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Experimental and clinical studies of lentinan, and its possible applications
WS4-3
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LENTINAN INDUCESTHE REGRESSIONOF METASTASES IN A MODELOF W O N CANCER IN RAT. J.F. JEANNIN, P. LAGADEC, F. MARTIN, Y. KANEKO, G. CHIHARA, INSERM, Faculty of medicine, Dijon, France; NCGRI, Tokyo and Ajinomoto Co. Tokyo, Japan. The emergence of metastases is the most devastating aspect of colon cancer. We have developped models of colon cancer metastases in rat. In the next experiments colon cancer cells were obtained from a chemically induced colon adenocaroinorna in BD IX rats. They were cultivated in vitro and cloned. A clone of cells giving numerous solid nodules, and not ascitic tumors when injected i.p., was selected. The treament started from day 14 after the tumor cell injection, when the rats beared numerous nodules from 1 to 5 mm. Lentinan was injected i.p. at the dose of 2 mg/kg and at the concentration of 200 ug/ml NaCI 9% . 5 injections i.p. 2 days apart were necessary. In these conditions lentinan induced the disappearance of tumors in 11 out of 30 treated rats autopsied 6 weeks after the tumor cell challenge. This effect was obtained in 3 independent experiments. Lentinan enhanced the life span of carcinomateous rats (p<0.001). 4 out of 10 treated rats were still alive 30 weeks after the tumor celt injection whereas the controls died between the 8th and the 10th week.
WS4-4
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E X P E R I M E N T A L AND C L I N I C A L STUDIES OF LENTINAN, AND ITS P O S S I B L E APPLICATIONS. T. Taguchi .I and Y. K a n e k o .2 *IDept. of O n c o l o g i c Surgery, R e s e a r c h Inst. for M i c r o b i a l Diseases, Osaka Univ., Osaka, Japan. * 2 P h a r m a c e u t i c a l s D e v e l o p m e n t Dept., A j i n o m o t o Co., Inc., Tokyo, Japan. Lentinan(LNT) is a p u r i f i e d p o l y s a c c h a r i d e , i s o l a t e d from a fruit body of an e d i b l e mushroom, L e n t i n u s edodes (Berk0 Singer.) by Chihara et al in 1969. LNT is a B - 1 , 3 - D - G l u c a n with a r e l a t i v e m o l e c u l a r mass of 500,000 d a l t o n s and its t e r t i a r y structure has been analyzed. In animal m o d e l e x p e r i m e n t a t i o n s , LNT has shown its v a r i o u s b i o l o g i c a l activities, such as a n t i - t u m o r e f f e c t s in a u t o c t h o n o u s and s y n g e n e i c tumor models, a n t i - v i r a l effects or a n t i - p a r a s i t i c effects. And mode of action of LNT has been c h a r a c t e r i z e d to s t i m u l a t e host defense m e c h a n i s m s such as m a c r o p h a g e s , helper T cells, NK cells and/or n e u t r o p h i l s . In human, clinical effectiveness of LNT has been c l e a r l y shown as an a n t i - t u m o r effect for stomach cancer p a t i e n t s by both s i g n i f i c a n t life p r o l o n g a t i o n and tumor r e g r e s s i o n effects. Further p o s s i b l e a p p l i c a t i o n s of LNT to human d i s e a s e s are now b e e i n g studied on other types of cancer and v i r a l disease such as AIDS, and a p p l i c a t i o n s to p a r a s i t o s e s of d o m e s t i c animals will be possible.
WS4-5
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COMBINED ANTITUMOR EFFECT OF MONOCLONAL ANTIBODY, 17-1A AND LENTINAN AGAINST HUMAN COLORECTAL CARCINOMA CELLS I N W T R O AND IN VIVO. Y.Akiyama , R.Chieda, K.Amikura, Y.Kaneko, D . H e r l y n ' , H.Koprowski*. Central Research L a b o r a t o r i e s , Ajinomoto Co., I n c . , Kawasaki, Japan. *The Wistar I n s t i t u t e , P h i l a d e l p h i a , PA, U.S.A. The ~(1~3)glucan, lentinan(LENT) was combinedly used w i t h 17-IA a g a i n s t human c o l o r e c t a l carcinoma c e l l l i n e SWl116 in o r d e r t o assess a s y n e r g i s t i c a n t i t u m o r e f f e c t i n v i t r o and i n viuo. P e r i t o n e a l macrophages from LENT-treated mice e x h i b i t e d s i g n i f i c a n t l y higher 17-1A-dependent macrophage-mediated cytotoxicity(ADMC) when compared w i t h c o n t r o l . LENTinduced enhancement of ADMC a c t i v i t y was accompanied by increased expression of Fc receptors(FcR) d e t e c t e d by r o s e t t e f o r m a t i o n . These e f f e t s o f LENT were observed i n ICR nu/nu mice as w e l l as ICR nu/+ mice, suggesting t h a t augmentation of ADMC a c t i v i t y and FcR expression by LENT i s exserted by the T c e l l - i n d e p e n d e n t mechanism. In a d d i t i o n , a s i g n i f i c a n t d i f f e r e n c e between LENT-induced and C.parvum-induced macrophages was noted w i t h regard t o expression of enzymatic markers f o r macrophage m a t u r a t i o n . Furthermore, combination of a n t i t u m o r e f f e c t of 17-IA and LENT was examined i n viuo. I t was found t h a t i n t r a v e n o u s a d m i n i s t r a t i o n of LENT augments the growth i n h i b i t o r y e f f e c t of 17-1A a g a i n s t SWIll6 t r a n s p l a n t e d in ICR nu/nu mice. These r e s u l t s may have i m p l i c a t i o n s i n developing approaches t o immunotherapy of human cancer.
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LENTINAN INDUCESTHE REGRESSIONOF METASTASES IN A MODELOF W O N CANCER IN RAT. J.F. JEANNIN, P. LAGADEC, F. MARTIN, Y. KANEKO, G. CHIHARA, INSERM, Faculty of medicine, Dijon, France; NCGRI, Tokyo and Ajinomoto Co. Tokyo, Japan. The emergence of metastases is the most devastating aspect of colon cancer. We have developped models of colon cancer metastases in rat. In the next experiments colon cancer cells were obtained from a chemically induced colon adenocaroinorna in BD IX rats. They were cultivated in vitro and cloned. A clone of cells giving numerous solid nodules, and not ascitic tumors when injected i.p., was selected. The treament started from day 14 after the tumor cell injection, when the rats beared numerous nodules from 1 to 5 mm. Lentinan was injected i.p. at the dose of 2 mg/kg and at the concentration of 200 ug/ml NaCI 9% . 5 injections i.p. 2 days apart were necessary. In these conditions lentinan induced the disappearance of tumors in 11 out of 30 treated rats autopsied 6 weeks after the tumor cell challenge. This effect was obtained in 3 independent experiments. Lentinan enhanced the life span of carcinomateous rats (p<0.001). 4 out of 10 treated rats were still alive 30 weeks after the tumor celt injection whereas the controls died between the 8th and the 10th week.
WS4-4
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E X P E R I M E N T A L AND C L I N I C A L STUDIES OF LENTINAN, AND ITS P O S S I B L E APPLICATIONS. T. Taguchi .I and Y. K a n e k o .2 *IDept. of O n c o l o g i c Surgery, R e s e a r c h Inst. for M i c r o b i a l Diseases, Osaka Univ., Osaka, Japan. * 2 P h a r m a c e u t i c a l s D e v e l o p m e n t Dept., A j i n o m o t o Co., Inc., Tokyo, Japan. Lentinan(LNT) is a p u r i f i e d p o l y s a c c h a r i d e , i s o l a t e d from a fruit body of an e d i b l e mushroom, L e n t i n u s edodes (Berk0 Singer.) by Chihara et al in 1969. LNT is a B - 1 , 3 - D - G l u c a n with a r e l a t i v e m o l e c u l a r mass of 500,000 d a l t o n s and its t e r t i a r y structure has been analyzed. In animal m o d e l e x p e r i m e n t a t i o n s , LNT has shown its v a r i o u s b i o l o g i c a l activities, such as a n t i - t u m o r e f f e c t s in a u t o c t h o n o u s and s y n g e n e i c tumor models, a n t i - v i r a l effects or a n t i - p a r a s i t i c effects. And mode of action of LNT has been c h a r a c t e r i z e d to s t i m u l a t e host defense m e c h a n i s m s such as m a c r o p h a g e s , helper T cells, NK cells and/or n e u t r o p h i l s . In human, clinical effectiveness of LNT has been c l e a r l y shown as an a n t i - t u m o r effect for stomach cancer p a t i e n t s by both s i g n i f i c a n t life p r o l o n g a t i o n and tumor r e g r e s s i o n effects. Further p o s s i b l e a p p l i c a t i o n s of LNT to human d i s e a s e s are now b e e i n g studied on other types of cancer and v i r a l disease such as AIDS, and a p p l i c a t i o n s to p a r a s i t o s e s of d o m e s t i c animals will be possible.
WS4-5
*s
COMBINED ANTITUMOR EFFECT OF MONOCLONAL ANTIBODY, 17-1A AND LENTINAN AGAINST HUMAN COLORECTAL CARCINOMA CELLS I N W T R O AND IN VIVO. Y.Akiyama , R.Chieda, K.Amikura, Y.Kaneko, D . H e r l y n ' , H.Koprowski*. Central Research L a b o r a t o r i e s , Ajinomoto Co., I n c . , Kawasaki, Japan. *The Wistar I n s t i t u t e , P h i l a d e l p h i a , PA, U.S.A. The ~(1~3)glucan, lentinan(LENT) was combinedly used w i t h 17-IA a g a i n s t human c o l o r e c t a l carcinoma c e l l l i n e SWl116 in o r d e r t o assess a s y n e r g i s t i c a n t i t u m o r e f f e c t i n v i t r o and i n viuo. P e r i t o n e a l macrophages from LENT-treated mice e x h i b i t e d s i g n i f i c a n t l y higher 17-1A-dependent macrophage-mediated cytotoxicity(ADMC) when compared w i t h c o n t r o l . LENTinduced enhancement of ADMC a c t i v i t y was accompanied by increased expression of Fc receptors(FcR) d e t e c t e d by r o s e t t e f o r m a t i o n . These e f f e t s o f LENT were observed i n ICR nu/nu mice as w e l l as ICR nu/+ mice, suggesting t h a t augmentation of ADMC a c t i v i t y and FcR expression by LENT i s exserted by the T c e l l - i n d e p e n d e n t mechanism. In a d d i t i o n , a s i g n i f i c a n t d i f f e r e n c e between LENT-induced and C.parvum-induced macrophages was noted w i t h regard t o expression of enzymatic markers f o r macrophage m a t u r a t i o n . Furthermore, combination of a n t i t u m o r e f f e c t of 17-IA and LENT was examined i n viuo. I t was found t h a t i n t r a v e n o u s a d m i n i s t r a t i o n of LENT augments the growth i n h i b i t o r y e f f e c t of 17-1A a g a i n s t SWIll6 t r a n s p l a n t e d in ICR nu/nu mice. These r e s u l t s may have i m p l i c a t i o n s i n developing approaches t o immunotherapy of human cancer.
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