Figure 5.

Relocation of Z cells to cancer lesions and Zfra suppression of pS14-WWOX correlates with cancer growth inhibition. (A) Nude mice were treated with or without Zfra once per week for three consecutive weeks, followed by inoculation with B16F10 cells. One month later, mice were sacrificed. Relocation of naïve and activated Z cells from the spleen to the tumor lesions via lymphatic vessels is shown (see red punctate). (B,C) Dramatic suppression of B16F10 melanoma growth is shown in the lung of Zfra-treated mice. As the lung turns normal, the level of Z cells is significantly reduced in the lung of Zfra-treated mice (n = 6). Non-activated Z cells accumulated in the B16F10 lesions of the lung but failed to kill cancer cells. Statistical analysis for C: * p < 0.05, n = 5, Student’s t test (Zfra group versus control group). (D,E) Suppression of cancer growth in the lung by Zfra correlates with inhibition of WWOX phosphorylation at Ser14. Statistical analysis for E: *** p < 0.001, n = 5, Student’s t test (all groups versus WWOX group). (F) Nude mice received Zfra4-10 (4 mM in 100 μL sterile MilliQ water) or an equal volume of sterile water for three consecutive weeks. A week later, these mice were inoculated with U87-MG cells on two subcutaneous sties of both flanks (2 × 10⁵ cells in 100 μL PBS). The whole mount lung tissue sections were stained with specific antibodies by immunohistochemistry and imaged by a scanner. (G) Compared to control mice, Zfra4-10 suppressed WWOX phosphorylation at S14 by greater than 70–90% in the lung, blocked the U87-MG tumor formation by ~50% in the skin, and inhibited U87-MG cell metastasis to the lung. Scale bar, 200 μm. (H) Zfra-treated nude mice resisted metastasis of glioblastoma 13-06-MG to the lung. (I) Compared to the Zfra4-10 peptide, Zfra(S8G)1-15 peptide failed to block BCC growth in mice. (J) Summary of Zfra-mediated Z cell activation in the spleen, Zfra suppression of pS14-WWOX in the cancer lesions, and Z cell killing of cancer cells in a target organ.