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

In Vivo. 2017 May-Jun;31(3):403-407. doi: 10.21873/invivo.11073.

Abstract

Background/aim: Our previous study indicated that Kita-kyushu lung cancer antigen-1 (KK-LC-1) is a cancer/testis antigen (CTA) expressed in 82% of gastric cancer cases. Here, we investigated the relationship between KK-LC-1 expression and Helicobacter pylori infection in Japanese patients with gastric cancer.

Patients and methods: We examined CTA expression in 25 surgical gastric cancer specimens and anti-H. pylori IgGs in the serum of each patient.

Results: KK-LC-1 was expressed in 80% of tumor samples, markedly higher than melanoma antigen gene (MAGE)-A1, MAGE-A3, MAGE-A4, synovial sarcoma, X breakpoint 4 (SSX4) and New York esophageal squamous cell carcinoma-1 (NY-ESO-1). Anti-H. pylori IgG titers from the KK-LC-1-positive patients were significantly higher (67.5±7.6) than those from KK-LC-1-negative patients (15.8±7.5, p<0.01) although there were no significant differences between patients positive and negative for MAGE-A1, -A3 and-A4, SSX4 and NY-ESO-1.

Conclusion: As far as we are aware, this is the first report of a correlation between a carcinogen and CTA expression in clinical samples. KK-LC-1 was frequently expressed in gastric cancer caused by H. pylori infection. The risk diagnosis for gastric cancer might be more accurate if KK-LC-1 expression status were also considered.

Keywords: Helicobacter pylori; KK-LC-1; cancer/testis antigen; carcinogen; gastric cancer.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Antigens, Neoplasm / metabolism*
  • Biomarkers, Tumor / metabolism
  • Female
  • Helicobacter Infections / metabolism*
  • Helicobacter Infections / microbiology
  • Helicobacter pylori / pathogenicity
  • Humans
  • Immunoglobulin G / metabolism
  • Lung Neoplasms / metabolism
  • Male
  • Melanoma / metabolism
  • Middle Aged
  • Neoplasm Proteins / metabolism
  • Prognosis
  • Sarcoma, Synovial / metabolism
  • Stomach Neoplasms / metabolism*
  • Stomach Neoplasms / microbiology*
  • Testis / metabolism*

Substances

  • Antigens, Neoplasm
  • Biomarkers, Tumor
  • CT83 protein, human
  • Immunoglobulin G
  • Neoplasm Proteins