• Archives of Pharmacal Research
• /
• v.23 no.4
• /
• pp.288-301
• /
• 2000

A series of 2-alkyl, 2-aryl, and 2-piperazinyl benzimidazole-4,7-dione derivatives (7a-h) and 16m-o) were prepared, and their cytotoxicities were tested against three cancer cell lines (mouse lymphocytic leukemia cell line P388, and human gastric carcinoma cell lines SNU-1 and SNU-16). These compounds showed potent cytotoxicity against all of three cell lines tested, and especially SNU-16 was sensitive to them. 2-Aryl (7g,h) and 2-piperazinyl benzimidazole-4,7-dione derivative (I6 m) were more potent than mitomycin C against P388 and SNU-16. Among benzimidazole-4,7-dione derivatives with alkyl group at position 2, 7a had the most potent cytotoxicity against all of the cell lines tested.

• Food Science and Biotechnology
• /
• v.15 no.3
• /
• pp.369-373
• /
• 2006

Water extracts obtained from cultured mountain ginseng (CMG) were evaluated for their ability to stimulate immune cells and inhibit cancer cell proliferation. The lymphocyte subpopulation in mouse splenocytes in vivo was significantly increased by the administration of the CMG extract (27.4 mg/mouse). Interleukin-2 and ${\gamma}$-interferon in the mice serum increased up to 30% in CMG extract-treated mice. At a concentration of 1.37 mg/mL, nitric oxide increased up to 400% in the macrophage cell line treated with CMG extract. The CMG extract significantly retarded the proliferation of human acute promyelocytic (HL60), human histiocytic (U937), and mouse lymphocytic (L1210) leukemia cell lines in vitro at concentrations over 2.74-13.7 mg/mL. In addition, CMG extract treatments (1.37 mg/mL and 2.74 mg/mL) lead to the increased expression of the p53 gene and protein in cultured U937 leukemia cell lines. These results indicate that water extracts of CMG are capable of both immune cell stimulation and cancer cell growth inhibition.

• IMMUNE NETWORK
• /
• v.20 no.1
• /
• pp.2.1-2.19
• /
• 2020

Acute viral infection or vaccination generates highly functional memory CD8 T cells following the Ag resolution. In contrast, persistent antigenic stimulation in chronic viral infection and cancer leads to a state of T-cell dysfunction termed T-cell exhaustion. We and other have recently identified a novel subset of exhausted CD8 T cells that act as stem cells for maintaining virus-specific CD8 T cells in a mouse model of chronic lymphocytic choriomeningitis virus infection. This stem cell-like CD8 T-cell subset has been also observed in both mouse and human tumor models. Most importantly, in both chronic viral infection and tumor models, the proliferative burst of Ag-specific CD8 T cells driven by PD-1-directed immunotherapy comes exclusively from this stem cell-like CD8 T-cell subset. Therefore, a better understanding of the mechanisms how CD8 T-cell subsets are regulated during chronic viral infection and cancer is required to improve the current immunotherapies that restore the function of exhausted CD8 T cells. In this review, we discuss the differentiation of virus-specific CD8 T cells during chronic viral infection, the characteristics and function of CD8 T-cell subsets, and the therapeutic intervention of PD-1-directed immunotherapy in cancer.

• Korean Journal of Head & Neck Oncology
• /
• v.13 no.1
• /
• pp.16-23
• /
• 1997

Although normal thyroid epithelial cells do not constitutively express HLA-DR antigen, their expression in wide spread within thyroid glands obtained from the human with autoimmune thyroid disease and with many neoplastic thyroids. We have, therefore, studied immunohistochemically with regard to the expression of HLA-DR antigen of thyroidectomy specimens from 50 patients of various thyroid diseases with use of paraffin-embedded tissue. One or two sections from each case were stained with commercially available mouse monoclonal antibody for class II HLA-DR antigen(HLA-DR/Alpha, DAKO) and examined by semiquantitative counting system for thyrocytes, neoplastic thyrocytes and other cells expressing HLA-DR antigen. All patients with lymphocytic thyroiditis(2/2) and diffuse hyperplasia(Graves' disease)(5/5), most patients with Hashimoto's disease(9/ll) expressed HLA-DR antigens in thyrocyte with abundant HLA-DR expressing lymphocytic infiltrates with lymph follicle formation in its vicinity or adjacent to the lesion. Most patients with papillary carcinoma(9/1l) had HLA-DR antigen detected in malignant thyrocytes ; while follicular carcinoma(0/3) and follicular adenoma(0/5) did not have detactable HLA-DR immunoreactivity. Adenomatous goiter(3/7) had HLA-DR antigen detected focally in lesser than half cases. Conversely, in four papillary carcinomas and three adenomatous goiters, HLA-DR expression of thyrocytes was found in the absence of HLA-DR expressing lymphoid infiltrates. In such cases therefore other factors more than thyroid autoimmunity must be causative for HLA-DR immunoreactivity. The results of this study indicate as follows. 1) The expression of HLA-DR on thyrocytes involved in autoimmune reactions appeared to be secondary to cytokine release from associated lymphocytic infiltrates. 2) Thyrocytes in thyroid lesions with equal degrees of lymphocytic infiltration without HLA­DR expression exhibited no HLA-DR immunoreactivity. 3) In neoplastic thyrocytes, most papillary carcinoma(9/11) exhibited detactable HLA-DR expression, while follicular carcinoma/adenoma(0/3/0/5) exhibited no detactable HLA-DR immunoreactivity which suggest the existence of divergent mechanisms inducing and modulating HLA-DR expression of different types of neoplastic thyrocytes.

• Bulletin of the Korean Chemical Society
• /
• v.18 no.11
• /
• pp.1204-1207
• /
• 1997

Effects of exogenous glycerophospholipids on oleate-dependent phospholipase D (PLD) activity were studied in lymphocytic mouse leukemia L1210 cells and in solubilized microsomal phospholipase D of rat brain. Among the phospholipids tested phosphatidic acid had the most stimulatory effects on both PLD activities up to about 3 folds. Lysophosphatidic acid also showed promoting effect on microsomal PLD activity but much less on L1210 cells compared to that of phosphatidic acid. While phosphatidylethanolamine increased PLD activity slightly, phosphatidylinositides were nearly ineffective in the tested sources. The stimulatory effect of phosphatidic acid observed can be utilized to improve the in vitro assay system for oleate-dependent PLD in mammalian sources.

• YAKHAK HOEJI
• /
• v.42 no.4
• /
• pp.345-352
• /
• 1998

Praecoxin A, an ellagitannin, purified from Alnus hirsuta var.microphlla was evaluated on the antitumor activity. Praecoxin A had the significant cytotoxicity to s ix tumor cell lines: human chronic myelogenous leukemia K-562, human promyelocytic leukemia HL-60, mouse leukemia P388, mouse lymphocytic leukemia L-1210, sarcoma-l8O, mouse lymphoma L5178Y except L-1210. And the most sensitive cell line was K-562 ($ED_{50}=2.43{\mu}g/ml$). The $ED_{50} of praecoxin A against HL-60, P388, L-1210, sarcoma7l8O and L5178Y were 6.28, 8.66, 10.00, 7.01, $9.32{\mu}g/ml$, respectively. Praecoxin A showed the increasing effect in life span by 36.8% on the 1st day after treatment of 10mg/kg in mice bearing sarcoma-180 tumor cells (ascitic form) via NCI (National Cancer Institute, U.S.A.) protocol in vivo assay. As a result, praecoxin A is considered to show the antitumor activity.

• Korean Journal of Plant Resources
• /
• v.10 no.3
• /
• pp.213-220
• /
• 1997

The present study has been undertaken to characterize availability of citrus as a medicinal plant with antineoplastic property. The crude extracts from 40 species of fruits with 12 species of the local Citrus in Cheju island were evaluated on their potential activities against mouse P388 lymphocytic leukaemia in vitro. The percent cytotoxicity varied from 25.40 to 97.94% at a concentration of $100{\mu}g/mL$. Among 40 spp., 8 species showed high toxicity more than 90% against P388 cells and Cheongkyool(C. nippokoreana) exhibited the most cytotoxicity as 97.94%($IC_{50}=20.2{\mu}g/mL$). Nine varieties of C. junos were showed insiginicant cytotoxicity. In trifoliate orange, immature fruit was stronger than mature and peel extract showed higher cytotoxicity($IC_{50}=18{\mu}g/mL$) than the other tissues. Hexane fraction from methanol(MeOH) extract of trifoliate orange showed highly significant inhibition of cell growth($IC_{50}=3.9{\mu}g/mL$). In addition, its cytotoxicity increased remarkably from 3.95 to $0.40{\mu}g/mL$ as exposure time legthened. Cytotoxic activities of crude extracts were decreased considerably during a six months storage period. It was apparent that there is considerable variation in cytotoxicity, depending upon species, maturity and storage time of extracts. There was no meaningful cytotoxic difference between archicitrus and metacitrus in the genus Citrus.

• YAKHAK HOEJI
• /
• v.43 no.3
• /
• pp.369-377
• /
• 1999

A new series of highly water soluble platinum(II) complexes {Pt(II)[1,3-bis(phenylthio) propane](trans- -1,2-diaminocyclohexane) (PC-1) and Pt(II)[1,3-bis-(phenythio)propane] cis-1,2-diaminocyclohexane(PC-2)} were synthesized, and characterized by their elemental analysis and by various spectroscopic techniques[infrared(IR), 13C-nuclear magnetic resonance (NMR)]. In vitro antitumor activity of new Pt(II) complexes was tested against P-388 and L-1210 mouse lymphocytic leukemia cell lines, PC-14 / P, PC-14/ADM and PC-14 / CDDP human pulmonary adenocarcinima, DU-145 human prostate carcinoma, HT-1376 human bladder carcinoma, ZR-75-1 human breast carcinoma, MKN-45/P and MKN-45/CDDP human gastric adenocarcinoma cell lines using colorimetric MTT[3-(4,5-dimethyl thiazol-2-yl)-2.5-diphenyltetrazoliumbromide] assay for cell survival and proliferation. PC-1 showed active against L-1210, P-388 leukemia, human lung, stomach, prostate, bladder and breast cancer cell lines, and the antitumor activity of these compounds were comparable or superior to those of PC-2 and displatin. The nephrotoxicities of PC-1 and PC-2 were found quite less than that of cisplatin using MTT and [3H] thymidine uptake in rabbit proximal tubule cells and human kidney cortical cells. Based on these results, this novel platinum (II) complex compound (PC-1) represents a valuable lead in the development of a new anticancer chemotherapeutic agent capable of improving antitumor activity and low nephrotoxicity.

• YAKHAK HOEJI
• /
• v.42 no.4
• /
• pp.382-387
• /
• 1998

Platycodon radix is a dried root of Platycodon grandiflorum (P. grandiflorum) A. DC, a perennial grown on the hills and fields in Korea and Japan, or cultivated in various districts. Recently, P. grandiflorum (Changkil) has been successfully cultivated for more than 20 years and generally has been employed as folk remedy for adult diseases such as hyperlipidemia, hypertension and diabetes. We investigated various biological activities of the extracts from Changkil. When treated in vitro with B16-F1 mouse melanoma cell lines, it showed 100% laminin-binding inhibitory activities at the concentration over 0.125mg/ml. In in vivo test it showed 61.5% reduction of the solid tumor weight transplanted in mice and exhibited anticancer activity of 128% ILS against Sarcoma-180 ascites. It also increased the ratio of positive cells of natural killer cells in lymphocytic composition against Sarcoma-18O ascites and solid tumor transplanted in ICR mice when tests were carried out by FACScan method.

• IMMUNE NETWORK
• /
• v.13 no.6
• /
• pp.264-274
• /
• 2013

The unrestricted population of $CD4^+Foxp3^+$ regulatory T (Treg) cells, which have been known to control the expression of autoimmune diseases and protective immunity to inflammatory reactions, has led to greater appreciation of functional plasticity. Detecting and/or isolating Ag-specific $CD4^+Foxp3^+$ Tregs at the single cell level are required to study their function and plasticity. In this study, we established and compared both MHC class II tetramer and intracellular CD154 staining, in order to detect $CD4^+Foxp3^+$ Treg specific for foreign Ag in acute and chronic infections with lymphocytic choriomeningitis virus (LCMV). Our results revealed that MHC class II tetramer staining showed a lower detection rate of LCMV $GP_{66-77}$-specific $CD4^+$ T cells because most of MHC class II tetramers were unbound and unstable when combined staining was performed with intracellular cytokines. In contrast, intracellular CD154 staining was revealed to be easier and simple for detecting LCMV $GP_{66-77}$-specific $CD4^+$ T cells, compared to MHC class II tetramer staining. Subsequently, we employed intracellular CD154 staining to detect LCMV $GP_{66-77}$-specific $CD4^+Foxp3^+$ Tregs using $Foxp3^{GFP}$ knock-in mouse, and found that LCMV $GP_{66-77}$-specific $CD4^+Foxp3^+$ Tregs and polyclonal $CD4^+Foxp3^+$ Tregs showed differential expansion in mice infected with LCMV Arms or Cl13 at acute (8 and 13 days pi) and chronic phases (35 days pi). Therefore, our results provide insight into the valuable use of intracellular CD154 staining to detect and characterize foreign Ag-specific $CD4^+Foxp3^+$ Treg in various models.