scholarly journals Long Non-Coding RNA MALAT1 Decreases the Sensitivity of Resistant Glioblastoma Cell Lines to Temozolomide

2017 ◽  
Vol 42 (3) ◽  
pp. 1192-1201 ◽  
Author(s):  
Hongwei Li ◽  
Xiaoli Yuan ◽  
Dongming Yan ◽  
Dongpeng Li ◽  
Fangxia Guan ◽  
...  

Background/Aim: Multidrug resistance (MDR) is largely responsible for the failure of chemotherapy. The long non-coding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript (MALAT1) has been reported to be closely related to tumor biology. In the present study, whether MALAT1 contributes to the resistance of glioblastoma cell lines to temozolomide (TMZ) was investigated. Methods: The glioblastoma cell lines U251 and U87 were exposed to increasing concentrations of TMZ to generate TMZ-resistant colonies (the U251/TMZ and U87/TMZ cell lines). The expression levels of MALAT1 and proteins related to epithelial-mesenchymal transition (EMT) were detected by real-time PCR and western blot, respectively. After the transfection of si-MALAT1 or pcDNA-MALAT1, cell viability, mRNA expression of MDR-associated proteins (MDR1, MRP5 and LRP1), and protein expression of EMT related proteins (ZEB1, Snail and SLUG) were evaluated. Results: The expression of MALAT1 was upregulated in the U251/TMZ and U87/TMZ cell lines compared to that in U251 and U87 cell lines, respectively. The treatment of si-MALAT1 decreased MDR1, MRP5, and LRP1 expression, enhanced cell sensitivity to TMZ, and downregulated ZEB1 protein expression, whereas pcDNA-MALAT1 had the opposite effects. However, the effects of si-MALAT1 on MDR -associated protein expression, cell viability, and EMT status were reversed by the transfection of pcDNA-ZEB1, and the effects of pcDNA-MALAT1 were reversed by the transfection of si-ZEB1. In vivo, MALAT1 overexpression enhanced tumors’ TMZ resistance and upregulated ZEB1 expression. Conclusion: MALAT1 decreased the sensitivity of resistant glioma cell lines to TMZ by regulating ZEB1.

Open Medicine ◽  
2020 ◽  
Vol 15 (1) ◽  
pp. 921-931
Author(s):  
Juan Zhao ◽  
Xue-Bin Zeng ◽  
Hong-Yan Zhang ◽  
Jie-Wei Xiang ◽  
Yu-Song Liu

AbstractLong non-coding RNA forkhead box D2 adjacent opposite strand RNA 1 (FOXD2-AS1) has emerged as a potential oncogene in several tumors. However, its biological function and potential regulatory mechanism in glioma have not been fully investigated to date. In the present study, RT-qPCR was conducted to detect the levels of FOXD2-AS1 and microRNA (miR)-506-5p, and western blot assays were performed to measure the expression of CDK2, cyclinE1, P21, matrix metalloproteinase (MMP)7, MMP9, N-cadherin, E-cadherin and vimentin in glioma cells. A luciferase reporter assay was performed to verify the direct targeting of miR-506-5p by FOXD2-AS1. Subsequently, cell viability was analyzed using the CCK-8 assay. Cell migration and invasion were analyzed using Transwell and wound healing assays, respectively. The results demonstrated that FOXD2-AS1 was significantly overexpressed in glioma cells, particularly in U251 cells. Knockdown of FOXD2-AS1 in glioma cells significantly inhibited cell proliferation, migration, invasion and epithelial–mesenchymal transition (EMT) and regulated the expression of CDK2, cyclinE1, P21, MMP7 and MMP9. Next, a possible mechanism for these results was explored, and it was observed that FOXD2-AS1 binds to and negatively regulates miR-506-5p, which is known to be a tumor-suppressor gene in certain human cancer types. Furthermore, overexpression of miR-506-5p significantly inhibited cell proliferation, migration, invasion and EMT, and these effects could be reversed by transfecting FOXD2-AS1 into the cells. In conclusion, our data suggested that FOXD2-AS1 contributed to glioma proliferation, metastasis and EMT via competitively binding to miR-506-5p. FOXD2-AS1 may be a promising target for therapy in patients with glioma.


2021 ◽  
Vol 17 (10) ◽  
pp. 1993-2002
Author(s):  
Haoran Yu ◽  
Chen Zhang ◽  
Wanpeng Li ◽  
Xicai Sun ◽  
Quan Liu ◽  
...  

To investigate the expression characteristics of long non-coding RNA SNHG14 in nasopharyngeal carcinoma (NPC) and its effects on epithelial-mesenchymal transition and development of nano-coated si-SNHG14 as an anti-tumor agent. The SNHG14 expression in cancerous and adjacent non-cancerous tissues was monitored using reverse transcriptionpolymerase chain reaction (RT-PCR). Gain- and loss-of-function experiments tested the regulation of SNHG14, miR- 5590-3p, and ZEB1 on PD-L1. The binding association between the above three factors was verified using bioinformatics analysis. EMT-related E-cadherin, N-cadherin, and Vimentin were tested using Western blot. Animal experiments in nude mice verified the function of SNHG14 in the EMT of NPC in vivo. The nano-coated si-SNHG14 was developed as an anti-tumor agent and was verified NPC cell in vitro. SNHG14 was upregulated in NPC tissues. Knocking down SNHG14 markedly inhibited the EMT of NPC. Additionally, the expression of ZEB1 was positively related to that of the SNHG14, while it was inversely correlated with that of miR-5590-3p. Moreover, ZEB1 transcription upregulated PD-L1 and promoted the EMT, while SNHG14 could accelerate the EMT of NPC in vivo by regulating the PD-1 and PD-L1. SNHG14-miR-5590- 3p-ZEB1 positively regulated PD-L1 and facilitate the EMT of NPC. Nano-coated si-SNHG14 significantly downregulated PD-L1 expression and decreased EMT.


2020 ◽  
Vol Volume 12 ◽  
pp. 12259-12267
Author(s):  
Ying Qi ◽  
Qingqing Cui ◽  
Wenjing Zhang ◽  
Renjie Yao ◽  
Dong Xu ◽  
...  

2016 ◽  
Vol 474 (1) ◽  
pp. 21-45 ◽  
Author(s):  
Shashi K. Gopal ◽  
David W. Greening ◽  
Alin Rai ◽  
Maoshan Chen ◽  
Rong Xu ◽  
...  

Cell–cell communication is critical across an assortment of physiological and pathological processes. Extracellular vesicles (EVs) represent an integral facet of intercellular communication largely through the transfer of functional cargo such as proteins, messenger RNAs (mRNAs), microRNA (miRNAs), DNAs and lipids. EVs, especially exosomes and shed microvesicles, represent an important delivery medium in the tumour micro-environment through the reciprocal dissemination of signals between cancer and resident stromal cells to facilitate tumorigenesis and metastasis. An important step of the metastatic cascade is the reprogramming of cancer cells from an epithelial to mesenchymal phenotype (epithelial–mesenchymal transition, EMT), which is associated with increased aggressiveness, invasiveness and metastatic potential. There is now increasing evidence demonstrating that EVs released by cells undergoing EMT are reprogrammed (protein and RNA content) during this process. This review summarises current knowledge of EV-mediated functional transfer of proteins and RNA species (mRNA, miRNA, long non-coding RNA) between cells in cancer biology and the EMT process. An in-depth understanding of EVs associated with EMT, with emphasis on molecular composition (proteins and RNA species), will provide fundamental insights into cancer biology.


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