Down-regulation of long non-coding RNA DUXAP8 suppresses proliferation, metastasis and EMT by modulating miR-498 through TRIM44-mediated AKT/mTOR pathway in non-small-cell lung cancer

Eur Rev Med Pharmacol Sci. 2020 Mar;24(6):3152-3165. doi: 10.26355/eurrev_202003_20682.

Abstract

Objective: The long non-coding RNA double homeobox A pseudogene 8 (DUXAP8) was reported to be involved in the initiation and development of multiple cancers. However, the detailed biological role of DUXAP8 in non-small-cell lung cancer (NSCLC) remains unclear. Herein, we aimed to explore the biological function and molecular mechanism of DUXAP8 in NSCLC.

Patients and methods: The levels of DUXAP8, microRNA-498 (miR-498) and tripartite motif-44 (TRIM44) were detected by Quantitative Real-time polymerase chain reaction (qRT-PCR). The cell proliferation, migration and invasion were detected by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and transwell assays. Protein expression levels were detected by Western blot. The target relationships among DUXAP8, miR-498 and TRIM44 were predicted by starBase2.0 and confirmed using luciferase reporter and RNA pull-down assays. To detect the role of DUXAP8 in vivo, tumor xenografts were created.

Results: DUXAP8 and TRIM44 were upregulated in NSCLC tissues and cell lines, while miR-498 was downregulated. Functionally, knockdown of DUXAP8 could repress proliferation, migration, invasion, Epithelial-Mesenchymal Transition (EMT) and phosphorylation of AKT/mTOR in NSCLC cells. This inhibition could be restored by inhibiting miR-498 or overexpressing TRIM44. Furthermore, we also observed a positive correlation between DUXAP8 and TRIM44 expression, while the expressions of miR-498 and DUXAP8, as well as miR-498 and TRIM44, were negatively correlated in NSCLC tissues. Importantly, DUXAP8 could regulate the expression of TRIM44 via miR-498. Moreover, knockdown of DUXAP8 notably decreased the xenograft tumor volume, weight and number of metastatic nodules in vivo.

Conclusions: Our results identified that LncRNA DUXAP8 could regulate cell proliferation, metastasis and EMT in NSCLC cells by inhibiting miR-498 through the activation of TRIM44-mediated AKT/mTOR pathway.

MeSH terms

  • Carcinoma, Non-Small-Cell Lung / metabolism*
  • Carcinoma, Non-Small-Cell Lung / pathology
  • Cell Proliferation
  • Cells, Cultured
  • Down-Regulation
  • Epithelial-Mesenchymal Transition
  • Humans
  • Intracellular Signaling Peptides and Proteins / metabolism*
  • Lung Neoplasms / metabolism*
  • Lung Neoplasms / pathology
  • MicroRNAs / genetics
  • MicroRNAs / metabolism*
  • Proto-Oncogene Proteins c-akt / metabolism*
  • RNA, Long Noncoding / genetics
  • RNA, Long Noncoding / metabolism*
  • TOR Serine-Threonine Kinases / metabolism*
  • Tripartite Motif Proteins / metabolism*

Substances

  • Intracellular Signaling Peptides and Proteins
  • MIRN498 microRNA, human
  • MicroRNAs
  • RNA, Long Noncoding
  • TRIM44 protein, human
  • Tripartite Motif Proteins
  • MTOR protein, human
  • TOR Serine-Threonine Kinases
  • Proto-Oncogene Proteins c-akt