Knockdown of B2M contributes to resistance to PD-L1 inhibitors by suppressing breast cancer cells proliferation and immune response

Our findings demonstrated that B2M KD in 4T1 cells led to reduced proliferation, accompanied by enhanced apoptosis. Notably, B2M KD in 4T1 cells resulted in decreased levels of PD-L1. PD-L1 enhanced 4T1 cells proliferation, invasion, and migration while inhibiting apoptosis, similar to the functions of B2M gene.

Interestingly, our vivo experiments revealed that B2M KD mice groups exhibited suppressed tumor weight and volume, and ineffectiveness upon PD-L1 inhibitors treatment.Conclusion Our study revealed that B2M gene knockdown may impair breast cancer cell proliferation and confer resistance to PD-L1 inhibitors by decreasing both immune cell recruitment and PD-L1 expression, thereby providing a novel insight for clinical therapy of breast cancer.