical Oncology Research Laboratory, Loma Linda VA Medical Center, Loma Linda, CA, U.S.A.
authors.forename: Mark E
authors.initials: ME
authors.lastname: Reeves
authors.affiliation: Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, CA, U.S.A. Center for Health Disparities and Molecular Medicine, Loma Linda University School of Medicine, Loma Linda, CA, U.S.A. pdhughes@llu.edu.
authors.forename: Penelope
authors.initials: P
authors.lastname: Duerksen-Hughes
mesh_terms: D045744:Cell Line, Tumor; D004249:DNA Damage; D005260:Female; D015870:Gene Expression; D005978:Glutathione / Q000378:metabolism; D052162:Human papillomavirus 16 / Q000235:genetics; D006801:Humans; D016023:Integrins / Q000378:metabolism*; D053078:Membrane Potential, Mitochondrial; D008928:Mitochondria / Q000378:metabolism*; D009856:Oncogene Proteins, Viral / Q000235:genetics* / Q000378:metabolism; D018384:Oxidative Stress; D030361:Papillomavirus Infections / Q000150:complications / Q000821:virology; D040901:Proteomics / Q000379:methods; D017382:Reactive Oxygen Species / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction; D002583:Uterine Cervical Neoplasms / Q000235:genetics* / Q000378:metabolism*
chemical_list: C068651:E6 protein, Human papillomavirus type 16; D016023:Integrins; D009856:Oncogene Proteins, Viral; D017382:Reactive Oxygen Species; D012097:Repressor Proteins; D005978:Glutathione
keywords: DNA damage; E6*; Human papillomavirus; Ingenuity Pathway Analysis; RhoA GTPase; alkaline phosphatase; alternative splicing; cell spreading; electron transport chain; glutathione; kindlin-1; mitochondrial membrane depolarization; mitochondrial membrane potential; oxidative phosphorylation; oxidative stress; β-integrin