Introduction

Immune checkpoint inhibitors that boost cytotoxic T cell-based immune responses have emerged as one of the most promising approaches in cancer treatment. However, it is increasingly being realized that T cell activation needs to be rationally combined with molecularly targeted therapeutics for a maximal anti-tumor outcome. Currently, two oncogenic drivers, MAPK and PI3K-mTOR have emerged as the two main molecular targets for combining with immunotherapy. However, there are major challenges in enabling such combinations: first, such combinations can result in high rates of toxicity. Second, while, these molecular targets could be driving tumor progression, they are essential for activation of the immune cells. So, the kinase inhibitors and immunotherapy can antagonize each other.

Objectives

We rationalized that the synergistic combination of kinase inhibitors and immunotherapy could be enabled by dual inhibitors-loaded supramolecular nanotherapeutics (DiLN) that can co-deliver PI3K- and MAPK-inhibitors to the cancer cells and activate immune response by T cell-modulating immunotherapy, resulting in greater anti-tumor efficacy while minimizing toxicity.

Methods

We engineered DiLNs by designing the amphiphilic building blocks (both drugs and co-lipids) that enables supramolecular nanoassembly. DiLNs were tested for their physiochemical properties including size, morphology, stability and drug release kinetics profiles. The efficacy of DiLNs was tested in drug-resistant cells such as BRAF^V600E melanoma (D4M), Clear cell ovarian carcinoma (TOV21G) cells. The tumor inhibition efficiency of DiLNs in combination with immune checkpoint inhibitor antibody was studied in syngeneic D4M animal model.

Results

DiLNs were stable for over a month and released the drugs in a sustained manner. In vitro cytotoxicity studies in D4M and TOV21G cells showed that DiLNs were significantly more effective than free drugs. In vivo studies showed that the combination of DiLNs with anti PD-L1 antibody resulted in superior antitumor effect and survival.

Conclusion

This study shows that the rational combination of DiLNs that target multiple oncogenic signaling pathways with immune checkpoint inhibitors could emerge as an effective strategy to improve immunotherapeutic response against drug resistant tumors.

中文翻译：

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靶向激酶信号通路的装载双抑制剂的纳米治疗药物与免疫检查点抑制剂协同作用。

介绍

增强基于细胞毒性 T 细胞的免疫反应的免疫检查点抑制剂已成为癌症治疗中最有希望的方法之一。然而，人们越来越意识到，T 细胞活化需要与分子靶向治疗合理结合，以获得最大的抗肿瘤效果。目前，两种致癌驱动因子 MAPK 和 PI3K-mTOR 已成为与免疫治疗相结合的两个主要分子靶点。然而，实现这种组合存在重大挑战：首先，这种组合可能导致高毒性率。其次，虽然这些分子靶点可能会推动肿瘤进展，但它们对于激活免疫细胞至关重要。因此，激酶抑制剂和免疫疗法可以相互拮抗。

目标

我们合理化了激酶抑制剂和免疫疗法的协同组合可以通过负载双重抑制剂的超分子纳米疗法 (DiLN) 实现，该药物可以将 PI3K 和 MAPK 抑制剂共同递送至癌细胞并通过 T 细胞调节免疫疗法激活免疫反应，导致更大的抗肿瘤功效，同时将毒性降至最低。

方法

我们通过设计能够实现超分子纳米组装的两亲性构件（药物和共脂质）来设计 DiLN。对 DiLNs 的物理化学性质进行了测试，包括大小、形态、稳定性和药物释放动力学曲线。DiLNs 的功效在耐药细胞中进行了测试，例如 BRAF ^V600E黑色素瘤 (D4M)、透明细胞卵巢癌 (TOV21G) 细胞。在同系D4M动物模型中研究了DiLNs与免疫检查点抑制剂抗体联合的抑癌效果。

结果

DiLNs 稳定了一个多月，并以持续的方式释放药物。D4M 和 TOV21G 细胞的体外细胞毒性研究表明，DiLNs 比游离药物更有效。体内研究表明，DiLNs 与抗 PD-L1 抗体的组合具有优异的抗肿瘤效果和存活率。

结论

该研究表明，靶向多种致癌信号通路的 DiLNs 与免疫检查点抑制剂的合理组合可能成为改善对耐药肿瘤的免疫治疗反应的有效策略。