Department of Microbiology, Immunology, & Molecular Genetics, David Geffen School of Medicine at UCLA, Johnson Comprehensive Cancer Center, University of California at Los Angeles, Los Angeles, CA 90025-1747, USA.
Crit Rev Oncog. 2024;29(4):1-17. doi: 10.1615/CritRevOncog.2024053096.
Recent advancements in cancer treatment have explored a variety of approaches to address the needs of patients. Recently, immunotherapy has evolved as an efficacious treatment for various cancers resistant to conventional therapies. Hence, significant milestones in immunotherapy were achieved clinically in a large subset of cancer patients. Unfortunately, some cancer types do not respond to treatment, and among the responsive cancers, some patients remain unresponsive to treatment. Consequently, there is a critical need to examine the mechanisms of immune resistance and devise strategies to target immune suppressor cells or factors, thereby allowing for tumor sensitivity to immune cytotoxic cells. M2 macrophages, also known as tumor-associated macrophages (TAMs), are of interest due to their role in suppressing the immune system and influencing antitumor immune responses through modulating T cell activity and immune checkpoint expression. TAMs are associated with signaling pathways that modulate the tumor microenvironment (TME), contributing to immune evasion. One approach targets TAMs, focusing on preventing the polarization of M1 macrophages into the protumoral M2 phenotype. Other strategies focus on direct or indirect targeting of M2 macrophages through understanding the interaction of TAMs with immune factors or signaling pathways. Clinically, biomarkers associated with TAMs' immune resistance in cancer patients have been identified, opening avenues for intervention using pharmacological agents or immunotherapeutic approaches. Ultimately, these multifaceted approaches are promising in overcoming immune resistance and improving cancer treatment outcomes.
近年来,癌症治疗的进展探索了多种方法来满足患者的需求。最近,免疫疗法已成为一种针对各种对传统疗法有抗药性的癌症的有效治疗方法。因此,在很大一部分癌症患者中,免疫疗法在临床上取得了重大里程碑式的进展。不幸的是,有些癌症类型对治疗没有反应,而在有反应的癌症中,有些患者对治疗仍然没有反应。因此,迫切需要研究免疫抵抗的机制,并制定针对免疫抑制细胞或因子的策略,从而使肿瘤对免疫细胞毒性敏感。M2 巨噬细胞,也称为肿瘤相关巨噬细胞(TAMs),由于其在抑制免疫系统方面的作用以及通过调节 T 细胞活性和免疫检查点表达来影响抗肿瘤免疫反应而受到关注。TAMs 与调节肿瘤微环境(TME)的信号通路有关,有助于免疫逃逸。一种方法针对 TAMs,重点是防止 M1 巨噬细胞向促肿瘤的 M2 表型极化。其他策略则通过了解 TAMs 与免疫因子或信号通路的相互作用,专注于直接或间接靶向 M2 巨噬细胞。临床上,已经确定了与癌症患者 TAMs 免疫抵抗相关的生物标志物,为使用药物或免疫治疗方法进行干预开辟了途径。最终,这些多方面的方法有望克服免疫抵抗并改善癌症治疗结果。