• Current Optics and Photonics
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• 제3권1호
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• pp.54-65
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• 2019

To develop a biomarker predicting tumor treatment efficacy is helpful to reduce time, medical expenditure, and efforts in oncology therapy. In clinics, microvessel density using immunohistochemistry has been proposed as an indicator that correlates with both tumor size and metastasis of cancer. In the preclinical study, we hypothesized that vascular morphometrics using optical coherence tomography angiography (OCTA) could be potential indicators to estimate the treatment efficacy of breast cancer. To verify this hypothesis, a 13762-MAT-B-III rat breast tumor was grown in a dorsal skinfold window chamber which was applied to a nude mouse, and the change in vascular morphology was longitudinally monitored during tumor growth and metronomic cyclophosphamide treatment. Based on the daily OCTA maximum intensity projection map, multiple vessel parameters (vessel skeleton density, vessel diameter index, fractal dimension, and lacunarity) were compared with the tumor size in no tumor, treated tumor, and untreated tumor cases. Although each case has only one animal, we found that the vessel skeleton density (VSD), vessel diameter index and fractal dimension (FD) tended to be positively correlated with tumor size while lacunarity showed a partially negative correlation. Moreover, we observed that the changes in the VSD and FD are prior to the morphological change of the tumor. This feasibility study would be helpful in evaluating the tumor vascular response to treatment in preclinical settings.

• 대한의생명과학회지
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• 제28권4호
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• pp.312-316
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• 2022

We have previously reported that genetically modified tumor cells with 4-1BBL have anti-cancer effects in a CT26 mouse colorectal tumor model. In this study, genetically modified tumor cells with 4-1BBL were evaluated for their potential as candidates for preventive and therapeutic cancer vaccine. To identify the effect of preventive and therapeutic vaccine of genetically modified tumor cells with 4-1BBL, tumor growth pattern of CT26-4-1BBL as a cancer vaccine was examined compared to CT26-beta-gal. In therapeutic vaccination, CT26-WT was inoculated into mice and then vaccinated mice with doxorubicin (Dox)-treated CT26-beta-gal and CT26-4-1BBL (single or three times). Triple vaccination with Dox-treated tumor cell inhibited tumor growth compared to single vaccination. Vaccination with CT26-4-1BBL showed an efficient tumor growth inhibition compared to vaccination with CT26-beta-gal. For preventive vaccination, Dox-treated CT26-beta-gal and CT26-4-1BBL was vaccinated into mice with three times and then administered mice with CT26-WT. Preventive vaccination with CT26-4-1BBL showed no tumor growth. Preventive vaccination with CT26-beta-gal also led to tumor-free mice. These results suggest that genetically modified tumor cells with 4-1BBL can be used as therapeutic or preventive cancer vaccine.

• IMMUNE NETWORK
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• 제5권2호
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• pp.110-116
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• 2005

Background: As an attempt to develop a strategy to improve the protective immune response to GM-CSF-secreting CT26 (GM-CSF/CT26) tumor vaccine, we have investigated whether the apoptogenic treatment of GM-CSF/CT26 prior to vaccination enhances the induction of anti-tumor immune response in mouse model. Methods: A carcinogeninduced mouse colorectal tumor, CT26 was transfected with GM-CSF gene using a retroviral vector to generate GM-CSF-secreting CT26 (CT26/GM-CSF). The CT26/GM-CSF was treated with ${\gamma}$-irradiation or mitomycin C to induce apoptosis and vaccinated into BALB/c mice. After 7 days, the mice were injected with a lethal dose of challenge live CT26 cells to examine the protective effect of tumor vaccination in vivo. Results: Although both apoptotic and necrotic CT26/GM-CSF vaccines were able to enhance anti-tumor immune response, apoptotic CT26/GM-CSF induced by pretreatment with ${\gamma}$-irradiation (50,000 rads) was the most potent in generating the anti-tumor immunity, and thus 100% of mice vaccinated with the apoptotic cells remained tumor free for more than 60 days after tumor challenge. Conclusion: Apoptogenic pretreatment of GM-CSF-secreting CT26 tumor vaccine by ${\gamma}$-irradiation (50,000 rads) resulted in a significant enhancement in inducing the protective anti-tumor immunity. A rapid induction of apoptosis of CT26/GM-CSF tumor vaccine at the vaccine site might be critical for the enhancement in anti-tumor immune response to tumor vaccine.

• 대한의생명과학회지
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• 제27권4호
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• pp.329-333
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• 2021

We previously identified that tumor cells genetically modified with a 4-1BBL co-stimulatory molecule had anticancer effects in a CT26 mouse colorectal tumor model. To identify the distinction between immune cells in a mouse tumor model treated with tumor cells genetically modified with 4-1BBL or β-gal, we examined the immune cells in CT26-WT, CT26-βgal, and CT26-4-1BBL tumor bearing mice 21 days after tumor cell administration. The CD8+ T cells population in mice treated with tumor cells genetically modified with 4-1BBL was significantly increased on day 21 compared to that of tumor cells genetically modified with β-gal in the spleen and tumor tissue. The CD4+ T cell population was not different between the two mice groups. The Foxp3+CD25^high CD4 T cell population decreased on day 21 in tumor tissues, but the decrease was not significant. We also found that CD8 T cells had pivotal roles in inhibiting tumor growth by treating mice with ant-CD4 and CD8 antibodies. These results suggest that tumor cells genetically modified with 4-1BBL could inhibit tumor growth by affecting on CD8 T lymphocytes.

• 식물조직배양학회지
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• 제26권1호
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• pp.31-35
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• 1999

연초 crown gall tumor와 genetic tumor의 형성시 형태적 특성과 조직배양시 식물호르몬에 대한 반응을 조사하였다. Crown gall tumor는 A. tumefaciens C58을 감염시켜 형질전환된 tumor조직으로부터 획득하였으며, genetic tumor는 N. glauca (2n=24)와 N. langsdorffii (2n=18)의 종간교배에 의하여 유기된 잡종식물체에서 자발적으로 발생한 tumor조직으로부터 획득하였다. 형성된 crown gall tumor, genetic tumor및 teratoma shoot의 형태적 특성은 매우 비슷하였으며, 식물조직배양시 식물호르몬이 전혀 첨가되지 않은 기본배지에서 생장이 왕성하였다. Crown gall tumor는 식물호르몬 무첨가배지에서 전형적인 tumor callus가 형성되었으며 teratoma shoot도 형성되었다. 반면에 genetic tumor는 2,4-D 0.5mg/L 첨가된 배지에서 tumor callus가 형성되었으며, 식물호르몬 무첨가배지에서는 많은 teratoma shoot가 형성되어 식물호르몬의 조절에 의해서 phenotype을 거의 비슷하게 할 수 있었다. Genetic tumor는 재분화시 정상적인 식물체보다는 뿌리를 갖지 못하는 teratoma shoots가 형성되는데 외부에서 인위적으로 식물호르몬인 IAA와 GA, 그리고 active carbon을 첨가하여 완전한 식물체를 생산하는 데는 실패하였다. 그러나 간혹 식물호르몬 무첨가배지에서 뿌리를 갖는 정상식물체로 생장하는 shoot가 형성되었는데 이런 식물체에서도 생장하면서 줄기부분에서 다시 genetic tumor가 형성되었으며, 잎절편을 다시 식물호르몬 무첨가배지에 접종할 경우에도 teratoma shoots를 형성하였다.

• Asian Pacific Journal of Cancer Prevention
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• 제16권2호
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• pp.831-836
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• 2015

Tumor fluid accumulation occurs in both human cancer and experimental tumor models. Solid tumors show a tendency to tumor fluid accumulation because of their anatomical and physiological features and this may be influenced by molecular factors. Fluid accumulation in the peri-tumor area also occurs in the Dunning model of rat prostate cancer as the tumor grows. In this study, the effects of tumor fluids that were obtained from Dunning prostate tumor-bearing Copenhagen rats on the strongly metastatic MAT-LyLu cell line were investigatedby examining the cell's migration and tumor fluid's toxicity and the kinetic parameters such as cell proliferation, mitotic index, and labelling index. In this research, tumor fluids were obtained from rats injected with $2{\times}10^5$ MAT-LyLu cells and treated with saline solution, and 200 nM tetrodotoxin (TTX), highly specific sodium channel blocker was used. Sterilized tumor fluids were added to medium of MAT-LyLu cells with the proportion of 20% in vitro. Consequently, it was demonstrated that Dunning rat prostate tumor fluid significantly inhibited proliferation (up to 50%), mitotic index, and labeling index of MAT-LyLu cells (up to 75%) (p<0.05) but stimulated the motility of the cells in vitro.

• IMMUNE NETWORK
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• 제16권5호
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• pp.305-310
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• 2016

In this study, we compared two different tumor cell vaccines for their induction of anti-tumor immunity; one was a tumor cell clone expressing a membrane-bound form of IL-12 p35 subunit (mbIL-12 p35 tumor clone), and the other was a tumor clone expressing heterodimeric IL-12 as a single chain (mb-scIL-12 tumor clone). The stimulatory effect of mb-scIL-12 on the proliferation of ConA-activated splenocytes was higher than that of mbIL-12 p35 in vitro. However, the stimulatory effect of mbIL-12 p35 was equivalent to that of recombinant soluble IL-12 (3 ng/ml). Interestingly, both tumor clones (mbIL-12 p35 and mb-scIL-12) showed similar tumorigenicity and induction of systemic anti-tumor immunity in vivo, suggesting that tumor cell expression of the membrane-bound p35 subunit is sufficient to induce anti-tumor immunity in our tumor vaccine model.

• Journal of Ginseng Research
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• 제11권1호
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• pp.56-65
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• 1987

인삼 crown gall tumor callus의 특성을 구명하기 위하여 Agrobacterium tumefaciens C58을 감염시켜서 얻어진 crown gall tumor를 phytohormone 무첨가 배지에서 배양하여 생육이 왕성한 tumor callus를 유기하였다. 이들 tumor callus는 정상조직에서 유기한 callus에 비해 외관상으로는 friable한 형태의 덩어리로 자라면서도 매우 단단한 양상을 보였으며, callus증식에 적합한 phytohormone 농도에서는 tumor callus의 생육이 오히려 억제되는 현상을 보였다. Tumor callus의 생육은 고체배양시 암배양이 광배양보다 생체중의 경우에는 2.4배, 건물중은 1.9배 가량이 더 많으며, 2,4-D가 함유된 최적조건에서 배양한 정상 callus의 생체중과는 비슷한 경향을 보였으나, 건물중은 tumor callus가 더 높았다. 그리고 현탁배양시에는 tumor callus가 정상 callus보다 생장속도가 2배 이상 빠른 경향이었다.

• Archives of Pharmacal Research
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• 제22권4호
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• pp.340-347
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• 1999

Dendritic cells (DCs) are potent professional antigen-presenting cells (APC) capable of inducing the primary T cell response to antigen. Although tumor cells express target antigens, they are incapable of stimulating a tumor-specific immune response due to a defect in the costimulatory signal that is required for optimal activation of T cells. In this work, we describe a new approach using tumor-DC coculture to improve the antigen presenting capacity of tumor cells which does not require a source of tumor-associated antigen. Immunization of a weakly immunogenic and progressive tumor cocultured with none marrow-derived DCs generated an effective tumor vaccine. Immunization with the cocutured DCs was able to induce complete protectiv immunity against tumor challenges and was effective for the induction of tumor-specific CTL (cytotoxic T lymphocyte) activity. Furthermore, high NK cell activity was observed in mice in which tumors were rejected. In addition, immunization with tumor-pulsed DC s induced delayed tumor growth, but not tumor eradication in tumor-bearing mice. Our results demonstrate that coculture of DCs with tumors generated antitumor immunity due to the NK cell activation as well as tumor-specific T cell. This approach would be used for designing tumor vaccines using DCs when the information about tumor antigens is limited.

• Animal cells and systems
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• 제12권4호
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• pp.193-201
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• 2008

The eventual goal of tumor immunotherapy is to develop a vaccine inducing a specific anti-tumor immunity. Cytokine gene therapy is an effective way at least in animal models, but limited efficacy and various side effects obstruct clinical applications. In this study, we developed a tumor vaccine expressing a membrane-bound form of IL-2(mbIL-2) and SDF-1 in B16F10 melanoma cells. The tumor clones expressing mbIL-2 showed reduced tumorigenicity, and additional expression of SDF-1 to mbIL-2 expressing tumor cells caused more severe reduction in tumorigenicity. However, expression of the SDF-1 alone did not affect on the tumorigenicity, probably because of limited production of SDF-1 in the SDF-1 transfected clones. When the mice once rejected mbIL-2/SDF-1 expressing tumor clone were re-challenged with wild type B16F10 tumor cells, all of the mice survived. This result suggests that mbIL-2/SDF-1 tumor clone is effective in inducing systemic anti-tumor immunity against wild type B16 melanoma. Furthermore, culture supernatant of tumor clones expressing SDF-1 induced lymphocyte migration in vitro. These results, all together, suggest that expression of mbIL-2 and SDF-1 in tumor cells enhances anti-tumor immune responses through different roles; the secreted SDF-1 may function as a chemoattractant to recruit immune cells to tumor vaccine injection site, and the mbIL-2 on tumor cells may provide costimulatory signal for CTL activation in physical contacts.