Abstract 1148: The factual evidence of gastric mucosal IL-8 mRNA expression, cagA gene H.pylori infection, and pepsinogen I/II ratio in Thai gastric cancer .
Authors: Yamada Sirikan , Kato Shunji , Matsuhisa Takeshi , Makonkawkeyoon Luksana , Chakrabandhu Bandhuphat , Chakrabandhu Thiraphat , Azuma Takeshi 
Published: August 2014

Background: Interleukine-8 (IL-8) gene expression was reported in vitro that it may relate to cagA gene in Japanese. There is no in vivo study demonstrated how its level related to cagA genotype and serum pepsinogen I/II ratio in other Asian Ethnic beside of East Asian such as in Japanese. We aimed to study the relative risk of the cytokine gene expression level in Thai gastric cancer and how its correlation to other co-factors Methods: There were 86 Thai gastric cancer patients and 134 Thai non-cancer volunteers who underwent endoscopic mucosal biopsies. The serum pepsinogen I, II, and Helicobacter pylori Immunoglobulin G antibody were tested. The extracted H.pylori DNA was genotyped for cagA mutation. The IL-8 mRNA expression was measured by Real Time relative quantitation polymerase chain reaction in all Thai tissue samples from the specific site of biopsy, 17 Japanese gastric cancer, and 12 non-cancer gastric mucosal samples. The multivariate analysis was used for the risk study. The student t-test and Mann-Whitney were used for quantitative analysis. The correlation study was done in the subgroup analysis. The STATA 11.0, USA, and SPSS version 16, USA were used for statistical analysis. The p-value &lt;0.05 was considered as a statistically significant. Results: There is high level of IL-8 mRNA expression in positive H.pylori in Thai gastric cancer cases. However,negative cagA gene is found in 86.8 per cent of Thai gastric cancer though high yields of East Asian type in positive cagA cases. The PGI/II ratio in gastric cancer is significant lower than in non-cancer group, p =0.045. The mean level of IL-8 mRNA expression in Thai and Japanese advance gastric cancer were 9,615.65 (log 10= 2.62) and 1509.11 (log 10=2.17), respectively, p= 0.014. The total mean IL-8 mRNA expression in non-cancer Thais is 2,262 (log 10=1.49) while that in Japanese non-cancer is 10.79(log10= 0.69), p&lt;0.001. The IL-8 expression is about 2 fold level higher in gastric cancer than in non-cancer gastric mucosal tisuues in both nations, p = 0.05. For gastric cancer risk cut off IL-8 expression level is log10&gt;2 in both Thais and Japanese, Odds ratio= 7.97 (95%CI=3.75-16.97, p&lt;0.001) and Odd ratios= 4 (95%CI=1.29-12.40), respectively. Serum PGI/II ratio at less than 3.0 and IL-8 mRNA expression ≥100 or log10 ≥2 are significantly cut off risk difference between Thai cancer and non-cancer, p= 0.03 and p &lt; 0.001, respectively.Conclusion: The IL-8 mRNA expression level and pepsinogen I/II ratio reflect individualized ethnic host stomach mucosal defense difference and cancer inflammation in Thai gastric cancer. H.pylori is at risk for gastric cancer but there is negative cagA gene in this population. Gastric mucosal IL-8 mRNA expression may be a useful marker for poorly differentiated type gastric cancer treatment in near by future.

Citation Format: Sirikan Yamada, Shunji Kato, Takeshi Matsuhisa, Luksana Makonkawkeyoon, Bandhuphat Chakrabandhu, Thiraphat Chakrabandhu, Takeshi Azuma. The factual evidence of gastric mucosal IL-8 mRNA expression, cagA gene H.pylori infection, and pepsinogen I/II ratio in Thai gastric cancer . [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1148. doi:10.1158/1538-7445.AM2013-1148