Lung cancer is the cancer with the highest mortality in the world. So further exploration of the pathogenesis of lung cancer is of great significance. In this study, the specific role and related mechanism of CRIF1 in non-small cell lung cancer (NSCLC) were explored in this research. TheRT-PCR, western blot and IHC assays were used to examine the expression level of CRIF1 in NSCLC tissue, tissue adjacent to carcinoma, NSCLC cell lines and human normal lung epithelial cells. Next, colony formation assay, Alamar blue Kit and EdU assays were employed to examine the proliferation of transfected A549 and NCI-H2009 cells. Measurement of mitochondrial permeability transition pore opening, ATP production and cellular oxygen consumption were used to evaluate the mitochondrial apoptosis of transfected NSCLC cells. Enzymatic activity assays for PYCR1, western blot and flow cytometry assays were used to explore the relationship between PYCR1 and CRIF1. The subcutaneous xenograft tumor mice model was established to explore the role of CRIF1 in vivo. Collectively, results revealed that CRIF1 was upregulated in NSCLC cells and tissues (p < 0.001). CRIF1 promoted proliferation of NSCLC cells (p < 0.001). CRIF1 inhibited mitochondrial apoptosis in NSCLC cells (p < 0.05). Moreover, CRIF1 promoted PYCR1 deacetylation and increased its activity through SIRT3 (p < 0.05). Deacetylation of PYCR1 reversed the antitumor effect of CRIF1 knockdown (p < 0.05). Finally, knockdown of CRIF1 inhibited the tumor growth of NSCLC in vivo (p < 0.05).This research found that CRIF1 promoted the progression of non-small-cell lung cancer by SIRT3- mediated deacetylation of PYCR1.

肺癌是世界上死亡率最高的癌症。因此进一步探讨肺癌的发病机制具有重要意义。本研究旨在探讨CRIF1在非小细胞肺癌（NSCLC）中的具体作用及相关机制。采用RT-PCR、Western blot和IHC法检测CRIF1在NSCLC组织、癌旁组织、NSCLC细胞系和人正常肺上皮细胞中的表达水平。接下来，采用集落形成测定、Alamar blue Kit和EdU测定来检查转染的A549和NCI-H2009细胞的增殖。测量线粒体通透性转换孔开放、ATP 产生和细胞耗氧量来评估转染 NSCLC 细胞的线粒体凋亡。使用PYCR1的酶活性测定、蛋白质印迹和流式细胞术测定来探讨PYCR1和CRIF1之间的关系。建立皮下移植瘤小鼠模型以探讨CRIF1在体内的作用。总的来说，结果显示 CRIF1 在 NSCLC 细胞和组织中表达上调 (p < 0.001)。 CRIF1 促进 NSCLC 细胞增殖 (p < 0.001)。 CRIF1 抑制 NSCLC 细胞中的线粒体凋亡 (p < 0.05)。此外，CRIF1 促进 PYCR1 脱乙酰化并通过 SIRT3 增加其活性 (p < 0.05)。 PYCR1 的去乙酰化逆转了 CRIF1 敲低的抗肿瘤作用 (p < 0.05)。最后，敲低CRIF1可抑制体内NSCLC的肿瘤生长（p < 0.05）。本研究发现CRIF1通过SIRT3介导的PYCR1去乙酰化促进非小细胞肺癌的进展。