Canine Natural Killer Cell-Derived Exosomes Exhibit Antitumor Activity in a Mouse Model of Canine Mammary Tumor

Abstract

Natural killer (NK) cells are key immune cells engaged in fighting infection and malignant transformation. In this study, we found that canine NK cell-derived exosomes (NK-exosomes) separated from activated cytotoxic NK cell supernatants express specific markers including CD63, CD81, Alix, HSP70, TSG101, Perforin 1, and Granzyme B. We examined the antitumor effects of NK-exosomes in an experimental murine mammary tumor model using REM134 canine mammary carcinoma cell line. We observed changes in tumor size, tumor initiation, progression, and recurrence-related markers in the control, tumor group, and NK-exosome-treated tumor group. We found that the tumor size in the NK-exosome-treated tumor group decreased compared with that of the tumor group in the REM134-driven tumorigenic mouse model. We observed significant changes including the expression of tumorigenesis-related markers, such as B cell-specific Moloney murine leukemia virus insertion site 1 (Bmi-1), vascular endothelial growth factor (VEGF), matrix metallopeptidase-3 (MMP-3), interleukin-1β (IL-1β), IL-6, tumor necrosis factor-α (TNF-α), multidrug resistance protein (MDR), tumor suppressor protein p53 (p53), proliferating cell nuclear antigen (PCNA), and the apoptotic markers, B cell lymphoma-2 associated X (Bax) and B cell lymphoma-extra large (Bcl-xL) belonging to the Bcl-2 family, in the tumor group compared with those in the control group. The expression of CD133, a potent cancer stem cell marker, was significantly higher than that of the control. By contrast, the NK-exosome-treated tumor group exhibited a significant reduction in Bmi-1, MMP-3, IL-1β, IL-6, TNF-α, Bax, Bcl-xL, and PCNA expression compared with that in the tumor group. Furthermore, the expression of CD133, which mediates tumorigenesis, was significantly decreased in the NK-exosome-treated tumor group compared with that in the tumor group. These findings indicate that canine NK-exosomes represent a promising therapeutic tool against canine solid tumors, including mammary carcinoma.

Natural Killer Cell-Derived Extracellular Vesicles as a Promising Immunotherapeutic Strategy for Cancer: A Systematic Review

“…Thus, preclinical study needs to be performed to extrapolate animal data to humans despite that it is also unreliable due to species differences. Table 2 describes studies that assess the performance of NK-EV therapy using the in vivo model of tumor-bearing animals and the range of doses per administration [ 45 , 46 , 47 , 50 , 53 , 60 , 90 ]. The four studies shown in Figure 4 that performed intra-tumoral (IT) infusion reported significant suppression ( p < 0.05) of tumor growth and lowered cancer cell viability in the neoplastic mass [ 45 , 53 , 60 , 90 ].…”

“…Table 2 describes studies that assess the performance of NK-EV therapy using the in vivo model of tumor-bearing animals and the range of doses per administration [ 45 , 46 , 47 , 50 , 53 , 60 , 90 ]. The four studies shown in Figure 4 that performed intra-tumoral (IT) infusion reported significant suppression ( p < 0.05) of tumor growth and lowered cancer cell viability in the neoplastic mass [ 45 , 53 , 60 , 90 ]. Similar results were reported in the seven studies that performed intravenous (IV) delivery of NK-EVs through the tail vein [ 45 , 46 , 47 , 49 , 50 , 58 , 90 ].…”

Effects of Exosomes on Tumor Bioregulation and Diagnosis

“…Other researchers have also found that canine natural killer cell-derived exosomes can act on mouse breast cancer cell lines to play an anticancer effect by downregulating cancer stem cell activity to regulate apoptotic protein expression and enhancing the inhibitory function of p53. 35 Ali Asadirad et al 36 modified and engineered dendritic cells (DCs) using miR-155-enriched exosomes and found that this construct had antitumor effects in mouse models of colorectal cancer. However, the roles of different genes play in it and the mechanism of antitumor remained to be further investigated.…”

Exosome-Based Nanoplatforms: The Emerging Tools for Breast Cancer Therapy

“…NK cell-derived exosomes have a natural and excellent killing effect on tumor cells. The canine NK-exosomes were capable of significantly suppressing tumor size and reducing CD133 expression, representing a promising vehicle for the treatment in an experimental murine BC model ( 21 ). Zhu et al.…”