title: Silencing the Peroxiredoxin III gene inhibits cell proliferation in breast cancer.
abstract: Peroxiredoxin III (Prx III), an antioxidant protein found in mitochondria, plays an essential role in mitochondrial homeostasis. Aberrant expression of Prx III has been implicated in the tumorigenesis of various cancers. In this study, we evaluated the expression of Prx III in breast cancer tissues and elucidated its role in cell proliferation, a hallmark of cancer. Breast tissue microarrays comprising 106 breast cancer sections were stained with Prx III antibody using immunohistochemisty and correlated with proliferating cell nuclear antigen (PCNA) immunostaining. To validate the role of Prx III in cell proliferation, expression of Prx III was analyzed at the mRNA and protein levels by real-time RT-PCR, Western blotting and immunofluorescence in vitro. siRNA mediated silencing of Prx III in MDA-MB-231 breast cancer cells was performed and the effect on the cell cycle was examined. Prx III expression in patient tissue microarray samples was found to be positively associated with PCNA immunostaining, a proliferative marker. Prx III was expressed in both MCF-7 and MDA-MB-231 breast cancer cell lines and transient transfection with siPrx III in MDA-MB-231 cells induced inhibition of cell proliferation and cell cycle arrest. The data suggests that Prx III has a significant role in cell cycle regulation and could be a potential proliferation marker in breast cancer.
authors.affiliation: Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, and Department of Pathology, Singapore General Hospital, MD10, S 117 597, Singapore.
authors.forename: Pei-Jou
authors.initials: PJ
authors.lastname: Chua
authors.forename: Eng-Hong
authors.initials: EH
authors.lastname: Lee
authors.forename: Yingnan
authors.initials: Y
authors.lastname: Yu
authors.forename: George Wai-Cheong
authors.initials: GW
authors.lastname: Yip
authors.forename: Puay-Hoon
authors.initials: PH
authors.lastname: Tan
authors.forename: Boon-Huat
authors.initials: BH
authors.lastname: Bay
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis / Q000235:genetics; D015153:Blotting, Western; D001943:Breast Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D002453:Cell Cycle / Q000235:genetics; D049109:Cell Proliferation; D005260:Female; D005455:Fluorescent Antibody Technique; D020868:Gene Silencing / Q000502:physiology*; D006801:Humans; D007150:Immunohistochemistry; D061105:Peroxiredoxin III; D054464:Peroxiredoxins / Q000235:genetics* / Q000378:metabolism; D034741:RNA, Small Interfering; D020133:Reverse Transcriptase Polymerase Chain Reaction; D046888:Tissue Array Analysis; D014162:Transfection
chemical_list: D014408:Biomarkers, Tumor; D034741:RNA, Small Interfering; C516115:PRDX3 protein, human; D061105:Peroxiredoxin III; D054464:Peroxiredoxins