Frequent High Expression of Kita-Kyushu Lung Cancer Antigen-1 (KK-LC-1) in Gastric Cancer

Abstract

Background: The tumor-associated antigen Kita-Kyushu lung cancer antigen-1 (KK-LC-1) has been reported as not being expressed in normal tissues, except for the testis, and in the setting of non-small cell lung cancer. The present study demonstrated that KK-LC-1 is expressed in gastric cancer.

Materials and methods: We analyzed the expression of KK-LC-1 and cancer/testis antigens (CTAs) in surgical specimens of 49 gastric carcinomas. The expression of KK-LC-1 and CTAs was assessed using reverse transcription-polymerase chain reaction.

Results: KK-LC-1 expression was observed in gastric carcinomas. The number of lesions with expression of KK-LC-1, Melanoma antigen gene encoding-A1 (MAGE-A1), MAGE-A3 and New York Esophageal squamous cell carcinoma-1 (NY-ESO-1) was 40 (81.6%), 17 (34.7%), 22 (44.9%) and 8 (16.3%) out of the 49 specimens, respectively.

Conclusion: KK-LC-1 should be categorized as a CTA. The frequency of KK-LC-1 expression was higher than that of the other CTAs. KK-LC-1 might be a useful target for immunotherapy and in diagnosis of gastric cancer.

Keywords: KK-LC-1; Kita-kyushu lung cancer antigen-1; cancer/testis antigen; gastric cancer.