RAB27A and RAB27B Expression May Predict Lymph Node Metastasis and Survival in Patients With Gastric Cancer

Abstract

Background/Aim: RAB27A and RAB27B are involved in exosome secretion. To date, there have been many attempts to elucidate the roles of RAB27A and RAB27B in the prognosis of various cancer types. The association of RAB27A and RAB27B expression with the clinical and pathological features was evaluated in patients with stomach cancer. Materials and Methods: A total of 360 patients who had undergone surgery for stomach cancer between January 1999 and December 2007 at Gyeongsang National University were enrolled in the study. Disease-free survival (DFS) and disease-specific survival (DSS) were compared according to immunohistochemistry of tumor samples. RAB27A and RAB27B mRNA and protein were also extracted from four stomach cancer cell lines using quantitative polymerase chain reaction and western blotting. Results: Strong nuclear RAB27A expression in tumor samples was statistically significantly correlated with lymph node metastasis. Cytoplasmic RAB27B expression was related to poor disease-free survival and its combined cytoplasmic and membranous expression was related to disease-specific survival of patients with different histopathological types of stomach cancer. High RAB27A expression and high RAB27B expression was found in four stomach cancer cell blocks. Among the four cell lines, NCI-N87 exhibited the lowest relative mRNA density and HS746T exhibited the highest relative protein density for both RAB27A and RAB27B. Conclusion: RAB27A and RAB27B expression may help predict lymph node metastasis and survival of patients with gastric cancer.

Rab27b, a Regulator of Exosome Secretion, Is Associated With Peritoneal Metastases in Gastric Cancer

“…High expression of Rab27b has been correlated with poor survival in patients with solid cancers, such as colorectal, pancreatic, and esophageal squamous cell cancer (21,(42)(43)(44)). An et al also reported that Rab27b expression predicts lymph node metastases and survival in GC patients (45). These findings suggest that Rab27b expression in tumor tissues can serve as a useful biomarker of poor prognosis in various malignancies.…”

Crosstalk between glioblastoma and tumor microenvironment drives proneural–mesenchymal transition through ligand-receptor interactions

“…The oncogene Rab27b, a member of the Rab family, facilitates the growth and invasion of some kinds of tumors. 79 Rab27b mediated the radioresistance of GBM cells, as demonstrated by Nishioka et al. 80 Following radiation, Rab27b causes the release of epithelial regulatory protein (EREG), which interacts with EGFR to encourage the development of neighboring cells.…”

Exosomes: Diagnostic and Therapeutic Implications in Cancer

“…Exosome formation requires RAB GTPases, tetraspanins (CD63, CD81, CD82, and CD9), and lipid-modifying enzymes such as sphingomyelinases [ 44 ]. RAB27A promotes the metastatic potential of melanoma cells by promoting the formation of pro-invasive exosomes [ 44 ] and regulates the secretion of exosomes in patients with gastric cancer [ 45 ]. The downregulation of RAB27A decreases the secretion of exosomes in gastric cancer cells and inhibits the peritoneal metastasis of gastric cancer cells without affecting the invasion potential of cancer cells [ 46 ].…”