This study was designed to establish an interleukin-12 (IL-12)-expressing murine Lewis lung carcinoma (LLC) cell vaccine (LLC/murine IL-12 [mIL-12]) and assess its antitumor efficacy and mechanism in vivo. The recombinant IL-12 plasmid was transfected into LLC cells and screened by G418, and positive clones were obtained. C57BL/6 tumor-bearing mouse model was established and tumor-bearing mice were randomly divided into three groups (n = 20), that is, treated with an intratumoral injection of phosphate-buffered solution, blank plasmid, or LLC/mIL-12 vaccine, respectively, at days 0, 7, and 14. Tumor size was measured before and after treatment. Tumor growth curve was plotted, cytolytic T lymphocyte (CTL) activity assay and natural killer (NK) cell activity assay were performed, CD4+ and CD8+ T lymphocyte were quantitated using flow cytometry, and the expression of interferon-γ (IFN-γ), IL-12, and interferon-inducible protein-10 (IP-10) in serum was detected by ELISA. Microvessel density was determined by immunohistochemistry after all mice were euthanized at day 21. The study revealed suppressed tumor growth, elevated levels of IFN-γ, IP-10, and IL-12, augmented NK and CTL cell activities, and decreased microvessel density of tumor tissues. There were abundant CD4+ and CD8+ T lymphocyte infiltration in the vaccine group. This study demonstrated that the antitumor mechanism of LLC/mIL-12 vaccine was to promote IFN-γ and IL-12 secretion, augment the NK and CTL cell activities, and decrease the microvessel density of tumors.
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References
1.
NagarajanS, SelvarajP. Human tumor membrane vesicles modified to express glycolipid-anchored IL-12 by protein transfer induce T cell proliferation in vitro. A potential approach for local delivery of cytokines during vaccination. Vaccine, 2006; 24:2264.
2.
SalemML, KadimaAN, ZhouYet al.Paracrine release of IL-12 stimulates IFN-gamma production and dramatically enhances the antigen-specific T cell response after vaccination with a novel peptide-based cancer vaccine. J Immunol, 2004; 172:5159.
3.
VermaV, SharmaV, ShrivastavaSKet al.IL-12 and IL-2 potentiate the tumor-specific activity of peripheral blood cells from cervical cancer patients in vitro. J Exp Clin Cancer Res, 2000; 19:367.
4.
AhnWS, BaeSM, KimTYet al.A therapy modality using recombinant IL-12 adenovirus plus E7 protein in a human papillomavirus 16 E6/E7-associated cervical cancer animal model. Hum Gene Ther, 2003; 14:1389.
5.
KekeF, HongyangZ, HuiQet al.A combination of flk1-based DNA vaccine and an immunomodulatory gene (IL-12) in the treatment of murine cancer. Cancer Biother Radiopharm, 2004; 19:649.
6.
SuzukiS, UmezuY, SaijoYet al.Exogenous recombinant human IL-12 augments MHC class I antigen expression on human cancer cells in vitro. Tohoku J Exp Med, 1998; 185:223.
7.
OshikawaK, IshiiY, HamamotoTet al.Particle-mediated gene transfer of murine interleukin-12 cDNA suppresses the growth of Lewis lung carcinoma. In Vivo, 1999; 13:397.
8.
PressleyJS, ElgertKD. Post-chemotherapeutic administration of interleukin-12 retards tumor growth and enhances immune cell function: Combination therapy using paclitaxel and IL-12. Cancer Invest, 2006; 24:351.
9.
TamuraT, NishiT, GotoTet al.Combination of IL-12 and IL-18 of electro-gene therapy synergistically inhibits tumor growth. Anticancer Res, 2003; 23:1173.
10.
CebonJ, JagerE, ShackletonMJet al.Two phase I studies of low dose recombinant human IL-12 with melan-A and influenza peptides in subjects with advanced malignant melanoma. Cancer Immun, 2003; 3:7.
11.
DuvicM, ShermanML, WoodGSet al.A phase II open-label study of recombinant human interleukin-12 in patients with stage IA, IB, or IIA mycosis fungoides. J Am Acad Dermatol, 2006; 55:807.
12.
GollobJA, MierJW, VeenstraKet al.Phase I trial of twice-weekly intravenous interleukin 12 in patients with metastatic renal cell cancer or malignant melanoma: Ability to maintain IFN-gamma induction is associated with clinical response. Clin Cancer Res, 2000; 6:1678.
13.
GollobJA, VeenstraKG, ParkerRAet al.Phase I trial of concurrent twice-weekly recombinant human interleukin-12 plus low-dose IL-2 in patients with melanoma or renal cell carcinoma. J Clin Oncol, 2003; 21:2564.
14.
MotzerRJ, RakhitA, SchwartzLHet al.Phase I trial of subcutaneous recombinant human interleukin-12 in patients with advanced renal cell carcinoma. Clin Cancer Res, 1998; 4:1183.
15.
MotzerRJ, RakhitA, ThompsonJAet al.Randomized multicenter phase II trial of subcutaneous recombinant human interleukin-12 vs. interferon-alpha 2a for patients with advanced renal cell carcinoma. J Interferon Cytokine Res, 2001; 21:257.
16.
SangroB, MazzoliniG, RuizJet al.Phase I trial of intratumoral injection of an adenovirus encoding interleukin-12 for advanced digestive tumors. J Clin Oncol, 2004; 22:1389.
17.
ImagawaY, SatakeK, KatoYet al.Antitumor and antiangiogenic effects of interleukin 12 gene therapy in murine head and neck carcinoma model. Auris Nasus Larynx, 2004; 31:239.
18.
SgadariC, AngiolilloAL, TosatoG. Inhibition of angiogenesis by interleukin-12 is mediated by the interferon-inducible protein 10. Blood, 1996; 87:3877.
19.
TakeuchiE, YanagawaH, SuzukiYet al.IL-12-induced production of IL-10 and interferon-gamma by mononuclear cells in lung cancer-associated malignant pleural effusions. Lung Cancer, 2002; 35:171.
20.
YinX-L, SunS-L, LiS-L. The construction and expression of murine interleukin-12 eukaryotic expression plasmid. Chinese journal of cancer prevention and treatment, 2006; 13:165.
21.
YinX-L, DuanH, PenZ-P. The empirical study on murine Lewis lung carcinoma treated by recombinate murine interleukin-12. Cancer, 2006; 25:1087.
22.
NCCLS. Clinical applications of flow cytometry: Quality assurance and immunophenotyping of peripheral blood lymphocytes. NCCLS Document H42-T, 1992; 12:1.
23.
LiuY, EhteshamM, SamotoKet al.In situ adenoviral interleukin 12 gene transfer confers potent and long-lasting cytotoxic immunity in glioma. Cancer Gene Ther, 2002; 9:9.
24.
ParkerJN, GillespieGY, LoveCEet al.Engineered herpes simplex virus expressing IL-12 in the treatment of experimental murine brain tumors. Proc Natl Acad Sci, 2000; 97:2208.
25.
YamanakaR, ZulloSA, RamseyJet al.Marked enhancement of antitumor immune responses in mouse brain tumor models by genetically modified dendritic cells producing semliki forest virus-mediated interleukin-12. J Neurosurg, 2002; 97:611.
26.
RenH, BoulikasT, LundstromKet al.Immunogene therapy of recurrent glioblastoma multiforme with a liposomally encapsulated replication-incompetent semliki forest virus vector carrying the human interleukin-12 gene: A phase I/II clinical protocol. J Neurooncol, 2003; 64:147.
JeanWC, SpellmanSR, WallenfriedmanMAet al.Interleukin-12-based immunotherapy against rat 9L glioma. Neurosurgery, 1998; 42:850.
29.
HaSJ, LeeSB, KimCMet al.Rapid recruitment of macrophages in interleukin-12-mediated tumor regression. Immunology, 1998; 95:152.
30.
BrundaMJ, LuistroL, WarrierRRet al.Antitumor and antimetastatic activity of interleukin 12 against murine tumors. Exp Med, 1993; 178:1223.
31.
KnutsonKL, DisisML. IL-12 enhances the generation of tumour antigen-specific Th1 CD4 T cells during ex vivo expansion. Clin Exp Immunol, 2004; 135:322.
32.
ColomboMP, TrinchieriG. Interleukin-12 in anti-tumor immunity and immunotherapy. Cytokine Growth Factor Rev, 2002; 13:155.
33.
SatohY, EscheC, GambottoAet al.Local administration of IL-12-transfected dendritic cells induces antitumor immune responses to colon adenocarcinoma in the liver in mice. J Exp Ther Oncol, 1998; 2:337.
34.
DesaknaiS, LumniczkyK, HidvegiEJet al.Brain tumor treatment with IL-2 and IL-12 producing autologous cancer cell vaccines. Adv Exp Med Biol, 2001; 495:369.
35.
KikuchiT, AkasakiY, AbeTet al.Vaccination of glioma patients with fusions of dendritic and glioma cells and recombinant human interleukin 12. J Immunother, 2004; 27:452.
36.
FewellJG, MatarM, SlobodkinGet al.Synthesis and application of a non-viral gene delivery system for immunogene therapy of cancer. J Controlled Release, 2005; 109:288.
