The Involvement of GRP78 on Estrogen Signaling in Gastric Cancer

It has been reported that GRP78 is highly expressed in gastric cancer, and it is considered as a marker for cancer progression and chemo-responsiveness, as well as target for cancer therapy. However, its potential role in gastric cancer development and progression is still unclear. Here, we found that GRP78 is highly expressed in tumor specimens from gastric cancer patients, and its expression was positively correlated with histological differentiation of human gastric adenocarcinoma. In addition, treatment gastric cancer SGC7901 cells with low concentration of 17β-Estradiol (E2) increased expressions of GRP78 and estrogen receptor-α 36 (ER-α36), a novel variant of ER-α, which was highly expressed, and its expression was correlated with lymph node metastasis of gastric cancer. Thus, we concluded that GRP78 could be a key player to be involved in the development and progression of gastric cancer that influenced by estrogen signaling.