Hyaluronic acid stimulates tumor-cell proliferation at wound sites.
BACKGROUND
For EMR, the submucosal injection of sodium hyaluronate has become popular, because this substance creates a more prominent and longer-lasting mucosal protrusion than normal saline solution. However, the effects of sodium hyaluronate on tumor growth at wound sites remain unclear.


METHODS
For these experiments, a murine model with artificial wounds was used. Forty mice were randomly divided into two groups according to the substance to be injected into a wound: a sodium hyaluronate group and a control group. Tumors were created by inoculation of transplantable adenocarcinoma cell line colon 26. Two weeks later, the size, weight, proliferating cell nuclear antigen-labeling index, and CD44 expression of the subcutaneous tumors were compared between the two groups of mice.


RESULTS
There were significantly greater increases in the growth and the weight of subcutaneous tumors in the sodium hyaluronate group compared with the control group. The PCNA-labeling index of cancer cells also was higher in the sodium hyaluronate group. Immunohistochemistry and Western blot analysis demonstrated that the CD44 protein expression of cancer cells was higher in the sodium hyaluronate group vs. the control group.


CONCLUSIONS
In this study, sodium hyaluronate enhanced both tumor growth and CD44 expression of cancer cells at wound sites, suggesting that the use of sodium hyaluronate for EMR might stimulate the growth of residual tumor cells.
Department of Surgery I, Oita University Faculty of Medicine, Japan.
Yoko
Y
Matsui
Masafumi
M
Inomata
Koichi
K
Izumi
Kazuya
K
Sonoda
Norio
N
Shiraishi
Seigo
S
Kitano
D000818:Animals; D015153:Blotting, Western; D002455:Cell Division / Q000187:drug effects; D045744:Cell Line, Tumor; D004724:Endoscopy / Q000379:methods*; D005260:Female; D018960:Hyaluronan Receptors / Q000032:analysis; D006820:Hyaluronic Acid / Q000009:adverse effects* / Q000494:pharmacology; D007150:Immunohistochemistry; D051379:Mice; D008807:Mice, Inbred BALB C; D009092:Mucous Membrane / Q000601:surgery; D009369:Neoplasms / Q000473:pathology*; D018809:Proliferating Cell Nuclear Antigen / Q000032:analysis; D011897:Random Allocation; D013194:Staining and Labeling
D018960:Hyaluronan Receptors; D018809:Proliferating Cell Nuclear Antigen; D006820:Hyaluronic Acid