Lgr5High/DCLK1High phenotype is more common in early stage and intestinal subtypes of gastric carcinomas.

BACKGROUND: Gastric carcinoma is the third most common malignancy and is one of the main causes of cancer deaths worldwide. Cancer stem cells (CSCs) are a subpopulation of tumour cells capable of self-renewal and differentiation, likely responsible for the initiation, recurrence, metastasis and chemo/radio-resistance.

OBJECTIVE: This study was conducted to evaluate the expression patterns and clinicopathologic significance of putative CSC markers, Lgr5 and DCLK1, in gastric carcinoma.

METHOD: The expression levels of Lgr5 and DCLK1 were examined in a well-defined series of gastric carcinoma tissues, including 75 (80%) from intestinal and 19 (20%) from diffuse subtypes, using tissue microarray (TMA). In addition, the correlation of the expression of these markers with clinicopathological factors was explored.

RESULTS: Higher expressions of Lgr5 and DCLK1 were mainly detected in intestinal subtypes of gastric carcinomas compared to diffuse subtypes (P= 0.005 and P= 0.050, respectively). We also found a higher expression of Lgr5 and DCLK1 more frequently in well-differentiated gastric carcinoma cases (P< 0.001 and P= 0.007). The combined analysis demonstrated that the co-expression of Lgr5 and DCLK1 (Lgr5High/DCLK1High) was more common in intestinal subtypes (P= 0.025) and well-differentiated gastric carcinoma samples (P< 0.001). Interestingly, there was a significant correlation between Lgr5High/DCLK1High phenotype and early-stage gastric carcinoma specimens (P= 0.045).

CONCLUSION: Our findings indicated that the Lgr5High/DCLK1High expression pattern may be considered as a signature phenotype for intestinal subtypes of gastric carcinoma.