• Asian Pacific Journal of Cancer Prevention
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• v.13 no.3
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• pp.761-766
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• 2012

Objective: Although various human cancer stem cells (CSCs) have been defined, their applications are restricted to immunocompromised models. Developing a novel CSC model which could be used in immunocompetent or transgenic mice is essential for further understanding of the biomolecular characteristics of tumor stem cells. Therefore, in this study, we analyzed murine lung cancer cells for the presence of CSCs. Methods: Side population (SP) cells were isolated by fluorescence activated cell sorting, followed by serum-free medium (SFM) culture, using Lewis lung carcinoma cell (LLC) line. The self-renewal, differentiated progeny, chemosensitivity, and tumorigenic properties in SP and non-SP cells were investigated through in vitro culture and in vivo serial transplantation. Differential expression profiles of stem cell markers were examined by RT-PCR. Results: The SP cell fraction comprised 1.1% of the total LLC population. SP cells were available to grow in SFM, and had significantly enhanced capacity for cell proliferation and colony formation. They were also more resistant to cisplatin in comparison to non-SP cells, and displayed increased tumorigenic ability. Moreover, SP cells showed higher mRNA expression of Oct-4, ABCG2, and CD44. Conclusion: We identified SP cells from a murine lung carcinoma, which possess well-known characteristics of CSCs. Our study established a useful model that should allow investigation of the biological features and pharmacosensitivity of lung CSCs, both in vitro and in syngeneic immunocompetent or transgenic/knockout mice.

• The Journal of Korean Society of Virology
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• v.30 no.2
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• pp.141-150
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• 2000

The effectiveness of noninfectious recombinant adenovirus encoding murine granulocyte-macrophage colony stimulating factor (mGM-CSF) for the treatment of Meth A fibrosarcoma was investigated in syngeneic BALB/C model. Meth A and HeLa cells transduced with the recombinant adenovirus (Ad.mGM-CSF) produced substantial amounts of mGM-CSF, while WEH1164 cells transduced with the virus did not produce mGM-CSF. Mice inoculated subcutaneously with $1{\times}10^6$ Meth A cells, followed by injection of Ad.dE1 as a control, developed large tumors that reached a mean tumor size of 22 mm by day 30. However, tumor development and tumorigenicity were significantly inhibited in mice with a single intratumoral injection of Ad.mGM-CSF at $1{\times}10^8\;pfu$. Histological examination of the tumors injected with Ad.mGM-CSF revealed dense infiltrates of neutrophils, histiocytes, lymphocytes, and eosinophils associated with apoptotic cell death. The results suggest that the recombinant adenovirus encoding GM-CSF have a potential use for cancer gene therapy.

• Archives of Pharmacal Research
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• v.25 no.4
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• pp.522-527
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• 2002

The antimetastatic effect of BCG-CWS, which was emulsified in an oil-in-water form with either Drakeol 6VR mineral oil (BCG-CWS/DK) or squalane (BCG-CWS/SQA), on lung metastasis produced by highly metastatic murine tumor cells, Colon26-M3.1 carcinoma cells and B16-BL6 melanoma cells, was investigated in syngeneic mice. An intravenous (i.v.) administration of BCG-CWS (100 mg/mouse) 1 day after tumor inoculation significantly inhibited tumor metastasis of both Colon26-M3.1 carcinoma and B16-BL6 melanoma cells in experimental lung metastasis models. No differences in the antitumor activity of the two oil-based formulations (BCG-CWS/DK and BCG-CWS/SQA) were obverved. However, BCG-CWS/SQA administered through subcutaneous (s.c.) route was shown to be effective only when it was consecutively injected (3 times) after tumor inoculation. An in vivo analysis for tumor-induced angiogenesis shwed that a single i.v. administration of BCG-CWS/SQA inhibited the number of tumor-induced blood vessels and suppressed tumor growth. Furthermore, the multiple administration of BCG-CWS/SQA given at on week intervals led to a significant reduction in spontaneous lung metastasis of B16-BL6 melanoma cells in a spontaneous metastasis model. These results suggest that BCG-CWS emulsified with squalane is a potent inhibitory agent of lung metastasis, and that the anti metastatic effect of BCG-CWS is related to the suppression of tumor growth and the inhibition of tumor-induced angiogenesis.

• Korean Journal of Pharmacognosy
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• v.24 no.4
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• pp.267-281
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• 1993

To find antitumor components from higher fungi, the mycelia of Collybia confluens (Pers. ex Fr.) Kummer were cultured in artificial media. For efficient production of the mycelia, the influences of various modifications of culture conditions were examined. A water-soluble protein-bound polysaccharide fraction, Fr. A, was obtained from the mycelia by hot water extraction. When Fr. A was purified and fractionated by DEAE-cellulose and Sepbadex G-200 gel filtration chromatographies into four fractions which were designated B, C, C-I and C-II. The tumor inhibition ratios of these fractions ranged from 46% to 75% against the solid forms of sarcoma 180 in ICR mice at doses of 20 and 50 mg/kg/day when given intraperitoneally. Especially, Fr. C which was named Collyban(CB) exhibited a marked life-prolonging effect of the mice against ascitic forms of sarcoma 180 at a dose of 50 mg via i.p. administration. To extend spectra of the antitumor activities and eliminate the effects of allograft rejection, the characterization of antitumor effects of CB was performed in syngeneic host-tumor systems. It did not show any antitumor activity against L1210 murine leukemia in $CD_2Fl$ mice but prolonged their life span against ascitic forms of $MM_{46}$ carcinoma in $C_3H/He$ mice. Also it exhibited antitumor activity against human cervical cancer HeLa cells that were xenografted into nude mice having BALB/c genetic backgrounds by the i.p. injection at a dose of 100 mg/kg/day. In order to characterize the antitumor components, CB was examined by chemical analysis. It was acidic protein-bound polysaccharides composed of 31% polysaccharide, 27% protein and 3% hexosamine. CB was fractionated into two fractions, Fr. C-I(M.W.: 500 Kd) and Fr. C-II(M.W.:30 and 8 Kd) by Sephadex G-200 gel filtration chromatography.

• IMMUNE NETWORK
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• v.4 no.1
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• pp.44-52
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• 2004

Background: As a potent antigen presenting cell and a powerful inducer of antigen specific immunity, dendritic cells (DCs) are being considered as a promising anti-tumor therapeutic module. The expected therapeutic effect of DCs in renal cell carcinoma was tested in the mouse model. Established late-stage tumor therapeutic (E-T) and minimal residual disease (MRD) model was considered in the in vivo experiments. Methods: Syngeneic renal cell carcinoma cells (RENCA) were inoculated either subcutaneously (E-T) or intravenously (MRD) into the Balb/c mouse. Tumor cell lysate pulsed-DCs were injected twice in two weeks. Intraperitoneal DC injection was started 3 week (E-T model) or one day (MRD model) after tumor cell inoculation. Two weeks after the final DC injection, the tumor growth and the systemic immunity were observed. Therapeutic DCs were cultured from the bone marrow myeloid lineage cells with GM-CSF and IL-4 for 7 days and pulsed with RENCA cell lysate for 18 hrs. Results: Compared to the saline treated group, tumor growth (E-T model) or formation (MRD model) was suppressed in pulsed-DC treated group. RENCA specific lymphocyte proliferation was observed in the RENCA tumor-bearing mice treated with pulsed-DCs. Primary cytotoxic T cell activity against RENCA cells was increased in pulsed-DC treated group. Conclusion: The data suggest the possible anti-tumor effect of cultured DCs in established or minimal residual disease/metastasis state of renal cell carcinoma. Systemic tumor specific immunity including cytotoxic T cell activity was modulated also in pulsed-DC treated group.

• Archives of Pharmacal Research
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• v.26 no.10
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• pp.861-867
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• 2003

Inhibitory effect of the lectins (KML-C) isolated from Korean mistletoe (KM; Viscum album coloratum) on tumor metastases produced by murine tumor cells (B16-BL6 melanoma, colon 26M3.1 carcinoma and L5178Y-ML25 lymphoma cells) was investigated in syngeneic mice. An intravenous (i.v.) administration of KML-C (20-50 ng/mouse) 2 days before tumor inoculation significantly inhibited lung metastases of both B16-BL6 and colon 26-M3.1 cells. The prophylactic effect of 50 ng/mouse of KML-C on lung metastasis was almost the same with that of 100 $\mu$ g/mouse of KM. Treatment with KML-C 1 day after tumor inoculation induced a significant inhibition of not only the experimental lung metastasis induced by B16-BL6 and colon 26M3.1 cells but also the liver and spleen metastasis of L5178Y-ML25 cells. Furthermore, multiple administration of KML-C given at 3 day-intervals after tumor inoculation led to a significant reduction of lung metastasis and suppression of the growth of B16-BL6 melanoma cells in a spontaneous metastasis model. In an assay for natural killer (NK) cell activity. i.v. administration of KML-C (50 ng/mouse) significantly augmented NK cytotoxicity against Yac-1 tumor cells 2 days after KML-C treatment. In addition, treatment with KML-C (50 ng/mouse) induced tumoricidal activity of peritoneal macrophages against B16-BL6 and 3LL cells. These results suggest that KML-C has an immunomodulating activity to enhance the host defense system against tumors, and that its prophylactic and therapeutic effect on tumor metastasis is associated with the activation of NK cells and macrophages.

• IMMUNE NETWORK
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• v.11 no.6
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• pp.383-389
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• 2011

Background: EY-6 is one of the newly synthesized indoledione derivatives to induce tumor cell-specific cell death. In this study, we investigated the mechanism of immunological death induced by EY-6 at mouse colon cancer cell as well as at the normal immune cell represented by dendritic cell. Methods: C57BL/6 mouse syngeneic colon cancer cell MC38 was treated with EY-6, and analyzed by MTT for viability test, flow cytometry for confirming surface expressing molecules and ELISA for detection of cytokine secretion. Normal myeloid-dendritic cell (DC) was ex vivo cultured from bone marrow hematopoietic stem cells of C57BL/6 mice with GM-CSF and IL-4 to analyze the DC uptake of dead tumor cells and to observe the effect of EY-6 on the normal DC. Results: EY-6 killed the MC38 tumor cells in a dose dependent manner (25, 50 and $100{\mu}M$) with carleticulin induction. And EY-6 induced the secretion of IFN-${\gamma}$ but not of TNF-${\alpha}$ from the MC38 tumor cells. EY-6 did not kill the ex-vivo cultured DCs at the dose killing tumor cells and did slightly but not significantly induced the DC maturation. The OVA-specific cross-presentation ability of DC was not induced by chemical treatment (both MHC II and MHC I-restricted antigen presentation). Conclusion: Data indicate that the EY-6 induced tumor cell specific and immunological cell death by modulation of tumor cell phenotype and cytokine secretion favoring induction of specific immunity eliminating tumor cells.

• IMMUNE NETWORK
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• v.11 no.6
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• pp.368-375
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• 2011

Background: Recent clinical observation reported that there was a significant correlation between change in circulating vascular endothelial growth factor (VEGF) levels and the occurrence of severe acute graft-versus-host disease (GVHD) following allogeneic hematopoietic stem cell transplantation (allo-HSCT), but the action mechanisms of VEGF in GVHD have not been demonstrated. Methods: This study investigated whether or not blockade of VEGF has an effect on acute GVHD in a lethally irradiated murine allo-HSCT model of $B6\;(H-2^b)\;{\rightarrow}B6D2F1\;(H-2^{b/d})$. Syngeneic or allogeneic recipient mice were injected subcutaneously with anti-VEGF peptides, dRK6 ($50{\mu}g/dose$) or control diluent every other day for 2 weeks (total 7 doses). Results: Administration of the dRK6 peptide after allo-HSCT significantly reduced survival with greaterclinical GVHD scores and body weight loss. Allogeneic recipients injected with the dRK6 peptide exhibited significantly increased circulating levels of VEGF and expansion of donor $CD3^+$ T cells on day +7 compared to control treated animals. The donor $CD4^+$ and $CD8^+$ T-cell subsets have differential expansion caused by the dRK6 injection. The circulating VEGF levels were reduced on day +14 regardless of blockade of VEGF. Conclusion: Together these findings demonstrate that the allo-reactive responses after allo-HSCT are exaggerated by the blockade of VEGF. VEGF seems to be consumed during the progression of acute GVHD in this murine allo-HSCT model.

• Molecules and Cells
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• v.39 no.7
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• pp.536-542
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• 2016

Interleukin-17A is a member of the IL-17 family, and is known as CTLA8 in the mouse. It is produced by T lymphocytes and NK cells and has proinflammatory roles, inducing cytokine and chemokine production. However, its role in tumor biology remains controversial. We investigated the effects of locally produced IL-17A by transferring the gene encoding it into CT26 colon cancer cells, either in a secretory or a membrane-bound form. Expression of the membrane-bound form on CT26 cells dramatically enhanced their proliferation in vitro. The enhanced growth was shown to be due to an increased rate of cell cycle progression: after synchronizing cells by adding and withdrawing colcemid, the rate of cell cycle progression in the cells expressing the membrane-bound form of IL-17A was much faster than that of the control cells. Both secretory and membrane-bound IL-17A induced the expression of Sca-1 in the cancer cells. When tumor clones were grafted into syngeneic BALB/c mice, the tumor clones expressing the membrane-bound form IL-17A grew rapidly; those expressing the secretory form also grew faster than the wild type CT26 cells, but slower than the clones expressing the membrane-bound form. These results indicate that IL-17A promotes tumorigenicity by enhancing cell cycle progression. This finding should be considered in treating tumors and immune-related diseases.

• Radiation Oncology Journal
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• v.16 no.3
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• pp.225-231
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• 1998

Purpose : To determine whether TNF-$\alpha$ increases the antitumor effect of radiotherapy in murine syngeneic tumor system. Materials and Methods : Syngeneic murine tumors of MCa-K or MCa-4 (mammary carcinoma), OCa-I (ovarian carcinoma), or HCa-I(hepatocarcinoma were grown in hind legs of C3Hf/HeJ mice. When tumors were grown to 6 mm in mean diameter mice were treated with TNF-$\alpha$, radiation, or combination of the both. Gamma-radiation was given as a single dose of 30 Gy for HCa-I and 15 Gy for other tumors using Cobalt-60 teletherapy unit. A novel TNF-$\alpha$ mutein developed in Korea, was intraperitoneally administered daily at a dose of 10 ug per mouse for 7 days. In combination of radiation and TNF-$\alpha$, the drug was started 1 hour after radiation. Tumor growth delay assay was used to measure the tumor response to the treatment. Results : Among 4 tested tumors, TNF-$\alpha$ alone showed significant antitumor activity in MCa-K and OCa-I tumors, which showed absolute growth delay (AGD) of 5.0 days and 6.5 days, respectively. In combination with radiation, TNF-$\alpha$ showed significant delay of AGD (41.1 days) in OCA-I compared to AGDs of TNF-$\alpha$ alone and radiation, i.e., 6.5 days and 26.9 days, respectively(p<0.05). Enhancement factor was 1.29 in OCa-I, which showed supraadditive effect. TNF-$\alpha$ did not show significant delay of AGDs in the remaining 3 tumors compared to AGDs of TNF-$\alpha$ alone and radiation. Conclusions: TNF-$\alpha$ alone showed antitumor effects in MCa-K and OCa-I. In combination with radiation, TNF-$\alpha$ acted in supraadditive way in OCa-I only. The results of this study imply that the combination of TNF-$\alpha$ and radiation has different therapeutic potential depending on tumor model and further study is advocated.