Suppression of mammary gland tumorigenesis in diabetic rats.
The aim of this study was to compare mammary gland tumorigenesis in diabetic and non-diabetic rats. Streptozotocin and N-nitroso-N-methylurea were used to induce diabetes and mammary tumors, respectively. A suppression of mammary carcinogenesis in diabetic rats was shown by a longer latency period, a lower number of tumors per animal and a smaller final tumor volume. An 84% of the lesions developed in diabetic animals were benign tumors. Eighty day-old diabetic rats had significantly lower plasma levels of total-IGF-I and insulin versus non-diabetic rats. We postulate that the decrease in the total IGF-I and insulin levels during the promotion phase of carcinogenesis in this model plays an important role in retarding the tumor development in diabetic animals and in favoring the development of benign mammary lesions.
Cocca
Claudia
C
Radioisotopes Laboratory, School of Pharmacy and Biochemistry, University of Buenos Aires, Junín, Buenos Aires 956-1113, Argentina.
Gutiérrez
Alicia
A
Núñez
Mariel
M
Croci
Máximo
M
Martín
Gabriela
G
Cricco
Graciela
G
Rivera
Elena
E
Bergoc
Rosa
R
D000477:Alkylating Agents / Q000633:toxicity; D000818:Animals; D003921:Diabetes Mellitus, Experimental / Q000097:blood / Q000150:complications* / Q000473:pathology; D005260:Female; D016762:Genes, fos / Q000502:physiology; D007150:Immunohistochemistry; D007328:Insulin / Q000097:blood; D007334:Insulin-Like Growth Factor I / Q000032:analysis; D008325:Mammary Neoplasms, Experimental / Q000097:blood / Q000150:complications* / Q000378:metabolism / Q000473:pathology*; D008770:Methylnitrosourea / Q000633:toxicity; D010179:Pancreas / Q000473:pathology; D018809:Proliferating Cell Nuclear Antigen / Q000096:biosynthesis; D051381:Rats; D013997:Time Factors
D000477:Alkylating Agents; D007328:Insulin; D018809:Proliferating Cell Nuclear Antigen; D007334:Insulin-Like Growth Factor I; D008770:Methylnitrosourea