Immunotherapy is a promising approach for specific targeting of cancer cells. Leukemia inhibitory factor (LIF) regulates several features of cancers and cancer stem cells (CSCs) through binding to LIF receptor (LIFR). In this study, we investigated the consensus of LIF and LIFR immunization on the growth of mouse mammary tumors. For this purpose, mouse LIF and LIFR were designed as truncated proteins, expressed in E. coli and then injected to mice as individual and mixed antigens. The results showed the production of neutralizing antibodies and secretion of interferon-γ and interleukin-2 in response to immunization. In continue, the immunized mice were subjected for tumor formation challenge by inoculation of the breast CSCs derived from MC4-L2 cells. Development of the breast tumors was observed in all the control mice, while the tumors appeared in 75% of animals in the LIF group. LIFR injection, individually or in combination with LIF, strongly inhibited the tumor growth to only 25% of the mice. Moreover, a delay in tumor appearance was observed in the immunized mice compared to the controls. Immunostaining of the tumor sections confirmed the expression of LIF and LIFR. In conclusion, LIF and LIFR might be effective targets for immunotherapy of the tumors that express these proteins.

免疫疗法是一种有前途的特异性靶向癌细胞的方法。白血病抑制因子 (LIF) 通过与 LIF 受体 (LIFR) 结合来调节癌症和癌症干细胞 (CSC) 的多种特征。在本研究中，我们研究了 LIF 和 LIFR 免疫对小鼠乳腺肿瘤生长的一致性。为此，小鼠 LIF 和 LIFR 被设计为截短蛋白，在大肠杆菌中表达，然后作为个体和混合抗原注射到小鼠体内。结果显示，免疫反应会产生中和抗体，并分泌干扰素-γ和白细胞介素-2。接下来，通过接种源自MC4-L2细胞的乳腺CSC，对免疫小鼠进行肿瘤形成攻击。在所有对照小鼠中均观察到乳腺肿瘤的形成，而 LIF 组中 75% 的动物出现了肿瘤。 LIFR 单独注射或与 LIF 联合注射，仅对 25% 的小鼠产生了强烈的肿瘤生长抑制作用。此外，与对照组相比，免疫小鼠的肿瘤出现延迟。肿瘤切片的免疫染色证实了LIF和LIFR的表达。总之，LIF 和 LIFR 可能是表达这些蛋白的肿瘤免疫治疗的有效靶点。