Antitumor activity of the Korean mistletoe lectin is attributed to activation of macrophages and NK cells.
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 26-M3.1 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 microg/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 26-M3.1 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.
Yoon
Taek Joon
TJ
Institute for Biomedical Research, Han Dong University, Namsong-Ri 3, Buk-Ku, Pohang, Korea.
Yoo
Yung Choon
YC
Kang
Tae Bong
TB
Song
Seong Kyu
SK
Lee
Kyung Bok
KB
Her
Erk
E
Song
Kyung Sik
KS
Kim
Jong Bae
JB
D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000009:adverse effects / Q000494:pharmacology / Q000627:therapeutic use*; D045744:Cell Line, Tumor; D003602:Cytotoxicity, Immunologic / Q000187:drug effects; D005260:Female; D007694:Killer Cells, Natural / Q000187:drug effects / Q000378:metabolism*; D007723:Korea; D008175:Lung Neoplasms / Q000188:drug therapy; D008262:Macrophage Activation / Q000187:drug effects* / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D009362:Neoplasm Metastasis / Q000188:drug therapy; D009368:Neoplasm Transplantation / Q000379:methods; D009374:Neoplasms, Experimental / Q000188:drug therapy; D008517:Phytotherapy; D010936:Plant Extracts / Q000737:chemistry / Q000627:therapeutic use; D037121:Plant Lectins / Q000302:isolation & purification* / Q000627:therapeutic use*; D010946:Plants, Medicinal / Q000737:chemistry; D028182:Viscum album / Q000737:chemistry
D000972:Antineoplastic Agents, Phytogenic; D010936:Plant Extracts; D037121:Plant Lectins