title: CD44 variant 6 is correlated with peritoneal dissemination and poor prognosis in patients with advanced epithelial ovarian cancer.
abstract: Cancer stem cells (CSCs) drive tumor initiation and metastasis in several types of human cancer. However, the contribution of ovarian CSCs to peritoneal metastasis remains unresolved. The cell adhesion molecule CD44 has been identified as a major marker for CSCs in solid tumors, including epithelial ovarian cancer. CD44 exists as a standard form (CD44s) and also as numerous variant isoforms (CD44v) generated by alternative mRNA splicing. Here we show that disseminated ovarian tumors in the pelvic peritoneum contain highly enriched CD44v6-positive cancer cells, which drive tumor metastasis and are responsible for tumor resistance to chemotherapy. Clinically, an increased number of CD44v6-positive cancer cells in primary tumors was associated with a shortened overall survival in stage III-IV ovarian cancer patients. Furthermore, a subpopulation of CD44v6-positive cancer cells manifested the ability to initiate tumor metastasis in the pelvic peritoneum in an in vivo mouse model, suggesting that CD44v6-positive cells show the potential to serve as metastasis-initiating cells. Thus, the peritoneal disseminated metastasis of epithelial ovarian cancer is initiated by the CD44v6-positive subpopulation, and CD44v6 expression is a biomarker for the clinical outcome of advanced ovarian cancer patients. Given that a distinct subpopulation of CD44v6-positive cancer cells plays a critical role in peritoneal metastasis, definitive treatment should target this subpopulation of CD44v6-positive cells in epithelial ovarian cancer.
authors.affiliation: Department of Obstetrics and Gynecology, Faculty of Life Sciences, Kumamoto University, Kumamoto City, Kumamoto, Japan.
authors.forename: Francisca
authors.initials: F
authors.lastname: Tjhay
authors.affiliation: Department of Obstetrics and Gynecology, Faculty of Life Sciences, Kumamoto University, Kumamoto City, Kumamoto, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Motohara
authors.affiliation: Department of Obstetrics and Gynecology, Faculty of Life Sciences, Kumamoto University, Kumamoto City, Kumamoto, Japan.
authors.forename: Shingo
authors.initials: S
authors.lastname: Tayama
authors.affiliation: Department of Obstetrics and Gynecology, Faculty of Life Sciences, Kumamoto University, Kumamoto City, Kumamoto, Japan.
authors.forename: Dashdemberel
authors.initials: D
authors.lastname: Narantuya
authors.affiliation: Department of Obstetrics and Gynecology, Faculty of Life Sciences, Kumamoto University, Kumamoto City, Kumamoto, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Fujimoto
authors.affiliation: Department of Obstetrics and Gynecology, Faculty of Life Sciences, Kumamoto University, Kumamoto City, Kumamoto, Japan.
authors.forename: Jianying
authors.initials: J
authors.lastname: Guo
authors.affiliation: Department of Obstetrics and Gynecology, Faculty of Life Sciences, Kumamoto University, Kumamoto City, Kumamoto, Japan.
authors.forename: Isao
authors.initials: I
authors.lastname: Sakaguchi
authors.affiliation: Department of Obstetrics and Gynecology, Faculty of Life Sciences, Kumamoto University, Kumamoto City, Kumamoto, Japan.
authors.forename: Ritsuo
authors.initials: R
authors.lastname: Honda
authors.affiliation: Department of Maternal-Newborn Nursing, Kumamoto University, Kumamoto City, Kumamoto, Japan.
authors.forename: Hironori
authors.initials: H
authors.lastname: Tashiro
authors.affiliation: Department of Obstetrics and Gynecology, Faculty of Life Sciences, Kumamoto University, Kumamoto City, Kumamoto, Japan.
authors.forename: Hidetaka
authors.initials: H
authors.lastname: Katabuchi
mesh_terms: D000818:Animals; D014408:Biomarkers, Tumor / Q000378:metabolism; D015820:Cadherins / Q000096:biosynthesis; D000077216:Carcinoma, Ovarian Epithelial; D002448:Cell Adhesion / Q000502:physiology; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D019008:Drug Resistance, Neoplasm; D058750:Epithelial-Mesenchymal Transition / Q000502:physiology; D005260:Female; D005353:Fibronectins / Q000096:biosynthesis; D006801:Humans; D018960:Hyaluronan Receptors / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D008875:Middle Aged; D009375:Neoplasms, Glandular and Epithelial / Q000401:mortality / Q000473:pathology*; D014411:Neoplastic Stem Cells / Q000473:pathology*; D010051:Ovarian Neoplasms / Q000401:mortality / Q000473:pathology*; D010053:Ovary / Q000473:pathology; D010534:Peritoneal Neoplasms / Q000556:secondary*; D010537:Peritoneum / Q000473:pathology*; D016896:Treatment Outcome; D014746:Vimentin / Q000096:biosynthesis
chemical_list: D014408:Biomarkers, Tumor; C112697:CD44v6 antigen; D015820:Cadherins; D005353:Fibronectins; D018960:Hyaluronan Receptors; D014746:Vimentin
keywords: CD44; Cancer stem cell; ovarian cancer; peritoneal metastasis; prognosis