We recently discovered that coxsackievirus B3 (CVB3) is a potent oncolytic virus against KRAS mutant lung adenocarcinoma. Nevertheless, the evident toxicity restricts the use of wild-type (WT)-CVB3 for cancer therapy. The current study aims to engineer the CVB3 to decrease its toxicity and to extend our previous research to determine its safety and efficacy in treating TP53/RB1 mutant small-cell lung cancer (SCLC). A microRNA-modified CVB3 (miR-CVB3) was generated via inserting multiple copies of tumor-suppressive miR-145/miR-143 target sequences into the viral genome. In vitro experiments revealed that miR-CVB3 retained the ability to infect and lyse KRAS mutant lung adenocarcinoma and TP53/RB1-mutant SCLC cells, but with a markedly reduced cytotoxicity toward cardiomyocytes. In vivo study using a TP53/RB1-mutant SCLC xenograft model demonstrated that a single dose of miR-CVB3 via systemic administration resulted in a significant tumor regression. Most strikingly, mice treated with miR-CVB3 exhibited greatly attenuated cardiotoxicities and decreased viral titers compared to WT-CVB3-treated mice. Collectively, we generated a recombinant CVB3 that is powerful in destroying both KRAS mutant lung adenocarcinoma and TP53/RB1-mutant SCLC, with a negligible toxicity toward normal tissues. Future investigation is needed to address the issue of genome instability of miR-CVB3, which was observed in ~40% of mice after a prolonged treatment.

我们最近发现，柯萨奇病毒B3（CVB3）是针对KRAS突变型肺腺癌的有效溶瘤病毒。然而，明显的毒性限制了野生型（WT）-CVB3在癌症治疗中的使用。本研究旨在改造CVB3，以降低其毒性，并扩展我们先前的研究，以确定其在治疗TP53 / RB1突变型小细胞肺癌（SCLC）中的安全性和有效性。通过将肿瘤抑制性miR-145 / miR-143靶序列的多个副本插入病毒基因组中，生成了经microRNA修饰的CVB3（miR-CVB3）。体外实验表明，miR-CVB3保留了感染和裂解KRAS突变型肺腺癌和TP53的能力。/ RB1-突变型SCLC细胞，但对心肌细胞的细胞毒性明显降低。使用TP53 / RB1-突变体SCLC异种移植模型进行的体内研究表明，单剂量的miR-CVB3通过全身给药导致明显的肿瘤消退。最引人注目的是，与WT-CVB3处理的小鼠相比，用miR-CVB3处理的小鼠表现出极大的心脏毒性减弱和病毒滴度降低。我们共同产生了一个重组CVB3，该重组CVB3在破坏KRAS突变型肺腺癌和TP53 / RB1-方面均具有强大的作用。突变SCLC，对正常组织的毒性可忽略不计。需要进一步的研究来解决miR-CVB3基因组不稳定性的问题，长时间治疗后在约40％的小鼠中观察到了这一问题。