scholarly journals USP7 is a novel Deubiquitinase sustaining PLK1 protein stability and regulating chromosome alignment in mitosis

2019 ◽  
Vol 38 (1) ◽  
Author(s):  
Yuchong Peng ◽  
Youhong Liu ◽  
Yingxue Gao ◽  
Bowen Yuan ◽  
Xuli Qi ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Protein Stability ◽  
Protein Degradation ◽  
Cell Apoptosis ◽  
Affinity Purification ◽  
Fluorescent Microscopy ◽  
Taxane Resistance ◽  
Tumor Tissues ◽  
Anticancer Mechanism

Abstract Background The deubiquitinase USP7 has been identified as an oncogene with key roles in tumorigenesis and therapeutic resistance for a series of cancer types. Recently small molecular inhibitors have been developed to target USP7. However, the anticancer mechanism of USP7 inhibitors is still elusive. Methods Cell viability or clonogenicity was tested by violet crystal assay. Cell apoptosis or cell cycle was analyzed by flow cytometry, and chromosome misalignment was observed by a fluorescent microscopy. The protein interaction of PLK1 and USP7 was detected by tandem affinity purification and high throughput proteomics, and further confirmed by co-immunoprecipitation, GST pull-down and protein co-localization. The correlation between USP7 level of tumor tissues and taxane-resistance was evaluated. Results Pharmacological USP7 inhibition by P5091 retarded cell proliferation and induced cell apoptosis. Further studies showed that P5091 induced cell cycle arrest at G2/M phase, and particularly induced chromosome misalignment, indicating the key roles of USP7 in mitosis. USP7 protein was detected in the PLK1-interacted protein complex. USP7 interacts with PLK1 protein through its PBD domain by catalytic activity. USP7 as a deubiquitinase sustained PLK1 protein stability via the C223 site, and inversely, USP7 inhibition by P5091 promoted the protein degradation of PLK1 through the ubiquitination-proteasome pathway. By overexpressing PLK1, USP7 that had been depleted by RNAi ceased to induce chromosome misalignment in mitosis and again supported cell proliferation and cell survival. Both USP7 and PLK1 were overexpressed in taxane-resistant cancer cells, and negatively correlated with the MP scores in tumor tissues. Either USP7 or PLK1 knockdown by RNAi significantly sensitized taxane-resistant cells to taxane cell killing. Conclusion This is the first report that PLK1 is a novel substrate of USP7 deubiquitinase, and that USP7 sustained the protein stability of PLK1. USP7 inhibition induces cell apoptosis and cell cycle G2/M arrest, and overcomes taxane resistance by inducing the protein degradation of PLK1, resulting in chromosome misalignment in mitosis.

scholarly journals LncRNA MNX1-AS1 promotes ovarian cancer process via targeting the miR-744-5p/SOX12 axis

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Yang Shen ◽  
Mengmeng Lv ◽  
Yichen Fang ◽  
Jin Lu ◽  
Yuzhong Wu
Keyword(s):  
Cell Cycle ◽  
Ovarian Cancer ◽  
Cell Proliferation ◽  
Western Blot ◽  
Cell Apoptosis ◽  
Luciferase Reporter ◽  
Migration And Invasion ◽  
Promoting Effect ◽  
Downstream Target ◽  
Tumor Tissues

Abstract Purpose Ovarian cancer (OC) is the most common malignancy in women with high mortality. Increasing studies have revealed that long non-coding RNA (lncRNA) MNX1-AS1 has a promoting effect on various cancers. However, the mechanisms of MNX1-AS1 in OC are still unclear. Therefore, this study focused on exploring the mechanisms of MNX1-AS1 in OC. Materials and methods The expression of SOX12 at the protein level was detected by western blot. Cell proliferation was detected by CCK8 assay and colony formation assay. Cell cycle and cell apoptosis were detected by flow cytometry. Wound-healing assay, transwell assay and western blot were used to detect the ability of cell migration and invasion. The target binding was confirmed through the luciferase reporter assay. Results The expression of MNX1-AS1 was increased in OC tumor tissues and cells. Elevated MNX1-AS1 expression is associated with advanced stage and lower overall survival rate. Knockdown of MNX1-AS1 inhibited cell proliferation, migration and invasion, blocked cell cycle, and promoted cell apoptosis in SKOV-3 and OVCAR-3 cells. MNX1-AS1 was competitively binding with miR-744-5p, and its downstream target gene was SOX12. miR-544-5p expression was decreased, while SOX12 expression was increased in OC tumor tissues and cells. Overexpression of miR-744-5p inhibited cell proliferation, migration, invasion and promoted cell apoptosis in SKOV-3 and OVCAR-3 cells. Conclusion MNX1-AS1 promoted the development of OC through miR-744-5p/SOX12 axis. This study revealed a novel mechanism of MNX1-AS1 in OC, which may provide a new treatment or scanning target for OC.

scholarly journals Positive feedback between lncRNA FLVCR1-AS1 and KLF10 may inhibit pancreatic cancer progression via the PTEN/AKT pathway

2021 ◽  
Vol 40 (1) ◽  
Author(s):  
Jiewei Lin ◽  
Shuyu Zhai ◽  
Siyi Zou ◽  
Zhiwei Xu ◽  
Jun Zhang ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Pancreatic Cancer ◽  
Cell Proliferation ◽  
Cancer Progression ◽  
Positive Feedback ◽  
Molecular Mechanisms ◽  
Tumor Tissues ◽  
And Migration

Abstract Background FLVCR1-AS1 is a key regulator of cancer progression. However, the biological functions and underlying molecular mechanisms of pancreatic cancer (PC) remain unknown. Methods FLVCR1-AS1 expression levels in 77 PC tissues and matched non-tumor tissues were analyzed by qRT-PCR. Moreover, the role of FLVCR1-AS1 in PC cell proliferation, cell cycle, and migration was verified via functional in vitro and in vivo experiments. Further, the potential competitive endogenous RNA (ceRNA) network between FLVCR1-AS1 and KLF10, as well as FLVCR1-AS1 transcription levels, were investigated. Results FLVCR1-AS1 expression was low in both PC tissues and PC cell lines, and FLVCR1-AS1 downregulation was associated with a worse prognosis in patients with PC. Functional experiments demonstrated that FLVCR1-AS1 overexpression significantly suppressed PC cell proliferation, cell cycle, and migration both in vitro and in vivo. Mechanistic investigations revealed that FLVCR1-AS1 acts as a ceRNA to sequester miR-513c-5p or miR-514b-5p from the sponging KLF10 mRNA, thereby relieving their suppressive effects on KLF10 expression. Additionally, FLVCR1-AS1 was shown to be a direct transcriptional target of KLF10. Conclusions Our research suggests that FLVCR1-AS1 plays a tumor-suppressive role in PC by inhibiting proliferation, cell cycle, and migration through a positive feedback loop with KLF10, thereby providing a novel therapeutic strategy for PC treatment.

Effect of Metformin Intervention on Pancreatic β-Cell Apoptosis

2022 ◽  
Vol 12 (4) ◽  
pp. 873-877
Author(s):  
Dongqian Xie ◽  
Zhicheng Gao ◽  
Mei Liu ◽  
Defeng Wang
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Endoplasmic Reticulum ◽  
Endoplasmic Reticulum Stress ◽  
Cell Apoptosis ◽  
Dependent Manner ◽  
Cycle Arrest ◽  
High Glucose Condition ◽  
M Phase ◽  
Signaling Activation

Metformin is shown to have hypoglycemic effects. However, the relationship between metformin’s intervention in FFA-induced endoplasmic reticulum stress-mediated insulin resistance (IR) and insulin β-cell apoptosis under high-glucose condition remains unclear. Our study intends to assess their relationship. Human pancreatic β-cells were treated with metformin and cell proliferation and IR were detected by MTT assay along with detection of Wnt/β-catenin signaling by RT-PCR, cell cycle and apoptosis by flow cytometry. Metformin inhibited β cell proliferation which was mediated by FFA-induced endoplasmic reticulum stress in a time-dependent and dose-dependent manner as well as induced cell cycle arrest at G2/M phase. In addition, metformin inhibited β-catenin signaling activation and decreased the expression of c-myc, Dvl-2, survivin, Dvl-3, GSK-3β (p-ser9) and promoted GSK-3 (p-tyr216) and Axin-2 expression. In conclusion, metformin inhibits Wnt/β-catenin signaling and promotes FFA to induce endoplasmic reticulum stress, thereby mediating pancreatic β-cells behaviors.

scholarly journals Upregulation of miRNA-23a-3p rescues high glucose-induced cell apoptosis and proliferation inhibition in cardiomyocytes

2020 ◽  
Vol 56 (10) ◽  
pp. 866-877
Author(s):  
Fang Wu ◽  
Feng Wang ◽  
Qian Yang ◽  
Yawen Zhang ◽  
Ke Cai ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
High Glucose ◽  
Cell Apoptosis ◽  
Myocardial Injury ◽  
Proliferation Inhibition ◽  
Cardiomyocyte Proliferation ◽  
Injury Model ◽  
Cell Proliferation Inhibition ◽  
Glucose Treatment

AbstractMaternal hyperglycemia potentially inhibits the development of the fetal heart by suppressing cardiomyocyte proliferation and promoting apoptosis. Different studies have indicated that miRNAs are key regulators of cardiomyocyte proliferation, differentiation, and apoptosis and play a protective role in a variety of cardiovascular diseases. However, the biological function of miRNA-23a in hyperglycemia-related cardiomyocyte injury is not fully understood. The present study investigated the effect of miRNA-23a-3p on cell proliferation and apoptosis in a myocardial injury model induced by high glucose. H9c2 cardiomyocytes were exposed to high glucose to establish an in vitro myocardial injury model and then transfected with miRNA-23a-3p mimics. After miRNA-23a-3p transfection, lens-free microscopy was used to dynamically monitor cell numbers and confluence and calculate the cell cycle duration. CCK-8 and EdU incorporation assays were performed to detect cell proliferation. Flow cytometry was used to measured cell apoptosis. Upregulation of miRNA-23a-3p significantly alleviated high glucose-induced cell apoptosis and cell proliferation inhibition (p < 0.01 and p < 0.0001, respectively). The cell cycle of the miRNA-23a-3p mimics group was significantly shorter than that of the negative control group (p < 0.01). The expression of cell cycle–activating and apoptosis inhibition-associated factors Ccna2, Ccne1, and Bcl-2 was downregulated by high glucose and upregulated by miRNA-23a-3p overexpression in high glucose-injured H9c2 cells. miRNA-23a-3p mimics transfection before high glucose treatment had a significantly greater benefit than transfection after high glucose treatment (p < 0.0001), and the rescue effect of miRNA-23a-3p increased as the concentration increased. This study suggests that miRNA-23a-3p exerted a dose- and time-dependent protective effect on high glucose-induced H9c2 cardiomyocyte injury.

scholarly journals Anticancer Activity of Binary Toxins from Lysinibacillus sphaericus IAB872 against Human Lung Cancer Cell Line A549

2014 ◽  
Vol 9 (1) ◽  
pp. 1934578X1400900
Author(s):  
Wenjuan Luo ◽  
Cuicui Liu ◽  
Ruijuan Zhang ◽  
Jianwei He ◽  
Bei Han
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Tumor Cell ◽  
Cancer Cells ◽  
Mtt Assay ◽  
Cell Apoptosis ◽  
Human Lung ◽  
Immunocytochemical Staining ◽  
Lysinibacillus Sphaericus ◽  
Proliferative Effect

The inhibitory effect of binary toxic (Bin) protein produced by Lysinibacillus sphaericus IAB872 on cell proliferation of human lung, liver, stomach and cervical tumor cell lines was assessed using MTT assay. The effect of Bin protein on A549 cell proliferation, apoptosis, cell cycle, migration and invasion were examined by MTT assay, Western blotting, Immunocytochemical staining, flow cytometry assay and wound-healing assay. Results showed that Bin protein inhibits proliferation of a range of human cancer cells in vitro. The anti-proliferative effect of Bin is associated with cell apoptosis as a result of an increased ratio of cellular Bax/bcl-2, up-regulated CyclinB1and down-regulated Cdc25c expression, and its anti-proliferative action was associated with cell cycle arrest in the G2/M-phase. Bin protein could promote apoptosis and inhibit motility and invasion of A549 cancer cells. The anti-proliferative effect of Bin protein was associated with the induction of apoptotic cell death and cell cycle disruption. These results show that Bin protein has the potential to be developed as a chemotherapeutic agent by induction of human tumor cell apoptosis.

scholarly journals Long non-coding RNA RP11-468E2.5 curtails colorectal cancer cell proliferation and stimulates apoptosis via the JAK/STAT signaling pathway by targeting STAT5 and STAT6

2019 ◽  
Vol 38 (1) ◽  
Author(s):  
Li Jiang ◽  
Xu-Hai Zhao ◽  
Yin-Ling Mao ◽  
Jun-Feng Wang ◽  
Hui-Jun Zheng ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Cell Cycle ◽  
Cell Proliferation ◽  
Signaling Pathway ◽  
Cell Apoptosis ◽  
Target Genes ◽  
Biological Activities ◽  
Janus Kinase ◽  
Normal Tissues ◽  
Stat Signaling

Abstract Background Long non-coding RNAs (lncRNAs) are tumor-associated biological molecules and have been found to be implicated in the progression of colorectal cancer (CRC). This study aims to examine the effects of lncRNA RP11-468E2.5 and its target genes (STAT5 and STAT6) on the biological activities of CRC cells via the Janus kinase-signal transducer and activator of transcription (JAK/STAT) signaling pathway. Methods We initially screened the GEO database for differentially expressed lncRNAs related to CRC and then made a prediction of the implicated target genes. Then we collected CRC tissues and adjacent normal tissues from 169 CRC patients. Human CRC HCT116 and SW480 cells were treated with small interference RNA (siRNA) against RP11-468E2.5, AG490 (an inhibitor of the JAK/STAT signaling pathway), or both in combination. Next, we measured the effects of RP11-468E2.5 treatment on cellular activities such as cell viability, cycle distribution and cell apoptosis, and studied interactions among RP11-468E2.5, STAT5/STAT6, and the JAK/STAT signaling pathway. Finally, an in vivo tumor formation assay was performed to observe the effect of RP11-468E2.5 on tumor growth. Results The CRC-related gene microarray data showed low expression of RP11-468E2.5 in CRC surgical specimens. However, RP11-468E2.5 was confirmed to target STAT5 and STAT6, which participate in the JAK/STAT signaling pathway. CRC tissues showed lower expression of RP11-468E2.5, higher expression of STAT5, STAT6 and of the cell cycle marker Cyclin D1 (CCND1), compared to the findings in adjacent normal tissues. The treatment of siRNA against RP11-468E2.5 increased expression of JAK2, STAT3, STAT5, STAT6, CCND1 and Bcl-2 along with the extent of STAT3, STAT5 and STAT6 phosphorylation, while lowering expression of P21 and P27. Treatment with AG490 exhibited approximately opposite effects, whereas siRNA against RP11-468E2.5 treatment stimulated CRC cell proliferation and reduced cell apoptosis, while promoting cell cycle entry; AG490 treatment reversed these results. Conclusions Altogether, we conclude that up-regulation of RP11-468E2.5 inhibits the JAK/STAT signaling pathway by targeting STAT5 and STAT6, thereby suppressing cell proliferation and promoting cell apoptosis in CRC.

Knockdown of RNF2 enhances the radiosensitivity of squamous cell carcinoma in lung

2019 ◽  
Vol 97 (5) ◽  
pp. 589-599 ◽  
Author(s):  
Jie Yang ◽  
Fan Yu ◽  
Jinlei Guan ◽  
Tao Wang ◽  
Changjiang Liu ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Squamous Cell Carcinoma ◽  
Cell Carcinoma ◽  
Squamous Cell ◽  
Cell Apoptosis ◽  
X Ray ◽  
Stable Transfectants

A previous study has reported that knockdown of RING finger protein 2 (RNF2) increases the radiosensitivity of esophageal cancer cells both in vitro and in vivo. However, the effect of RNF2 knockdown on radiosensitivity in squamous cell carcinoma (SqCC) remains unknown. For this, NCI-H226 and SK-MES-1 cells were exposed to X-ray irradiation and then RNF2 levels were determined. RNF2 was knocked-down and stable transfectants were selected. Radiosensitivity, cell proliferation, apoptosis, cell cycle, and γ-H2AX foci formation were evaluated. Interaction among ataxia telangiectasia mutated protein (ATM), mediator of DNA damage checkpoint 1 (MDC1), and H2AX were examined. Xenograft models were used to explore the effect of RNF2 knockdown on radiosensitivity in vivo. The results showed that RNF2 expression was significantly increased by X-ray irradiation. RNF2 knockdown combined with X-ray irradiation markedly inhibited cell proliferation, caused cell cycle arrest at the G1 phase, and induced cell apoptosis. In addition, RNF2 knockdown enhanced the radiosensitivity of SqCC cells, inhibited irradiation-induced γ-H2AX foci formation, and impaired the interactions among ATM, MDC1, and H2AX. Furthermore, combination of RNF2 knockdown and X-ray irradiation suppressed tumor growth and promoted tumor cell apoptosis in vivo. RNF2 may be a new therapeutic target to enhance the radiosensitivity of SqCC cells in lung.

scholarly journals A Novel Gene RNF138 Expressed in Human Gliomas and Its Function in the Glioma Cell Line U251

2012 ◽  
Vol 35 (3) ◽  
pp. 167-178 ◽  
Author(s):  
You-xin Zhou ◽  
San-song Chen ◽  
Ting-feng Wu ◽  
Da-dong Ding ◽  
Xiong-hui Chen ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Cell Line ◽  
Brain Tissue ◽  
Cell Lines ◽  
Cell Apoptosis ◽  
Glioma Cell ◽  
Glioma Cell Line ◽  
Glioma Tissue ◽  
Glioma Cell Lines

Background: The gliomas represent the most common primary malignant brain tumors; however, little is known about the molecular pathogenesis of these tumors. Recent research reveals that the oncogenesis and development of gliomas have a close relation to the overexpression of several oncogenes and the inactivation of tumor suppressor genes. Whether the RING finger protein, RNF138, a newly discovered protein, plays a role in glioma oncogenesis is unknown. The present study investigates the expression levels of RNF138 mRNA in glioma samples and noncancerous brain samples and its function in the human glioma cell line U251.Methods: RT-PCR was used to ascertain the expression of RNF138 mRNA in the glioma cell lines U251, SHG44, U87, A172, and U373. The RNF138 mRNA expression levels of 35 pathological confirmed glioma samples (Grade I – 4 cases, Grade II – 13 cases, Grade III – 11 cases, and Grade IV – 7 cases) and five noncancerous brain tissue samples were analyzed by real-time quantitative PCR. By RNA interference (RNAi) with the lentivirus vector system, the expression of RNF138 was inhibited in the human astrocytomas-glioblastoma multiforme cell line U251. The effects of RNF138-knockdown on cell proliferation were assessed by Cellomics, and cell cycle and cell apoptosis were assessed by FACS.Results: The RNF138 mRNA is expressed in the five glioma cell lines, and its expression level is significantly higher in glioma tissue than in noncancerous brain tissue. By down-regulation of RNF138 expression, U251 cell proliferation was inhibited and cell apoptosis increased. At the same time, S stage cells lessened and G2 stage cells increased.Conclusion: The RNF138 gene is highly expressed in glioma tissue and glioma cell lines. It plays an important role in glioma cell proliferation, apoptosis, and cell cycle.

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