LINC00152 promotes Ovarian tumor progression and Predicts Poor Prognosis by inhibiting the  ubiquitination of BCL6

2020 ◽  
Author(s):  
Shunni Wang ◽  
Weiwei Weng ◽  
Tingting Chen ◽  
Midie Xu ◽  
Ping Wei ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Tumor Progression ◽  
Protein Interactions ◽  
Ovarian Tumor ◽  
Molecular Mechanisms ◽  
Tumor Proliferation ◽  
In Vivo Experiments ◽  
Rna Immunoprecipitation

Abstract Background : Long non-coding RNA 00152 (LINC00152) has been found oncogenic in multiple somatic malignancies. But its roles in the ovarian cancer remain elusive. We aim to investigate its functions and mechanism in the ovarian tumor progression. Methods: We used RNAscope and RT-qPCR assays to detect the LINC00152 levels in 152 pairs of ovarian tumor and paratumorous tissues, conducted in vitro and in vivo experiments to evaluate its biological functions, and performed RNA immunoprecipitation, RNA-pulldown, MS/LS analysis, mutant construction and ubiquitination assays to explore the LINC00152-BCL6 binding and regulation. Results: LINC00152 was abnormally increased in the ovarian tumor tissues and its high expression predicted poorer survivals of patients; overexpression of LINC00152 promoted ovarian tumor proliferation and metastasis both in vitro and in vivo ; LINC00152 bond to Serine333 and Serine343 of BCL6 and then suppressed its ubiquitination; Finally, LINC00152 facilitated its oncogenic functions in a BCL6-mediated manner in ovarian cancer. Conclusions: LINC00152 is the independent prognostic predictor of ovarian cancer; and the abnormal expression of LINC00152 facilitates ovarian tumor proliferation and invasion by suppress the ubiquitination of BCL6. Our data might be helpful in exploring the molecular mechanisms of lncRNA-protein interactions, and might provide the potential target for the tumor pharmacology of ovarian cancer.

scholarly journals The polypeptide GALNT6 Displays Redundant Functions upon Suppression of its Closest Homolog GALNT3 in Mediating Aberrant O-Glycosylation, Associated with Ovarian Cancer Progression

2019 ◽  
Vol 20 (9) ◽  
pp. 2264 ◽  
Author(s):  
Razan Sheta ◽  
Magdalena Bachvarova ◽  
Elizabeth Macdonald ◽  
Stephane Gobeil ◽  
Barbara Vanderhyden ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Cancer Progression ◽  
Molecular Mechanisms ◽  
Survival Rates ◽  
Functional Redundancy ◽  
Tumor Formation ◽  
Migration And Invasion ◽  
Gene Ablation

Epithelial ovarian cancer (EOC) represents the most lethal gynecologic malignancy; a better understanding of the molecular mechanisms associated with EOC etiology could substantially improve EOC management. Aberrant O-glycosylation in cancer is attributed to alteration of N-acetylgalactosaminyltransferases (GalNAc-Ts). Reports suggest a genetic and functional redundancy between GalNAc-Ts, and our previous data are indicative of an induction of GALNT6 expression upon GALNT3 suppression in EOC cells. We performed single GALNT3 and double GALNT3/T6 suppression in EOC cells, using a combination of the CRISPR-Cas9 system and shRNA-mediated gene silencing. The effect of single GALNT3 and double GALNT3/T6 inhibition was monitored both in vitro (on EOC cells roliferation, migration, and invasion) and in vivo (on tumor formation and survival of experimental animals). We confirmed that GALNT3 gene ablation leads to strong and rather compensatory GALNT6 upregulation in EOC cells. Moreover, double GALNT3/T6 suppression was significantly associated with stronger inhibitory effects on EOC cell proliferation, migration, and invasion, and accordingly displayed a significant increase in animal survival rates compared with GALNT3-ablated and control (Ctrl) EOC cells. Our data suggest a possible functional redundancy of GalNAc-Ts (GALNT3 and T6) in EOC, with the perspective of using both these enzymes as novel EOC biomarkers and/or therapeutic targets.

scholarly journals New Actors Driving the Epithelial–Mesenchymal Transition in Cancer: The Role of Leptin

Biomolecules ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1676
Author(s):  
Monserrat Olea-Flores ◽  
Juan C. Juárez-Cruz ◽  
Miriam D. Zuñiga-Eulogio ◽  
Erika Acosta ◽  
Eduardo García-Rodríguez ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Tumor Progression ◽  
Epithelial Mesenchymal Transition ◽  
Migration And Invasion ◽  
Mesenchymal Transition ◽  
Epithelial Cancers ◽  
Patients With Cancer

Leptin is a hormone secreted mainly by adipocytes; physiologically, it participates in the control of appetite and energy expenditure. However, it has also been linked to tumor progression in different epithelial cancers. In this review, we describe the effect of leptin on epithelial–mesenchymal transition (EMT) markers in different study models, including in vitro, in vivo, and patient studies and in various types of cancer, including breast, prostate, lung, and ovarian cancer. The different studies report that leptin promotes the expression of mesenchymal markers and a decrease in epithelial markers, in addition to promoting EMT-related processes such as cell migration and invasion and poor prognosis in patients with cancer. Finally, we report that leptin has the greatest biological relevance in EMT and tumor progression in breast, lung, prostate, esophageal, and ovarian cancer. This relationship could be due to the key role played by the enriched tumor microenvironment in adipose tissue. Together, these findings demonstrate that leptin is a key biomolecule that drives EMT and metastasis in cancer.

scholarly journals METTL3 promotes the initiation and metastasis of ovarian cancer by inhibiting CCNG2 expression via promoting the maturation of pri-microRNA-1246

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Xuehan Bi ◽  
Xiao Lv ◽  
Dajiang Liu ◽  
Hongtao Guo ◽  
Guang Yao ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Molecular Mechanisms ◽  
High Expression ◽  
Ovarian Cancer Cells ◽  
Inadequate Knowledge ◽  
And Migration ◽  
Cancer Tissues

AbstractOvarian cancer is a common gynecological malignant tumor with a high mortality rate and poor prognosis. There is inadequate knowledge of the molecular mechanisms underlying ovarian cancer. We examined the expression of methyltransferase-like 3 (METTL3) in tumor specimens using RT-qPCR, immunohistochemistry, and Western blot analysis, and tested the methylation of METTL3 by MSP. Levels of METTL3, miR-1246, pri-miR-1246 and CCNG2 were then analyzed and their effects on cell biological processes were also investigated, using in vivo assay to validate the in vitro findings. METTL3 showed hypomethylation and high expression in ovarian cancer tissues and cells. Hypomethylation of METTL3 was pronounced in ovarian cancer samples, which was negatively associated with patient survival. Decreased METTL3 inhibited the proliferation and migration of ovarian cancer cells and promoted apoptosis, while METTL3 overexpression exerted opposite effects. Mechanistically, METTL3 aggravated ovarian cancer by targeting miR-1246, while miR-1246 targeted and inhibited CCNG2 expression. High expression of METTL3 downregulated CCNG2, promoted the metabolism and growth of transplanted tumors in nude mice, and inhibited apoptosis. The current study highlights the promoting role of METTL3 in the development of ovarian cancer, and presents new targets for its treatment.

scholarly journals Chloroquine enhances temozolomide cytotoxicity in malignant gliomas by blocking autophagy

2014 ◽  
Vol 37 (6) ◽  
pp. E12 ◽  
Author(s):  
Encouse B. Golden ◽  
Hee-Yeon Cho ◽  
Ardeshir Jahanian ◽  
Florence M. Hofman ◽  
Stan G. Louie ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Malignant Gliomas ◽  
Glioma Cells ◽  
In Vivo Model ◽  
Autophagosome Formation ◽  
Individual Drug ◽  
In Vivo Experiments ◽  
Associated Proteins

Object In a recent clinical trial, patients with newly diagnosed glioblastoma multiforme benefited from chloroquine (CQ) in combination with conventional therapy (resection, temozolomide [TMZ], and radiation therapy). In the present study, the authors report the mechanism by which CQ enhances the therapeutic efficacy of TMZ to aid future studies aimed at improving this therapeutic regimen. Methods Using in vitro and in vivo experiments, the authors determined the mechanism by which CQ enhances TMZ cytotoxicity. They focused on the inhibition-of-autophagy mechanism of CQ by knockdown of the autophagy-associated proteins or treatment with autophagy inhibitors. This mechanism was tested using an in vivo model with subcutaneously implanted U87MG tumors from mice treated with CQ in combination with TMZ. Results Knockdown of the autophagy-associated proteins (GRP78 and Beclin) or treatment with the autophagy inhibitor, 3-methyl adenine (3-MA), blocked autophagosome formation and reduced CQ cytotoxicity, suggesting that autophagosome accumulation precedes CQ-induced cell death. In contrast, blocking autophagosome formation with knockdown of GRP78 or treatment with 3-MA enhanced TMZ cytotoxicity, suggesting that the autophagy pathway protects from TMZ-induced cytotoxicity. CQ in combination with TMZ significantly increased the amounts of LC3B-II (a marker for autophagosome levels), CHOP/GADD-153, and cleaved PARP (a marker for apoptosis) over those with untreated or individual drug-treated glioma cells. These molecular mechanisms seemed to take place in vivo as well. Subcutaneously implanted U87MG tumors from mice treated with CQ in combination with TMZ displayed higher levels of CHOP/GADD-153 than did untreated or individual drug-treated tumors. Conclusions Taken together, these results demonstrate that CQ blocks autophagy and triggers endoplasmic reticulum stress, thereby increasing the chemosensitivity of glioma cells to TMZ.

scholarly journals Membrane type 1 matrix metalloproteinase proteolytic activity in initial adhesive and invasive events of ovarian cancer metastasis

2014 ◽  
Author(s):  
◽  
Lana Bruney
Keyword(s):  
Ovarian Cancer ◽  
Extracellular Matrix ◽  
Proteolytic Activity ◽  
Ovarian Tumor ◽  
Molecular Mechanisms ◽  
Cancer Metastasis ◽  
Ectodomain Shedding ◽  
Metastatic Process

Epithelial ovarian cancer (EOC) is one of the most common gynecologic malignancies, generally developing in women over the age of forty. When EOC are diagnosed prior to metastatic dissemination, the overall 5-year survival rate is 92%; however, nearly 85% of women with EOC are diagnosed with metastasis already present, dropping the survival rate to less than 30%. EOC, arises, arguably, from the single layer of cells that cover the ovary or fallopian tube. Metastatic ovarian tumors develop once an epithelial cell transforms, inducing detachment from the primary tumor site. These shed cells travel throughout the peritoneal cavity, escaping anoikis to survive as single cells and multicellular aggregates (MCA), and metastasize intraperitoneally through adhesion to and invasion of the mesothelial cell layer covering the peritoneum, the primary microenvironment for ovarian cancer metastasis. These mesothelial cells lie atop a collagen type I-rich extracellular matrix; subsequent to the initial attachment of ovarian cancer cells, proteolytic activity catalyzes migration through the mesothelial monolayer and promotes invasion of the sub-mesothelial matrix. Elucidating the early molecular mechanisms involved in this metastatic process, specifically the adhesion of EOC cells to mesothelial cells and penetration of the associated sub-mesothelial extracellular matrix, is essential to the development of future therapeutic agents. Enzymatic activity of matrix type 1 metalloproteinase (MT1-MMP), a transmembrane proteinase that degrades interstitial collagen, has been shown to be critical to this process. MT1-MMP activity has been directly implicated in both the invasion of the sub-mesothelial collagen I matrix, and in the shedding of metastatic MCA, but the molecular mechanisms behind these events are not completely understood. Considering the well-established role of MT1-MMP in the EOC metastatic process, identification of the molecules contributing to these pro-metastatic phenotypes is critical to future understanding of EOC metastatic spread. This research investigated the initial adhesive and invasive events of ovarian cancer metastasis, as associated with MT1-MMP proteolytic activity. Specifically, the effect of MT1-MMP activity on ovarian tumor cell ectodomain shedding and the in vitro, relationship between MT1-MMP and a potential phosphorylator, integrin linked kinase (ILK), on adhesion and invasion was assessed. Investigations utilized in vitro models of homotypic and heterotypic cell-cell adhesion, meso-mimetic invasion assays, and ex vivo tissue explants. Results suggest that ILK activity may catalyze phosphorylation of MT1-MMP to promote pro-metastatic events, including strengthening of adhesive contacts, invasion of the collagen-rich sub-mesothelial matrix, and MCA formation. Additionally, MT1-MMP expression may induce MUC16/CA-125 ectodomain shedding, which may then expose integrins at the ovarian tumor cell surface for high affinity cell-cell and cell-ECM binding.

scholarly journals CLDN6 Suppresses c–MYC–Mediated Aerobic Glycolysis to Inhibit Proliferation by TAZ in Breast Cancer

2021 ◽  
Vol 23 (1) ◽  
pp. 129
Author(s):  
Huinan Qu ◽  
Da Qi ◽  
Xinqi Wang ◽  
Yuan Dong ◽  
Qiu Jin ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Molecular Mechanisms ◽  
Aerobic Glycolysis ◽  
Lactate Production ◽  
Suppressor Gene ◽  
Binding Motif ◽  
Cancer Proliferation ◽  
In Vivo Experiments

Claudin 6 (CLDN6) was found to be a breast cancer suppressor gene, which is lowly expressed in breast cancer and inhibits breast cancer cell proliferation upon overexpression. However, the mechanism by which CLDN6 inhibits breast cancer proliferation is unclear. Here, we investigated this issue and elucidated the molecular mechanisms by which CLDN6 inhibits breast cancer proliferation. First, we verified that CLDN6 was lowly expressed in breast cancer tissues and that patients with lower CLDN6 expression had a worse prognosis. Next, we confirmed that CLDN6 inhibited breast cancer proliferation through in vitro and in vivo experiments. As for the mechanism, we found that CLDN6 inhibited c–MYC–mediated aerobic glycolysis based on a metabolomic analysis of CLDN6 affecting cellular lactate levels. CLDN6 interacted with a transcriptional co–activator with PDZ-binding motif (TAZ) and reduced the level of TAZ, thereby suppressing c–MYC transcription, which led to a reduction in glucose uptake and lactate production. Considered together, our results suggested that CLDN6 suppressed c–MYC–mediated aerobic glycolysis to inhibit the proliferation of breast cancer by TAZ, which indicated that CLDN6 acted as a novel regulator of aerobic glycolysis and provided a theoretical basis for CLDN6 as a biomarker of progression in breast cancer.

scholarly journals The Long Non-coding RNA TMPO-AS1  Promotes Bladder Cancer Growth and Progression via OTUB1-induced E2F1 Deubiquitination

2020 ◽  
Author(s):  
Yeyu Zhang ◽  
Yuxing Zhu ◽  
Mengqing Xiao ◽  
Yaxin Cheng ◽  
Dong He ◽  
...  
Keyword(s):  
Bladder Cancer ◽  
Molecular Mechanisms ◽  
Luciferase Reporter ◽  
Migration And Invasion ◽  
Dependent Manner ◽  
E2f Transcription Factor ◽  
Rna Immunoprecipitation ◽  
Regulatory Loop

Abstract BackgroundBladder cancer (BC) is the most common malignant tumor of the urinary system. Increasing evidence indicates long non-coding RNAs (lncRNAs) play crucial roles in cancer tumorigenesis, development, and progression. However, the role of TMPO antisense RNA 1 (TMPO-AS1) is still need to be explored in BC.MethodsThe lncRNA TMPO-AS1 expression was evaluated by bioinformatics analysis and further validated by qRT-PCR. Loss- and gain-of- function assays were performed to determine the biological functions of TMPO-AS1 in BC proliferation, migration, and invasion. Chromatin immunoprecipitation, luciferase reporter assays, western blotting, RNA pull-down, RNA immunoprecipitation assays, and fluorescence in situ hybridization were conducted to explore the molecular mechanisms of TMPO-AS1/E2F transcription factor 1 (E2F1) loop. ResultsTMPO-AS1 is upregulated in bladder cancer and is associated with BC patients’ poor prognoses. Functional experiments demonstrated that TMPO-AS1 promotes bladder cancer cell proliferation, migration, invasion, and inhibits cell apoptosis in vivo and in vitro. Mechanically, E2F1 is responsible for the TMPO-AS1 upregulation. Additionally, TMPO-AS1 facilitates the interaction of E2F1 with OTU domain-containing ubiquitin aldehyde binding 1 (OTUB1), leading to E2F1 deubiquitination and stabilization, thereby promotes BC malignant phenotypes. Furthermore, rescue experiments showed that TMPO-AS1 promotes BC growth in an E2F1-dependent manner.ConclusionsOur study is the first to uncover a novel positive regulatory loop of TMPO-AS1/E2F1 important for the promotion of BC malignant behaviors. The TMPO-AS1/E2F1 loop should be considered in the quest for new BC therapeutic options.

scholarly journals Matrine inhibits the development and progression of ovarian cancer by repressing cancer associated phosphorylation signaling pathways

2019 ◽  
Vol 10 (10) ◽  
Author(s):  
Xi Zhang ◽  
Guoqing Hou ◽  
Andong Liu ◽  
Hui Xu ◽  
Yang Guan ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Side Effects ◽  
Cancer Cells ◽  
Signaling Pathways ◽  
Molecular Mechanisms ◽  
Chemotherapy Resistance ◽  
Treatment Strategies ◽  
Ovarian Cancer Cells

Abstract Ovarian cancer remains the most lethal gynecologic malignancy with late detection and acquired chemoresistance. Advanced understanding of the pathophysiology and novel treatment strategies are urgently required. A growing body of proteomic investigations suggest that phosphorylation has a pivotal role in the regulation of ovarian cancer associated signaling pathways. Matrine has been extensively studied for its potent anti-tumor activities. However, its effect on ovarian cancer cells and underlying molecular mechanisms remain unclear. Herein we showed that matrine treatment inhibited the development and progression of ovarian cancer cells by regulating proliferation, apoptosis, autophagy, invasion and angiogenesis. Matrine treatment retarded the cancer associated signaling transduction by decreasing the phosphorylation levels of ERK1/2, MEK1/2, PI3K, Akt, mTOR, FAK, RhoA, VEGFR2, and Tie2 in vitro and in vivo. Moreover, matrine showed excellent antitumor effect on chemoresistant ovarian cancer cells. No obvious toxic side effects were observed in matrine-administrated mice. As the natural agent, matrine has the potential to be the targeting drug against ovarian cancer cells with the advantages of overcoming the chemotherapy resistance and decreasing the toxic side effects.

scholarly journals Downregulation of MYPT1 increases tumor resistance in ovarian cancer by targeting the Hippo pathway and increasing the stemness

2020 ◽  
Vol 19 (1) ◽  
Author(s):  
Sandra Muñoz-Galván ◽  
Blanca Felipe-Abrio ◽  
Eva M. Verdugo-Sivianes ◽  
Marco Perez ◽  
Manuel P. Jiménez-García ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Molecular Mechanisms ◽  
Target Genes ◽  
Hippo Pathway ◽  
Ovarian Tumors ◽  
Tumor Resistance ◽  
Functional Link ◽  
The Hippo Pathway

Abstract Background Ovarian cancer is one of the most common and malignant cancers, partly due to its late diagnosis and high recurrence. Chemotherapy resistance has been linked to poor prognosis and is believed to be linked to the cancer stem cell (CSC) pool. Therefore, elucidating the molecular mechanisms mediating therapy resistance is essential to finding new targets for therapy-resistant tumors. Methods shRNA depletion of MYPT1 in ovarian cancer cell lines, miRNA overexpression, RT-qPCR analysis, patient tumor samples, cell line- and tumorsphere-derived xenografts, in vitro and in vivo treatments, analysis of data from ovarian tumors in public transcriptomic patient databases and in-house patient cohorts. Results We show that MYPT1 (PPP1R12A), encoding myosin phosphatase target subunit 1, is downregulated in ovarian tumors, leading to reduced survival and increased tumorigenesis, as well as resistance to platinum-based therapy. Similarly, overexpression of miR-30b targeting MYPT1 results in enhanced CSC-like properties in ovarian tumor cells and is connected to the activation of the Hippo pathway. Inhibition of the Hippo pathway transcriptional co-activator YAP suppresses the resistance to platinum-based therapy induced by either low MYPT1 expression or miR-30b overexpression, both in vitro and in vivo. Conclusions Our work provides a functional link between the resistance to chemotherapy in ovarian tumors and the increase in the CSC pool that results from the activation of the Hippo pathway target genes upon MYPT1 downregulation. Combination therapy with cisplatin and YAP inhibitors suppresses MYPT1-induced resistance, demonstrating the possibility of using this treatment in patients with low MYPT1 expression, who are likely to be resistant to platinum-based therapy.

scholarly journals Bromodomain-containing protein 4 regulates interleukin-34 expression in mouse ovarian cancer cells

2020 ◽  
Vol 40 (1) ◽  
Author(s):  
Nanumi Han ◽  
Delnur Anwar ◽  
Naoki Hama ◽  
Takuto Kobayashi ◽  
Hidefumi Suzuki ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Tumor Growth ◽  
Tumor Progression ◽  
Cancer Cells ◽  
Molecular Mechanisms ◽  
Ovarian Cancer Cell Line ◽  
Cancer Cell Line ◽  
Ovarian Cancer Cells ◽  
Mouse Tumor

Abstract Background Interleukin (IL)-34 acts as an alternative ligand for the colony-stimulating factor-1 receptor and controls the biology of myeloid cells, including survival, proliferation, and differentiation. IL-34 has been reported to be expressed in cancer cells and to promote tumor progression and metastasis of certain cancers via the promotion of angiogenesis and immunosuppressive macrophage differentiation. We have shown in our previous reports that targeting IL-34 in chemo-resistant tumors in vitro resulted in a remarkable inhibition of tumor growth. Also, we reported poor prognosis in patients with IL-34-expressing tumor. Therefore, blocking of IL-34 is considered as a promising therapeutic strategy to suppress tumor progression. However, the molecular mechanisms that control IL-34 production are still largely unknown. Methods IL-34 producing ovarian cancer cell line HM-1 was treated by bromodomain and extra terminal inhibitor JQ1. The mRNA and protein expression of IL-34 was evaluated after JQ1 treatment. Chromatin immunoprecipitation was performed to confirm the involvement of bromodomain-containing protein 4 (Brd4) in the regulation of the Il34 gene. Anti-tumor effect of JQ1 was evaluated in mouse tumor model. Results We identified Brd4 as one of the critical molecules that regulate Il34 expression in cancer cells. Consistent with this, we found that JQ1 is capable of efficiently suppressing the recruitment of Brd4 to the promotor region of Il34 gene. Additionally, JQ1 treatment of mice bearing IL-34-producing tumor inhibited the tumor growth along with decreasing Il34 expression in the tumor. Conclusion The results unveiled for the first time the responsible molecule Brd4 that regulates Il34 expression in cancer cells and suggested its possibility as a treatment target.

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