• Korean Journal of Plant Tissue Culture
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• v.26 no.1
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• pp.31-35
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• 1999

Morphological characteristic during formation of tobacco crown gall tumor and genetic tumor, and their differential response to growth regulator were investigated in in vitro culture. Crown gall tumor was induced from tumor tissue transformed by infecting Agrobacterium tumefaciens C58. Genetic tumor was induced from tumor tissue which was induced spontaneously from reciprocal interspecific hybrids between Nicotiana glauca (2n=24) and Nicotiana langsdorffii (2n=18). Morphological characteristic of crown gall tumor, genetic tumor, and teratoma shoot was very similar, and they were actively proliferated on hormone-free medium. Typical tumor callus and teratoma shoot formed from crown gall tumor on the hormone-free medium. On the contrary, tumor callus derived from genetic tumor formed as a crown gall tumor callus on the medium supplemented with 0.5 mg/L of 2,4-D, and lots of teratoma shoots without any root formed on the hormone-free medium. Root development from the teratoma shoots was hardly obtained on the medium with IAA, GA and active carbon. However, teratoma shoots with roots, as normal shoots, were initiated occasionally on the hormone-free medium. These shoots also formed new genetic tumor on the stem, which leaves formed lots of teratoma shoot on the hormone-free medium in in vitro culture.

• Journal of Ginseng Research
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• v.11 no.1
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• pp.56-65
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• 1987

Grown-gall tumor was induced from the infection of Panax ginseng C.A. Meyer by Agrobacterium tumefaciens C58 and the tumor calli were formed on the phytohormone free MS medium. The calli were friable and rough in appearance. Calli obtained from crown gall tumor were similar to and indistinguishable from each other. The tumor callus was quite different from normal callus. Tumor callus grew rapidly, whereas mal callus appeared late. The growth of tumor callus was better in the dark than in the light. In suspension culture, the fresh weight of tumor callus was twice as much in comparison with normal callus.

• Biomedical Science Letters
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• v.27 no.4
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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.

• Current Optics and Photonics
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• v.3 no.1
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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.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.2
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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.

• Biomedical Science Letters
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• v.28 no.4
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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.

• Proceedings of the KAIS Fall Conference
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• 2011.05b
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• pp.1068-1071
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• 2011

Cyclooxygenases (COX)-2 has been highly expressed in a variety of tumor cells and involved inflammatory process, tumor-associated angiogenesis, and vascular functions but the underlying mechanism is not clearly elucidated. We here investigated the molecular mechanism by which COX-2 regulates tumor-associated angiogenesis. In vivo, we injected B16-F1 cells overexpressed with COX-2 or mock in wild type or eNOS-deficient mice. Tumor cells overexpressed with COX-2 increase tumor-associated angiogenesis and tumor growth compared with control cells and that the effect of COX-2 was lower in eNOS-deficient mice than wild type mice. These results may contribute to further understanding of the regulation of angiogenesis by COX during tumor metastasis and inflammation.

• IMMUNE NETWORK
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• v.5 no.2
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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.

• Korean Journal of Head & Neck Oncology
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• v.9 no.1
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• pp.74-87
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• 1993

Immunohistochemical studies on S-100 protein and lactoferrin were carried out to evaluate the existence and distribution pattern of S-100 protein and lactoferrin positive cells in salivary gland tumors. The specimens used were 25 cases of pleomorphic adenoma, 2 cases of monomorphic adenoma, 2 cases of mucoepidermoid tumor, 2 cases of acinic cell tumor, 3 cases of adenoid cystic carcinoma and 2 cases of adenocarcinoma occured in parotid and submandibular salivary gland. ABC kits(Dako corp. Copenhagen. Denmark) for S-100 protein and lactoferrin were used. The results obtained were summarized as follows: In the normal salivary gland. positive immunoreaction for S-100 protein was observed in myoepithelial cells of acini and intercalated ducts. Positive immunoreaction for lactoferrin was observed in serous acinic cells, epithelial cells of intercalated ducts, and excretory material in the ductal lumina. In the pleomorphic and monomorphic adenomas. most of tumor cells were positive for S-100 protein, while luminal tumor cells in gland-like or duct-like structures were rarely positive for lactoferrin. In mucoepidermoid tumor, most of squamous cells and a few of intermediate cells were positive for S-100 protein, but all of tumor cells were negative for lactoferrin. In acinic cell tumor, most of tumor cells were positive for lactoferrin, but all of tumor cells were negative for S-100 protein. In adenoid cystic carcinoma, basaloid tumor cells in trabecular structure were focally positive for S-100 protein. and in adenocarcinoma, many of tumor cells were posivive for both S-100 protein and lactoferrin. Thus, according to the embryonic stage of the development of the tumor cell origin, it was possible to classify the salivary gland tumor as followings: mucoepidermoid carcinoma which originated from the earliest stage, acinic cell tumor which originated from the end stage. Between these two extremes, there were pleomorphic adenoma, adenoid cystic carcinoma and adenocarcinoma which originated in the middle stage of the development of .the salivary glands. Based on the above results, it can be stated that S-100 protein is demonstrated in tumor cells orginated from myoepithelial cells and lactoferrin in glandular differentiated tumor cells.

• Animal cells and systems
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• v.12 no.4
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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.