Mammary Tumors Induce Central Pro-inflammatory Cytokine Expression, but Not Behavioral Deficits in Balb/C Mice

• Published in: Scientific reports Vol. 7; no. 1; pp. 8152 - 13
• Main Authors: Walker Ii, William H, Borniger, Jeremy C, Surbhi, Zalenski, Abigail A, Muscarella, Stevie L, Fitzgerald, Julie A, Zhang, Ning, Gaudier-Diaz, Monica M, DeVries, A Courtney
• Format: Journal Article
• Language: English
• Published: England Nature Publishing Group 15.08.2017; Nature Publishing Group UK; Nature Portfolio
• Subjects: Animals; Behavior, Animal; Body Mass Index; Breast cancer; Cell Line, Tumor; Cognitive ability; Cytokines; Cytokines - genetics; Cytokines - metabolism; Doublecortin protein; Fear conditioning; Female; Gene Expression Regulation, Neoplastic; Hippocampus; Immune response; Inflammation; Inflammation Mediators - metabolism; Interleukin 6; Learning; Mammary Neoplasms, Animal - genetics; Mammary Neoplasms, Animal - metabolism; Mental depression; Mice; Mice, Inbred BALB C; Mood; Motor Activity; Population studies; Rodents; Spleen - metabolism; Tumor necrosis factor-α; Tumors; γ-Interferon
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-017-07596-9

Breast cancer survivors are more likely to develop mood disorders and cognitive deficits than women in the general population. Previous studies suggest that peripheral tumors elicit central pro-inflammatory cytokine production, in turn leading to depression and cognitive deficits. In the current study, two cohorts of female Balb/C mice received bilateral orthotopic injections of syngeneic 67NR, 4T07, or 4T1cells (1 × 10 cells per injection) to induce mammary tumors. Approximately three weeks later, learned fear (via fear conditioning) or depressive-like behavior (via tail suspension and forced swim test) was assessed. Proinflammatory cytokine levels were increased in the serum (IL-1β, TNFα, IFNγ) and livers (IL-1β, IL-6, TNFα) of mice with 4T07 or 4T1 tumors compared to 67NR tumors and the vehicle control. IL-1β was increased in both the hippocampus and cortex of mice injected with 4T07 or 4T1 cell lines relative to the other treatment groups. However, mammary tumors had no effect on hippocampal doublecortin + and did not alter depressive-like behavior or learned fear. These data demonstrate that similarly sized tumors can produce differential immune responses and that tumor-induced central pro-inflammatory cytokine production can exist in the absence of depressive-like behavior or cognitive deficits.