Zfra activates memory Hyal-2+ CD3- CD19- spleen cells to block cancer growth, stemness, and metastasis in vivo

// Ming-Hui Lee 1, * , Wan-Pei Su 1, * , Wan-Jen Wang 1, * , Sing-Ru Lin 1, * , Chen-Yu Lu 1, * , Yu-An Chen 1, * , Jean-Yun Chang 1 , Shenq-Shyang Huang 1 , Pei-Yi Chou 1 , Siou-Ru Ye 1 , Szu-Jung Chen 1 , Huan He 1 , Ting-Hsiu Liu 1 , Ying-Tsen Chou 2 , Li-Jin Hsu 3, 4, * , Feng-Jie Lai 5 , Shean-Jen Chen 6 , Hoong-Chien Lee 7 , David Kakhniashvili 8 , Steven R. Goodman 8 , Nan-Shan Chang 1, 2, 4, 6, 9 1 Institute of Molecular Medicine, National Cheng Kung University Medical College, Tainan, Taiwan, ROC 2 Institute of Basic Medical Sciences, National Cheng Kung University Medical College, Tainan, Taiwan, ROC 3 Department of Medical Laboratory Science and Biotechnology, National Cheng Kung University Medical College, Tainan, Taiwan, ROC 4 Center of Infectious Disease and Signal Research, National Cheng Kung University, Tainan, Taiwan, ROC 5 Department of Dermatology, Chi-Mei Medical Center, Tainan, Taiwan, ROC 6 Advanced Optoelectronic Technology Center, National Cheng Kung University Medical College, Tainan, Taiwan, ROC 7 Graduate Institute of Systems Biology and Bioinformatics, National Central University, Zhongli, Taiwan, ROC 8 Institute of Biomedical Sciences and Technology, Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY, USA 9 Department of Neuroscience and Physiology, SUNY Upstate Medical University, Syracuse, NY, USA * These authors have contributed equally to this work Correspondence to: Nan-Shan Chang, e-mail: nschang13827@gmail.com Keywords: Zfra, skin cancer, melanoma, metastasis, stemness Received: September 18, 2014      Accepted: December 11, 2014      Published: February 20, 2015 ABSTRACT Zfra is a 31-amino-acid zinc finger-like protein, which participates in the tumor necrosis factor signaling. Here, we determined that when nude mice and BALB/c mice were pre-injected with nanogram levels of a synthetic Zfra1–31 or truncated Zfra4–10 peptide via tail veins, these mice became resistant to the growth, metastasis and stemness of melanoma cells, and many malignant cancer cells. The synthetic peptides underwent self-polymerization in phosphate-buffered saline. Alteration of the Ser8 phosphorylation site to Gly8 abolished Zfra aggregation and its-mediated cancer suppression in vivo . Injected Zfra peptide autofluoresced due to polymerization and was trapped mainly in the spleen. Transfer of Zfra-stimulated spleen cells to naive mice conferred resistance to cancer growth. Zfra-binding cells, designated Hyal-2+ CD3- CD19- Z cells, are approximately 25–30% in the normal spleen, but are significantly downregulated (near 0–3%) in tumor-growing mice. Zfra prevented the loss of Z cells caused by tumors. In vitro stimulation or education of naive spleen cells with Zfra allowed generation of activated Z cells to confer a memory anticancer response in naive or cancer-growing mice. In particular, Z cells are abundant in nude and NOD-SCID mice, and can be readily activated by Zfra to mount against cancer growth.