title: PUMA and NF-kB Are Cell Signaling Predictors of Reovirus Oncolysis of Breast Cancer.
abstract: OBJECTIVE
  Reovirus is a ubiquitous RNA virus that exploits aberrant signaling pathways for its replication. The oncolytic potential of reovirus against numerous cancers under pre-clinical/clinical conditions has been documented by us and others. Despite its proven clinical activity, the underlying mechanisms of reovirus oncolysis is still not well elucidated. If reovirus therapy is to be optimized for cancer, including breast cancer patients, it is imperative to understand the mechanisms of reovirus oncolysis, especially in treatment of resistant tumour.
  In the present study global gene expression profiling was utilized as a preliminary roadmap to tease-out pivotal molecules involved in reovirus induced apoptosis in breast cancer. Reovirus treated HTB133 and MCF7 breast cancer cells revealed transcriptional alteration of a defined subset of apoptotic genes and members of the nuclear factor-kappa B (NF-kB) family and p53 upregulated modulator of apoptosis (PUMA) were prominent. Since NF-kB can paradoxically suppress or promote apoptosis in cancer, the significance of NF-kB in reovirus oncolysis of breast cancer was investigated. Real time PCR analysis indicated a 2.9-4.3 fold increase in NF-kB p65 message levels following reovirus infection of MCF7 and HTB133, respectively. Nuclear translocation of NF-kB p65 protein was also dramatically augmented post reovirus treatment and correlated with enhanced DNA binding. Pharmacologic inhibition of NF-kB lead to oncolytic protection and significant down regulation of PUMA message levels. PUMA down regulation using siRNA suppressed reovirus oncolysis via significantly repressed apoptosis in p53 mutant HTB133 cells.
  
  
  CONCLUSIONS
  This study demonstrates for the first time that a prominent pathway of reovirus oncolysis of breast cancer is mediated through NF-kB and that PUMA upregulation is dependent on NF-kB activation. These findings represent potential therapeutic indicators of reovirus treatment in future clinical trials.
authors.affiliation: Translation Research Laboratories, Tom Baker Cancer Centre, Calgary, Alberta, Canada.
authors.forename: Chandini
authors.identifier: http://orcid.org/0000-0002-2740-1176
authors.initials: C
authors.lastname: Thirukkumaran
authors.affiliation: Translation Research Laboratories, Tom Baker Cancer Centre, Calgary, Alberta, Canada.
authors.forename: Zhong-Qiao
authors.initials: ZQ
authors.lastname: Shi
authors.affiliation: Alberta Provincial Laboratories, Hospital Dr N.W., Calgary, Alberta, Canada.
authors.forename: Ponnampalam
authors.initials: P
authors.lastname: Thirukkumaran
authors.affiliation: Calgary Laboratory Services, Foothills Medical Centre, Calgary, Alberta, Canada.
authors.forename: Joanne
authors.initials: J
authors.lastname: Luider
authors.affiliation: Dept of Cancer Epidemiology and Prevention Research, Cancer Control Alberta, AHS, Holy Cross Centre, SW, Calgary, Alberta, Canada.
authors.forename: Karen
authors.initials: K
authors.lastname: Kopciuk
authors.affiliation: Translation Research Laboratories, Tom Baker Cancer Centre, Calgary, Alberta, Canada.
authors.forename: Jason
authors.initials: J
authors.lastname: Spurrell
authors.affiliation: Translation Research Laboratories, Tom Baker Cancer Centre, Calgary, Alberta, Canada.
authors.forename: Kate
authors.initials: K
authors.lastname: Elzinga
authors.affiliation: Translation Research Laboratories, Tom Baker Cancer Centre, Calgary, Alberta, Canada.|Department of Medicine and Oncology, University of Calgary, Tom Baker Cancer Centre, Calgary, Alberta, Canada.
authors.forename: Don
authors.initials: D
authors.lastname: Morris
mesh_terms: D017209:Apoptosis / Q000502:physiology; D051017:Apoptosis Regulatory Proteins / Q000235:genetics / Q000378:metabolism*; D001943:Breast Neoplasms / Q000628:therapy*; D045744:Cell Line, Tumor; D024202:Electrophoretic Mobility Shift Assay; D006801:Humans; D061986:MCF-7 Cells; D050130:Oncolytic Virotherapy / Q000379:methods*; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics; D012087:Reoviridae / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology; D051996:Transcription Factor RelA / Q000378:metabolism*
chemical_list: D051017:Apoptosis Regulatory Proteins; C438378:BBC3 protein, human; D011518:Proto-Oncogene Proteins; C498143:RELA protein, human; D034741:RNA, Small Interfering; D051996:Transcription Factor RelA