Dysregulation of microRNA biosynthesis enzyme Dicer plays an important role in gastric cancer progression.

Background And Aim: Dicer is one of the most important components in microRNA biogenesis. Although studies have revealed the aberrantly expression of Dicer in types of cancer, the results were greatly controversial. Here we aimed to study the expression of Dicer in gastric cancer (GC) and further explored the possible roles of Dicer in cancer progression.

Methods: The alteration of Dicer-expression in GC and its clinical significance was retrospectively studied with immunohistochemical analyses on 377 cases of cancer tissues using tissue microarray (TMA). Dicer mRNA and protein levels were also examined in 8 paired of GC tissues and non-neoplastic surrounding gastric epithelium with real time RT-PCR and western blot.

Results: We found that Dicer was reduced in GC tissues in both mRNA and protein levels. Moreover, down-regulation of Dicer was correlated highly with tumor differentiation (P<0.05) and lymph node invasion (P<0.05) in GC tissues, which suggested an essential role of Dicer in cancer invasion.

Conclusions: Considering that Dicer might be closely related to progression of GC, we proposed that Dicer might offer a promising target for prevention of metastatic progression in GC.