Figure 3. Proposed models that miRNAs regulate the autophagy and the balance between autophagy and apoptosis. (A) An illustration of miRNA regulation of autophagy. A single miRNA can modulate multiple targets in different steps of autophagy. Alternatively, several co-regulated miRNAs can modulate the different steps in a cooperative manner although each miRNA regulates its specific target. (B) A working model for miRNA-mediated crosstalk between autophagy and apoptosis. Transcripts involved in different cellular processes but with common miRNA binding sites can modulate each other by competing for miRNA binding. For example, overexpression of autophagy-related genes will result in binding of more miRNA molecules,thereby leading to fewer miRNA molecules free to bind to apoptosis-related transcripts, which share similar miRNA binding sites. Thus, the miRNA-medicated conversation between autophagy and apoptosis is regular and intensive.