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

The expression of CEACAM1 on tumor cells has been implicated as a prognostic factor while different associations have been observed depending on tumor types and the stage of the cancer. Stable expression of CEACAM1 on melanoma cells enhanced invasion and migration of the cells in vitro [9] Reduced expression of CEACAM1 was reported upon malignant transformation in mice [10] and in samples of human colorectal cancer [11] . Similarly, CEACAM1 expression inversely correlated with survival of breast cancer patients [8] . Frequent loss of CEACAM1 in benign and malignant colorectal neoplasias was also reported [7] . Additionally, Thom et al., found a significant positive correlation between CEACAM-1 expression on primary tumor lymph nodes and metastases [12] . Furthermore, expression of CEACAM1 on primary cutaneous melanoma lesions was linked to the development of metastatic disease and poor prognosis [13] . Thus, the biology of CEACAM1 appears complex, with disparate pathophysiological effects manifested in a context-dependent manner.