1990 Fiscal Year Final Research Report Summary

Analysis of the Mechanisms of Skin Tumor Promotion in Mice Resistant and Sensitive to TPA.

Research Project

Project/Area Number	01570194
Research Category	Grant-in-Aid for General Scientific Research (C)
Allocation Type	Single-year Grants
Research Field	Experimental pathology
Research Institution	Hiroshima University
Principal Investigator	WATANABE Hiromitsu Hiroshima Univ., Res. Inst. Nucl. Med. Biol., Associate Professor., 原爆放射能医学研究所, 助教授 (00034653)
Co-Investigator(Kenkyū-buntansha)	ITO Akihiro Hiroshima Univ., Res. Inst. Nucl. Med. Biol., Professor., 原爆放射能医学研究所, 教授 (60034633)
Project Period (FY)	1989 – 1990
Keywords	C57BL mouse / DBA mouse / Initiation-promotiom / Skin tumor / MNNG / TPA / Benzoyl peroxide / SOD activity
Research Abstract	Strain difference of mouse skin tumor promotion by benzoyl peroxide (BzP) and by 12-0-Tetradecanoyl-Phorbol-13-Acetate (TPA) was examined. After initiation by 4.0mu mol of N-Methyl-N'-nitro-N-nitrosoguannidine (MNNG), 8-week-old female DBA/2N, C57BL/6, C3H/C^b_s, and C3H/HeN mice (in progress) were promoted by 10 mg or 20 mg BzP or 10 n mol of TPA for 30 weeks. The incidence of skin tumors in DBA, C^b_s and C57BL mice promoted by TPA were 72%, 58% and 37%, respectively. By promotion with 10 mg or 20 mg Bzp, the incidences were 74% and 35% in DBA mice, 6% and 25% in C57BL mice, and 0% in C^b_s mice. The results suggest that genetic factors controlling susceptibility to TPA promotion also control sensitivity to other classes of promoters.