Expression of Lgr5, a Potential Cancer Stem Cell Marker, in Gastric Cancer subtypes

Objective: Cancer stem cell (CSC) based gene expression signatures are associated with tumor initiation, progression, and matastasis in various tumor types. Recently, thecharacterization and isolation of CSC biomarkers have gained considerable interest. The present investigation was designed to assess the expression levels of Wnt targetgene Lgr5 as specific markers of gastrointestinal malignancy and its clinical significance in a series of Gastric Cancers (GC). Materials and Methods: Lgr5 expression was examined in a well-defined series of 114 gastric tissues, including 81(71%) of intestinal and 33(29%) of diffuse subtypes, which were embedded in tissue microarray (TMA) blocks using immunohistochemistry. The correlation of Lgr5 expression with clinicopathologic parameters was also assessed. Results: Among 114 gastric cases, higher immunohistochemical expression of Lgr5 was detected in 46% of intestinal and 24% of diffused subtypes. Univariate analysis showed an inverse significant difference between Lgr5 expression with GC subtypes (P=0.02) and tumour differentiation (P= 0.001), indicating the higher level of Lgr5 expression in intestinal subtype (P=0.02) and well differentiation cases (P= 0.001). Conclusion: Our observation showed that the higher level of Lgr5 expression was not detected in highly aggressive growth form of gastric cancer. These findings warrant further investigation of Lgr5 as a potential CSC marker to understand its value as a target for the development of new therapeutic strategies in human GC.

Expression of Lgr5, a Potential Cancer Stem Cell Marker, in Gastric Cancer subtypes Keywords:

Gastric cancer , Tissue microarray , Immunohistochemistry , Lgr5