Ovarian endometriosis-associated stromal cells reveal persistently high affinity for iron.
Ovarian endometriosis is a recognized risk for infertility and epithelial ovarian cancer, presumably due to iron overload resulting from repeated hemorrhage. To find a clue for early detection and prevention of ovarian endometriosis-associated cancer, it is mandatory to evaluate catalytic (labile) ferrous iron (catalytic Fe(II)) and to study iron manipulation in ovarian endometriotic lesions. By the use of tissues from women of ovarian endometriosis as well as endometrial tissue from women with and without endometriosis, we for the first time performed histological analysis and cellular detection of catalytic Fe(II) with a specific fluorescent probe (HMRhoNox-M), and further evaluated iron transport proteins in the human specimens and in co-culture experiments using immortalized human eutopic/ectopic endometrial stromal cells (ESCs) in the presence or absence of epithelial cells (EpCs). The amounts of catalytic Fe(II) were higher in ectopic endometrial stromal cells (ecESCs) than in normal eutopic endometrial stromal cells (n-euESCs) both in the tissues and in the corresponding immortalized ESCs. ecESCs exhibited higher transferrin receptor 1 expression both in vivo and in vitro and lower ferroportin expression in vivo than n-euESCs, leading to sustained iron uptake. In co-culture experiments of ESCs with iron-loaded EpCs, ecESCs received catalytic ferrous iron from EpCs, but n-euESCs did not. These data suggest that ecESC play a protective role for cancer-target epithelial cells by collecting excess iron, and that these characteristics are retained in the immortalized ecESCs.
Department of Pathology and Biological Responses, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan; Department of Obstetrics and Gynecology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
Masahiko
M
Mori
Department of Pathology and Biological Responses, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan.
Fumiya
F
Ito
Department of Pathology and Biological Responses, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan.
Lei
L
Shi
Department of Pathology and Biological Responses, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan.
Yue
Y
Wang
Department of Pathology and Biological Responses, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan; Department of Obstetrics and Gynecology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
Chiharu
C
Ishida
Department of Obstetrics and Gynecology, Nagoya Ekisaikai Hospital, Nagoya, Japan.
Yuka
Y
Hattori
Laboratory of Pharmaceutical and Medical Chemistry, Gifu Pharmaceutical University, Gifu, Japan.
Masato
M
Niwa
Laboratory of Pharmaceutical and Medical Chemistry, Gifu Pharmaceutical University, Gifu, Japan.
Tasuku
T
Hirayama
Laboratory of Pharmaceutical and Medical Chemistry, Gifu Pharmaceutical University, Gifu, Japan.
Hideko
H
Nagasawa
Department of Obstetrics and Gynecology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
Akira
A
Iwase
Department of Obstetrics and Gynecology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
Fumitaka
F
Kikkawa
Department of Pathology and Biological Responses, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan. Electronic address: toyokuni@med.nagoya-u.ac.jp.
Shinya
S
Toyokuni
D045744:Cell Line, Tumor; D018920:Coculture Techniques; D004715:Endometriosis / Q000378:metabolism / Q000473:pathology*; D005260:Female; D006801:Humans; D007501:Iron / Q000378:metabolism*; D010049:Ovarian Diseases / Q000378:metabolism / Q000473:pathology*; D010053:Ovary / Q000378:metabolism; D011990:Receptors, Transferrin; D017154:Stromal Cells / Q000378:metabolism*
D011990:Receptors, Transferrin; D007501:Iron
Catalytic ferrous iron; Ferroportin; Ovarian endometriosis; Stromal cells; Transferrin receptor