Role of microRNAs in solid tumors

Accumulating experimental evidence indi-cates that microRNAs play important roles in various biological processes, such as cell differ-entiation, proliferation, metabolism and apopto-sis. In addition, several reports concluded that altered expression of specific microRNA genes contributes to the initiation and progression of cancer. Here, we summarize the current knowl-edge about aberrant expression of various microRNAs in human solid cancers (e.g., lung, breast, and gastric cancers), their target pro-teins, and the relationship between their expression and response to chemotherapies. We also review the potential for using microRNAs as biomarkers for the diagnosis and cancer therapy. The development of treatment strategies against human solid cancers based on the profile and/or certain features of microRNAs is promising.