title: DDX4 (DEAD box polypeptide 4) colocalizes with cancer stem cell marker CD133 in ovarian cancers.
abstract: DDX4 (DEAD box polypeptide 4), characterized by the conserved motif Asp-Glu-Ala-Asp (DEAD), is an RNA helicase which is implicated in various cellular processes involving the alteration of RNA secondary structure, such as translation initiation, nuclear and mitochondrial splicing, and ribosome and spliceosome assembly. DDX4 is known to be a germ cell-specific protein and is used as a sorting marker of germline stem cells for the production of oocytes. A recent report about DDX4 in ovarian cancer showed that DDX4 is overexpressed in epithelial ovarian cancer and disrupts a DNA damage-induced G2 checkpoint. We investigated the relationship between DDX4 and ovarian cancer stem cells by analyzing the expression patterns of DDX4 and the cancer stem cell marker CD133 in ovarian cancers via tissue microarray. Both DDX4 and CD133 were significantly increased in ovarian cancer compared to benign tumors, and showed similar patterns of expression. In addition, DDX4 and CD133 were mostly colocalized in various types of ovarian cancer tissues. Furthermore, almost all CD133 positive ovarian cancer cells also express DDX4 whereas CD133-negative cells did not possess DDX4, suggesting a strong possibility that DDX4 plays an important role in cancer stem cells, and/or can be used as an ovarian cancer stem cell marker.
authors.affiliation: Department of Obstetrics and Gynecology, Pusan National University School of Medicine, Busan, Republic of Korea; Biomedical Research Institute and Pusan Cancer Center, Pusan National University Hospital, Busan, Republic of Korea.
authors.forename: Ki Hyung
authors.initials: KH
authors.lastname: Kim
authors.affiliation: Department of Parasitology and Genetics, Kosin University College of Medicine, Busan, Republic of Korea.
authors.forename: Yun-Jeong
authors.initials: YJ
authors.lastname: Kang
authors.affiliation: Department of Parasitology and Genetics, Kosin University College of Medicine, Busan, Republic of Korea.
authors.forename: Jin-Ok
authors.initials: JO
authors.lastname: Jo
authors.affiliation: Department of Parasitology and Genetics, Kosin University College of Medicine, Busan, Republic of Korea.
authors.forename: Mee Sun
authors.initials: MS
authors.lastname: Ock
authors.affiliation: Department of Obstetrics and Gynecology, Pusan National University School of Medicine, Busan, Republic of Korea; Biomedical Research Institute and Pusan Cancer Center, Pusan National University Hospital, Busan, Republic of Korea.
authors.forename: Soo Hyun
authors.initials: SH
authors.lastname: Moon
authors.affiliation: Department of Obstetrics and Gynecology, Pusan National University School of Medicine, Busan, Republic of Korea; Biomedical Research Institute and Pusan Cancer Center, Pusan National University Hospital, Busan, Republic of Korea.
authors.forename: Dong Soo
authors.initials: DS
authors.lastname: Suh
authors.affiliation: Department of Obstetrics and Gynecology, Pusan National University School of Medicine, Busan, Republic of Korea; Biomedical Research Institute and Pusan Cancer Center, Pusan National University Hospital, Busan, Republic of Korea.
authors.forename: Man Soo
authors.initials: MS
authors.lastname: Yoon
authors.affiliation: Vincent Center for Reproductive Biology, Massachusetts General Hospital, Harvard Medical School, MA, USA.
authors.forename: Eun-Sil
authors.initials: ES
authors.lastname: Park
authors.affiliation: Department of Obstetrics and Gynecology, The Catholic University, Seoul, Republic of Korea.
authors.forename: Namkung
authors.initials: N
authors.lastname: Jeong
authors.affiliation: Department of Internal Medicine, Kyung Hee University, Seoul, Republic of Korea.
authors.forename: Wan-Kyu
authors.initials: WK
authors.lastname: Eo
authors.affiliation: Department of Obstetrics and Gynecology, Kosin University College of Medicine, Busan, Republic of Korea. Electronic address: hykyale@yahoo.com.
authors.forename: Heung Yeol
authors.initials: HY
authors.lastname: Kim
authors.affiliation: Department of Parasitology and Genetics, Kosin University College of Medicine, Busan, Republic of Korea; Institute for Medical Science, Kosin University College of Medicine, Busan, Republic of Korea. Electronic address: hcha@kosin.ac.kr.
authors.forename: Hee-Jae
authors.initials: HJ
authors.lastname: Cha
mesh_terms: D000071916:AC133 Antigen; D000328:Adult; D000368:Aged; D015703:Antigens, CD / Q000378:metabolism*; D014408:Biomarkers, Tumor / Q000378:metabolism*; D053487:DEAD-box RNA Helicases / Q000378:metabolism*; D005260:Female; D006023:Glycoproteins / Q000378:metabolism*; D006801:Humans; D008875:Middle Aged; D014411:Neoplastic Stem Cells / Q000378:metabolism* / Q000473:pathology; D010051:Ovarian Neoplasms / Q000378:metabolism* / Q000473:pathology; D010455:Peptides / Q000378:metabolism*; D040081:Protein Array Analysis; D014407:Tumor Cells, Cultured
chemical_list: D000071916:AC133 Antigen; D015703:Antigens, CD; D014408:Biomarkers, Tumor; D006023:Glycoproteins; C000606023:PROM1 protein, human; D010455:Peptides; C498288:DDX4 protein, human; D053487:DEAD-box RNA Helicases
keywords: CD133; Cancer stem cells; DDX4; Ovarian cancer