Epigenetics in myeloid derived suppressor cells: a sheathed sword towards cancer

// Chao Zhang 1,3 , Shuo Wang 1,3 , Yufeng Liu 4 and Cheng Yang 2,3 1 Department of Urology, Zhongshan Hospital, Fudan University, Shanghai, China 2 Department of Plastic Surgery, Zhongshan Hospital, Fudan University, Shanghai, China 3 Shanghai Key Laboratory of Organ Transplantation, Shanghai, China 4 General Surgery, Department of Nursing, Zhongshan Hospital, Fudan University, Shanghai, China Correspondence to: Cheng Yang, email: // Keywords : epigenetics; myeloid derived suppressor cell (MDSC); microRNA (miRNA); small interfering RNA (siRNA); DNA methylation Received : April 25, 2016 Accepted : July 10, 2016 Published : July 21, 2016 Abstract Myeloid-derived suppressor cells (MDSCs), a heterogeneous population of cells composed of progenitors and precursors to myeloid cells, are deemed to participate in the development of tumor-favoring immunosuppressive microenvironment. Thus, the regulatory strategies targeting MDSCs’ expansion, differentiation, accumulation and function could possibly be effective “weapons” in anti-tumor immunotherapies. Epigenetic mechanisms, which involve DNA modification, covalent histone modification and RNA interference, result in the heritable down-regulation or silencing of gene expression without a change in DNA sequences. Epigenetic modification of MDSC’s functional plasticity leads to the remodeling of its characteristics, therefore reframing the microenvironment towards countering tumor growth and metastasis. This review summarized the pertinent findings on the DNA methylation, covalent histone modification, microRNAs and small interfering RNAs targeting MDSC in cancer genesis, progression and metastasis. The potentials as well as possible obstacles in translating into anti-cancer therapeutics were also discussed.