Characterization of murine CEACAM1 in vivo reveals low expression on CD8(+) T cells and no tumor growth modulating activity by anti-CEACAM1 mAb CC1

McLeod, Robbie L.; Angagaw, Minilik H.; Baral, Toya Nath; Liu, Liming; Moniz, Raymond Joseph; Laskey, Jason; Hsieh, SuChun; Lee, Mike; Han, Jin-Hwan; Issafras, Hassan; Javaid, Sarah; Loboda, Andrey; Sadekova, Svetlana; O'Connor, Joann A.; Tse, Archie; Punnonen, Juha

Early experiments investigating CEACAM1 in tumorigenesis denoted a pivotal role for CEACAM1 as a tumor suppressor. For example, prostate cancer cell line PC-3 transfected with CEACAM-1 demonstrated significantly lower growth rates and less tumorigenicity in vivo relative to controls [6] . Nittka et al. found that the Research Paper www.oncotarget.com absence of CEACAM1 on hyperplastic tumors correlated with reduced apoptosis of malignant cells [7] . Moreover, a lack of CEACAM1 in WAP-T tumor cells resulted in increased Wnt signaling, promoted cellular invasiveness, and strongly enhanced the rate of metastasis of mammary adenocarcinomas in vivo [8] . On the other hand, other investigations have suggested a role for CEACAM1 in angiogenesis and suppression of the neoantigen-specific anti-tumor response [3] .