CEA-targeted CAR-NK cells derived from embryonic stem cells exhibit potent anti-tumor activity against colorectal...

Carcinoembryonic antigen (CEA) is overexpressed in most colorectal cancers (CRC) and serves as a promising immunotherapeutic target. However, current immune cell therapies against CRC show limited clinical efficacy, and the lack of renewable, standardized cell sources hampers broader application. The present study aimed to establish a scalable source of CEA-targeted natural killer (NK) cells from engineered human embryonic stem cells (hESCs).

hESCs were genetically engineered to express a CEA‑specific chimeric antigen receptor (CAR). The modified hESCs were subsequently differentiated into NK cells, yielding a homogeneous population of CAR hESC-NK cells. In vitro cytotoxicity against CEA-high CRC cell lines was evaluated using LDH and IFN-γ release assays. For in vivo assessment, we established a xenograft mouse model bearing CEA-positive CRC tumors. Following adoptive transfer of CAR-hESC-NK cells, tumor growth was monitored by bioluminescence imaging, overall survival was recorded for Kaplan-Meier analysis, and the persistence of transferred cells in peripheral blood was examined by flow cytometric analysis at serial time points.

In vitro, CAR hESC‑NK cells demonstrated potent and specific cytotoxicity against CEA-high CRC cell lines, along with significantly enhanced cytokine secretion compared to unmodified NK cells. In the xenograft model, adoptive transfer of CAR hESC‑NK cells resulted in marked tumor growth inhibition and prolonged survival, with no observable off‑target toxicity. Importantly, the CAR CEA‑ESC line maintained stable transgene expression and could serve as a renewable seed cell source.

We have established a scalable platform for producing CEA‑targeted NK cells from engineered hESCs, providing an off‑the‑shelf, homogeneous cell product with robust antitumor activity. This strategy provides effective and specific immunotherapy against CEA-positive colorectal cancer and holds potential for other CEA-expressing malignancies.