Tsai B.-Y.Suen J.-L.BOR-LUEN CHIANG2021-07-022021-07-0220100969-7128https://www.scopus.com/inward/record.uri?eid=2-s2.0-77955665641&doi=10.1038%2fgt.2010.38&partnerID=40&md5=783931dd58e3164a16d68079aad5113fhttps://scholars.lib.ntu.edu.tw/handle/123456789/567888Foxp3, a member of the forkhead transcription factor family, is a master gene that controls the development and function of CD4+ CD25 + regulatory T (Treg) cells. It is thought to contribute to pathogenesis of many different tumors, including ovarian carcinoma and pancreatic, breast and pancreatic ductal adenocarcinoma. Selectively depleted Foxp3-expressing cells with anit-CD25 antibodies or vaccination of Foxp3 mRNA-transfected dendritic cells engender protective immunity against tumor. This study targeted silencing Foxp3 gene expression using RNA interference (RNAi) delivered by a lentiviral vector to evaluate the therapeutic role of Foxp3 short-hairpin RNAs (shRNAs) in a murine model of leukemia. RL1, a mouse CD4+ CD25+ leukemia cell with Foxp3 expression, was used as the leukemia animal model. By infecting RL1 cells with Lenti-Foxp3-siRNA, we reduced Foxp3 gene expression and the suppressive function of CD4+ CD25+ effector cells stimulated with ConA. Moreover, lentiviral-mediated Foxp3 RNAi transduced into RL1 cell or injected into the tumor showed suppressive effects on tumor growth and prolonged the survival of tumor-transplanted mice. However, this suppressive effect was abrogated in NOD-SCID mice transplanted with Lenti-Foxp3-siRNA-infected RL1 cells. In conclusion, inhibiting Foxp3 gene expression by shRNAs effectively decreases tumor growth of Treg cell-like leukemia. The results may provide a novel strategy for future immunotherapy against cancers. ? 2010 Macmillan Publishers Limited All rights reserved.Foxp3; lentivirus; leukemia; RL♂1; RNAi[SDGs]SDG3lentivirus vector; short hairpin RNA; transcription factor FOXP3; animal cell; animal experiment; animal model; antineoplastic activity; article; cancer inhibition; cancer survival; CD4+ CD25+ T lymphocyte; controlled study; gene expression; gene silencing; human; human cell; leukemia; male; mouse; nonhuman; priority journal; protein degradation; regulatory T lymphocyte; RNA interference; RNA sequence; Animals; Cell Line, Tumor; Forkhead Transcription Factors; Gene Therapy; Lentivirus; Leukemia, Experimental; Leukemia, T-Cell; Male; Mice; Mice, Inbred BALB C; RNA Interference; RNA Stability; Animalia; Lentivirus; Murinae; Musjournal article10.1038/gt.2010.38203578292-s2.0-77955665641