Induction of apoptosis in an estrogen-responsive mouse Leydig tumor cell by leukotriene.
For estrogen-responsive B-1F cells, established from estrogen-responsive mouse Leydig cell tumor, it has been reported that the 5-lipoxygenase (5-LOX) metabolic pathway appears to be associated with cell growth. The addition of 5-LOX inhibitor 2-(12-hydroxydodeca-5,10-diyl)-3,5,6-trimethyl-1,4-benzoquinone (AA861) to the medium resulted in a dose-dependent increase in cell yield as described previously. When the growth of the palpable tumors was measured, AA861 had stimulated in vivo tumor growth in adult male mouse inoculated B-1F cells. The effects of AA861 and 17beta-estradiol (E2) on the contents of various arachidonic acid metabolites in B-1F cells and their conditioned medium were examined. Although AA861 and E2 decreased the contents of leukotrienes (LTs), the two did not significantly change those of prostaglandins, thromboxan, prostacyclin, 12-hydroxyeicosatetraenoic acid (HETE) and 15-HETE. In immunohistochemical study B-1F cells show positive staining for 5-LOX in the E2-depleted condition, while E2 decreased the expression of 5-LOX. The decrease of the intensities of 79-kDa 5-LOX protein and 403-bp RT-PCR product bands was observed. The growth of Morpholino-anti oligo delivered B-1F cells was higher than that of Standard control oligo delivered cells. The delivery of Morpholino-anti oligo into B-1F cells caused the decrease of contents of LTs and 5-HETE in the cells and medium, and the reduction of 5-LOX activity. When LTD4 was added in the culture medium, the increasing concentrations of LTD4 resulted in a significant inhibition of cell yields of E2-treated B-1F cells. Morphological changes such as nuclear condensation and fragmentation, and DNA ladder pattern were demonstrated in E2-stimulated B-1F cells treated with LTD4 as well as in control cells cultured in the basal medium. These results implicate that 5-LOX at least plays an important role in the growth of B-1F cells and LD4 induces the apoptosis of B-1F cells.
Goto
H G
HG
Department of Pathology, Research Institute, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka 537-8511, Japan.
Nishizawa
Y
Y
Katayama
H
H
Murashima
T
T
Yamasaki
M
M
Tanigaki
Y
Y
Kimura
S
S
Fushiki
S
S
Nishizawa
Y
Y
D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D001094:Arachidonate 5-Lipoxygenase / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D016718:Arachidonic Acid / Q000037:antagonists & inhibitors / Q000378:metabolism; D016227:Benzoquinones / Q000494:pharmacology; D048708:Cell Growth Processes / Q000187:drug effects; D004958:Estradiol / Q000494:pharmacology*; D017998:Leukotriene D4 / Q000494:pharmacology*; D007984:Leydig Cell Tumor / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology*; D016859:Lipoxygenase Inhibitors; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D016376:Oligonucleotides, Antisense / Q000235:genetics / Q000494:pharmacology; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D014407:Tumor Cells, Cultured
D016227:Benzoquinones; D016859:Lipoxygenase Inhibitors; D016376:Oligonucleotides, Antisense; D012333:RNA, Messenger; D016718:Arachidonic Acid; D004958:Estradiol; D017998:Leukotriene D4; C036837:2,3,5-trimethyl-6-(12-hydroxy-5,10-dodecadiynyl)-1,4-benzoquinone; D001094:Arachidonate 5-Lipoxygenase