Cluster of differentiation 44 (CD44) and octamer-binding transcription factor 3/4 (Oct3/4) are important factors influencing cancer stem cell (CSC) development, but their clinical applications on pancreatic cancer are still unknown. Here, we tested the hypothesis that expression of CD44 and Oct3/4 correlates with the clinicopathological parameters of pancreatic ductal adenocarcinomas (PDACs). Firstly, data on the mRNA expression levels in PDACs and normal pancreatic tissues were collected from Gene Expression Omnibus (GEO) repository datasets. Immunohistochemical analyses of CD44 and Oct3/4 were next performed in tissue microarrays of 80 surgical specimens derived from a Chinese population, which included 9 normal pancreatic ducts and 71 PDACs, amongst which 12 were well differentiated, 47 moderately differentiated, and 12 poorly differentiated. From the GEO results, mRNA expression levels of both CD44 and Oct3/4 were higher in PDACs than in normal pancreatic tissues. In addition, immunostaining scores of these biomarkers were higher in most PDACs than in non-neoplastic pancreatic ducts. The intensity of CD44 and Oct3/4 staining in normal pancreatic tissues was weak and limited to small areas. Although CD44 and Oct3/4 overexpression in PDACs tended to be associated with advanced histologic grades of PDACs, the correlation of CD44 and Oct3/4 expression with the American Joint Committee on Cancer (AJCC) pathological stage was not statistically significant. In conclusion, CD44 and Oct3/4 overexpression may imply malignant transformation of pancreatic ducts and could help pathologists make a more accurate diagnosis and decision on clear surgical margins.
Keywords: cancer stem cell; CD44; Oct3/4; pancreatic carcinoma.