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

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 naïve 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 naïve spleen cells with Zfra allowed generation of activated Z cells to confer a memory anticancer response in naïve 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.

Zfra induction of memory anticancer response via a novel immune cell

“…Hyaluronidase Hyal-2 is a receptor for Zfra. 6 We postulate that Zfra activates Z cell via the Hyal-2/WWOX/Smad pathway. 7,8 Healthy BALB/c mice have 25-29% of Z cell in the spleen, whereas tumorgrowing mice have only less than 3.3%.…”

“…It is still effective in cancer prevention even as Zfra4-10, containing just seven amino acids (RRSSSCK). 6 Zfra blocks cancer metastasis, cancer stem cell development, and spontaneous cancer formation. 6 Zfra undergoes self-polymerization in a covalent manner under enzyme-free conditons.…”

“…6 Zfra blocks cancer metastasis, cancer stem cell development, and spontaneous cancer formation. 6 Zfra undergoes self-polymerization in a covalent manner under enzyme-free conditons. 6 Alteration of the Ser8 phosphorylation site abolishes Zfra polymerization and in turn its anticancer function.…”

“…6 Zfra undergoes self-polymerization in a covalent manner under enzyme-free conditons. 6 Alteration of the Ser8 phosphorylation site abolishes Zfra polymerization and in turn its anticancer function.…”

“…1). 6 Despite immunodeficiency, Z cell in nude and NOD-SCID mice can be primed for activation by Zfra to fight against cancer. Activated Z cell recognize many cancer cell types, suggesting that polymerized Zfra exhibits cancer-like antigens so that activated Z cell can recognize and destruct cancer cells.…”