title: Sox9 and Hif-2α regulate TUBB3 gene expression and affect ovarian cancer aggressiveness.
abstract: SOX9 [(sex determining region Y)-box9] gene has been implicated in the development and progression of different neoplasms. This study investigated the role of Sox9 in the expression of TUBB3 gene, a marker of aggressiveness in ovarian cancer (OC), encoding βIII-tubulin protein. Gene expression was assessed by quantitative polymerase chain reaction (qPCR) in OC models. Using chromatin immunoprecipitation (ChIP) we found that Sox9 engages TUBB3 promoter at minus 980 base pairs from the transcriptional start site with transcriptional enhancing effects. Furthermore we found that Sox9 is a downstream target of Hif-2α, a transcription factor encoded by endothelial PAS domain protein-1 (EPAS1). Hypoxic microenvironment is a common feature of solid tumors associated with cancer aggressiveness. In the present work we found that knockdown of either SOX9 or EPAS1 abolished TUBB3 gene induction in hypoxia. This phenomenon was associated with a decrease in the number of cell colonies capable of growing in an anchorage-independent way. Using a nanofluidic genetic analyzer, the expression of SOX9, TUBB3 and EPAS1 was evaluated in 182 OC specimens. Double staining immunohistochemistry was employed to evaluate the expression and prognostic role of both Sox9 and βIII-tubulin. Results obtained in cellular models matched the pattern of clinical specimens. We documented a direct correlation among the expression of EPAS1, SOX9 and TUBB3 at mRNA level. Patients displaying no expression for the three genes had the best outcome. A poor prognosis significant in multivariate analysis was visible in patients featuring high expression of βIII-tubulin and nuclear Sox9.
  
  
  CONCLUSIONS
  Sox9 allows the survival of OC cells upon hypoxic condition, through the activation of βIII-tubulin expression and its aberrant activation in OC is prominent in patients with aggressive OC.
authors.affiliation: Translational Research Centre in Gynecological Cancer, Department of Gynecology, Catholic University of the Sacred Heart, Rome, Italy. Electronic address: giuseppina.raspaglio@rm.unicatt.it.
authors.forename: Giuseppina
authors.initials: G
authors.lastname: Raspaglio
authors.affiliation: Translational Research Centre in Gynecological Cancer, Department of Gynecology, Catholic University of the Sacred Heart, Rome, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Petrillo
authors.affiliation: Translational Research Centre in Gynecological Cancer, Department of Gynecology, Catholic University of the Sacred Heart, Rome, Italy.
authors.forename: Enrica
authors.initials: E
authors.lastname: Martinelli
authors.affiliation: Translational Research Centre in Gynecological Cancer, Department of Gynecology, Catholic University of the Sacred Heart, Rome, Italy.
authors.forename: Domenica Donatella
authors.initials: DD
authors.lastname: Li Puma
authors.affiliation: Danbury Hospital Research Institute, Danbury, CT, USA.
authors.forename: Marisa
authors.initials: M
authors.lastname: Mariani
authors.affiliation: Translational Research Centre in Gynecological Cancer, Department of Gynecology, Catholic University of the Sacred Heart, Rome, Italy.
authors.forename: Marta
authors.initials: M
authors.lastname: De Donato
authors.affiliation: Translational Research Centre in Gynecological Cancer, Department of Gynecology, Catholic University of the Sacred Heart, Rome, Italy.
authors.forename: Flavia
authors.initials: F
authors.lastname: Filippetti
authors.affiliation: Translational Research Centre in Gynecological Cancer, Department of Gynecology, Catholic University of the Sacred Heart, Rome, Italy.
authors.forename: Simona
authors.initials: S
authors.lastname: Mozzetti
authors.affiliation: Translational Research Centre in Gynecological Cancer, Department of Gynecology, Catholic University of the Sacred Heart, Rome, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Prislei
authors.affiliation: Department of Pathology, Catholic University of the Sacred Heart, Rome, Italy.
authors.forename: Gian Franco
authors.initials: GF
authors.lastname: Zannoni
authors.affiliation: Translational Research Centre in Gynecological Cancer, Department of Gynecology, Catholic University of the Sacred Heart, Rome, Italy; Department of Oncology, Jean Paul II Research Foundation, Campobasso, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Scambia
authors.affiliation: Danbury Hospital Research Institute, Danbury, CT, USA; Department of Oncology, Jean Paul II Research Foundation, Campobasso, Italy.
authors.forename: Cristiano
authors.initials: C
authors.lastname: Ferlini
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000378:metabolism*; D015687:Cell Hypoxia / Q000235:genetics; D045744:Cell Line, Tumor; D002470:Cell Survival; D005260:Female; D005500:Follow-Up Studies; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000235:genetics; D008875:Middle Aged; D010051:Ovarian Neoplasms / Q000188:drug therapy / Q000235:genetics* / Q000473:pathology*; D011401:Promoter Regions, Genetic; D055758:SOX9 Transcription Factor / Q000235:genetics / Q000378:metabolism*; D014404:Tubulin / Q000235:genetics* / Q000378:metabolism; D000099162:Endothelial PAS Domain-Containing Protein 1
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D055758:SOX9 Transcription Factor; D014404:Tubulin; D000099162:Endothelial PAS Domain-Containing Protein 1; C497442:HIF1A protein, human; C527932:SOX9 protein, human; C498585:TUBB3 protein, human
keywords: Ovarian cancer; Poor prognosis; SOX9; Tumor hypoxia; βΙΙΙ-tubulin