circ-NOTCH1 acts as a sponge of miR-637 and affects the expression of its target gene Apelin to regulate gastric cancer cell growth

2020 ◽  
Vol 98 (2) ◽  
pp. 164-170 ◽  
Author(s):  
Encui Guan ◽  
Xiaoguang Xu ◽  
Fangxi Xue

Gastric cancer (GC) is a major cause of cancer-related deaths worldwide, and has a low survival rate, low cure rate, high recurrence rate, and poor prognosis. Recent studies have indicated that circular RNAs (circRNAs) have important functions in the occurrence and progression of GC. Studies on circ-NOTCH1, which was shown to be highly expressed in GC, have indicated that miR-637 binds to circ-NOTCH1 at multiple sites, and a dual-luciferase reporter gene assay further confirmed that miR-637 indeed targeted circ-NOTCH1 and Apelin. Circ-NOTCH1 and Apelin are highly expressed in GC cells and tissues, whereas the expression of miR-637 is reduced. Circ-NOTCH1 and miR-637 do not regulate each other’s expression levels, but circ-NOTCH1significantly upregulates the expression of the miR-637 target gene Apelin, whereas miR-637 inhibites the expression of Apelin. Examination of GC cells showed that circ-NOTCH1 enhances cell proliferation and invasiveness, and reduces cell apoptosis; these effects were reversed by miR-637, which could terminate the above effects of circ-NOTCH1. When co-transfected with the circ-NOTCH1 overexpression plasmid and Apelin siRNAs, there were no obvious changes to the levels of cell proliferation, apoptosis, or invasiveness. Therefore, in GC cells, circ-NOTCH1 inhibits the transcriptional activity of miR-637, thereby upregulating the expression of its target gene Apelin and regulating cell proliferation, apoptosis, and invasiveness. This finding provides more experimental evidence for the function of circRNA in GC.

2021 ◽  
Author(s):  
Yaping Liu ◽  
Xu Zhao ◽  
Yinnan Chen ◽  
Gang Guo ◽  
Jiansheng Wang ◽  
...  

Abstract To evaluate the expression of PITPNA-AS1 and miR-98-5p in gastric cancer tissues as well as their association with progression of gastric cancer, and investigate the role of PITPNA-AS1 and miR-98-5p in developing platinum resistance. RNA sequencing was used to identify candidate lncRNAs and microRNAs related to local recurrence of gastric cancer. qRT-PCR was used to investigate the expression of PITPNA-AS1 and miR-98-5p. CCK-8 and caspase3/7 activity were used to evaluate the cell proliferation and apoptosis rate. Dual luciferase reporter gene assay and RNA pull down were used to evaluate the cross talk between PITPNA-AS1 and miR-98-5p. PITPNA-AS1 and miR-98-5p could regulate cell proliferation and inhibit apoptosis in gastric cancer cell lines. Cisplatin and lobaplatin could significantly suppress the expression of PITPNA-AS1, which interacted with negatively regulated miR-98-5p expression. PITPNA-AS1 overexpression impaired the effect of platinum, which was partially reversed by downregulation of miR-98-5p knock down. In gastric cancer, PITPNA-AS1 and miR-98-5p could regulat cell growth, apoptosis and platinum resistance. They have the potential to be biomarkers and curative therapeutic targets. However, further research on molecular mechanisms are needed.


BMC Cancer ◽  
2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Houkun Li ◽  
Limin He ◽  
Yuan Tuo ◽  
Yansheng Huang ◽  
Bing Qian

Abstract Background Circular RNAs (circRNAs) have emerged as a novel category of non-coding RNA, which exhibit a pivotal effect on regulating gene expression and biological functions, yet how circRNAs function in osteosarcoma (OSA) still demands further investigation. This study aimed at probing into the function of hsa_circ_0000282 in OSA. Methods The expressions of circ_0000282 and miR-192 in OSA tissues and cell lines were examined by quantitative real-time polymerase chain reaction (qRT-PCR), and the correlation between the expression level of circ_0000282 and clinicopathological features of OSA patients was analyzed. The expressions of X-linked inhibitor of apoptosis protein (XIAP), B-cell lymphoma-2 (Bcl-2) and Bcl-2 associated X protein (Bax) in OSA cells were assayed by Western blot. The proliferation and apoptosis of OSA cells were examined by CCK-8, BrdU and flow cytometry, respectively. Bioinformatics analysis, dual-luciferase reporter gene assay and RIP experiments were employed to predict and validate the targeting relationships between circ_0000282 and miR-192, and between miR-192 and XIAP, respectively. Results Circ_0000282 was highly expressed in OSA tissues and cell lines, which represented positive correlation with Enneking stage of OSA patients and negative correlation with tumor differentiation degree. In vitro experiments confirmed that overexpression of circ_0000282 markedly facilitated OSA cell proliferation and repressed cancer cell apoptosis in comparison to control group. Besides, knockdown of circ_0000282 repressed OSA cell proliferation and promoted apoptosis. Additionally, the binding relationships between circ_0000282 and miR-192, and between miR-192 and XIAP were validated. Circ_0000282 indirectly up-regulated XIAP expression by adsorbing miR-192, thereby playing a role in promoting cancer in OSA. Conclusion Circ_0000282 was a novel oncogenic circRNA in OSA. Circ_0000282/miR-192/XIAP axis regulated OSA cell proliferation apoptosis with competitive endogenous RNA mechanism.


Author(s):  
Fang Liu ◽  
Yan-Li Wang ◽  
Jie-Mei Wei ◽  
Zhao-Dong Huang

Abstract Circular RNAs (circRNAs) play an important regulatory role in a variety of malignancies. Nevertheless, the role of circ_0000142 in multiple myeloma (MM) and its regulatory mechanism remains largely unknown. Real-time polymerase chain reaction was employed to detect the expressions of circ_0000142 and miR-610 in MM tissues and cell lines. The expression of AKT3 and apoptosis-related proteins (Bcl-2, Bax) in MM cells was detected by western blot. The correlation between the expression level of circ_0000142 and the clinicopathological parameters of MM patients was analysed. Cell proliferation, apoptosis, migration and invasion were monitored by Cell Counting Kit 8 assay, flow cytometry analysis and Transwell assay, respectively. The dual-luciferase reporter gene assay and RNA immunoprecipitation assay were employed to verify the targeting relationship between circ_0000142 and miR-610. In this study, it was demonstrated that, circ_0000142 was highly expressed in MM patients, and its high expression level was significantly associated with increased International Staging System and Durie–Salmon stage. Overexpression of circ_0000142 enhanced MM cell proliferation, migration, invasion and suppressed cell apoptosis, while knocking down circ_0000142 had the opposite effects. Mechanistically, circ_0000142 functioned as a competitive endogenous RNA, directly targeting miR-610 and positively regulating AKT3 expression. In brief, circ_0000142 enhances the proliferation and metastasis of MM cells by modulating the miR-610/AKT3 axis.


2021 ◽  
Vol 27 ◽  
Author(s):  
Lei Zheng ◽  
Liying Kang ◽  
Yan Cheng ◽  
Junli Cao ◽  
Lijie Liu ◽  
...  

Gastric cancer (GC) is one of the major malignancies worldwide. Emerging evidence has revealed the potential involvement of long noncoding RNA (lncRNA) in human genetic disorders and cancer, but the role of LOC100505817 remains unknown. Thus, in this study, we isolated tissues from GC patients to characterize the functional importance of LOC100505817 in GC tumorigenesis. We also proposed a hypothesis that the regulation of Wnt/β-catenin pathway by LOC100505817 was regulated by miR-20a-mediated WT1. After the collection of cancer tissues and adjacent tissues were obtained from GC patients, expression of LOC100505817, Wnt/β-catenin pathway- and EMT-related genes was quantified. Ectopic expression and knockdown experiments were applied in order to investigate the protective role of LOC100505817 in the progression of GC. Subsequently, cell viability, flow cytometry for apoptosis and cell cycle were detected via CCK-8, while migration and invasion were determined using scratch test and Transwell assay respectively. Then interactions among LOC100505817, miR-20a and WT1 were explored by dual luciferase reporter gene assay, RNA pull down assay and RNA binding protein immunoprecipitation (RIP) assay. The results found poor expression LOC100505817 was poorly expressed in GC cells and tissues. Overexpressed LOC100505817 resulted in the significant reduction of cell proliferation, migration and invasion as well as the expression of Wnt2b, β-catenin, CyclinD1, N-cadherin, Vimentin and snail, while increased cell apoptosis along with the expression of E-cadherin. Wnt/β-catenin pathway and EMT in GC cells were suppressed by LOC100505817 through miR-20a-inhibted WT1. In summary, our results provided evidence suggesting that LOC100505817 inhibits GC through LOC100505817-mediated inhibition of Wnt/β-catenin pathway, that leads to the overall restraining of GC cell proliferation, migration and invasion through miR-20a-reduced WT1.


2020 ◽  
Vol 98 (3) ◽  
pp. 396-404
Author(s):  
Yu Zheng ◽  
Chao-jiang Chen ◽  
Zhuo-yuan Lin ◽  
Jian-xin Li ◽  
Jie Liu ◽  
...  

Prostate cancer (PCa) is the second leading cause of death in men, and current studies have shown that circular RNAs (circRNAs) play important roles in its occurrence and development. Detection of circRNAs in PCa cells showed that circ_KATNAL1 is down-regulated, mainly located in the cytoplasm, and contains multiple binding sites of miR-145-3p, which is an anticancer miRNA. RNA immunoprecipitation with anti-AGO2 antibody, RNA pull-down assays with biotin-labeled circ_KATNAL1 probe or an miR-145-3p mimic, and dual luciferase reporter gene assays confirmed that circ_KATNAL1 binds directly to miR-145-3p in cells, and that WISP1, which is highly expressed in many types of tumors, is an important target gene of miR-145-3p. Circ_KATNAL1 and miR-145-3p promote each other’s expression, and down-regulate the expression of the target gene WISP1. Both circ_KATNAL1 and miR-145-3p inhibit cell proliferation, invasiveness, and migration, down-regulate the expression of MMP-2 and MMP-9, promote cell apoptosis and the activation of caspase-3, caspase-8, caspase-9, and PARP, whereas WISP1 has the opposite effect, and the above-mentioned functions of circ_KATNAL1 were achieved through the miR-145-3p/WISP1 pathway. Therefore, circ_KATNAL1 plays an anticancer role in PCa cells through the miR-145-3p/WISP1 pathway, which could be an important target for the diagnosis and treatment of PCa.


2021 ◽  
Vol 26 (1) ◽  
Author(s):  
Zhiyuan Lu ◽  
Dawei Wang ◽  
Xuming Wang ◽  
Jilong Zou ◽  
Jiabing Sun ◽  
...  

Abstract Background More and more studies have confirmed that miRNAs play an important role in maintaining bone remodeling and bone metabolism. This study investigated the expression level of miR-206 in the serum of osteoporosis (OP) patients and explored the effect and mechanism of miR-206 on the occurrence and development of osteoporosis. Methods 120 postmenopausal women were recruited, including 63 cases with OP and 57 women without OP. The levels of miR-206 were determined by qRT-PCR technology. Spearman correlation coefficient was used to evaluate the correlation of miR-206 with bone mineral density (BMD). An ROC curve was used to evaluate the diagnostic value of miR-206 in osteoporosis. The effects of miR-206 on cell proliferation and cell apoptosis of hFOBs were measured by CCK-8 assay and flow cytometry, respectively. Luciferase reporter gene assay was used to confirm the interaction of miR-206 and the 3′UTR of HDAC4. Results Serum miR-206 had low expression level in osteoporosis patient group compared with control group. The expression level of serum miR-206 had diagnostic value for osteoporosis, and the serum miR-206 levels were positively correlated with BMD. The down-regulated miR-206 could inhibit cell proliferation and promote cell apoptosis. Luciferase analysis indicated that HDAC4 was the target gene of miR-206. Conclusions MiR-206 could be used as a new potential diagnostic biomarker for osteoporosis, and in in vitro cell experiments, miR-206 may regulate osteoblast cell proliferation and apoptosis by targeting HDAC4.


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Xinxin Kou ◽  
Hui Ding ◽  
Lei Li ◽  
Hongtu Chao

Purpose. Cisplatin is one of the most effective drugs for treating ovarian carcinoma (OC), which is among the most lethal types of carcinoma. However, the chemoresistance to cisplatin that develops over time leads to a poor clinical outcome for many OC patients. Therefore, it is necessary to clearly understand the molecular mechanisms of chemoresistance. In this study, we examined how Hsa-miR-105-1 functions in cisplatin-resistant OC cells. Methods. The levels of Hsa-miR-105-1 expression in cisplatin-sensitive and resistant OC cell lines were detected by qRT-PCR. The target gene of Hsa-miR-105-1 was predicted by using the TargetScan and Starbase databases and verified by the double luciferase reporter gene assay. The target gene of Hsa-miR-105-1 was identified as ANXA9, and ANXA9 expression was evaluated by qRT-PCR, western blotting, and immunofluorescence. To validate the function of Hsa-miR-105-1 in OC cells, we silenced or overexpressed Hsa-miR-105-1 in cisplatin-sensitive or resistant OC cell lines, respectively. Furthermore, the expression levels of several apoptosis-related proteins, including P53, P21, E2F1, Bcl-2, Bax, and caspase-3, were examined by western blot analysis. Results. The levels of Hsa-miR-105-1 expression were abnormally downregulated in cisplatin-resistant OC cells, while ANXA9 expression was significantly upregulated in those cells. Treatment with an Hsa-miR-105-1 inhibitor promoted the expression of ANXA9 mRNA and protein, enhanced the resistance to cisplatin, and attenuated the cell apoptosis induced by cisplatin in cisplatin-sensitive OC cells. Moreover, treatment with Hsa-miR-105-1 mimics inhibited ANXA9 expression, which further increased the levels of P53, P21, and Bax expression and decreased the levels of E2F1 and Bcl-2 expression, finally resulting in an increased sensitivity to cisplatin in cisplatin-resistant OC cells. Conclusion. We found that a downregulation of Hsa-miR-105-1 expression enhanced cisplatin-resistance, while an upregulation of Hsa-miR-105-1 restored the sensitivity of OC cells to cisplatin. The Hsa-miR-105-1/ANXA9 axis plays an important role in the cisplatin-resistance of OC cells.


2021 ◽  
Vol 17 (9) ◽  
pp. 1882-1889
Author(s):  
Suqin Wang ◽  
Lina Xu ◽  
Zhiqiang Zhang ◽  
Ping Wang ◽  
Rong Zhang ◽  
...  

Dysregulation expression of miR-375 is noted to correlate with progression of cervical cancer. This study attempted to investigate the impact of overexpressed miR-375-loaded liposome nanoparticles on proliferation of cervical cancer (CC), to provide an insight on pathogenesis of CC disorder. CC cells were co-cultured with pure liposome nanoparticles (empty vector group), miR-375 agonist-loaded liposome nanoparticles, or transfected with miR-375 antagonist. Besides, some cells were exposed to TGF-β/Smads signaling pathway inhibitor or activator whilst cell proliferation was assessed by MTT assay, and expressions of FZD4 and miR-375 were determined. Western blot analysis was carried out to detect the expression of TGF-β pathway factors (TGF-β, Smad2, Smad7, p-Smad2) and its downstream Smads pathway. The interaction between miR-375 and FZD4 was evaluated by dual-luciferase reporter gene assay. Overexpression of miR-375 induced arrest at the G0/G1 phase of cell cycle and elevation of Smad2 protein expression (P <0.05), with lower expressions of TGF-β, Smad7, p-Smad2, and FZD4, while transfection with miR-375 inhibitor exhibited opposite activity. Presence of miR-375 agonist-loaded liposome nanoparticles induced decreased cell proliferation. There was a targeting relationship between miR-375 and FZD4, and administration with TGF-β/Smads agonist resulted in increased miR-375 and Smad2 expressions, as well as decreased TGF-β, Smad7, p-Smad2, FZD4 protein expression, and the number of S phase and G2/M phase cells (P < 0.05). The signaling inhibitor oppositely suppressed cell proliferation decreasing miR-375 expression. miR-375-loaded liposome nanoparticles activated TGF-β/Smads signaling pathway to restrain cell cycle and suppress cell division, and proliferation through targeting FZD4 in CC. Its molecular mechanism is related to activation of TGF-β/Smads signaling pathway.


2020 ◽  
Author(s):  
Zhi-Li Hu ◽  
Yang-zhi Hu ◽  
Qing Li ◽  
Tian-you Liao ◽  
Hai-ping Jiang

Abstract Background: It has been reported that reduction of miR-126 can promote the progression of gastric cancer (GC). However, the regulation of miR-126 in GC is still unclear. This study aims to explore the correlation between lncRNA MALAT1 and miR-126 in gastric cancer and disclose the underlying mechanisms.Methods: We analyzed the correlation of MALAT1 levels and clinical features by analysis of bioinformatic data and human samples. Then we down-regulate the expression of MALAT1 in AGS cells and examined the characteristics of cell proliferation, cycle, apoptosis, migration, invasion, and the effect on miR-126 as well as VEGFA and signaling pathway. In addition, we demonstrated the role of MALAT1/miR-126 axis in GC with dual-luciferase reporter gene assay and treatment of miR-126 inhibitor.Results: The expression of MALAT1 was higher in cancer tissues than para-cancer tissues. In addition, high MALAT1 level suggested greater malignancy and poorer prognosis. Down-regulating the expression of MALAT1 in AGS cells inhibited cell proliferation, migration, and invasion by targeting VEGFA, which is consistent with up-regulation of miR-126. According to dual-luciferase reporter gene assay and treatment of miR-126 inhibitor, we demonstrated that MALAT1 down-regulated miR-126 in GC, which leads to the up-regulation of VEGFA and activation of mTOR signaling pathway.Conclusions: MALAT1/miR-126 axis promotes growth and metastasis of gastric cancer through regulation of VEGFA via mTOR signaling pathway.Fund This article is supported by Science and Technology Funding Project of Hunan Province, China (No.2017SK4010)


2021 ◽  
Author(s):  
Zhang Jieling ◽  
Li Kai ◽  
Zheng Huifen ◽  
Zhu Yiping

Abstract Background: MicroRNAs play an important role in the genesis and progression of tumors, including colorectal cancer (CRC), which has a high morbidity and mortality rate. In this research, the role of miR-495-3p and HMGB1 in CRC was investigated.Methods: We performed qRT-PCR to detect the expression of miR-495-3p in colorectal cancer tissues and cell lines. Functional experiments such as CCK-8 assay, EDU assay, Transwell assay and apoptosis assay were conducted to explore the effects of miR-495-3p on the proliferation, migration and apoptosis of CRC cells in vitro. Then, the use of database prediction, dual-luciferase reporter gene assay and functional experiments verified the role of miR-495-3p target gene HMGB1 in CRC. Finally, rescue experiments was performed to investigate whether overexpression of HMGB1 could reverse the inhibitory effect of miR-495-3p on CRC cell proliferation in vivo and in vitro.Results: miR-495-3p was down-regulated in colorectal cancer tissues and cell lines, and could inhibit the proliferation and migration of colorectal cancer cells, and promote cell apoptosis. The database prediction and dual-luciferase reporter gene assay showed that HMGB1 was the downstream target gene of miR-495-3p. We finally demonstrated that miR-495-3p inhibited CRC cell proliferation by targeting HMGB1 in vitro and in vivo.Conclusion: Our research shows that miR-495-3p inhibits the progression of colorectal cancer by down-regulating the expression of HMGB1, which indicates that miR-495-3p may become a potential therapeutic target for colorectal cancer.


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