J Cancer 2017; 8(18):3803-3811. doi:10.7150/jca.21228

Research Paper

LncRNA MALAT1 Inhibits Apoptosis and Promotes Invasion by Antagonizing miR-125b in Bladder Cancer Cells

Haibiao Xie1, 2*, Xinhui Liao1, 3*, Zhicong Chen1, 2*, Yuan Fang1, Anbang He1, Yucheng Zhong1, Qunjun Gao1, Huizhong Xiao1, Jianfa Li1, 2, 4✉, Weiren Huang1✉, Yuchen Liu1, 2✉

1. Key Laboratory of Medical Reprogramming Technology, Department of Urology, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen 518039, Guangdong Province, China;
2. Shantou University Medical College, Shantou 515041, Guangdong Province, China;
3. Department of Urology, Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Shenzhen 518039, Guangdong Province, China;
4. Guangdong and Shenzhen Key Laboratory of Male Reproductive Medicine and Genetics, Institute of Urology, Peking University Shenzhen Hospital, Peking University, Shenzhen 518036, China.
* Equal contributors

Abstract

Accumulating evidences suggest that longnon-coding RNAs (lncRNAs) play functional roles in development of different cancers, including cancer initiation and progression. Metastasis associated lung adenocarcinoma transcript 1(MALAT1) is a well-known lncRNA which was previously shown to be a direct target of miR-125b in bladder cancer (BCa) and to promote cancer progression and invasion. However, little is known whether MALAT1 can also target miR-125b. In the present study, using CRISPR-based technologies and qRT-PCR, we show that MALAT1 is capable of suppressing mature miR-125b and increasing the expression of its target genes (Bcl-2 and MMP-13), but has no effect on pri-miR-125b and pre-miR-125b. We observe that the biotin-labeled MALAT1-RNA probe is able to pull down Ago2 and miR-125b and that the negative regulation of miR-125b by MALAT1 is dependent on Ago2. Importantly, the results of flow cytometry assay and transwell assay reveal that the MALAT1-mediated cancer progression is in part due to specific suppression of miR-125b and activation of its two target genes. All together, these data suggest that the “MALAT1-miR-125b-Bcl-2 / MMP-13” axis plays an important role in the progression of BCa, thereby may provide a potential therapeutic strategy for the treatment of human BCa.

Keywords: MALAT1, miR-125b, Ago-2, bladder cancer, CRISPR-based technology.

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How to cite this article:
Xie H, Liao X, Chen Z, Fang Y, He A, Zhong Y, Gao Q, Xiao H, Li J, Huang W, Liu Y. LncRNA MALAT1 Inhibits Apoptosis and Promotes Invasion by Antagonizing miR-125b in Bladder Cancer Cells. J Cancer 2017; 8(18):3803-3811. doi:10.7150/jca.21228. Available from http://www.jcancer.org/v08p3803.htm