Heparanase regulates esophageal keratinocyte differentiation through nuclear translocation and heparan sulfate cleavage.
Heparanase is an endo-beta-glucuronidase that specifically cleaves heparan sulfate (HS) chains. Heparanase is involved in the process of metastasis and angiogenesis through the degradation of HS chains of the extracellular matrix and cell surface. Recently, we demonstrated that heparanase was localized in the cell nucleus of normal esophageal epithelium and esophageal cancer, and that its expression was correlated with cell differentiation. However, the nuclear function of heparanase remains unknown. To elucidate the role of heparanase in esophageal epithelial differentiation, primary human esophageal cells were grown in monolayer as well as organotypic cultures, and cell differentiation was induced. Expression of heparanase, HS, involucrin, and p27 was determined by immunostaining and Western blotting. SF4, a novel pharmacological inhibitor, was used to specifically inhibit heparanase activity. Upon esophageal cell differentiation, heparanase was translocated from the cytoplasm to the nucleus. Such translocation of heparanase appeared to be associated with the degradation of HS chains in the nucleus and changes in the expression of keratinocyte differentiation markers such as p27 and involucrin, whose induction was inhibited by SF4. Furthermore, these in vitro observations agreed with the expression pattern of heparanase, HS, involucrin, cytokeratin 13, and p27 in normal esophageal epithelium. Nuclear translocation of heparanase and its catalytic cleavage of HS may play a critical role in the differentiation of esophageal epithelial cells. Our study provides a novel insight into the role of heparanase in an essential differentiation process.
Kobayashi
Masahiko
M
Department of Gastroenterological Surgery Transplant, and Surgical Oncology, Graduate School of Medicine and Dentistry, Okayama University, 2-5-1 Shikatacho, Okayama 700-8558, Japan.
Naomoto
Yoshio
Y
Nobuhisa
Tetsuji
T
Okawa
Takaomi
T
Takaoka
Munenori
M
Shirakawa
Yasuhiro
Y
Yamatsuji
Tomoki
T
Matsuoka
Junji
J
Mizushima
Takaaki
T
Matsuura
Hironori
H
Nakajima
Motowo
M
Nakagawa
Hiroshi
H
Rustgi
Anil
A
Tanaka
Noriaki
N
D015153:Blotting, Western; D002454:Cell Differentiation / Q000502:physiology*; D002467:Cell Nucleus / Q000378:metabolism*; D004947:Esophagus / Q000166:cytology*; D005966:Glucuronidase / Q000502:physiology*; D006497:Heparan Sulfate / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D015603:Keratinocytes / Q000166:cytology*; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D011498:Protein Precursors / Q000378:metabolism; D000099175:Heparanase
D005966:Glucuronidase; D006497:Heparan Sulfate; D018809:Proliferating Cell Nuclear Antigen; D011498:Protein Precursors; D000099175:Heparanase; C413374:p27 antigen; C032253:involucrin