Abstract 4055: Immune checkpoint protein expression is up-regulated in tumor-bearing elderly mice

• Published in: Cancer research (Chicago, Ill.) Ill.), 2015-08, Vol.75 (15_Supplement), p.4055-4055
• Main Authors: Lim, So Jung, Kim, Jeong Min, Lee, Won Suk, Kwon, Woo Sun, Kim, Tae Soo, Park, Kyu Hyun, Chung, Hyen Cheol, Rha, Sun Young
• Format: Article
• Language: English
• ISSN: 0008-5472; 1538-7445
• DOI: 10.1158/1538-7445.AM2015-4055

Advancing age is a high risk factor of cancer occurrence. Also, cancer incidence rate of elderly people have been increased. Accordingly, treatment of elderly patients with cancer is one of the important worldwide issues. Aging is associated with dysregulated immune response, immunosenescence. In this study, we investigated that immunosenescence in tumor-bearing xenograft model was related to change of T cell subsets. MC38 colon carcinoma cells were injected s.c. in 2 months (young adolescent), 6 months (adult) and 18 months (elderly) old C57/BL6 mice. After 8 days, 10mg/kg oxaliplatin administered 1 time by intraperitoneal (IP) injection and tumor volume measured. We divided 4 groups in each age group (2, 6 and 18-months-old), vehicle (PBS)-treated normal mice, oxaliplatin-treated normal mice, tumor-bearing mice, and oxalpilatin-treated tumor-bearing mice, in 7 mice of each aged groups (2, 6 and 18-months-old). On day 30, mice were sacrificed. Splenocytes were stained with anti- CD4+, CD8+, CD44+, CD62L+, CD27+, CD28+, PD-1+ and TIM3+ to measure specific molecule expression of CD4+ and CD8+ T cells in the spleen. First, we analyzed the CD4+ and CD8+ T cell population whether T cell character was changed based on Aging. In elderly mice, total number of T cells was 52±10% decline compared to 2-month-old mice (p