Effects of social stress on tumor development in dominant male mice with diverse behavioral activity profiles

Se examinó la influencia del perfil psicológico individual y del comportamiento social en el desarrollo tumoral de ratones macho dominantes. Los animales fueron sometidos a un test de campo abierto (OFT) para medir la actividad locomotora y la latencia. Posteriormente, los animales se dividieron en tres grupos: Stress-No-Inoculado (SNI), Stress-Inoculado (SI) y Control-Inoculado (CI). SI y CI fueron inoculados con células tumorales y SNI con vehículo. Los grupos SI y CI fueron sometidos a estrés mediante la interacción con un animal intruso anósmico, seis (T1) y veintiún (T2) días después de la inoculación y analizada su conducta. Finalmente los animales fueron sacrificados y se contaron las metastásis pulmonares. SI desarrolló más metástasis que CI, indicando un efecto del estrés a pesar de su estatus de ganador. Los animales activos desarrollaron menos metástasis que los pasivos. Aunque no se encontraron diferencias conductuales a T1, sí se encontraron diferencias a T2 entre SI y SNI, y entre activos y pasivos. Estas diferencias indican que existe un efecto del desarrollo tumoral en la conducta social que es más evidente en los sujetos pasivos.

We examined the influence of individual psychological profile and social behavior on tumor develop- ment in dominant male mice. Male OF1 mice were subjected to an open field test (OFT) to observe their motor activity and latency. Subsequently, the animals were divided into three groups: Stress-Non- Inoculated (SNI), Stress-Inoculated (SI) and Control-Inoculated (CI). The SI and CI groups were ino- culated with tumor cells and the SNI group with vehicle. SNI and SI were exposed to social stress with an anosmic intruder six (T1) and twenty one (T2) days after inoculation and their behavior was analy- zed. After T2, subjects were put down and the pulmonary metastatic foci counted. SI developed grea- ter pulmonary metastasis than CI, indicating an effect of stress despite the animal’s dominant status. Active animals developed less pulmonary metastasis than their passive counterparts. No differences were found in social behavior at T1. Differences were found, however, in some behavioral categories at T2 between SI and SNI, and between active and passive animals. These differences indicate an ef- fect of tumor development on social behavior that is more evident in passive subjects.