KRAS mutant (KRAS^mut) lung adenocarcinoma is a refractory cancer without available targeted therapy. The current study explored the possibility to develop coxsackievirus type B3 (CVB3) as an oncolytic agent for the treatment of KRAS^mut lung adenocarcinoma. In cultured cells, we discovered that CVB3 selectively infects and lyses KRAS^mut lung adenocarcinoma cells (A549, H2030, and H23), while sparing normal lung epithelial cells (primary, BEAS2B, HPL1D, and 1HAEo) and EGFR^mut lung adenocarcinoma cells (HCC4006, PC9, H3255, and H1975). Using stable cells expressing a single driver mutation of either KRAS^G12V or EGFR^L858R in normal lung epithelial cells (HPL1D), we further showed that CVB3 specifically kills HPL1D-KRAS^G12V cells with minimal harm to HPL1D-EGFR^L858R and control cells. Mechanistically, we demonstrated that aberrant activation of extracellular signal-regulated kinase 1/2 (ERK1/2) and compromised type I interferon immune response in KRAS^mut lung adenocarcinoma cells serve as key factors contributing to the sensitivity to CVB3-induced cytotoxicity. Lastly, we conducted in vivo xenograft studies using two immunocompromised mouse models. Our results revealed that intratumoral injection of CVB3 results in a marked tumor regression of KRAS^mut lung adenocarcinoma in both non-obese diabetic (NOD) severe combined immunodeficiency (SCID) gamma (NSG) and NOD-SCID xenograft models. Together, our findings suggest that CVB3 is an excellent candidate to be further developed as a targeted therapy for KRAS^mut lung adenocarcinoma.

KRAS突变（KRAS ^mut）肺腺癌是一种难治性癌症，没有有效的靶向治疗方法。当前的研究探索了开发B3型柯萨奇病毒（CVB3）作为治疗KRAS ^mut肺腺癌的溶瘤剂的可能性。在培养的细胞中，我们发现CVB3选择性感染并裂解KRAS ^mut肺腺癌细胞（A549，H2030和H23），而保留正常的肺上皮细胞（原代，BEAS2B，HPL1D和1HAEo）和EGFR ^mut肺腺癌细胞（HCC4006） ，PC9，H3255和H1975）。使用表达KRAS ^G12V或EGFR的单个驱动程序突变的稳定细胞在正常肺上皮细胞（HPL1D）中使用^L858R，我们进一步显示CVB3特异性杀伤HPL1D- KRAS ^G12V细胞，对HPL1D- EGFR ^L858R和对照细胞的伤害最小。从机制上讲，我们证明了KRAS ^mut肺腺癌细胞中细胞外信号调节激酶1/2（ERK1 / 2）异常激活和I型干扰素免疫应答受损是导致CVB3诱导的细胞毒性敏感性的关键因素。最后，我们使用两种免疫功能低下的小鼠模型进行了体内异种移植研究。我们的结果表明，瘤内注射CVB3导致KRAS ^mut明显消退非肥胖糖尿病（NOD）严重联合免疫缺陷（SCID）γ（NSG）和NOD-SCID异种移植模型中的肺腺癌。总之，我们的发现表明CVB3是作为KRAS ^mut肺腺癌的靶向疗法而进一步开发的优秀候选者。