MicroRNAs (miRNAs) are a large family of small noncoding RNAs ( 22 nucleotide long) that negatively regulate protein-coding gene expression posttranscriptionally by interacting with messenger RNAs (mRNAs), causing either their degradation or translation inhibition. While miRNAs were first discovered as important regulators of developmental timing, subsequent studies have shown that their deregulations are critically involved in various diseases, including cancer. This is evident from the crucial roles they play in regulating a wide range of cellular processes such as cell survival, apoptosis, proliferation, differentiation, motility, and stemness. It has been found that miRNA expression levels are altered in all types of cancer and they play important roles in almost all the aspects of cancer pathogenesis such as initiation, promotion, metastasis, responses to drug treatment, and so forth. These recognitions and other accumulating evidence clearly suggest that miRNAs can serve as novel targets for cancer therapies. Indeed, targeting abnormally expressed miRNAs has been shown to have great potential in suppressing primary tumor growth, reducing tumor metastasis, and overcoming anticancer drug resistance. It is anticipated that miRNAs can be valuable cancer-specific targets and novel miRNA-based targeted therapies can be formulated to provide effective treatments for cancer.

The main focus of this special issue is to give a comprehensive and state-of-the-art coverage of multifaceted roles of miRNAs in cancer pathogenesis and the cellular responses to various cancer therapies. We are interested in original research articles as well as review articles on subjects related to examining the role of miRNAs in cancer therapy in cell culture, animal model, and clinical studies. Potential topics include, but are not limited to:

• Modulation of miRNAs as novel cancer therapies
• Synergistic effect of miRNAs with classical cancer therapies
• miRNA expression levels/profiles as indicators of anticancer drug responses
• miRNA involvement in classical cancer therapy and drug resistance
• miRNA regulation of cancer cell cycle, apoptosis, and cancer stem cell property
• Body fluid miRNAs as biomarkers for cancer diagnosis, prognosis, and therapeutic responses
• Novel and efficient miRNA delivery methods and their applications in cancer therapy

Before submission authors should carefully read over the journal’s Author Guidelines, which are located at http://www.hindawi.com/journals/bmri/guidelines/. Prospective authors should submit an electronic copy of their complete manuscript through the journal Manuscript Tracking System at http://mts.hindawi.com/submit/journals/bmri/cell.biology/menc/ according to the following timetable: