scholarly journals Ki-67 promotes sequential stages of tumourigenesis by enabling cellular plasticity

2019 ◽  
Author(s):  
K. Mrouj ◽  
P. Singh ◽  
M. Sobecki ◽  
G. Dubra ◽  
E. Al Ghoul ◽  
...  

ABSTRACTRecent studies have shown that the cell proliferation antigen Ki-67 is not required for cell proliferation. Here, we demonstrate that Ki-67 enables implementation of transcriptional programmes conferring cellular plasticity, and is required for each step of tumour initiation, growth and metastasis. Ki-67 knockout causes global transcriptome remodelling, which, in mammary carcinoma cells, inhibits the epithelial-mesenchymal transition in a polycomb-repressive complex 2-dependent manner. This results in suppression of stem cell characteristics and sensitisation to various drug classes. Cancer cells lacking Ki-67 proliferate normally in vivo, but tumour growth is inhibited due to disrupted angiogenesis, and metastasis is abrogated. Finally, mice lacking Ki-67 are resistant to chemical or genetic induction of intestinal tumourigenesis. Thus, Ki-67, which is expressed in all proliferating cancer cells, confers the plasticity required for different steps of carcinogenesis.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Camille Contant ◽  
Mahmoud Rouabhia ◽  
Lionel Loubaki ◽  
Fatiha Chandad ◽  
Abdelhabib Semlali

AbstractOral cancer is one of the major public health problems. The aim of this study was to evaluate the effects of anethole, 1-methoxy-4-[(E)-1-propenyl]-benzene, on growth and apoptosis of oral tumor cells, and to identify the signaling pathways involved in its interaction with these cancer cells. Cancer gingival cells (Ca9-22) were treated with different concentrations of anethole. Cell proliferation and cytotoxic effects were measured by MTT and LDH assays. Cell death, autophagy and oxidative stress markers were assessed by flow cytometry while cell migration was determined by a healing capacity assay. The effect of anethole on apoptotic and pro-carcinogenic signaling pathways proteins was assessed by immunoblotting. Our results showed that anethole selectively and in a dose-dependent manner decreases the cell proliferation rate, and conversely induces toxicity and apoptosis in oral cancer cells. This killing effect was mediated mainly through NF-κB, MAPKinases, Wnt, caspase 3, 9 and PARP1 pathways. Anethole showed an ability to induce autophagy, decrease reactive oxygen species (ROS) production and increased intracellular glutathione (GSH) activity. Finally, anethole treatment inhibits the expression of oncogenes (cyclin D1) and up-regulated cyclin-dependent kinase inhibitor (p21WAF1), increases the expression of p53 gene, but inhibits the epithelial-mesenchymal transition markers. These results indicate that anethole could be a potential molecule for the therapy of oral cancer.


2020 ◽  
Author(s):  
Wataru Goto ◽  
Shinichiro Kashiwagi ◽  
Yuka Asano ◽  
Koji Takada ◽  
Tamami Morisaki ◽  
...  

Abstract Background Iron is required for the proliferation of cancer cells, and its depletion suppresses tumor growth. Eribulin mesylate (eribulin), a non-taxane microtubule inhibitor, disrupts the tumor microenvironment via vascular remodeling and obstruction of the epithelial-mesenchymal transition (EMT). Herein, we investigated the effects of the iron chelator deferoxamine (DFO) on tumor-related properties of breast cancer cells and the effects of DFO plus eribulin on tumor growth in vivo . Methods A triple-negative breast cancer (TNBC) cell line (MDA-MB-231) was used in our study. Cell proliferation, cell migration, cell cycle position, and gene expression were analyzed via MTT assays, wound-healing assays, flow cytometry, and quantitative real-time-polymerase chain reaction, respectively. For the in vivo experiments, mice with MDA-MB-231 xenografts were treated with the inhibitors, alone or together, and tumor volume was determined. Results DFO inhibited breast cancer cell proliferation and migration and decreased the proportion of S-phase cells. Conversely, it induced hypoxia, angiogenesis, EMT, and immune checkpoints, as determined by quantifying the expression of marker mRNAs. Eribulin suppressed the expression of the EMT marker mRNAs in the presence of DFO. DFO plus eribulin inhibited tumor growth in vivo to a greater extent than did either inhibitor alone. Conclusions Although DFO induces oncogenic events (hypoxia, angiogenesis, EMT, and immune checkpoints), it may be an effective treatment for breast cancer when administered in combination with eribulin.


2021 ◽  
Vol 10 ◽  
Author(s):  
Wu-Ping Zheng ◽  
Feng-Ying Huang ◽  
Shu-Zhen Dai ◽  
Jin-Yan Wang ◽  
Ying-Ying Lin ◽  
...  

Toxicarioside O (TCO), a natural product derived from Antiaris toxicaria, has been identified to be a promising anticancer agent. In this study, we aimed to investigate the effect of TCO on the proliferation and epithelial-mesenchymal transition (EMT) of lung cancer cells and its molecular mechanisms. Here, we indicated that TCO inhibits the proliferation of lung cancer cells both in vitro and in vivo. Our results demonstrated that TCO induces apoptosis in lung cancer cells. Moreover, we found that TCO suppresses EMT program and inhibits cell migration in vitro. Mechanistically, TCO decreases the expression of trophoblast cell surface antigen 2 (Trop2), resulting in inhibition of the PI3K/Akt pathway and EMT program. Overexpression of Trop2 rescues TCO-induced inhibition of cell proliferation and EMT. Our findings demonstrate that TCO markedly inhibits cell proliferation and EMT in lung cancer cells and provides guidance for its drug development.


Cancers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1469
Author(s):  
Hanmin Wang ◽  
Evgeny Chirshev ◽  
Nozomi Hojo ◽  
Tise Suzuki ◽  
Antonella Bertucci ◽  
...  

We aimed to determine the mechanism of epithelial–mesenchymal transition (EMT)-induced stemness in cancer cells. Cancer relapse and metastasis are caused by rare stem-like cells within tumors. Studies of stem cell reprogramming have linked let-7 repression and acquisition of stemness with the EMT factor, SNAI1. The mechanisms for the loss of let-7 in cancer cells are incompletely understood. In four carcinoma cell lines from breast cancer, pancreatic cancer, and ovarian cancer and in ovarian cancer patient-derived cells, we analyzed stem cell phenotype and tumor growth via mRNA, miRNA, and protein expression, spheroid formation, and growth in patient-derived xenografts. We show that treatment with EMT-promoting growth factors or SNAI1 overexpression increased stemness and reduced let-7 expression, while SNAI1 knockdown reduced stemness and restored let-7 expression. Rescue experiments demonstrate that the pro-stemness effects of SNAI1 are mediated via let-7. In vivo, nanoparticle-delivered siRNA successfully knocked down SNAI1 in orthotopic patient-derived xenografts, accompanied by reduced stemness and increased let-7 expression, and reduced tumor burden. Chromatin immunoprecipitation demonstrated that SNAI1 binds the promoters of various let-7 family members, and luciferase assays revealed that SNAI1 represses let-7 transcription. In conclusion, the SNAI1/let-7 axis is an important component of stemness pathways in cancer cells, and this study provides a rationale for future work examining this axis as a potential target for cancer stem cell-specific therapies.


2021 ◽  
pp. 1-16
Author(s):  
Masaki Nakano ◽  
Yachiyo Mitsuishi ◽  
Lei Liu ◽  
Naoki Watanabe ◽  
Emi Hibino ◽  
...  

Background: Brain amyloid-β (Aβ) peptide is released into the interstitial fluid (ISF) in a neuronal activity-dependent manner, and Aβ deposition in Alzheimer’s disease (AD) is linked to baseline neuronal activity. Although the intrinsic mechanism for Aβ generation remains to be elucidated, interleukin-like epithelial-mesenchymal transition inducer (ILEI) is a candidate for an endogenous Aβ suppressor. Objective: This study aimed to access the mechanism underlying ILEI secretion and its effect on Aβ production in the brain. Methods: ILEI and Aβ levels in the cerebral cortex were monitored using a newly developed ILEI-specific ELISA and in vivo microdialysis in mutant human Aβ precursor protein-knockin mice. ILEI levels in autopsied brains and cerebrospinal fluid (CSF) were measured using ELISA. Results: Extracellular release of ILEI and Aβ was dependent on neuronal activation and specifically on tetanus toxin-sensitive exocytosis of synaptic vesicles. However, simultaneous monitoring of extracellular ILEI and Aβ revealed that a spontaneous fluctuation of ILEI levels appeared to inversely mirror that of Aβ levels. Selective activation and inhibition of synaptic receptors differentially altered these levels. The evoked activation of AMPA-type receptors resulted in opposing changes to ILEI and Aβ levels. Brain ILEI levels were selectively decreased in AD. CSF ILEI concentration correlated with that of Aβ and were reduced in AD and mild cognitive impairment. Conclusion: ILEI and Aβ are released from distinct subpopulations of synaptic terminals in an activity-dependent manner, and ILEI negatively regulates Aβ production in specific synapse types. CSF ILEI might represent a surrogate marker for the accumulation of brain Aβ.


2020 ◽  
Vol 29 ◽  
pp. 096368972092998 ◽  
Author(s):  
Chuang Du ◽  
Yan Wang ◽  
Yingying Zhang ◽  
Jianhua Zhang ◽  
Linfeng Zhang ◽  
...  

Triple-negative breast cancer (TNBC) is one of the most aggressive cancer types with high recurrence, metastasis, and drug resistance. Recent studies report that long noncoding RNAs (lncRNAs)-mediated competing endogenous RNAs (ceRNA) play an important role in tumorigenesis and drug resistance of TNBC. Although elevated lncRNA DLX6 antisense RNA 1 (DLX6-AS1) has been observed to promote carcinogenesis in various cancers, the role in TNBC remained unclear. In this study, expression levels of DLX6-AS1 were increased in TNBC tissues and cell lines when compared with normal tissues or breast fibroblast cells which were determined by quantitative real-time PCR (RT-qPCR). Then, CCK-8 assay, cell colony formation assay and western blot were performed in CAL-51 cells transfected with siRNAs of DLX6-AS1 or MDA-MB-231 cells transfected with DLX6-AS1 over expression plasmids. Knock down of DLX6-AS1 inhibited cell proliferation, epithelial-mesenchymal transition (EMT), decreased expression levels of BCL2 apoptosis regulator (Bcl-2), Snail family transcriptional repressor 1 (Snail) as well as N-cadherin and decreased expression levels of cleaved caspase-3, γ-catenin as well as E-cadherin, while up regulation of DLX6-AS1 had the opposite effect. Besides, knockdown of DLX6-AS1 in CAL-51 cells or up regulation of DLX6-AS1 in MDA-MB-231 cells also decreased or increased cisplatin resistance of those cells analyzed by MTT assay. Moreover, by using dual luciferase reporter assay, RNA immunoprecipitation and RNA pull down assay, a ceRNA which was consisted by lncRNA DLX6-AS1, microRNA-199b-5p (miR-199b-5p) and paxillin (PXN) was identified. And DLX6-AS1 function through miR-199b-5p/PXN in TNBC cells. Finally, results of xenograft experiments using nude mice showed that DLX6-AS1 regulated cell proliferation, EMT and cisplatin resistance by miR-199b-5p/PXN axis in vivo. In brief, DLX6-AS1 promoted cell proliferation, EMT, and cisplatin resistance through miR-199b-5p/PXN signaling in TNBC in vitro and in vivo.


2018 ◽  
Vol 45 (6) ◽  
pp. 2213-2224 ◽  
Author(s):  
Meng Zhao ◽  
Yahui Liu ◽  
Ran Liu ◽  
Jin Qi ◽  
Yongwang Hou ◽  
...  

Background/Aims: Cytokines are key players in tumorigenesis and are potential targets in cancer treatment. Although IL-6 has attracted considerable attention, interleukin 11 (IL-11), another member of the IL-6 family, has long been overlooked, and little is known regarding its specific function in non-small cell lung cancer (NSCLC). In this study, we explored IL-11’s role in NSCLC and the detailed mechanism behind it. Methods: Cell proliferation in response to IL-11 was determined by colony formation, BrdU incorporation and MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) assay. Cell motility was measured by Transwell and wound healing assays. NSCLC xenograft models were used to confirm oncogenic function of IL-11 in vivo. Immunohistochemical staining and western blot assay were performed to detect epithelial–mesenchymal transition (EMT) markers and cell signaling pathway alterations. Eighteen NSCLC patients and 5 normal lung samples were collected together with data from an online database to determine the link between IL-11 expression and malignant progression. Results: We observed that IL-11 was upregulated in NSCLC samples compared with normal tissue samples and correlated with poor prognosis. Data from in vitro and in vivo models indicated that IL-11 promotes cell proliferation and tumorigenesis. Cell migration and invasion were also enhanced by IL-11. Epithelial–mesenchymal transition (EMT) was also observed after IL-11 incubation. Furthermore, IL-11 activated AKT and STAT3 in our experimental models. In addition, we observed that hypoxia induced IL-11 expression in NSCLC cells. Deferoxamine (DFX) or dimethyloxalylglycine (DMOG) induced hypoxia-inducible factor 1-alpha (HIF1α) upregulation, which enhanced IL-11 expression in NSCLC cells. Conclusions: Taken together, our results indicate that IL-11 is an oncogene in NSCLC, and elucidating the mechanism behind it may provide insights for NSCLC treatment.


Cancers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 172
Author(s):  
Izabela Papiewska-Pająk ◽  
Patrycja Przygodzka ◽  
Damian Krzyżanowski ◽  
Kamila Soboska ◽  
Izabela Szulc-Kiełbik ◽  
...  

During metastasis, cancer cells undergo phenotype changes in the epithelial-mesenchymal transition (EMT) process. Extracellular vesicles (EVs) released by cancer cells are the mediators of intercellular communication and play a role in metastatic process. Knowledge of factors that influence the modifications of the pre-metastatic niche for the migrating carcinoma cells is important for prevention of metastasis. We focus here on how cancer progression is affected by EVs released from either epithelial-like HT29-cells or from cells that are in early EMT stage triggered by Snail transcription factor (HT29-Snail). We found that EVs released from HT29-Snail, as compared to HT29-pcDNA cells, have a different microRNA profile. We observed the presence of interstitial pneumonias in the lungs of mice injected with HT29-Snail cells and the percent of mice with lung inflammation was higher after injection of HT29-Snail-EVs. Incorporation of EVs released from HT29-pcDNA, but not released from HT29-Snail, leads to the increased secretion of IL-8 from macrophages. We conclude that Snail modifications of CRC cells towards more invasive phenotype also alter the microRNA cargo of released EVs. The content of cell-released EVs may serve as a biomarker that denotes the stage of CRC and EVs-specific microRNAs may be a target to prevent cancer progression.


2020 ◽  
Author(s):  
Hanshu Ji ◽  
Xiaoyu Zhang

Abstract Purpose: lncRNA NEAT1 has been reported as a tumor-promoting gene in a variety of tumors, but few studies have explored its role and mechanism in gastric cancer. In the face of increasing incidence of gastric cancer, how to improve the diagnostic accuracy and therapeutic effect of gastric cancer is a major clinical problem. Therefore, we studied the effect and mechanism of lncRNA NEAT1 on the proliferation, invasion and epithelial-mesenchymal transition of gastric cancer cells. To inquiry into the effect of lncRNA NEAT1 on the proliferation, invasion and epithelial-mesenchymal transition (EMT) of gastric cancer (GC) cells by regulating miR-129-5p/PBX3 axis. Methods: Totally 63 GC diagnosed and treated in our hospital were selected as the study subjects, whose paired GC tissues and pericarcinomatous tissues were collected as the study specimens after obtaining their consent. QRT-PCR was employed to detect the NEAT1 expression in tissues and cells to analyze the relationship between NEAT1 and clinicopathological data of GC patients. In addition, stable and transient overexpression and inhibition vectors were established and transfected into GC cells HCG-27 and MKN-45. CCK-8, traswell, and flow cytometry were employed to evaluate the proliferation, invasion, and apoptosis of transfected cells. The correlation of miR-129-5p between PBX3 and NEAT1 was assessed using dual luciferase reporter assay, while that between NEAT1 and miR-129-5p was assessed by RNA-binding protein immunoprecipitation (RIP) . Western blot was applied for the detection of apoptosis and EMT related proteins.Results: NEAT1 was overexpressed in GC patients and had a high diagnostic value. The expression of NEAT1 was related to the pathological stage, differentiation degree, tumor size and lymph node metastasis of patients with GC. Down-regulated NEAT1 brought decreased cell proliferation, invasion and EMT, and increased apoptosis. According to dual luciferase reporter assay, NEAT1 could target miR-129-5p, while in turn miR-129-5p could target PBX3. Functional analysis exhibited that miR-129-5p overexpression inhibited PBX3 in GC cells, affecting cell proliferation, invasion, EMT and apoptosis, and rescue experiments demonstrated that these effects were eliminated by up-regulating NEAT1 expression.Conclusion: Inhibition of NEAT1 could mediate miR-129-5p/PBX3 axis to promote apoptosis of GC cells, and reduce cell proliferation, invasion and EMT.


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