KLF13 suppresses the proliferation and growth of colorectal cancer cells through transcriptionally inhibiting HMGCS1-mediated cholesterol biosynthesis
KLF13 suppresses the proliferation and growth of colorectal cancer cells through transcriptionally inhibiting HMGCS1-mediated cholesterol biosynthesis
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KLF13 通过转录抑制 HMGCS1 介导的胆固醇生物合成来抑制结直肠癌细胞的增殖和生长
DOI：
10.1186/s13578-020-00440-0
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发表时间：
2020-06-08
影响因子：
7.5
通讯作者：
Luo, Xiaoya
中科院分区：
文献类型：
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作者：
Yao, Weilong;Jiao, Yue;Luo, Xiaoya
结直肠癌（CRC）是世界上第四大最致命的恶性肿瘤。大量研究表明，kruppel样因子（KLFs）在癌症发展中起着至关重要的作用。然而，KLF13在结直肠癌中的作用尚不清楚。方法应用Cancer Genome Atlas数据库分析KLF13在结直肠癌和正常组织中的表达。用慢病毒系统过表达和敲低KLF13。RT-qPCR和Western blot检测mRNA和蛋白的表达。通过CCK-8、集落形成、细胞周期分析和EdU染色来评估KLF13在结直肠癌细胞中的体外功能。采用异种移植肿瘤生长来评估KLF13在结直肠癌中的体内作用。采用指定试剂盒测定胆固醇含量。荧光素酶活性测定分析转录活性。通过ChIP-qPCR检测KLF13与HMGCS1启动子的相互作用。结果TCGA数据库、RT-qPCR和Western blot结果显示，KLF13在结直肠癌组织中表达下调。与正常结直肠癌细胞NCM460相比，结直肠癌细胞HT-26、HCT116和SW480的KLF13表达降低。功能实验表明，敲低KLF13可促进HT-29和HCT116细胞的增殖和集落形成。在KLF13过表达的细胞中观察到相反的结果。此外，KLF13过表达导致裸鼠HCT116细胞周期阻滞在G0/G1期，减少EdU的掺入，抑制肿瘤生长。在机制上，KLF13转录抑制HMGCS1和胆固醇的生物合成。HMGCS1的下调抑制了胆固醇的生物合成和KLF13沉默的结直肠癌细胞的增殖。此外，胆固醇生物合成抑制剂显著延缓了两种细胞的集落生长。结论本研究表明，KLF13通过负向调节hmgcs1介导的胆固醇生物合成在结直肠癌中发挥抑瘤作用。
Background Colorectal cancer (CRC) is the fourth most deadly malignancy throughout the world. Extensive studies have shown that Kruppel-like factors (KLFs) play essential roles in cancer development. However, the function of KLF13 in CRC is unclear. Methods The Cancer Genome Atlas database was applied to analyze the expression of KLF13 in CRC and normal tissues. Lentivirus system was used to overexpress and to knock down KLF13. RT-qPCR and Western blot assays were performed to detect mRNA and protein expression. CCK-8, colony formation, cell cycle analysis and EdU staining were used to assess the in vitro function of KLF13 in CRC cells. Xenografter tumor growth was used to evaluate the in vivo effect of KLF13 in CRC. Cholesterol content was measured by indicated kit. Transcription activity was analyzed by luciferase activity measurement. ChIP-qPCR assay was performed to assess the interaction of KLF13 to HMGCS1 promoter. Results KLF13 was downregulated in CRC tissues based on the TCGA database and our RT-qPCR and Western blot results. Comparing with normal colorectal cells NCM460, the CRC cells HT-26, HCT116 and SW480 had reduced KLF13 expression. Functional experiments showed that KLF13 knockdown enhanced the proliferation and colony formation in HT-29 and HCT116 cells. Opposite results were observed in KLF13 overexpressed cells. Furthermore, KLF13 overexpression resulted in cell cycle arrest at G0/G1 phase, reduced EdU incorporation and suppressed tumor growth of HCT116 cells in nude mice. Mechanistically, KLF13 transcriptionally inhibited HMGCS1 and the cholesterol biosynthesis. Knockdown of HMGCS1 suppressed cholesterol biosynthesis and the proliferation of CRC cells with silenced KLF13. Furthermore, cholesterol biosynthesis inhibitor significantly retarded the colony growth in both cells. Conclusions Our study reveals that KLF13 acts as a tumor suppressor in CRC through negatively regulating HMGCS1-mediated cholesterol biosynthesis.