scholarly journals The Many Potential Fates of Non-Canonical Protein Substrates Subject to NEDDylation

Cells ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2660
Author(s):  
Kartikeya Vijayasimha ◽  
Brian P. Dolan

Neuronal precursor cell-expressed developmentally down-regulated protein 8 (NEDD8) is a ubiquitin-like protein (UBL) whose canonical function involves binding to, and thus, activating Cullin–Ring finger Ligases (CRLs), one of the largest family of ubiquitin ligases in the eukaryotic cell. However, in recent years, several non-canonical protein substrates of NEDD8 have been identified. Here we attempt to review the recent literature regarding non-canonical NEDDylation of substrates with a particular focus on how the covalent modification of NEDD8 alters the protein substrate. Like much in the study of ubiquitin and UBLs, there are no clear and all-encompassing explanations to satisfy the textbooks. In some instances, NEDD8 modification appears to alter the substrates localization, particularly during times of stress. NEDDylation may also have conflicting impacts upon a protein’s stability: some reports indicate NEDDylation may protect against degradation whereas others show NEDDylation can promote degradation. We also examine how many of the in vitro studies measuring non-canonical NEDDylation were conducted and compare those conditions to those which may occur in vivo, such as cancer progression. It is likely that the conditions used to study non-canonical NEDDylation are similar to some types of cancers, such as glioblastoma, colon and rectal cancers, and lung adenocarcinomas. Although the full outcomes of non-canonical NEDDylation remain unknown, our review of the literature suggests that researchers keep an open mind to the situations where this modification occurs and determine the functional impacts of NEDD8-modification to the specific substrates which they study.

Oncogene ◽  
2021 ◽  
Author(s):  
Jiuna Zhang ◽  
Xiaoyu Jiang ◽  
Jie Yin ◽  
Shiying Dou ◽  
Xiaoli Xie ◽  
...  

AbstractRING finger proteins (RNFs) play a critical role in cancer initiation and progression. RNF141 is a member of RNFs family; however, its clinical significance, roles, and mechanism in colorectal cancer (CRC) remain poorly understood. Here, we examined the expression of RNF141 in 64 pairs of CRC and adjacent normal tissues by real-time PCR, Western blot, and immunohistochemical analysis. We found that there was more expression of RNF141 in CRC tissue compared with its adjacent normal tissue and high RNF141 expression associated with T stage. In vivo and in vitro functional experiments were conducted and revealed the oncogenic role of RNF141 in CRC. RNF141 knockdown suppressed proliferation, arrested the cell cycle in the G1 phase, inhibited migration, invasion and HUVEC tube formation but promoted apoptosis, whereas RNF141 overexpression exerted the opposite effects in CRC cells. The subcutaneous xenograft models showed that RNF141 knockdown reduced tumor growth, but its overexpression promoted tumor growth. Mechanistically, liquid chromatography-tandem mass spectrometry indicated RNF141 interacted with KRAS, which was confirmed by Co-immunoprecipitation, Immunofluorescence assay. Further analysis with bimolecular fluorescence complementation (BiFC) and Glutathione-S-transferase (GST) pull-down assays showed that RNF141 could directly bind to KRAS. Importantly, the upregulation of RNF141 increased GTP-bound KRAS, but its knockdown resulted in a reduction accordingly. Next, we demonstrated that RNF141 induced KRAS activation via increasing its enrichment on the plasma membrane not altering total KRAS expression, which was facilitated by the interaction with LYPLA1. Moreover, KRAS silencing partially abolished the effect of RNF141 on cell proliferation and apoptosis. In addition, our findings presented that RNF141 functioned as an oncogene by upregulating KRAS activity in a manner of promoting KRAS enrichment on the plasma membrane in CRC.


2018 ◽  
Vol 18 (2) ◽  
pp. 156-165 ◽  
Author(s):  
Jiaqiang Wang ◽  
Chien-shan Cheng ◽  
Yan Lu ◽  
Xiaowei Ding ◽  
Minmin Zhu ◽  
...  

Background: Propofol, a widely used intravenous anesthetic agent, is traditionally applied for sedation and general anesthesia. Explanation: Recent attention has been drawn to explore the effect and mechanisms of propofol against cancer progression in vitro and in vivo. Specifically, the proliferation-inhibiting and apoptosis-inducing properties of propofol in cancer have been studied. However, the underlying mechanisms remain unclear. Conclusion: This review focused on the findings within the past ten years and aimed to provide a general overview of propofol's malignance-modulating properties and the potential molecular mechanisms.


2020 ◽  
Vol 160 (11-12) ◽  
pp. 650-658
Author(s):  
Yichen Le ◽  
Yi He ◽  
Meirong Bai ◽  
Ying Wang ◽  
Jiaxue Wu ◽  
...  

Ajuba has been found to be mutated or aberrantly regulated in several human cancers and plays important roles in cancer progression via different signaling pathways. However, little is known about the role of Ajuba in hepatocellular carcinoma (HCC). Here, we found an upregulation of Ajuba expression in HCC tissues compared with normal liver tissues, while a poor prognosis was observed in HCC patients with high Ajuba expression. Knockout of Ajuba in HCC cells inhibited cell growth in vitro and in vivo, suppressed cell migration, and enhanced the cell apoptosis under stress. Moreover, re-expression of Ajuba in Ajuba-deficient cells could restore the phenotype of Ajuba-deficient cells. In conclusion, these results indicate that Ajuba is upregulated in HCC and promotes cell growth and migration of HCC cells, suggesting that Ajuba could possibly be a new target for HCC diagnosis and treatment.


Oncogenesis ◽  
2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Xin Huang ◽  
Yichao Hou ◽  
Xiaoling Weng ◽  
Wenjing Pang ◽  
Lidan Hou ◽  
...  

AbstractExploring novel anticancer drugs to optimize the efficacy may provide a benefit for the treatment of colorectal cancer (CRC). Disulfiram (DSF), as an antialcoholism drug, is metabolized into diethyldithiocarbamate-copper complex (CuET) in vivo, which has been reported to exert the anticancer effects on various tumors in preclinical studies. However, little is known about whether CuET plays an anti-cancer role in CRC. In this study, we found that CuET had a marked effect on suppressing CRC progression both in vitro and in vivo by reducing glucose metabolism. Mechanistically, using RNA-seq analysis, we identified ALDH1A3 as a target gene of CuET, which promoted cell viability and the capacity of clonal formation and inhibited apoptosis in CRC cells. MicroRNA (miR)-16-5p and 15b-5p were shown to synergistically regulate ALDH1A3, which was negatively correlated with both of them and inversely correlated with the survival of CRC patients. Notably, using co-immunoprecipitation followed with mass spectrometry assays, we identified PKM2 as a direct downstream effector of ALDH1A3 that stabilized PKM2 by reducing ubiquitination. Taken together, we disclose that CuET treatment plays an active role in inhibiting CRC progression via miR-16-5p and 15b-5p/ALDH1A3/PKM2 axis–mediated aerobic glycolysis pathway.


Biomolecules ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 37
Author(s):  
An-Jen Chiang ◽  
Chia-Jung Li ◽  
Kuan-Hao Tsui ◽  
Chung Chang ◽  
Yuan-chin Ivan Chang ◽  
...  

Cervical cancer is a common gynecological malignancy, accounting for 10% of all gynecological cancers. Recently, targeted therapy for cervical cancer has shown unprecedented advantages. Several studies have shown that ubiquitin conjugating enzyme E2 (UBE2C) is highly expressed in a series of tumors, and participates in the progression of these tumors. However, the possible impact of UBE2C on the progression of cervical squamous cell carcinoma (CESC) remains unclear. Here, we carried out tissue microarray analysis of paraffin-embedded tissues from 294 cervical cancer patients with FIGO/TNM cancer staging records. The results indicated that UBE2C was highly expressed in human CESC tissues and its expression was related to the clinical characteristics of CESC patients. Overexpression and knockdown of UBE2C enhanced and reduced cervical cancer cell proliferation, respectively, in vitro. Furthermore, in vivo experiments showed that UBE2C regulated the expression and activity of the mTOR/PI3K/AKT pathway. In summary, we confirmed that UBE2C is involved in the process of CESC and that UBE2C may represent a molecular target for CESC treatment.


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.


Tumor Biology ◽  
2021 ◽  
Vol 43 (1) ◽  
pp. 11-26
Author(s):  
Maike Busch ◽  
Natalia Miroschnikov ◽  
Jaroslaw Thomas Dankert ◽  
Marc Wiesehöfer ◽  
Klaus Metz ◽  
...  

BACKGROUND: Retinoblastoma (RB) is the most common childhood eye cancer. Chemotherapeutic drugs such as etoposide used in RB treatment often cause massive side effects and acquired drug resistances. Dysregulated genes and miRNAs have a large impact on cancer progression and development of chemotherapy resistances. OBJECTIVE: This study was designed to investigate the involvement of retinoic acid receptor alpha (RARα) in RB progression and chemoresistance as well as the impact of miR-138, a potential RARα regulating miRNA. METHODS: RARα and miR-138 expression in etoposide resistant RB cell lines and chemotherapy treated patient tumors compared to non-treated tumors was revealed by Real-Time PCR. Overexpression approaches were performed to analyze the effects of RARα on RB cell viability, apoptosis, proliferation and tumorigenesis. Besides, we addressed the effect of miR-138 overexpression on RB cell chemotherapy resistance. RESULTS: A binding between miR-138 and RARα was shown by dual luciferase reporter gene assay. The study presented revealed that RARα is downregulated in etoposide resistant RB cells, while miR-138 is endogenously upregulated. Opposing RARα and miR-138 expression levels were detectable in chemotherapy pre-treated compared to non-treated RB tumor specimen. Overexpression of RARα increases apoptosis levels and reduces tumor cell growth of aggressive etoposide resistant RB cells in vitro and in vivo. Overexpression of miR-138 in chemo-sensitive RB cell lines partly enhances cell viability after etoposide treatment. CONCLUSIONS: Our findings show that RARα acts as a tumor suppressor in retinoblastoma and is downregulated upon etoposide resistance in RB cells. Thus, RARα may contribute to the development and progression of RB chemo-resistance.


Author(s):  
Jun-Xian Du ◽  
Yi-Hong Luo ◽  
Si-Jia Zhang ◽  
Biao Wang ◽  
Cong Chen ◽  
...  

Abstract Background Intensive evidence has highlighted the effect of aberrant alternative splicing (AS) events on cancer progression when triggered by dysregulation of the SR protein family. Nonetheless, the underlying mechanism in breast cancer (BRCA) remains elusive. Here we sought to explore the molecular function of SRSF1 and identify the key AS events regulated by SRSF1 in BRCA. Methods We conducted a comprehensive analysis of the expression and clinical correlation of SRSF1 in BRCA based on the TCGA dataset, Metabric database and clinical tissue samples. Functional analysis of SRSF1 in BRCA was conducted in vitro and in vivo. SRSF1-mediated AS events and their binding motifs were identified by RNA-seq, RNA immunoprecipitation-PCR (RIP-PCR) and in vivo crosslinking followed by immunoprecipitation (CLIP), which was further validated by the minigene reporter assay. PTPMT1 exon 3 (E3) AS was identified to partially mediate the oncogenic role of SRSF1 by the P-AKT/C-MYC axis. Finally, the expression and clinical significance of these AS events were validated in clinical samples and using the TCGA database. Results SRSF1 expression was consistently upregulated in BRCA samples, positively associated with tumor grade and the Ki-67 index, and correlated with poor prognosis in a hormone receptor-positive (HR+) cohort, which facilitated proliferation, cell migration and inhibited apoptosis in vitro and in vivo. We identified SRSF1-mediated AS events and discovered the SRSF1 binding motif in the regulation of splice switching of PTPMT1. Furthermore, PTPMT1 splice switching was regulated by SRSF1 by binding directly to its motif in E3 which partially mediated the oncogenic role of SRSF1 by the AKT/C-MYC axis. Additionally, PTPMT1 splice switching was validated in tissue samples of BRCA patients and using the TCGA database. The high-risk group, identified by AS of PTPMT1 and expression of SRSF1, possessed poorer prognosis in the stage I/II TCGA BRCA cohort. Conclusions SRSF1 exerts oncogenic roles in BRCA partially by regulating the AS of PTPMT1, which could be a therapeutic target candidate in BRCA and a prognostic factor in HR+ BRCA patient.


Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 987
Author(s):  
Eric J. O’Neill ◽  
Deborah Termini ◽  
Alexandria Albano ◽  
Evangelia Tsiani

Cancer is a disease characterized by aberrant proliferative and apoptotic signaling pathways, leading to uncontrolled proliferation of cancer cells combined with enhanced survival and evasion of cell death. Current treatment strategies are sometimes ineffective in eradicating more aggressive, metastatic forms of cancer, indicating the need to develop novel therapeutics targeting signaling pathways which are essential for cancer progression. Historically, plant-derived compounds have been utilized in the production of pharmaceuticals and chemotherapeutic compounds for the treatment of cancer, including paclitaxel and docetaxel. Theaflavins, phenolic components present in black tea, have demonstrated anti-cancer potential in cell cultures in vitro and in animal studies in vivo. Theaflavins have been shown to inhibit proliferation, survival, and migration of many cancer cellswhile promoting apoptosis. Treatment with theaflavins has been associated with increased levels of cleaved poly (ADP-ribose) polymerase (PARP) and cleaved caspases-3, -7, -8, and -9, all markers of apoptosis, and increased expression of the proapoptotic marker Bcl-2-associated X protein (Bax) and concomitant reduction in the antiapoptotic marker B-cell lymphoma 2 (Bcl-2). Additionally, theaflavin treatment reduced phosphorylated Akt, phosphorylated mechanistic target of rapamycin (mTOR), phosphatidylinositol 3-kinase (PI3K), and c-Myc levels with increased expression of the tumour suppressor p53. This review summarizes the current in vitro and in vivo evidence available investigating the anti-cancer effects of theaflavins across various cancer cell lines and animal models.


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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