scholarly journals Importin 13 promotes NSCLC progression by mediating RFPL3 nuclear translocation and hTERT expression upregulation

2020 ◽  
Vol 11 (10) ◽  
Author(s):  
Bisan Abdalfatah Zohud ◽  
Ping Guo ◽  
Batoul Abdalfatah Zohud ◽  
Fengzhou Li ◽  
Jiao J. Hao ◽  
...  

Abstract Our previous studies have reported that RFPL3 protein exerts its unique function as a transcriptional factor of hTERT promoter after being transported into the lung cancer cell nucleus. However, the detailed mechanism by which RFPL3 undergoes nuclear transport has not been reported yet. Here, we identified RFPL3 as a potential import cargo for IPO13, which was found to be overexpressed in NSCLC cells and tissues. IPO13 interacted with RFPL3 in lung cancer cells, and the knockdown of IPO13 led to the cytoplasmic accumulation of RFPL3, the decreased anchoring of RFPL3 at hTERT promoter, and the downregulation of hTERT expression. Moreover, IPO13 silencing suppressed tumor growth in vitro and in vivo. IHC analysis confirmed the positive correlation between the expression levels of IPO13 and hTERT in the tumor tissues from patients with lung cancer. Furthermore, the mechanistic study revealed that IPO13 recognized RFPL3 via a functional nuclear localization signal (NLS), which is located in the B30.2 domain at the C-terminal region of RFPL3. Of note, the presence of EGFR mutations was significantly related to the increased IPO13 expression. The EGFR-TKI Osimertinib downregulated IPO13 expression level in NSCLC cell lines with EGFR mutations, but not in EGFR wild-type ones. In summary, our data suggest that inhibition of IPO13 transport activity itself might be an alternative and potential therapeutic strategy for NSCLC.

2021 ◽  
Vol 12 (8) ◽  
Author(s):  
Weijie Zhang ◽  
Ruochen Zhang ◽  
Yuanyuan Zeng ◽  
Yue Li ◽  
Yikun Chen ◽  
...  

AbstractLung cancer is recognized as the leading cause of cancer-related death worldwide, with non-small cell lung cancer (NSCLC) being the predominant subtype, accounting for approximately 85% of lung cancer cases. Although great efforts have been made to treat lung cancer, no proven method has been found thus far. Considering β, β-dimethyl-acryl-alkannin (ALCAP2), a natural small-molecule compound isolated from the root of Lithospermum erythrorhizon. We found that lung adenocarcinoma (LUAD) cell proliferation and metastasis can be significantly inhibited after treatment with ALCAP2 in vitro, as it can induce cell apoptosis and arrest the cell cycle. ALCAP2 also significantly suppressed the volume of tumours in mice without inducing obvious toxicity in vivo. Mechanistically, we revealed that ALCAP2-treated cells can suppress the nuclear translocation of β-catenin by upregulating the E3 ligase NEDD4L, facilitating the binding of ubiquitin to β-catenin and eventually affecting the wnt-triggered transcription of genes such as survivin, cyclin D1, and MMP9. As a result, our findings suggest that targeting the oncogene β-catenin with ALCAP2 can inhibit the proliferation and metastasis of LUAD cells, and therefore, ALCAP2 may be a new drug candidate for use in LUAD therapeutics.


2020 ◽  
Author(s):  
Hao Gong ◽  
Yongwen Li ◽  
Yin Yuan ◽  
Weiting Li ◽  
Hongbing Zhang ◽  
...  

Abstract Background: Lung cancer is the leading cause of cancer-related death worldwide. Non–small-cell lung cancer (NSCLC) is the most common type of lung cancer. Traditional anticancer therapies involving epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (EGFR-TKIs) have been proven beneficial in the treatment of patients with EGFR mutations. However, patients with EGFR wild-type NSCLC usually fail to respond to EGFR-TKIs. Enhancer of zeste homolog 2 (EZH2), a key molecule of the PRC2 complex, plays an important role in epigenetic regulation and is overexpressed in various tumors. EZH2 inhibitors sensitize various types of tumor cells to antitumor drugs. Therefore, this study aimed to investigate whether the EZH2 inhibitors GSK343 and DZNep, whencombined with gefitinib, can reverse EGFR-TKI resistance in EGFR wild-type NSCLC. Methods:EZH2 expression was evaluated using the RNA sequencing dataset of NSCLC patients (502 lung squamous cell carcinoma cases including 49 paracancerous lung tissues and 513 lung adenocarcinoma cases including 59 paracancerous lung tissues) from The Cancer Genome Atlas (TCGA). We simultaneously also verified EZH2 expressionin 40 NSCLC samples and their corresponding paracancerous lung tissues from our institution via quantitative PCR. The lung adenocarcinoma cell lines A549 and H1299 were treated with EZH2-specific small interfering RNA or EZH2 inhibitors and subjected to analyses of cell viability and apoptosis as well as of EGFR pathway protein expressions by western blotting. Results: EZH2 was upregulated in human NSCLC tissues and was correlated with poor prognosis in patients with lung adenocarcinoma based on data from both TCGA and our institution. Both EZH2 inhibitors sensitized A549 and H1299 cells to gefitinib and suppressed cell viability and proliferation in vitroby downregulating the phosphorylation of EGFR and AKT and inducing cell apoptosis. Co-administration of EZH2 inhibitors (GSK343 or DZNep) with gefitinib exerted stronger inhibitory effects on tumor activity, cell proliferation, and cell migration than single drug administration in vitro and in vivo.Conclusion: Co-administration of EZH2 inhibitors with EGFR-TKIs may be feasible for the treatment of EGFR wild-type NSCLC in patients who refuse traditional chemotherapy.


2020 ◽  
Author(s):  
Matias S Ciarlantini ◽  
Andrea Barquero ◽  
diana wetzler ◽  
Juan Bayo ◽  
Martín M. Dodes Traian ◽  
...  

<p>Rac1 (Ras-related C3 botulinum toxin substrate 1), is a member of the family of Rho GTPases involved in the dynamic control of cytoskeleton reorganization and other fundamental cellular functions including growth, motility and survival. Aberrant activity of Rac1 and its regulators is common in human cancer. In particular, deregulated expression/activity of Rac Guanine nucleotide Exchange Factors (GEFs), responsible for Rac activation, has been largely associated to a metastatic phenotype and drug resistance. Thus, the development of novel Rac1-GEF interaction inhibitors is a promising strategy for finding new preclinical candidates. In this work, we have studied structure-activity relationships within a new family of N,N’-disubstituted guanidine as Rac1-GEF protein-protein interaction inhibitors, starting from our first developed member 1A-116. We found that new analogue 1D-142, bearing a pyridine ring instead of benzene ring, presents improved antiproliferative activity in human cancer cell lines and higher potency as Rac1-GEF interaction inhibitor in vitro. In addition, 1D-142 reduces TNFα-induced NF-κB nuclear translocation, a mechanisms mediated by Rac1 during cell proliferation and migration in NSCLC. Notably, 1D-142 was used to show for the first time the application of a Rac1 inhibitor in a lung cancer animal model.<br></p>


2020 ◽  
Author(s):  
Matias S Ciarlantini ◽  
Andrea Barquero ◽  
diana wetzler ◽  
Juan Bayo ◽  
Martín M. Dodes Traian ◽  
...  

<p>Rac1 (Ras-related C3 botulinum toxin substrate 1), is a member of the family of Rho GTPases involved in the dynamic control of cytoskeleton reorganization and other fundamental cellular functions including growth, motility and survival. Aberrant activity of Rac1 and its regulators is common in human cancer. In particular, deregulated expression/activity of Rac Guanine nucleotide Exchange Factors (GEFs), responsible for Rac activation, has been largely associated to a metastatic phenotype and drug resistance. Thus, the development of novel Rac1-GEF interaction inhibitors is a promising strategy for finding new preclinical candidates. In this work, we have studied structure-activity relationships within a new family of N,N’-disubstituted guanidine as Rac1-GEF protein-protein interaction inhibitors, starting from our first developed member 1A-116. We found that new analogue 1D-142, bearing a pyridine ring instead of benzene ring, presents improved antiproliferative activity in human cancer cell lines and higher potency as Rac1-GEF interaction inhibitor in vitro. In addition, 1D-142 reduces TNFα-induced NF-κB nuclear translocation, a mechanisms mediated by Rac1 during cell proliferation and migration in NSCLC. Notably, 1D-142 was used to show for the first time the application of a Rac1 inhibitor in a lung cancer animal model.<br></p>


2018 ◽  
Author(s):  
Xin-Chun Zhao ◽  
Gui-Zhen Wang ◽  
Yong-Chun Zhou ◽  
Liang Ma ◽  
Jie Liu ◽  
...  

AbstractTo systematically identify ubiquitin pathway genes that are critical to lung carcinogenesis, we used a genome-wide silencing method in this study to knockdown 696 genes in non-small cell lung cancer (NSCLC) cells. We identified 31 candidates that were required for cell proliferation in two NSCLC lines, among which the E2 ubiquitin conjugase CDC34 represented the most significant one. CDC34 was elevated in tumor tissues in 67 of 102 (65.7%) NSCLCs, and smokers had higher CDC34 than nonsmokers. The expression of CDC34 was inversely associated with overall survival of the patients. Forced expression of CDC34 promoted, whereas knockdown of CDC34 inhibited lung cancerin vitroandin vivo. CDC34 bound EGFR and competed with E3 ligase c-Cbl to inhibit the polyubiquitination and subsequent degradation of EGFR. In EGFR-L858R and EGFR-T790M/Del(exon 19)-driven lung cancer in mice, knockdown of CDC34 by lentivirus mediated transfection of short hairpin RNA significantly inhibited tumor formation. These results demonstrate that an E2 enzyme is capable of competing with E3 ligase to inhibit ubiquitination and subsequent degradation of oncoprotein substrate, and CDC34 represents an attractive therapeutic target for NSCLCs with or without drug-resistant EGFR mutations.


2021 ◽  
Vol 11 ◽  
Author(s):  
Ying-Ming Tsai ◽  
Kuan-Li Wu ◽  
Yu-Wei Liu ◽  
Wei-An Chang ◽  
Yung-Chi Huang ◽  
...  

BackgroundAngiogenesis is required for tumor development and metastasis, which is a major part in a pro-tumor microenvironment. Vascular mimicry (VM) is a process in which cancer cells, rather than endothelia, create an alternative perfusion system to support the tumor progression.ObjectivesTo validate the role of VM and to develop a strategy to inhibit angiogenesis in lung cancer.MethodsIn this study, we utilized lung cancer samples to verify the existence of VM and conducted several experimental methods to elucidate the molecular pathways.ResultsH1299 and CL1-0 lung cancer cells were unable to form capillary-like structures. VM formation was induced by cancer-associated fibroblast (CAFs) in both in vitro and in vivo experiments. Notch2–Jagged1 cell–cell contact between cancer cells and CAFs contributes to the formation of VM networks, supported by Notch intracellular domain (NICD) 2 nuclear translocation and N2ICD target gene upregulated in lung cancer cells mixed with CAFs. The polarization of tumor-promoting N2-type neutrophil was increased by VM networks consisting of CAF and cancer cells. The intravasation of cancer cells and N2-type neutrophils were increased because of the loose junctions of VM. Disruption of cancer cell–CAF connections by a γ‐secretase inhibitor enforced the anticancer effect of anti‐vascular endothelial growth factor antibodies in a mouse model.ConclusionThis study provides the first evidence that CAFs induce lung cancer to create vascular-like networks. These findings suggest a therapeutic opportunity for improving antiangiogenesis therapy in lung cancer.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Chuncao Xu ◽  
Lei Zhang ◽  
Daifei Wang ◽  
Shiqin Jiang ◽  
Di Cao ◽  
...  

AbstractPatients with EGFR mutations in non-small cell lung cancer (NSCLC) have been greatly benefited from gefitinib, however, the therapeutic has failed due to the presence of acquired resistance. In this study, we show that gefitinib significantly induces downregulation of Sterol Regulator Element Binding (SREBP1) in therapy-sensitive cells. However, this was not observed in EGFR mutant NSCLC cells with acquired resistance. Lipidomics analysis showed that gefitinib could differently change the proportion of saturated phospholipids and unsaturated phospholipids in gefitinib-sensitive and acquired-resistant cells. Besides, levels of ROS and MDA were increased upon SREBP1 inhibition and even more upon gefitinib treatment. Importantly, inhibition of SREBP1 sensitizes EGFR-mutant therapy-resistant NSCLC to gefitinib both in vitro and in vivo models. These data suggest that sustained de novo lipogenesis through the maintenance of active SRBEP-1 is a key feature of acquired resistance to gefitinib in EGFR mutant lung cancer. Taken together, targeting SREBP1-induced lipogenesis is a promising approach to overcome acquired resistance to gefitinib in EGFR-mutant lung cancer.


Author(s):  
Xiaohua Jie ◽  
William Pat Fong ◽  
Rui Zhou ◽  
Ye Zhao ◽  
Yingchao Zhao ◽  
...  

AbstractRadioresistance is regarded as the main barrier to effective radiotherapy in lung cancer. However, the underlying mechanisms of radioresistance remain elusive. Here, we show that lysine-specific demethylase 4C (KDM4C) is overexpressed and correlated with poor prognosis in lung cancer patients. We provide evidence that genetical or pharmacological inhibition of KDM4C impairs tumorigenesis and radioresistance in lung cancer in vitro and in vivo. Moreover, we uncover that KDM4C upregulates TGF-β2 expression by directly reducing H3K9me3 level at the TGF-β2 promoter and then activates Smad/ATM/Chk2 signaling to confer radioresistance in lung cancer. Using tandem affinity purification technology, we further identify deubiquitinase USP9X as a critical binding partner that deubiquitinates and stabilizes KDM4C. More importantly, depletion of USP9X impairs TGF-β2/Smad signaling and radioresistance by destabilizing KDM4C in lung cancer cells. Thus, our findings demonstrate that USP9X-mediated KDM4C deubiquitination activates TGF-β2/Smad signaling to promote radioresistance, suggesting that targeting KDM4C may be a promising radiosensitization strategy in the treatment of lung cancer.


2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Yipengchen Yin ◽  
Yongjing Li ◽  
Sheng Wang ◽  
Ziliang Dong ◽  
Chao Liang ◽  
...  

Abstract Background The recently developed biomimetic strategy is one of the mostly effective strategies for improving the theranostic efficacy of diverse nanomedicines, because nanoparticles coated with cell membranes can disguise as “self”, evade the surveillance of the immune system, and accumulate to the tumor sites actively. Results Herein, we utilized mesenchymal stem cell memabranes (MSCs) to coat polymethacrylic acid (PMAA) nanoparticles loaded with Fe(III) and cypate—an derivative of indocyanine green to fabricate Cyp-PMAA-Fe@MSCs, which featured high stability, desirable tumor-accumulation and intriguing photothermal conversion efficiency both in vitro and in vivo for the treatment of lung cancer. After intravenous administration of Cyp-PMAA-Fe@MSCs and Cyp-PMAA-Fe@RBCs (RBCs, red blood cell membranes) separately into tumor-bearing mice, the fluorescence signal in the MSCs group was 21% stronger than that in the RBCs group at the tumor sites in an in vivo fluorescence imaging system. Correspondingly, the T1-weighted magnetic resonance imaging (MRI) signal at the tumor site decreased 30% after intravenous injection of Cyp-PMAA-Fe@MSCs. Importantly, the constructed Cyp-PMAA-Fe@MSCs exhibited strong photothermal hyperthermia effect both in vitro and in vivo when exposed to 808 nm laser irradiation, thus it could be used for photothermal therapy. Furthermore, tumors on mice treated with phototermal therapy and radiotherapy shrank 32% more than those treated with only radiotherapy. Conclusions These results proved that Cyp-PMAA-Fe@MSCs could realize fluorescence/MRI bimodal imaging, while be used in phototermal-therapy-enhanced radiotherapy, providing desirable nanoplatforms for tumor diagnosis and precise treatment of non-small cell lung cancer.


Author(s):  
Jiongwei Pan ◽  
Gang Huang ◽  
Zhangyong Yin ◽  
Xiaoping Cai ◽  
Enhui Gong ◽  
...  

AbstractSignificantly high-expressed circFLNA has been found in various cancer cell lines, but not in lung cancer. Therefore, this study aimed to explore the role of circFLNA in the progression of lung cancer. The target gene of circFLNA was determined by bioinformatics and luciferase reporter assay. Viability, proliferation, migration, and invasion of the transfected cells were detected by CCK-8, colony formation, wound-healing, and transwell assays, respectively. A mouse subcutaneous xenotransplanted tumor model was established, and the expressions of circFLNA, miR-486-3p, XRCC1, CYP1A1, and related genes in the cancer cells and tissues were detected by RT-qPCR, Western blot, or immunohistochemistry. The current study found that miR-486-3p was low-expressed in lung cancer. MiR-486-3p, which has been found to target XRCC1 and CYP1A1, was regulated by circFLNA. CircFLNA was located in the cytoplasm and had a high expression in lung cancer cells. Cancer cell viability, proliferation, migration, and invasion were promoted by overexpressed circFLNA, XRCC1, and CYP1A1 but inhibited by miR-486-3p mimic and circFLNA knockdown. The weight of the xenotransplanted tumor was increased by circFLNA overexpression yet reduced by miR-486-3p mimic. Furthermore, miR-486-3p mimic reversed the effect of circFLNA overexpression on promoting lung cancer cells and tumors and regulating the expressions of miR-486-3p, XRCC1, CYP1A1, and metastasis/apoptosis/proliferation-related factors. However, overexpressed XRCC1 and CYP1A1 reversed the inhibitory effect of miR-486-3p mimic on cancer cells and tumors. In conclusion, circFLNA acted as a sponge of miR-486-3p to promote the proliferation, migration, and invasion of lung cancer cells in vitro and in vivo by regulating XRCC1 and CYP1A1.


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