OPTIMAL LACTATION EARLY IN LIFE ACTIVATES THE EXTRINSIC APOPTOTIC PATHWAY IN MAMMARY TUMORS IN ADULTHOOD

LÓPEZ FONTANA CM; CAMPO VERDE FIORELLA; CARÓN RW; SANTIANO FE; LÓPEZ AGUILERA F; PISTONE CREYDT V; ZYLA LEILA; SASSO CV; PISTONE CREYDT V; LÓPEZ FONTANA CM; ZYLA LEILA; CAMPO VERDE FIORELLA; CARÓN RW; SANTIANO FE; LÓPEZ AGUILERA F; SASSO CV

Buenos Aires

Congreso; REUNION CONJUNTA DE SOCIEDADES DE BIOCIENCIAS; 2017

Sociedad Argentina de Investigación Clínica

Studies in rodent models show that exposures to diet during the posnatal life, in periods when the mammary gland undergoes extensive modeling and re-modeling, alter susceptibility to carcinogen-induced mammary tumors. The objective of the present study was to analyze if adequate breastfeeding generates changes in the biology of mammary tumors developed in adult life. To do this we used Sprague Dawley female litters divided into 3 (L3), 8 (L8) or 12 (L12) pups per mother, and, at the age of 55 days, they were treated with a single dose of dimethylbenzanthracene (15 mg / rat) to study the latency, incidence, progression and tumor bilology. We performed a microscopic analysis of mitosis and apoptosis to asses the effect of differential lactation on the development of the tumors. We additionally evaluated mitosis by IHC of PCNA and determined the expression of caspase 8, Bid, Bax, Bcl2 and caspase 9 by western blot from the tumors. Incidence was expressed as percentages and compared by Fisher test. Other comparisons were performed by ANOVA I and Bonferroni´s test as post hoc. There was a lower incidence and a higher latency in L3 compared to the other groups. The mitotic index was significantly augmented in tumors of L12 rats compared with L3 and L8 (p