LncRNA SNHG6 is Associated with Poor Prognosis of Gastric Cancer and Promotes Cell Proliferation and EMT through Epigenetically Silencing p27 and Sponging miR-101-3p

Background/Aims: Long noncoding RNAs (lncRNAs) are aberrantly expressed in multiple malignant tumors involved in tumor growth and metastasis. Accumulating data show that small nucleolar RNA host gene (SNHG) 1/12/20 plays a key role in the progression of hepatocellular carcinoma (HCC). However, the molecular mechanisms by which SNHG8 contributes to HCC remain elusive and merit exploration. Methods: The association between SNHG8 expression and the clinicopathological characteristics and prognoses in HCC patients was analysed by using qRT-PCR analysis and the data from The Cancer Genome Atlas. Cell growth and metastatic potential were determined by MTT, colony formation, Transwell assays, and the mouse xenograft tumor model and lung metastasis model. Epithelial–mesenchymal transition markers were detected by western blot analysis. The binding capacity of SNHG8 with miRNAs was evidenced by bioinformatic analysis and a luciferase reporter assay. In addition, the rescue experiments were performed based on co-transfection with sh-SNHG8 and a miR-149 inhibitor in HCC cells. Results: The expression levels of lncRNA SNHG8 were dramatically increased in HCC tissues and cell lines as compared with the adjacent normal tissues, and SNHG8 expression was an independent prognostic factor of tumor recurrence in HCC patients. Furthermore, knockdown of SNHG8 inhibited cell proliferation, invasion, and lung metastasis in vitro and in vivo, whereas overexpression of SNHG8 reversed these effects. SNHG8 acted as a sponge of miR-149 and counteracted the tumor suppressive effects of mi R-149 in HCC cells. Expression of phosphatase, Mg2+/Mn2+ dependent 1F, a target of R-149, displayed a negative correlation with miR-149 expression but a positive correlation with SNHG8 expression in HCC specimens. Conclusion: As lncRNA SNHG8 may promote HCC tumorigenesis and metastasis by sponging miR-149, it is a potential candidate marker and therapeutic target for HCC.

Section: Knockdown Of Snhg8 Inhibited Xenograft Tumor Growth and Lungcontrasting

confidence: 40%

Section: Cellular Physiology and Biochemistry Cellular Physiology Andmentioning

confidence: 54%

lncRNA SNHG8 Promotes the Tumorigenesis and Metastasis by Sponging miR-149-5p and Predicts Tumor Recurrence in Hepatocellular Carcinoma

Dong

Teng

Guo

et al. 2018

“…SNHG6 functions as a competing endogenous RNA to promote cancer progression [34,36] and regulates ZEB1 expression by competitively binding miR-101-3p and interacting with UPF1 in hepatocellular carcinoma [37]. In addition, SNHG6 is associated with poor prognosis and enhanced tumor growth and epithelial-mesenchymal transition via suppressing p27 and sponging miR-101-3p in gastric cancer [38]. We here showed that SNHG6 was overexpressed in colorectal cancers and high level of SNHG6 was associated with advanced tumor stage in colorectal cancers, which is in consistent with the above findings.…”

Section: Discussionmentioning

confidence: 99%

SNHG6 Promotes Tumor Growth via Repression of P21 in Colorectal Cancer

Qiu

Qiu³

et al. 2018

Background/Aims: SNHG6 (Small Nucleolar RNA Host Gene 6) is a novel non-coding RNA (ncRNA) and its cellular function is largely unknown. Methods: Cell Counting Kit-8 (CCK-8) cell growth assay, colony formation and flow cytometry were used to determine colorectal cancer cell proliferation, cell cycle progression and apoptosis in vitro. The xenograft tumor formation assay in nude mice was established to evaluate tumor growth in vivo. RNA immunopreciptation (RIP) analysis was performed to examine whether SNHG6 could bind to EZH2 (enhancer of zeste 2 polycomb repressive complex 2 subunit), and chromatin immunoprecipitation (ChIP) assay was conducted to examine whether SNHG6 could repress p21 transcription by recruiting EZH2 to the p21 promoter. Results: Here we found that SNHG6 was upregulated and its expression levels were positively correlated with advanced tumor stage in colorectal cancer. Survival analysis suggested that higher expression of SNHG6 predicted poor prognosis in patients with colorectal cancer. Functional studies indicated that SNHG6 could promote cell proliferation via a direct suppression of p21 expression in colorectal cancer cells. Moreover, SNHG6 repressed p21 transcription through recruiting EZH2 to the p21 promoter in colorectal cancer cells. Conclusion: Taken together, our study demonstrates that SNHG6 promotes tumor growth via repression of p21 in colorectal cancer, which may provide a promising target for novel anticancer therapeutics.

“…Functioned as oncogenes or tumor suppressors, lncRNAs participate in several vital steps of GC tumorigenesis and progression. Some lncRNAs including HOTAIR, HULC, LINC00152, MALAT1, MALAT2, H19, SNHG6, GHET1 and GACAT3 have been demonstrated to act as oncogenes, while other lncRNAs such as LEIGC, GAS5 and FER1L4 have been classified as tumor suppressors [9][10][11][12]. Mechanistically, lncRNAs may act as chromatin remodeler, transcriptional modulator, splicing regulator, posttranscriptional processor, enhancer, molecular decoys for miRNAs, or as a guide for protein-protein, protein-DNA and protein-RNA interaction [4,5,13,14].…”

Section: Introductionmentioning

confidence: 99%

LncRNA MT1JP Suppresses Gastric Cancer Cell Proliferation and Migration Through MT1JP/MiR-214-3p/RUNX3 Axis

Xü

Zhang

Zou

et al. 2018

Background/Aims: Emerging evidence points towards an important role of long noncoding RNAs (lncRNAs) in the tumorigenesis and progression of gastric cancer (GC). MT1JP has recently been reported to be differentially expressed and act as a tumor suppressor in different tumors, with its mechanisms not fully understood in GC. Methods: RT-qPCR was used to detect the expression of MT1JP, miR-214-3p and RUNX3 in tumor tissues and cell lines of GC. The CCK-8 assay, colony formation, Transwell assay and wound healing assay were used to evaluate the proliferation, invasion and migration of GC cells, respectively. Bioinformatics analysis and luciferase reporter assay were performed to disclose the interaction between MT1JP, miR-214-3p and RUNX3. Western blot and immunofluorescence were applied to assess the downstream signaling of RUNX3. Results: MT1JP was found downregulated in GC tissues and cells. Low expression of MT1JP was significantly correlated with advanced TNM stage and lymphatic metastasis. The expression of plasma MT1JP was also found decreased in GC patients compared to healthy controls, with an area under the ROC curve (AUC) of 0.649 for diagnosis of GC. Gain-and loss-of-function of MT1JP revealed that MT1JP functioned as a ceRNA for miR-214-3p to facilitate RUNX3 expression and then upregulated p21 and Bim levels suppressing GC cell proliferation, invasion and migration, and promoting apoptosis. Furthermore, MT1JP overexpression suppressed tumor growth and inhibited the expression of miR-214-3p and proliferation antigen Ki-67, but increased the expression of RUNX3, p21 and Bim in vivo. Conclusions: Our results suggest a potential ceRNA regulatory network involving MT1JP regulates RUNX3 expression by competitively binding endogenous miR-214-3p in tumorigenesis and progression of GC. This mechanism may contribute to a better understanding of GC pathogenesis and provide potential therapeutic strategy for GC.