Human ROR1 Stable Cell Line - CT26

Cancer is one of the leading causes of morbidity and mortality worldwide, with an estimated 19.3 million new cases and nearly 10 million cancer deaths in 2020.ROR1 is a tumor-associated antigen that is overexpressed in a wide range of malignancies. In this study, researchers designed and produced different murine ROR1 fusion proteins to enhance the immunogenicity and protective potency of ROR1. These fusion proteins contained the extracellular region of murine ROR1, an immunogenic fragment of tetanus toxin (TT), and the Fc region of murine IgG2a. The researchers used these fusion proteins to immunize Balb/C mice and evaluated the humoral and cellular immune responses and anti-tumor effects of these fusion proteins in two different syngeneic mouse ROR1+ tumor models. The results showed that all immunized groups of mice produced ROR1-specific antibodies, and in particular, mice immunized with the TT-mROR1-Fc fusion proteins had significantly higher levels of IFN-γ, IL-17, and IL-22 cytokines and a higher frequency of ROR1-specific CTLs. Ultimately, tumor challenge results in immunized mice showed that immunization with the TT-mROR1-Fc fusion protein completely inhibited the growth of ROR1+ tumor cells in both syngeneic tumor models until day 120 post-tumor challenge. These preclinical studies demonstrate for the first time these fusion proteins as potential vaccine candidates for active immunotherapy of ROR1-expressing malignancies.

Figure 1. The researchers used the Balb/C mouse model to study the role of the Human ROR1 stable cell line-CT26 in an in vivo tumor protection assay. Two weeks after immunization, the researchers tumor-challenged the mice with CT26-ROR1+ and 4T1-ROR1+ tumor cells. They then analyzed immunosuppressive cell populations in splenocytes by flow cytometry and measured tumor volume to assess immune response and survival. These approaches revealed the potential of CT26-ROR1+ in immunotherapy. (Hassannia H, et al., 2022)