Wang Huipeng, Ye Tao, Cai Yuankun, Chen Wenjie, Xie Hongwei, Ke Chongwei
Department of General Surgery, The Fifth People's Hospital of Shanghai, Fudan University, Shanghai, China.
J Gastrointest Oncol. 2021 Apr;12(2):630-638. doi: 10.21037/jgo-21-183.
Colorectal cancer (CRC) is the third most common cancer, according to recently published literature. While the incidence and the mortality of CRC has decreased due to effective cancer screening measures, there has been an increase in the number of young patients diagnosed with colon cancer due to unclear reasons. As a target molecule of the Wnt signaling pathway, Ascl2 is an important marker of CRC stem cells and plays an important role in maintaining the nature of colon cancer stem/precursor cells. However, the role of Ascl2 in autophagy in CRC cells is rarely elucidated.
In this study, we found that Ascl2 was increased in CRC compared with adjacent tissue. Downregulation of Ascl2 in CRC cells could suppress proliferation and invasion, and induce apoptosis, of CRC cells. Moreover, we found that autophagy-relative protein LC3 increased after Ascl2 knockdown. Furthermore, we treated CRC cells with autophagy inhibitors 3-MA (3-Methyladenine) and CQ (Chloroquine).
The results showed that autophagy inhibitors could prevent apoptosis, which was induced by Ascl2 knockdown. Finally, we confirmed that the downregulation of Ascl2 in CRC cells could alleviate the pathological process by xenograft experiment.
Our findings indicated that si-Ascl2 (small/short interfering) exerted a tumor suppression function in CRC by inducing autophagic cell death, and suggest that Ascl2 targeted therapy represents a novel strategy for CRC treatment.
根据最近发表的文献,结直肠癌(CRC)是第三大常见癌症。虽然由于有效的癌症筛查措施,CRC的发病率和死亡率有所下降,但原因不明的是,被诊断为结肠癌的年轻患者数量有所增加。作为Wnt信号通路的靶分子,Ascl2是CRC干细胞的重要标志物,在维持结肠癌干细胞/前体细胞的特性中发挥重要作用。然而,Ascl2在CRC细胞自噬中的作用鲜有阐述。
在本研究中,我们发现与相邻组织相比,Ascl2在CRC中表达增加。CRC细胞中Ascl2的下调可抑制CRC细胞的增殖和侵袭,并诱导其凋亡。此外,我们发现Ascl2敲低后自噬相关蛋白LC3增加。此外,我们用自噬抑制剂3-MA(3-甲基腺嘌呤)和CQ(氯喹)处理CRC细胞。
结果表明,自噬抑制剂可阻止Ascl2敲低诱导的凋亡。最后,我们通过异种移植实验证实,CRC细胞中Ascl2的下调可减轻病理过程。
我们的研究结果表明,si-Ascl2(小干扰RNA)通过诱导自噬性细胞死亡在CRC中发挥肿瘤抑制功能,并表明Ascl2靶向治疗是一种新的CRC治疗策略。