MiR-552-3p promotes malignant progression of gallbladder carcinoma by reactivating the Akt/β-catenin signaling pathway due to inhibition of the tumor suppressor gene RGMA.

Abstract

BACKGROUND:

Gallbladder carcinoma (GBC) remains a highly lethal disease worldwide. MiR-552 family members promote the malignant progression of a variety of digestive system tumors, but the role of miR-552-3p in GBC has not been elucidated. miR-552-3p was predicted to target the 3'-untranslated region (3'UTR) of the mRNA for the tumor suppressor gene "repulsive guidance molecule BMP co-receptor a" (RGMA). The aim of the present study was to clarify the roles and mechanisms of miR-552-3p targeting RGMA in the malignant progression of GBC.

METHODS:

In vitro: expression of miR-552-3p was detected by real-time quantitative PCR (qRT-PCR) in tumor and non-tumor adjacent tissues (NATs). Lentivirus-miR-552-3p was employed to knockdown this miRNA in GBC cell lines. Stem cell-related transcription factors and markers were assessed by qRT-PCR. Cell Counting Kit-8 (CCK-8), sphere formation and transwell assays were used to determine the malignant phenotypes of GBC cells. Targeting the 3'UTR of RGMA by miR-552-3p was verified by integrated analysis including bioinformatics prediction, luciferase assays, measures of changes of gene expression and rescue experiments. In vivo: mouse models of subcutaneous tumors and lung metastases were established to observe the effect of miR-552-3p on tumorigenesis and organ metastasis, respectively.

RESULTS:

MiR-552-3p was abnormally highly expressed in GBC tissues and cancer stem cells. Interference with miR-552-3p in SGC-996 and GBC-SD cells significantly inhibited GBC stem cell expansion. Reciprocally, miR-552-3p promoted GBC cell proliferation, migration and invasion both in vitro and in vivo; hence, interference with this miRNA impeded the malignant progression of GBC. Furthermore, the important tumor suppressor gene RGMA was identified as a target of miR-552-3p. The effects of miR-552-3p on cell proliferation and metastasis were abrogated or enhanced by gain or loss of RGMA function, respectively. Mechanistically, miR-552-3p promoted GBC progression by reactivating the Akt/β-catenin pathway and epithelial-mesenchymal transformation (EMT). Clinically, miR-552-3p correlated with multi-malignant characteristics of GBC and acted as a prognostic marker for GBC outcome.

CONCLUSIONS:

MiR-552-3p promotes the malignant progression of GBC by inhibiting the mRNA of the tumor suppressor gene RGMA, resulting in reactivation of the Akt/β-catenin signaling pathway.

• Authors: Fengliang Song, Zhao Yang, Liang Li, Yanping Wei, Xuewu Tang, Shuowu Liu, Miao Yu, Jin Chen, Suyang Wang, Jingbo Fu, Kecheng Zhang, Pinghua Yang, Xinwei Yang, Zhong Chen, Baohua Zhang, Hongyang Wang
• Journal: Annals of translational medicine (Ann Transl Med) Vol. 9 Issue 17 Pg. 1374 (Sep 2021) ISSN: 2305-5839 [Print] China
• PMID: 34733926 (Publication Type: Journal Article)
• Copyright: 2021 Annals of Translational Medicine. All rights reserved.