A study on the correlation of MyD88 expression with gastric cancer

Int J Clin Exp Pathol. 2018 Oct 1;11(10):4836-4844. eCollection 2018.

Abstract

Objective: The myeloid differentiation factor-88 (MyD88) plays a key role in mediating the innate immune signal transduction of toll-like receptor (TLR) and interleukin-1 (IL-1) family members, and it also participates in the regulation of tumorigenesis in various cancer models Our study sought to determine whether there is any correlation with MyD88 and the development of gastric cancer and, if such a correlation exists, to find out whether it can be used to improve the prognosis of gastric cancer patients.

Patients and methods: The expression of MyD88 in 108 cases of gastric cancer specimens, 15 cases of adenoma, and 15 cases of normal mucosa was detected by immunohistochemistry, and the correlations of the MyD88 expression with clinicopathologic changes (including disease-free survival [DFS] and overall survival [OS] were analyzed. The level of MyD88 was detected in well-differentiated MGC-803 and poorly-differentiated BGC-823 cell lines by qPCR and western blot. The expression of MyD88 was then measured by western blot after the treatment of an MyD88 overexpression vector or MyD88 inhibitor. Cell proliferation was determined by overexpression or suppression of MyD88.

Results: In clinical cases, MyD88 was highly expressed in 23% of patients with gastric cancer as compared to those in normal mucosa and adenoma. There was a significant correlation of MyD88 overexpression with gastric metastasis (P<0.01). The overexpression of MyD88 significantly promoted the proliferation of MGC-803 and BGC-823 cell lines in gastric cancer. According to the single factor analysis, a high expression of MyD88 was strongly associated with poor DFS and OS (P<0.01), and MyD88 was an independent prognostic factor of OS.

Conclusion: This study demonstrates that a high expression of MyD88 is associated with the gastric cancer patients with liver metastasis, and facilitates the proliferation of gastric cancer cells. MyD88 is an independent predictive factor for the poor prognosis of gastric cancer patients, which provides a potential tool for future clinical diagnosis.

Keywords: MyD88; correlation; gastric cancer.