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Antipancreatic cancer effect of DNT KIN59 and the underlying mechanism
a Department of General Surgery, Anhui Provincial Hospital Affiliated to Anhui Medical University, 17 Lujiang Road, Hefei, 230001, Anhui Province, PR China
b Anhui Province Key Laboratory of Hepatopancreatobiliary Surgery, Hefei, 230001, PR China
Received in revised form
Available online 15 December 2018
Objectives: This study aimed to explore double-negative T (DNT) cell cytotoxicity to pancreatic cancer and the effect of the Fas (CD95, APO-1)/FasL (CD178) signaling pathway on this process.
Methods: DNT cells from the peripheral blood of healthy volunteers were expanded in vitro. The inhibitory effect of DNT cells on pancreatic cancer cells was investigated using a CCK-8 assay and nude mouse tumor model. A mechanistic study was performed using pathway blocking assays. Results: DNT cells were amplified in vitro with >90% purity, and the growth of pancreatic cancer in vitro was significantly inhibited by DNT cells. After coculture with DNT cells, Fas, caspase-8 and cleaved caspase-8 showed increased expression in pancreatic cancer cells. When blocking agent decoy receptor 3 (DcR3) was added, the antitumor effect of DNT cells and the expression of Fas, caspase-8 and cleaved caspase-8 were reduced in pancreatic cancer cells. In the nude mouse tumor model, the tumor volume and weight were lower in the DNT cell group and gemcitabine group than in the blank control group. Additionally, the expression of Fas, caspase-8 and cleaved caspase-8 was higher in the DNT cell group than in the blank control group. Moreover, DNT cells promoted apoptosis in cancer cells and animal model tissues.
Conclusion: DNT cells inhibited the growth of pancreatic cancer, and the Fas/FasL signaling pathway was involved in this process.
© 2018 IAP and EPC. Published by Elsevier B.V. All rights reserved.
Pancreatic cancer is a highly malignant tumor with a poor prognosis; despite a variety of available treatment methods, the desired treatment effect cannot be achieved, resulting in a five-year survival rate of less than 5% [1,2]. Currently, surgical resection is the most effective treatment, but pancreatic cancer is locally invasive and surrounded by a dense desmoplastic reaction, which could involve adjacent vital structures. Therefore, the opportunity for complete excision may be limited to 10e20% of patients who can be treated with surgery, but the five-year survival rate is only 15e25%. The failure of traditional therapeutic approaches to treat this devastating disease necessitates a new therapeutic approach for pancreatic cancer. Targeted therapies with agents such as r> * Corresponding author. Department of General Surgery, Anhui Provincial hos-pital, anhui Medical University, 17 Lujiang Road, Hefei, Anhui, 230001, PR China. E-mail address: [email protected] (J. Chen).
1 These authors contributed equally to this work.
antibodies, small molecule inhibitors or downstream signaling molecules have been clinically successful in various cancers.
Double-negative T (DNT) cells are phenotypically cell differen-tiation cluster 3þ (CD3þ) CD4( ) CD8( ) cells, which constitute a small but important proportion of T cells. Although the develop-ment of DNT cells has been extensively investigated [3,4], the origin of this cell type remains unclear. According to Thomson et al. , DNT cells account for 1e5% of the peripheral T cell population in mice and humans. DNT cells play an important role in the regula-tion of the immune response in models of transplant rejection, autoimmunity, and inflammatory diseases. Recent studies have demonstrated the antitumor effects of DNT cells. According to Young et al. , DNT cells can kill Ld þ A20 tumor cells in vivo. Based on findings by Merims et al. , upon expansion in vitro with allogeneic donor lymphocytes, DNT cells can suppress the growth of lymphoma cells as well as the growth of allogeneic and autolo-gous primary leukemic blasts in vivo and in vitro. However, reports on DNT cell cytotoxicity to pancreatic cancer are lacking, and the underlying mechanism remains unclear. Fas, a transmembrane protein that belongs to the tumor necrosis factor (TNF) receptor
superfamily, has only one ligand, Fas ligand (FasL). FasL is expressed on the surface of a variety of lymphocytes, including DNT cells [6,8e10]. FasL binds to the Fas receptor of target cells and can induce apoptosis in target cells. According to the previous study, DNT cells are cytotoxic to lymphoma cells via the Fas/FasL signaling pathway . More importantly, Fas was found to be highly expressed in pancreatic cancer cells compared to normal pancreatic cells [11,12]. Therefore, the Fas/FasL signaling pathway may also be involved in the mechanism of DNT cell cytotoxicity to pancreatic cancer.