Chen Yuan, Fang Lei, Zhang Jiali, Li Gefei, Ma Mengni, Li Changxi, Lyu Jianxin, Meng Qing H
Key Laboratory of Laboratory Medicine, Ministry of Education of China, Zhejiang Provincial Key Laboratory of Medical Genetics, School of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou 325035, China.
Department of Laboratory Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.
Int J Mol Sci. 2017 Mar 9;18(3):570. doi: 10.3390/ijms18030570.
GlyoxalaseI (GLOI) is an enzyme that catalyzes methylglyoxal metabolism. Overexpression of GLOI has been documented in numerous tumor tissues, including colorectal cancer (CRC). The antitumor effects of GLOI depletion have been demonstrated in some types of cancer, but its role in CRC and the mechanisms underlying this activity remain largely unknown. Our purpose was to investigate the antitumor effects of depleted GLOI on CRC in vitro and in vivo. RNA interference was used to deplete GLOI activity in four CRC cell lines. The cells' proliferation, apoptosis, migration, and invasion were assessed by using the Cell Counting Kit-8, plate colony formation assay, flow cytometry, and transwell assays. Protein and mRNA levels were analyzed by western blot and quantitative real-time PCR (qRT-PCR), respectively. The antitumor effect of GLOI depletion in vivo was investigated in a SW620 xenograft tumor model in BALB/c nude mice. Our results show that GLOI is over-expressed in the CRC cell lines. GLOI depletion inhibited the proliferation, colony formation, migration, and invasion and induced apoptosis of all CRC cells compared with the controls. The levels of signal transducer and activator of transcription 1 (STAT1), p53, and Bcl-2 assaciated X protein (Bax) were upregulated by GLOI depletion, while cellular homologue of avian myelocytomatosis virus oncogene (c-Myc) and B cell lymphoma/lewkmia-2 (Bcl-2) were downregulated. Moreover, the growth of SW620-induced CRC tumors in BALB/c nude mice was significantly attenuated by GLOI depletion. The expression levels of STAT1, p53, and Bax were increased and those of c-Myc and Bcl-2 were decreased in the GLOI-depleted tumors. Our findings demonstrate that GLOI depletion has an antitumor effect through the STAT1 or p53 signaling pathways in CRC, suggesting that GLOI is a potential therapeutic target.
乙二醛酶I（GLOI）是一种催化甲基乙二醛代谢的酶。在包括结直肠癌（CRC）在内的众多肿瘤组织中，已证实存在GLOI的过表达。在某些类型的癌症中，已证明GLOI缺失具有抗肿瘤作用，但其在结直肠癌中的作用以及这种活性的潜在机制仍 largely 未知。我们的目的是研究GLOI缺失对结直肠癌在体外和体内的抗肿瘤作用。采用RNA干扰技术降低四种结直肠癌细胞系中的GLOI活性。使用细胞计数试剂盒-8、平板集落形成试验、流式细胞术和Transwell试验评估细胞的增殖、凋亡、迁移和侵袭。分别通过蛋白质印迹法和定量实时PCR（qRT-PCR）分析蛋白质和mRNA水平。在BALB/c裸鼠的SW620异种移植肿瘤模型中研究了GLOI缺失在体内的抗肿瘤作用。我们的结果表明，GLOI在结直肠癌细胞系中过表达。与对照组相比，GLOI缺失抑制了所有结直肠癌细胞的增殖、集落形成、迁移和侵袭，并诱导了细胞凋亡。信号转导和转录激活因子1（STAT1）、p53和Bcl-2相关X蛋白（Bax）的水平因GLOI缺失而上调，而禽成髓细胞瘤病毒癌基因细胞同源物（c-Myc）和B细胞淋巴瘤/白血病-2（Bcl-2）则下调。此外，GLOI缺失显著减弱了BALB/c裸鼠中SW620诱导的结直肠癌肿瘤的生长。在GLOI缺失的肿瘤中，STAT1、p53和Bax的表达水平升高，而c-Myc和Bcl-2的表达水平降低。我们的研究结果表明，GLOI缺失通过STAT1或p53信号通路在结直肠癌中发挥抗肿瘤作用，提示GLOI是一个潜在的治疗靶点。
