Long non-coding RNA LINC00982 up-regulates CTSF expression to inhibit gastric cancer progression via the transcription factor HEY1

Author(s):  
Lei Zheng ◽  
Junli Cao ◽  
Lijie Liu ◽  
Hongmei Xu ◽  
Lanlan Chen ◽  
...  

Upregulating the expression of long non-coding RNA LINC00982 controlled cell proliferation in gastric cancer, but the regulatory molecular mechanisms are yet to be expounded. We here aimed to elaborate how LINC00982 regulated the malignancy of gastric cancer cells. RT-qPCR and Western blot analysis were used to detect the expression of LINC00982 and CTSF in gastric cancer tissues and cells. Modulatory effect of LINC00982 on gastric cancer cells was assessed by CCK-8, colony formation, Transwell migration and invasion assays. The relationship between LINC00982, HEY1 and CTSF was examined by RIP, luciferase assay, and ChIP, and their interaction in the regulation of gastric cancer cellular functions was analyzed by performing gain-of-function and rescue assays. The nude mouse model of tumor formation was developed to examine the effects of LINC00982 on tumorigenesis. LINC00982 was lowly expressed in gastric cancer tissues, while its overexpression impaired the proliferative, migratory and invasive properties of gastric cancer cells. Furthermore, LINC00982 could bind to transcription factor HEY1 and inhibited its expression. Through blocking the binding of HEY1 to CTSF promoter. LINC00982 promoted the expression of CTSF. Overexpression of HEY1 or inhibition of CTSF could reverse the anti-tumor effects of LINC00982 on gastric cancer, which were further demonstrated in vivo. Taken together, LINC00982 acted as a tumor suppressor in gastric cancer, which is therefore suggested to be a potential anti-tumor target for gastric cancer.

2020 ◽  
pp. 1-11
Author(s):  
Li-Juan Pei ◽  
Peng-Jun Sun ◽  
Kui Ma ◽  
Yan-Yan Guo ◽  
Ling-Yan Wang ◽  
...  

Gastric cancer (GC) remains poor prognosis and survival issues due to the resistance of chemotherapies, such as cisplatin. The long non-coding RNA small nucleolar RNA host gene 7 (lncRNA-SNHG7) is known as an oncogenic molecule in diverse cancers. Here, we demonstrate that SNHG7 was significantly upregulated in gastric cancer and positively correlated with cisplatin resistance of gastric cancer cells that SNHG7 was significantly upregulated in cisplatin resistant cells. Silencing SNHG7 dramatically sensitized cisplatin resistant cells. In contrast, a negative correlation between lncRNA-SNHG7 and miR-34a was found that miR-34a was downregulated in gastric cancer patient tissues and significantly sensitized cisplatin resistant gastric cancer cells. Intriguingly, bioinformatical analysis indicated miR-34a has putative biding site for SNHG7 and such negative association between SNHG7 and miR-34a was verified in gastric cancer tissues. The cisplatin resistant cells displayed increased glycolysis rate and SNHG7 promoted cellular glycolysis rate of gastric cancer cells. Luciferase assay illustrated LDHA, a glycolysis enzyme, was the direct target of miR-34a. Importantly, inhibiting SNHG7 successfully suppressed LDHA expressions and sensitized cisplatin resistant cells and such inhibitory effects could be recovered by further anti-miR-34a. These findings suggest an important regulator mechanism for the SNHG7-mediated cisplatin resistance via miR-34a/LDHA-glycolysis axis.


2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Hong Chen ◽  
Lu Xu ◽  
Zhi-li Shan ◽  
Shu Chen ◽  
Hao Hu

Abstract Background Glutathione Peroxidase 8 (GPX8) as a member of the glutathione peroxidase (GPx) family plays an important role in anti-oxidation. Besides, dysregulation of GPX8 has been found in gastric cancer, but its detailed molecular mechanism in gastric cancer has not been reported. Methods Our study detected the expression of GPX8 in gastric cancer tissues and cell lines using immunohistochemistry (IHC), western blot and qRT-PCR, and determined the effect of GPX8 on gastric cancer cells using CCK-8, colony formation, transwell migration and invasion assays. Besides, the effect of GPX8 on the Wnt signaling pathway was determined by western blot. Furthermore, the transcription factor of GPX8 was identified by bioinformatics methods, dual luciferase reporter and chromatin immunoprecipitation (CHIP) assays. In addition, the effect of GPX8 on tumor formation was measured by IHC and western blot. Results The over-expression of GPX8 was observed in gastric cancer tissues and cells, which facilitated the proliferation, migration and invasion of gastric cancer cells as well as the tumor growth. GPX8 knockdown effectively inhibited the growth of gastric cancer cells and tumors. Moreover, GPX8 could activate the Wnt signaling pathway to promote the cellular proliferation, migration and invasion through. Furthermore, FOXC1 was identified as a transcription factor of GPX8 and mediated GPX8 expression to affect cell development processes. Conclusions These findings contribute to understanding the molecular mechanism of GPX8 in gastric cancer. Additionally, GPX8 can be a potential biomarker for gastric cancer therapy.


2014 ◽  
Vol 32 (3_suppl) ◽  
pp. 56-56
Author(s):  
Xu Yanjun ◽  
Zhou Tianhua ◽  
Si Jianmin ◽  
Zhuo Wei

56 Background: Migration and invasion of cancer cells are essential process during cancer metastatic procession. In gastric cancer, cells invasion into the surrounding tissue is a crucial early step. However, the mechanisms have not been fully understood. MicroRNAs, which are a class of small single-stranded non-coding RNA, participate in the malignant progressions of cancer, including metastasis. We study the association between specific dysregulated miRNA and specific metastasis step of gastric cancer, which will provide insights into the potential mechanisms of gastric cancer cells migration, invasion and metastasis. Methods: The expression of miR-375 was assayed using the quantitative real-time PCR analysis. Scratch-wound healing assay, Transwell migration and invasion assay were conducted to study the migration and invasion abilities of cells. Animal experiment was also conducted to examine the effect on liver and lung metastases by overexpression of miR-375. Luciferase assay was conducted to study the association between Snail and miR-375. Results: MiR-375 is downregulated in gastric cancer cells with greater migration and invasion abilities. The expression level of miR-375 is decreased in gastric cancer tissues from metastasis-positive patients compared with that from metastasis-free patients. Overexpression of miR-375 inhibits the migration and invasion abilities of gastric cancer cells. JAK2, which may be a target gene of miR-375, could reverses miR-375 induced inhibition of gastric cancer cells migration and invasion. Liver metastasis was not detected in mice injected with miR-375 overexpressed cells but was apparent in mice injected with cells which were transfected with control vector. The transcription factor Snail, which binds directly to the putative promoter of miR-375, could reduce the expression level of miR-375 significantly. A distinct inverse correlation was found between miR-375 expression and Snail mRNA level. Conclusions: These findings demonstrate that tumor suppressor miR-375, whose expression is directly regulated by the transcription factor Snail, inhibits gastric cancer cells migration, invasion and metastasis by targeting an important protein JAK2.


Author(s):  
Chunsheng Li ◽  
Jingrong Dong ◽  
Zhenqi Han ◽  
Kai Zhang

MicroRNAs (miRNAs) are reportedly involved in gastric cancer development and progression. In particular, miR-219-5p has been reported to be a tumor-associated miRNA in human cancer. However, the role of miR-219-5p in gastric cancer remains unclear. In this study, we investigated for the first time the potential role and underlying mechanism of miR-219-5p in the proliferation, migration, and invasion of human gastric cancer cells. miR-219-5p was found to be markedly decreased in gastric cancer tissues and cell lines compared with adjacent tissues and normal gastric epithelial cells. miR-219-5p mimics or anti-miR-219-5p was transfected into gastric cancer cell lines to overexpress or suppress miR-219-5p expression, respectively. Results showed that miR-219-5p overexpression significantly decreased the proliferation, migration, and invasion of gastric cancer cells. Conversely, miR-219-5p suppression demonstrated a completely opposite effect. Bioinformatics and luciferase reporter assays indicated that miR-219-5p targeted the 3′-untranslated region of the liver receptor homolog-1 (LRH-1), a well-characterized oncogene. Furthermore, miR-219-5p inhibited the mRNA and protein levels of LRH-1. LRH-1 mRNA expression was inversely correlated with miR-219-5p expression in gastric cancer tissues. miR-219-5p overexpression significantly decreased the Wnt/β-catenin signaling pathway in gastric cancer cells. Additionally, LRH-1 restoration can markedly reverse miR-219-5p-mediated tumor suppressive effects. Our study suggests that miR-219-5p regulated the proliferation, migration, and invasion of human gastric cancer cells by suppressing LRH-1. miR-219-5p may be a potential target for gastric cancer therapy.


2018 ◽  
Vol 48 (2) ◽  
pp. 838-846 ◽  
Author(s):  
Yuan He ◽  
Hao Hu ◽  
Yandong Wang ◽  
Hao Yuan ◽  
Zipeng Lu ◽  
...  

Background/Aims: Mounting evidence suggests that epitranscriptional modifications regulate multiple cellular processes. N6-Methyladenosine (m6A), the most abundant reversible methylation of mRNA, has critical roles in cancer pathogenesis. However, the mechanisms and functions of long non-coding RNA (lncRNA) methylation remain unclear. Pancreatic cancer resulted in 411,600 deaths globally in 2015. By the time of pancreatic cancer diagnosis, metastasis has often occurred in other parts of the body. The present study sought to investigate lncRNA m6A modification and its roles in pancreatic cancer. Methods: Differential expression between cancer cells and matched normal cells was evaluated to identify candidate lncRNAs. The lncRNA KCNK15-AS1 was detected in cancer tissues and various pancreatic cells using RT-qPCR. KCNK15-AS1 was transfected into cells to explore its role in migration and invasion. Then, m6A RNA immunoprecipitation was performed to detect methylated KCNK15-AS1 in tissues and cells. Epithelial–mesenchymal transition (EMT) markers were used to evaluate KCNK15-AS1-mediated EMT processes. Results: KCNK15-AS1 was downregulated in pancreatic cancer tissues compared with paired adjacent normal tissues. KCNK15-AS1 inhibited migration and invasion in MIA PaCa-2 and BxPC-3 cells. Furthermore, total RNA methylation in cancer cells was significantly enriched relative to that in immortalized human pancreatic duct epithelial (HPDE6-C7) cells. In addition, the m6A eraser ALKBH5 was downregulated in cancer cells, which can demethylate KCNK15-AS1 and regulate KCNK15-AS1-mediated cell motility. Conclusion: Our results have revealed a novel mechanism by which ALKBH5 inhibits pancreatic cancer motility by demethylating lncRNA KCNK15-AS1, identifying a potential therapeutic target for pancreatic cancer.


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