scholarly journals TERT Promoter Revertant Mutation Inhibits Melanoma Growth through Intrinsic Apoptosis

Biology ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 141
Author(s):  
Yanbing Wang ◽  
Yiwu Chen ◽  
Chang Li ◽  
Zhiwei Xiao ◽  
Hongming Yuan ◽  
...  

Human telomerase is a specialized DNA polymerase whose catalytic core includes both TERT and human telomerase RNA (hTR). Telomerase in humans, which is silent in most somatic cells, is activated to maintain the telomere length (TEL) in various types of cancer cells, including melanoma. In the vast majority of tumor cells, the TERT promoter is mutated to promote proliferation and inhibit apoptosis. Here, we exploited NG-ABEmax to revert TERT -146 T to -146 C in melanoma, and successfully obtained TERT promoter revertant mutant cells. These TERT revertant mutant cells exhibited significant growth inhibition both in vitro and in vivo. Moreover, A375−146C/C cells exhibited telomere shortening and the downregulation of TERT at both the transcription and protein levels, and migration and invasion were inhibited. In addition, TERT promoter revertant mutation abrogated the inhibitory effect of mutant TERT on apoptosis via B-cell lymphoma 2 (Blc-2), ultimately leading to cell death. Collectively, the results of our work demonstrate that reverting mutations in the TERT promoter is a potential therapeutic option for melanoma.

Author(s):  
Jie Zhang ◽  
Xiao-Yan Li ◽  
Ping Hu ◽  
Yuan-Sheng Ding

Previous study indicates that long noncoding RNA NORAD could serve as a competing endogenous RNA to pancreatic cancer metastasis. However, its role in colorectal cancer (CRC) needs to be investigated. In the present study, we found that the expression of NORAD was significantly upregulated in CRC tissues. Furthermore, the expression of NORAD was positively related with CRC metastasis and patients’ poor prognosis. Knockdown of NORAD markedly inhibited CRC cell proliferation, migration, and invasion but induced cell apoptosis in vitro. In vivo experiments also indicated an inhibitory effect of NORAD on tumor growth. Mechanistically, we found that NORAD served as a competing endogenous RNA for miR-202-5p. We found that there was an inverse relationship between the expression of NORAD and miR-202-5p in CRC tissues. Moreover, overexpression of miR-202-5p in SW480 and HCT116 cells significantly inhibited cellular proliferation, migration, and invasion. Taken together, our study demonstrated that the NORAD/miR-202-5p axis plays a pivotal function on CRC progression.


2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Enhui Ma ◽  
Qianqian Wang ◽  
Jinhua Li ◽  
Xinqi Zhang ◽  
Zhenjia Guo ◽  
...  

Abstract Background Prostate cancer (PCa) is a kind of malignancy occurring in the prostate gland. Substantial researches have proved the major role of long noncoding RNAs (lncRNAs) in PCa. However, the role of long intergenic non-protein coding RNA 1006 (LINC01006) in PCa has not been investigated yet. Methods RT-qPCR was used to examine the expression levels of LINC01006 and its downstream targets. The function of LINC01006 in PCa was tested by in vitro and in vivo assays. With application of RNA pull down, RNA immunoprecipitation (RIP) and luciferase reporter assays, the interaction among LINC01006, miR-34a-5p and disheveled associated activator of morphogenesis 1 (DAAM1) were verified. Results LINC01006 expression presented high in PCa cell lines. LINC01006 silencing suppressed cell proliferative, migratory, invasive capacities while accelerated apoptotic rate. Besides, LINC01006 knockdown also suppressed tumor growth and metastasis in vivo. Furthermore, miR-34a-5p, a tumor suppressor in PCa, was sponged by LINC01006. Moreover, DAAM1 was targeted by miR-34a-5p and promoted PCa progression. More intriguingly, rescue assays suggested that the inhibitory effect of LINC01006 knockdown on PCa development was offset by DAAM1 overexpression. Conclusions LINC01006 promoted PCa progression by sponging miR-34a-5p to up-regulate DAAM1, providing a novel target for PCa therapy.


2020 ◽  
Author(s):  
Xiaolei Ding ◽  
Lingzhi Xu ◽  
Xiuhua Sun ◽  
Xiaoxuan Zhao ◽  
Bing Gao ◽  
...  

Abstract Background: Exosomes play important roles in intercellular communication by delivering microRNAs (miRNAs) that mediate tumor initiation and development, including those in diffuse large B cell lymphoma (DLBCL). To date, however, limited studies on the inhibitory effect of exosomes derived from human bone marrow-derived mesenchymal stem cells (hBMSCs) on DLBCL progression have been reported. Therefore, this study aimed to investigate the role of hBMSC-secreted exosomes carrying microRNA-124-3p in the development of DLBCL.Methods: Microarray-based expression analysis was adopted to identify differentially expressed genes and regulatory miRNAs, which revealed the candidate NFATc1. Next, the binding affinity between miR-124-3p and NFATc1 was using luciferase activity assays. The mechanism underlying NFATc1 regulation was investigated using lentiviral transfections. Subsequently, DLBCL cells were cocultured with exosomes derived from hBMSCs transfected with a miR-124-3p mimic or control. Proliferation and apoptosis were measured in vitro. Finally, the effects of hBMSC-derived miR-124-3p on tumor growth were investigated in vivo.Results: MiR-124-3p was downregulated while NFATc1 was upregulated in DLBCL cells. MiR-124-3p specifically targeted and negatively regulated the expression of NFATc1 in DLBCL cells, upregulated miR-124-3p-inhibited DLBCL cell proliferation and promoted apoptosis. In addition, we found that hBMSC-derived exosomes carrying miR-124-3p repressed DLBCL cell proliferation both in vitro and in vivo.Conclusion: hBMSC-derived exosomal miR-124-3p represses the development of DLBCL through the downregulation of NFATc1.


2019 ◽  
Author(s):  
Wei Bian ◽  
Yishuai Li ◽  
Haiyong Zhu ◽  
Shaolin Gao ◽  
Ren Niu ◽  
...  

Abstract Background miRNA dysregulation has been implicated in cancer development.Methods In the present study, we use cell culture and transfection, the tissue specimens, RNA isolation and RT-PCR, Western blot and so on to explore the role of miR-493 in esophageal cancer.Results Overexpression of miR-493 attenuates esophageal cancer cell proliferation, migration, and invasion in vivo and in vitro. Moreover, miR-493 downregulation is an unfavorable factor in EC and negatively correlated with Wnt5A. The existence of miR-493 is also an important attribute of metabolism. Based on mechanism analyses, we show that miR-493 inhibits the activity of c-JUN and p-PI3K/p-AKT with enhanced p21 and directly regulates Wnt5A expression and function, while, c-JUN binds the promoter region of miR-493 and suppressed the expression of miR-493, forming a negative feedback loop. Moreover, miR-493 regulates the expression of PD-L1 by c-JUN and then the sensitivity of EC cells to DDP.Conclusions the results elucidate a molecular feedback loop that involves miR-493, Wnt5A, c-JUN and PD-L1 in EC. In future, these mechanistic findings provide a useful therapeutic option for the treatment of EC.


2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Guoyan Tian ◽  
Jin Chen ◽  
Yan Luo ◽  
Jin Yang ◽  
Tao Gao ◽  
...  

Abstract Background The present study investigated the pharmacological activity and mechanism of ethanol extract of Ligustrum lucidum Ait. leaves (EEL) on HCC. Methods Cell viability was determined using cell counting kit-8 (CCK-8) assay. The effects of EEL on cellular biological activities were analyzed by flow cytometry (FCM), cell wound scratch assay and transwell assay. The expression levels of related mRNA and protein were determined by performing quantitative real-time PCR (qRT-PCR), Western blotting assay and immunocytochemistry. Methylation-specific PCR (MSP) was carried out to investigate the possible mechanism underlying the DNA methylation of PTEN. Results EEL showed cytotoxicity to both Bel-7402 and Huh-7 cell lines. We also found that EEL enhanced the apoptosis of Bel-7402 and Huh-7 cells by regulating the expressions of Bcl-2 associated X (Bax), B cell lymphoma 2 (Bcl-2) and Cytochrome-C and the activity of caspase-3 and therefore promoted cell cycle arrest. Moreover, EEL also suppressed cell migration and invasion. EEL increased the expression of tissue inhibitor of metalloproteinases 2 (TIMP2) but decreased the expressions of matrix metalloproteinase2 (MMP2) and MMP9. Furthermore, EEL inhibited the phosphorylation of PI3K/Akt pathway. MSP results showed that EEL promoted the demethylation of PTEN, suggesting that the inactivation of PI3K/Akt may be related to DNA de-methylation of PTEN. In addition, EEL inhibited the tumor growth of HCC in vivo. Conclusions EEL exerted anti-tumor effect on HCC in vitro and in vivo. EEL mediated by the inhibition of PI3K/Akt may be closely related to DNA de-methylation of PTEN. Thus, EEL could be used as a potential anti-cancer therapeutic agent of HCC.


2020 ◽  
Author(s):  
Zhichao Xue ◽  
Vivian Wai Yan Lui ◽  
Yongshu Li ◽  
Jia Lin ◽  
Chanping You ◽  
...  

Abstract Background: Recent genomic analyses revealed that druggable molecule targets could only be detected in around 6% of nasopharyngeal carcinoma (NPC) patients. Yet, an addiction to dysregulated CDK4/6-cyclinD1 signalling pathway is an essential event in the pathogenesis of NPC. Using our newly established xenografts and cell lines derived from primary, recurrent and metastatic NPC, we aimed to evaluate the therapeutic efficacy of a specific CDK4/6 inhibitor, palbociclib, and its compatibility with other chemodrugs in treating NPC.Methods: The efficacy of single treatment of palbociclib on NPC models was first evaluated, followed by concurrent treatment with cisplatin or suberanilohydroxamic acid (SAHA). RNA sequencing was used to profile the related pathways in governing the drug response. Palbociclib-resistant NPC cell lines were also established to demonstrate if cisplatin could be used as a second-line treatment once the cells developed resistance to palbociclib. The efficacy of palbociclib treatment on cisplatin-resistant NPC cells was also examined. Results: Palbociclib single drug treatment was confirmed to have a cell cycle arresting effect of NPC cells in G1 phase in vitro. It also had a significant inhibitory effect in all the 6 NPC tumor models in vivo, with a substantial reduction in total tumor volume and proliferation marker Ki-67. Concurrent use of palbociclib dampened the cytotoxic effect of cisplatin in NPC cells in vitro. Notably, combination of palbociclib with SAHA resulted in synergistic cell death of NPC both in vitro and in vivo. Autophagy-associated cell death was found to be involved in the enhanced tumor growth inhibitory effect in the combined palbociclib+SAHA treatment. NPC cell lines trained to sustain growth in high dose of palbociclib and cisplatin remained sensitive in subsequent treatment of cisplatin or palbociclib respectively.Conclusions: This study provides essential evidences to position palbociclib as an alternative therapeutic option to NPC treatment, and to aware the effective administrative timing of palbociclib with other chemodrugs. The findings give the basis for planning of the first-in-human clinical trials of palbociclib regimens in NPC patients.


2019 ◽  
Vol 18 (3) ◽  
pp. 45-53
Author(s):  
S. N. Lavrentiev ◽  
M. B. Aksenenko ◽  
A. S. Averchuk ◽  
A. V. Komina ◽  
N. V. Palkina ◽  
...  

Various types of tissues was analyzed, and the algorithm for summing neutron and photon doses in neutronMiRNA s are involved in the regulation of numerous critical biological processes, including cell proliferation, differentiation, migration and invasion. They function as oncogenes or tumor suppressors according to the nature of the target. It has been previously determined that miR-204-5p miRNA is characterized by the increased level in melanoma. The aim of this study was to determine the effects of changes in the level of microRNA expression when dacarbazine was exposed to melanoma cells in vitro and synthetic miR-204-5p in vivo. The expression levels of miR-204-5p and miR-211 in melanoma cells were determined by real-time PCR. Antitumor effects in vivo were verified in assessing the growth dynamics of the tumor node. Toxic effects were assessed by animal behavior, fluid intake, feed, and ALT , AST , creatinine, urea levels. In the model of melanoma C57BL6, it was revealed that the introduction of the synthetic miR-204-5p did not cause significant changes in the investigated microRNA in tumor cells. At the same time, the antitumor effects of dacarbazine in melanoma cells in vitro led to an increase in the level of the investigated microRNA by more than 20 times. The results of the study indicated the possibility of compensating the level of miR-204-5p under the influence of cytostatic therapy. Taking into account the previously revealed miR-204-5p inhibitory effect on the proliferation of melanoma cells, we can assume that this miRNA can play a role in maintaining the dermal state of tumor cells. Further studies are required to understand the metastasis development and predict the response to antitumor therapy for melanoma.


2020 ◽  
Vol 11 (11) ◽  
Author(s):  
Wenbin Li ◽  
Yue Yan ◽  
Zongheng Zheng ◽  
Qiaohua Zhu ◽  
Qian Long ◽  
...  

AbstractHepatocellular carcinoma (HCC) has a high mortality rate and lacks an effective therapeutic target. Elevated expression of human telomerase reverse transcriptase (TERT) is an important hallmark in cancers, but the mechanism by which TERT is activated differentially in cancers is poorly understood. Here, we have identified nuclear receptor coactivator-3 (NCOA3) as a new modulator of TERT expression and tumor growth in HCC. NACO3 specifically binds to the TERT promoter at the -234 to -144 region and transcriptionally activates TERT expression. NCOA3 promotes HCC cell growth and tumor progression in vitro and in vivo through upregulating the TERT signaling. Knockdown of NACO3 suppresses HCC cell viability and colony formation, whereas TERT overexpression rescues this suppression. NCOA3 interacts with and recruits SP1 binding on the TERT promoter. Knockdown of NCOA3 also inhibits the expression of the Wnt signaling-related genes but has no effect on the Notch signaling-targeting genes. Moreover, NCOA3 is positively correlated with TERT expression in HCC tumor tissues, and high expression of both NCOA3 and TERT predicts a poor prognosis in HCC patients. Our findings indicate that targeting the NCOA3-SP1-TERT signaling axis may benefit HCC patients.


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Dongshao Chen ◽  
Xiaoting Lin ◽  
Jing Gao ◽  
Lin Shen ◽  
Zhongwu Li ◽  
...  

Based on the mechanisms by which Wee1 inhibitor and cisplatin played their own role, a promising strategy of Wee1 inhibitor combined with cisplatin was proposed, which was investigated in gastric cancer (GC). Either Wee1 inhibitor AZD1775 or cisplatin alone had a certain inhibitory effect on in vitro cell proliferation; however, the inhibitory effect was more significant when AZD1775 combined with cisplatin in vitro and in vivo. The underlying mechanisms unveiled that the increased DNA damage indicated by increased γH2AX protein, as well as augmented cell apoptosis indicated by upregulated proapoptotic proteins, was responsible for the significant inhibitory effect of AZD1775 plus cisplatin. Moreover, compared to any single drug, in vitro cell migration and invasion abilities were further attenuated by AZD1775 combined with cisplatin. There were suggestive results that the potentiated cytotoxicity between AZD1775 and cisplatin deserved a deep exploration in the future.


2009 ◽  
Vol 102 (12) ◽  
pp. 1265-1273 ◽  
Author(s):  
István Kenessey ◽  
Erika Simon ◽  
Krisztina Futosi ◽  
Bíborka Bereczky ◽  
Andrea Kiss ◽  
...  

SummaryHeparin and its derivatives have been shown to inhibit angiogenesis and metastasis formation. Accordingly, we investigated the effect of heparin fragments containing 4 to 22 monomers on human melanoma cell proliferation, migration and invasion in vitro as well as on the in vivo metastatic potential in a SCID mouse model. Only oligosaccharide dp18 had significant inhibitory effect on cell proliferation. In contrast, cell migration was inhibited by all oligosaccharides studied except dp8 and dp22. Anti CD44v3 antibody stimulated cell migration and invasion, and this effect could be attenuated by oligosaccharides dp4 and dp18. These fragments also inhibited the catalytic activity of myosin light chain phosphatase as well. Moreover, oligosaccharides dp4 and dp18 reduced the number of lung colonies formed in SCID mice intravenously injected with human melanoma cells, while dp22 proved to be ineffective in this respect.These studies revealed that fragments of heparin have an antimigratory and antimetastatic potential. These fragments lack the haemostatic effect of heparin, suggesting that they are potential specific antimetastatic agents in anticancer therapy.


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