Effect of radiation on the expression of carcinoembryonic antigen of human gastric adenocarcinoma cells

✍ Scribed by Masato Hareyama; Kohzoh Imai; Kihei Kubo; Hiroki Takahashi; Hirofumi Koshiba; Yuji Hinoda; Mitsuo Shidou; Atsushi Oouchi; Akira Yachi; Kazuo Morita

• Publisher: John Wiley and Sons
• Year: 1991
• Tongue: English
• Weight: 524 KB
• Volume: 67
• Category: Article
• ISSN: 0008-543X
• DOI: 10.1002/1097-0142(19910501)67:9<2269::aid-cncr2820670910>3.0.co;2-z

✦ Synopsis

The changes of antigenic expression of cultured human gastric adenocarcinoma MKN45 cells caused by irradiation were investigated to elucidate the immune responses to localized irradiation. The expression of carcinoembryonic antigen (CEA) showed remarkable increases in the culture supernatant and on the surface of the membrane of irradiated cells. The expression of major histocompatibility complex Class I antigen on the membrane also was enhanced by irradiation. In addition, the irradiated cell groups, when analyzed using a CEA-specific probe, showed remarkable increases in the CEA mRNA. These enhancements increased in the 10-Gy and 15-Gy irradiated populations compared with the 5-Gy irradiated population. These results suggest that the enhancement of expression of CEA by radiation takes place at the CEA gene expression (mRNA) level but not at the protein level. Cancer 672269-2274,1991. EVERAL INVESTIGATORS1-3 have studied the im-S munosuppressive effects of radiation therapy on host defenses. Oboshi et ~l . , ~. ~

however, reported that the histologic finding of lymphocyte infiltration surrounding cancer cells during or after radiation therapy might be related to increased immunologic responses to the tumor. A more recent study6 suggested immunohistopathologically that the subsets of the infiltrating lymphocytes of tumors were mainly composed of T-lymphocytes. Suppression of pulmonary metastases in a locally irradiated group has been reported in contrast with a surgically treated group in an experiment using rats bearing KMT-17 tumor cells.' These studies suggest that the irradiated tumor cells undergo immunologic changes in the host.