Transdifferentiation via transcription factors or microRNAs: Current status and perspective

• Transdifferentiation is simpler and less risky of tumorigenesis compared to iPSC.
• Transdifferentiation is largely achieved via overexpression of transcription factors.
• In situ transdifferentiation does not require in vitro procedures of cells.
• MicroRNAs have potential advantages to be used for transdifferentiation.
• Transdifferentiation into unipotent cells may be an ideal strategy.

Transdifferentiation as a new approach for obtaining the ideal cells for transplantation has gradually become a hot research topic. Compared with the induced pluripotent stem cells technique, transdifferentiation may have better efficiency and safety. Although the mechanism of transdifferentiation is still unknown, many studies have achieved transformation of one cell type to another through transcription factors or microRNA. The current major strategy for transdifferentiation is via transcription factors; however, there are some safety issues with the use of transcription factors. In contrast, microRNA as a novel tool for inducing transdifferentiation through post-transcriptional regulation may be more safe and efficient. In addition, the present transdifferentiation strategies involve obtaining the terminal cell directly, so the amount of cells produced may not be sufficient and they may have low capacity for cell immigration and integration. Therefore, an indirect transdifferentiation strategy for producing unipotent cells is ideal as it can preserve the proliferation capacity and differentiation pathway.