Change in E-cadherin expression after X-ray irradiation of a human cancer cell line in vitro and in vivo.
OBJECTIVE
To investigate changes in E-cadherin expression after X-ray irradiation of a human cancer cell line in vitro and in vivo.


METHODS
E-cadherin expression on a human squamous cell carcinoma of the thyroid gland (T-SCC cell), which was established in our laboratory, at 24 h after graded single doses of irradiation and at 7 successive times after 10-Gy irradiation were investigated in vitro by immunoblot analysis with the monoclonal antibody to human E-cadherin. The changes in E-cadherin expression caused by irradiation of T-SCC tumors that were transplanted into athymic nude mice were also determined in vivo by immunohistochemical staining and immunoblot analysis in a similar fashion to that in vitro.


RESULTS
In vitro studies revealed that E-cadherin expression had increased significantly on T-SCC cells at 24 h after irradiation with doses of 2 to 10 Gy and that, in a time-course analysis, the expression had increased significantly at 3 to 72 h after irradiation compared with an unirradiated control cell, although it was not observed at 1 h after irradiation. In in vivo studies, a significant increase in E-cadherin expression was observed at 24 h after irradiation with 5 and 10 Gy by immunohistochemical staining and time-course studies demonstrated that E-cadherin increased temporarily at 12 to 24 h after 10-Gy irradiation; however, immunoblot analysis did not show alteration of E-cadherin expression by irradiation.


CONCLUSIONS
X-ray irradiation upregulated E-cadherin expression on T-SCC cells in vitro and in vivo.
Ebara
T
T
Department of Radiology and Radiation Oncology, Gunma University School of Medicine, Maebashi, Japan.
Mitsuhashi
N
N
Saito
Y
Y
Akimoto
T
T
Niibe
H
H
D000818:Animals; D015820:Cadherins / Q000378:metabolism / Q000528:radiation effects*; D002448:Cell Adhesion; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009363:Neoplasm Proteins / Q000378:metabolism / Q000528:radiation effects*; D011829:Radiation Dosage; D014407:Tumor Cells, Cultured / Q000378:metabolism / Q000528:radiation effects
D015820:Cadherins; D009363:Neoplasm Proteins