Skip to main content
main-content

01.12.2018 | Research | Ausgabe 1/2018 Open Access

Molecular Cancer 1/2018

STAT3-induced lncRNA HAGLROS overexpression contributes to the malignant progression of gastric cancer cells via mTOR signal-mediated inhibition of autophagy

Zeitschrift:
Molecular Cancer > Ausgabe 1/2018
Autoren:
Jin-Fei Chen, Peng Wu, Rui Xia, Jian Yang, Xin-Ying Huo, Dong-Ying Gu, Cui-Ju Tang, Wei De, Fen Yang
Wichtige Hinweise

Electronic supplementary material

The online version of this article (https://​doi.​org/​10.​1186/​s12943-017-0756-y) contains supplementary material, which is available to authorized users.

Abstract

Background

Long noncoding RNAs (lncRNAs) are an important class of functional regulators involved in human cancers development, including gastric cancer (GC). Studying aberrantly expressed lncRNAs may provide us with new insights into the occurrence and development of gastric cancer by acting as oncogenes or tumor suppressors. In this study, we aim to examine the expression pattern of lncRNA HAGLROS in GC and its clinical significance as well as its biological role in tumor progression.

Methods

Bioinformatics analysis and qRT-PCR were performed to detect the relative expression of HAGLROS in GC tissues and cell lines. Gain or loss of function approaches were used to investigate the biological functions of HAGLROS. The effect of HAGLROS on proliferation was evaluated by MTT, colony formation assay and nude mouse xenograft model. Wound healing and Transwell assays were used to study the invasion and migration of GC cells. FISH, RIP, RNA-seq, Luciferase report assays, RNA pulldown and Western blot were fulfilled to measure molecular mechanisms. Results are shown as means ± S.D. and differences were tested for significance using Student’s t-test (two-tailed).

Results

We screened out HAGLROS, whose expression was significantly increased and correlated with outcomes of GC patients by publicly available lncRNAs expression profiling and integrating analyses. Exogenous down-regulation of HAGLROS expression significantly suppressed the cell proliferation, invasion and migration. Mechanistic investigations showed that HAGLROS was a direct target of transcriptional factor STAT3. Moreover, HAGLROS knockdown decreased mTOR expression and increased autophagy-related genes ATG9A and ATG9B expression. Further investigation showed that HAGLROS regulated mTOR signals in two manners. In the one hand, HAGLROS competitively sponged miR-100-5p to increase mTOR expression by antagonizing miR-100-5p-mediated mTOR mRNA inhibition. On the other hand, HAGLROS interacted with mTORC1 components to activate mTORC1 signaling pathway which was known to be an important negative signal of autophagy. Here activation of mTORC1 signaling pathway by HAGLROS inhibited autophagy, thereby promoted excessive proliferation and maintained the malignant phenotype of GC cells.

Conclusion

The present study demonstrates that HAGLROS overexpression contributes to GC development and poor prognosis and will be a target for GC therapy and further develop as a potential prognostic biomarker.
Zusatzmaterial
Additional file 1: Table S1. The relationship between HAGLROS expression and clinicopathological factors of GC patients. (DOCX 14 kb)
12943_2017_756_MOESM1_ESM.docx
Additional file 2: Table S2. Primers used for qRT-PCR,RT-PCR, CHIP and siRNAs/shRNA oligonucleotides. (XLSX 12 kb)
12943_2017_756_MOESM2_ESM.xlsx
Additional file 3: Figure S1. The relative lncRNAs expression from 12 GC patients were validated by qRT-PCR. Error bars indicate the means ± S.E.M. *P < 0.05, **P < 0.01 for carcinoma vs paracarcinoma. (TIFF 165 kb)
12943_2017_756_MOESM3_ESM.tiff
Additional file 4: Table S3. Univariate and multivariate analyses of the clinicopathological factors for overall survival in 84 patients with GC. (DOCX 16 kb)
12943_2017_756_MOESM4_ESM.docx
Additional file 5: Figure S2. (a) Relative areas of the wound scratch assay by Image J software. *P < 0.05 for siRNAs vs Ctrl siRNAs and pcDNA3.1-HAGLROS vs vector. (b) Transcription efficiencies of siRNAs, shRNAs and pcDNA3.1-HAGLROS. **P < 0.01. Error bars indicate the means ± S.E.M. (TIFF 1170 kb)
12943_2017_756_MOESM5_ESM.tif
Additional file 6: Figure S3. RNA-sequencing analysis of HAGLROS siRNA vs Ctrl. (a) 194 differentially expressed genes upon HAGLROS siRNA vs Ctrl. (b) GO analysis of differentially expressed genes. (c) Pathway enrichment analysis of differentially expressed genes. (TIFF 3460 kb)
12943_2017_756_MOESM6_ESM.tif
Additional file 7: Figure S4. The relative expression levels of downstream signals were validated by qRT-PCR upon HAGLROS knockdown in accordance with RNA high-throughput sequencing guidelines. (a) Down-regulated genes were validated by qRT-PCR upon HAGLROS knockdown. (b) Up-regulated genes were validated by qRT-PCR upon HAGLROS knockdown. Error bars indicate the means ± S.E.M. *P < 0.05, **P < 0.01. (TIFF 1840 kb)
12943_2017_756_MOESM7_ESM.tiff
Literatur
Über diesen Artikel

Weitere Artikel der Ausgabe 1/2018

Molecular Cancer 1/2018 Zur Ausgabe

Neu im Fachgebiet Onkologie

Mail Icon II Newsletter

Bestellen Sie unseren kostenlosen Newsletter Update Onkologie und bleiben Sie gut informiert – ganz bequem per eMail.

Bildnachweise