scholarly journals Synthetic circular miR-21 RNA decoys enhance tumor suppressor expression and impair tumor growth in mice

NAR Cancer ◽  
2020 ◽  
Vol 2 (3) ◽  
Author(s):  
Simon Müller ◽  
Alice Wedler ◽  
Janina Breuer ◽  
Markus Glaß ◽  
Nadine Bley ◽  
...  

Abstract Naturally occurring circular RNAs efficiently impair miRNA functions. Synthetic circular RNAs may thus serve as potent agents for miRNA inhibition. Their therapeutic effect critically relies on (i) the identification of optimal miRNA targets, (ii) the optimization of decoy structures and (iii) the development of efficient formulations for their use as drugs. In this study, we extensively explored the functional relevance of miR-21-5p in cancer cells. Analyses of cancer transcriptomes reveal that miR-21-5p is the by far most abundant miRNA in human cancers. Deletion of the MIR21 locus in cancer-derived cells identifies several direct and indirect miR-21-5p targets, including major tumor suppressors with prognostic value across cancers. To impair miR-21-5p activities, we evaluate synthetic, circular RNA decoys containing four repetitive binding elements. In cancer cells, these decoys efficiently elevate tumor suppressor expression and impair tumor cell vitality. For their in vivo delivery, we for the first time evaluate the formulation of decoys in polyethylenimine (PEI)-based nanoparticles. We demonstrate that PEI/decoy nanoparticles lead to a significant inhibition of tumor growth in a lung adenocarcinoma xenograft mouse model via the upregulation of tumor suppressor expression. These findings introduce nanoparticle-delivered circular miRNA decoys as a powerful potential therapeutic strategy in cancer treatment.

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Lanlan Xi ◽  
Quanlin Liu ◽  
Wei Zhang ◽  
Linshan Luo ◽  
Jingfeng Song ◽  
...  

Abstract Background Circular RNAs (circRNAs) have been reported to play vital roles in colorectal cancer (CRC). However, only a few circRNAs have been experimentally validated and functionally described. In this research, we aimed to reveal the functional mechanism of circCSPP1 in CRC. Methods 36 DOX sensitive and 36 resistant CRC cases participated in this study. The expression of circCSPP1, miR-944 and FZD7 were detected by quantitative real time polymerase chain reaction (qRT-PCR) and the protein levels of FZD7, MRP1, P-gp and LRP were detected by western blot. Cell proliferation, migration, invasion, and apoptosis were assessed by 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide (MTT) assay, transwell assay, or flow cytometry analysis, respectively. The interaction between miR-944 and circCSPP1 or frizzled-7 (FZD7) was predicted by Starbase 3.0 and verified by the dual luciferase reporter assay, RNA immunoprecipitation (RIP) assay and RNA pull down assay. Xenograft tumor assay was performed to examine the effect of circCSPP1 on tumor growth in vivo. Results The expression of circCSPP1 and FZD7 was upregulated while miR-944 expression was downregulated in doxorubicin (DOX)-resistant CRC tissues and cells. CircCSPP1 knockdown significantly downregulated enhanced doxorubicin sensitivity, suppressed proliferation, migration, invasion, and induced apoptosis in DOX-resistant CRC cells. Interestingly, we found that circCSPP1 directly downregulated miR-944 expression and miR-944 decreased FZD7 level through targeting to 3′ untranslated region (UTR) of FZD7. Furthermore, circCSPP1 mediated DOX-resistant CRC cell progression and doxorubicin sensitivity by regulating miR-944/FZD7 axis. Besides, circCSPP1 downregulation dramatically repressed CRC tumor growth in vivo. Conclusion Our data indicated that circCSPP1 knockdown inhibited DOX-resistant CRC cell growth and enhanced doxorubicin sensitivity by miR-944/FZD7 axis, providing a potential target for CRC therapy.


2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Shih-Hsun Cheng ◽  
Chia-Hui Chu ◽  
Nai-Tzu Chen ◽  
Jeffrey S. Souris ◽  
Chin-Tu Chen ◽  
...  

Photodynamic therapy (PDT) for cancer treatment involves the pathology’s uptake of photosensitizers, which produce cytotoxic reactive oxygen species by photoirradiation. The use of nanoparticles as carriers of photosensitizers is one promising approach to this endeavor, owing to their small size, unique physicochemical properties, and easy/diverse functionalization. In the current work, we report on thein vivoassessment of PDT efficacy of these nanoconstructs in a murine model of human breast cancer, following a single (one-shot) nanoparticle dose and photoirradiation. Palladium-porphyrin (PdTPP) was administered intratumorally via injection of aqueous suspensions of either free PdTPP or MSN-conjugated PdTPP (MSN-PdTPP) at a dose of 50 μg. Mice were then exposed to a single photoirradiation session with total energy of 80 J. One month after one-shot PDT treatment, significantly greater reductions in tumor growth were observed in MSN-Pd treated animals than in PdTPP cohorts. Electron microscopy of tumor specimens harvested at various timepoints revealed excellent MSN-PdTPP uptake by cancer cells while immunohistologic analysis demonstrated marked increases in apoptotic response of MSN-PdTPP treated animals relative to PdTPP controls. Taken together, these findings suggest that considerable improvements in PDT efficacy can readily be achieved via the use of nanoparticle-based photosensitizers.


2018 ◽  
Vol 11 (04) ◽  
pp. 1850016 ◽  
Author(s):  
Jie Chen ◽  
Xu Tan ◽  
Shenglin Luo ◽  
Lei Long ◽  
Lang Liu ◽  
...  

Phototherapy, mainly including photodynamic therapy (PDT) and photothermal therapy (PTT), is a noninvasive and effective approach for cancer treatment. Since integration of PDT and PTT for simultaneous synergistic PDT/PTT treatment enables us to improve phototherapeutic efficacy significantly, it has been attracting a lot of investigations in current days. Here, we introduce IR-52, a new mitochondria-targeting near infrared (NIR) fluorescent small molecule, which possesses structure-inherent PTT and PDT synergistic phototherapeutic effects without conjugation to specific ligands. After NIR light irradiation (808[Formula: see text]nm, 2[Formula: see text]W/cm2, 5[Formula: see text]min), both the hyperthermia and excessive singlet oxygen levels were determined when dissolving IR-52 in aqueous solutions. In vitro photoinduced cytotoxicity studies showed significant lower cell viabilities and higher necrotic/apoptotic rates when cancer cells were treated with IR-52 and irradiation, and its’ mitochondrial localization in cancer cells would partially explain its high cytotoxicity. Further in vivo synergetic PDT and PTT effects were demonstrated by high tumor surface temperature and significant inhibition of tumor growth. Our results strongly suggest that IR-52, which possesses excellent photosensitivity, may provide a promising strategy for tumor treatment with decreased side effects.


2018 ◽  
Vol 115 (47) ◽  
pp. 12028-12033 ◽  
Author(s):  
Andrew V. Schally ◽  
Haibo Wang ◽  
Jinlin He ◽  
Renzhi Cai ◽  
Wei Sha ◽  
...  

The effects of the growth hormone-releasing hormone (GHRH) agonist MR409 on various human cancer cells were investigated. In H446 small cell lung cancer (SCLC) and HCC827 and H460 (non-SCLC) cells, MR409 promoted cell viability, reduced cell apoptosis, and induced the production of cellular cAMP in vitro. Western blot analyses showed that treatment of cancer cells with MR409 up-regulated the expression of cyclins D1 and D2 and cyclin-dependent kinases 4 and 6, down-regulated p27kip1, and significantly increased the expression of the pituitary-type GHRH receptor (pGHRH-R) and its splice-variant (SV1). Hence, in vitro MR409 exerts agonistic action on lung cancer cells in contrast to GHRH antagonists. However, in vivo, MR409 inhibited growth of lung cancers xenografted into nude mice. MR409 given s.c. at 5 μg/day for 4 to 8 weeks significantly suppressed growth of HCC827, H460, and H446 tumors by 48.2%, 48.7%, and 65.6%, respectively. This inhibition of tumor growth by MR409 was accompanied by the down-regulation of the expression of pGHRH-R and SV1 in the pituitary gland and tumors. Tumor inhibitory effects of MR409 in vivo were also observed in other human cancers, including gastric, pancreatic, urothelial, prostatic, mammary, and colorectal. This inhibition of tumor growth parallel to the down-regulation of GHRH-Rs is similar and comparable to the suppression of sex hormone-dependent cancers after the down-regulation of receptors for luteinizing hormone-releasing hormone (LHRH) by LHRH agonists. Further oncological investigations with GHRH agonists are needed to elucidate the underlying mechanisms.


Author(s):  
Minghuan Mao ◽  
Liang Yang ◽  
Jingyao Hu ◽  
Bing Liu ◽  
Xiling Zhang ◽  
...  

AbstractThe neuronally expressed developmentally downregulated 4 (NEDD4) gene encodes a ubiquitin ligase that targets the epithelial sodium channel for degradation and has been implicated in tumor growth in various cancers. Hence, in this study, we intended to characterize the functional relevance of the NEDD4-mediated Kruppel-like factor 8/microRNA-132/nuclear factor E2-related factor 2 (KLF8/miR-132/NRF2) axis in the development of bladder cancer. NEDD4 and KLF8 were overexpressed in bladder cancer tissues and were associated with poorer patient survival rates. In bladder cancer cells, NEDD4 intensified the stability and transcriptional activity of KLF8 through ubiquitination to augment cell viability and migratory ability. Our investigations revealed that NEDD4 promotes the binding of KLF8 to the miR-132 promoter region and inhibits the expression of miR-132. KLF8 inhibited the expression of miR-132 to augment the viability and migratory ability of bladder cancer cells. Furthermore, miR-132 downregulated the expression of NRF2 to restrict the viability and migratory ability of bladder cancer cells. In addition, in vivo findings verified that NEDD4 regulates the KLF8/miR-132/NRF2 axis by accelerating tumor growth and lung metastasis. In conclusion, this study highlights NEDD4 as a potential therapeutic target against tumor recurrence and metastasis in bladder cancer.


2019 ◽  
Vol 65 (5) ◽  
pp. 760-765
Author(s):  
Margarita Tyndyk ◽  
Irina Popovich ◽  
A. Malek ◽  
R. Samsonov ◽  
N. Germanov ◽  
...  

The paper presents the results of the research on the antitumor activity of a new drug - atomic clusters of silver (ACS), the colloidal solution of nanostructured silver bisilicate Ag6Si2O7 with particles size of 1-2 nm in deionized water. In vitro studies to evaluate the effect of various ACS concentrations in human tumor cells cultures (breast cancer, colon carcinoma and prostate cancer) were conducted. The highest antitumor activity of ACS was observed in dilutions from 2.7 mg/l to 5.1 mg/l, resulting in the death of tumor cells in all studied cell cultures. In vivo experiments on transplanted Ehrlich carcinoma model in mice consuming 0.75 mg/kg ACS with drinking water revealed significant inhibition of tumor growth since the 14th day of experiment (maximally by 52% on the 28th day, p < 0.05) in comparison with control. Subcutaneous injections of 2.5 mg/kg ACS inhibited Ehrlich's tumor growth on the 7th and 10th days of the experiment (p < 0.05) as compared to control.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Ronggang Luo ◽  
Yi Zhuo ◽  
Quan Du ◽  
Rendong Xiao

Abstract Background To detect and investigate the expression of POU domain class 2 transcription factor 2 (POU2F2) in human lung cancer tissues, its role in lung cancer progression, and the potential mechanisms. Methods Immunohistochemical (IHC) assays were conducted to assess the expression of POU2F2 in human lung cancer tissues. Immunoblot assays were performed to assess the expression levels of POU2F2 in human lung cancer tissues and cell lines. CCK-8, colony formation, and transwell-migration/invasion assays were conducted to detect the effects of POU2F2 and AGO1 on the proliferaion and motility of A549 and H1299 cells in vitro. CHIP and luciferase assays were performed for the mechanism study. A tumor xenotransplantation model was used to detect the effects of POU2F2 on tumor growth in vivo. Results We found POU2F2 was highly expressed in human lung cancer tissues and cell lines, and associated with the lung cancer patients’ prognosis and clinical features. POU2F2 promoted the proliferation, and motility of lung cancer cells via targeting AGO1 in vitro. Additionally, POU2F2 promoted tumor growth of lung cancer cells via AGO1 in vivo. Conclusion We found POU2F2 was highly expressed in lung cancer cells and confirmed the involvement of POU2F2 in lung cancer progression, and thought POU2F2 could act as a potential therapeutic target for lung cancer.


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