Correlation Between Expression of the Cancer/Testis Antigen KK-LC-1 and Helicobacter pylori Infection in Gastric Cancer

Abstract

Abstract. Background/Aim: Our previous study indicatedthat Kita-kyushu

Detection of Kita-Kyushu Lung Cancer Antigen-1, a Cancer/testis Antigen, in the stomach closer to the cancerous condition.

“…In an earlier study, we reported that Hp infection induces expression of speci c CTAs, in addition to causing malignant transformation of host cells. Additionally, we found that, in clinical GC, there is a correlation between KK-LC-1 expression and Hp infection [13], [14]. These ndings suggest a possible correlation between KK-LC-1 expression and Hp infection, an early cancer-causing event.…”

“…Furthermore, in an earlier study, Fukuyama et al clari ed the speci c phenomena at the basis of the correlation between KK-LC-1 expression and Hp infection. Additionally, we previously showed how KK-LC-1 expression was frequently detected at non-tumour sites of the stomach occurring GC [14,16]. However, from these studies, it remained unclear whether KK-LC-1 was expressed in the stomach of patients who were not carrying a tumour and with Hp infection.…”

Hypomethylation‐mediated activation of cancer/testis antigen KK‐LC‐1 facilitates hepatocellular carcinoma progression through activating the Notch1/Hes1 signalling

“…KK-LC-1 is expressed in 40% of non-small-cell lung cancer tissues, 4 81.6% of gastric cancer 5 and 75% of triple-negative breast cancer. Correlated with Helicobacter pylori infection, 7 KK-LC-1 can be frequently detected even in early stage of gastric cancer 8 and at the pre-cancerous condition of the stomach. Correlated with Helicobacter pylori infection, 7 KK-LC-1 can be frequently detected even in early stage of gastric cancer 8 and at the pre-cancerous condition of the stomach.…”

Helicobacter Pylori Infection Induces Gastric Cancer and the Cancer/Testis Antigens Expression

“…The titer was significantly higher in the group with expression of KK-LC-1 than in those without the expression. There was no difference observed between the groups with and without CTA ( Table 1) [16], which implied that HP infection induces the expression of the specific CTA, KK-LC-1, with tumorigenesis. In addition, the discrepancy in the effect of HP between mouse Mage-A3 induction in vitro and human MAGE-A3 of clinical gastric cancer was attributed to the fact that homology between human and mouse MAGE-A3/Mage-A3 is 42% [19] and that HP directly induces mouse Mage-A3 expression.…”

“…The expression rate of the CTAs-encoding gene is commonly less than 40% (Table 1) [12][13][14][15][16], except for the specific CTA in the specific tissue cancer such as 80% expression of MAGE-A1 in hepatic cell carcinoma [17]. Although the expression rate of Kitakyushu lung cancer antigen-1 (KK-LC-1) was typical in other tissue cancers (Table 2), it was highest among the CTAs in gastric cancer [18], implying that KK-LC-1 would be induced by specific tumorigenic factors, such as HP, in the stomach.…”