Effect ofNocardia rubracell-wall skeleton treatment on tumor formation in two-stage chemical carcinogenesis of mouse skin

✍ Scribed by Tamotsu Inoue; Takahiko Yoshimoto; Takeshi Ogura; Fumio Hirao; Ichiro Azuma; Yuichi Yamamura

• Book ID: 104660648
• Publisher: Springer-Verlag
• Year: 1981
• Tongue: English
• Weight: 329 KB
• Volume: 11
• Category: Article
• ISSN: 0340-7004
• DOI: 10.1007/bf00199492

✦ Synopsis

In two-stage chemical carcinogenesis of mouse skin, Nocardia rubra cell-wall skeleton (N-CWS), a potent immunopotentiator, was injected SC at various times. The dorsal skin of C57BL/6 male mice (about 10 cm 2) was painted with 20 #g 7,12-dimethylbenz(a)anthracene (DMBA) in 0.1 ml acetone when the animals were 11 weeks old (initiation). Seven weeks later, they were painted with 2.5 ~g 12-O-tetradecanoyl-phorbol-13-acetate (TPA) in 0.1 ml acetone twice weekly for 30 weeks (promotion). The timing of N-CWS treatment was important. N-CWS treatment before initiation reduced the incidence of skin tumor and the mean number of skin tumors per mouse most effectively. It is speculated that the antitumor activity of N-CWS may be composed of at least two mechanisms, being achieved through the enhancement of immunological surveillance and through changes in the metabolism of chemical carcinogens.