scholarly journals Investigating Tunneling Nanotubes in Cancer Cells: Guidelines for Structural and Functional Studies through Cell Imaging

2020 ◽  
Vol 2020 ◽  
pp. 1-16 ◽  
Author(s):  
Fatéméh Dubois ◽  
Magalie Bénard ◽  
Bastien Jean-Jacques ◽  
Damien Schapman ◽  
Hélène Roberge ◽  
...  

By allowing insured communication between cancer cells themselves and with the neighboring stromal cells, tunneling nanotubes (TNTs) are involved in the multistep process of cancer development from tumorigenesis to the treatment resistance. However, despite their critical role in the biology of cancer, the study of the TNTs has been announced challenging due to not only the absence of a specific biomarker but also the fragile and transitory nature of their structure and the fact that they are hovering freely above the substratum. Here, we proposed to review guidelines to follow for studying the structure and functionality of TNTs in tumoral neuroendocrine cells (PC12) and nontumorigenic human bronchial epithelial cells (HBEC-3, H28). In particular, we reported how crucial is it (i) to consider the culture conditions (culture surface, cell density), (ii) to visualize the formation of TNTs in living cells (mechanisms of formation, 3D representation), and (iii) to identify the cytoskeleton components and the associated elements (categories, origin, tip, and formation/transport) in the TNTs. We also focused on the input of high-resolution cell imaging approaches including Stimulated Emission Depletion (STED) nanoscopy, Transmitted and Scanning Electron Microscopies (TEM and SEM). In addition, we underlined the important role of the organelles in the mechanisms of TNT formation and transfer between the cancer cells. Finally, new biological models for the identification of the TNTs between cancer cells and stromal cells (liquid air interface, ex vivo, in vivo) and the clinical considerations will also be discussed.

Cancers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 4577
Author(s):  
Rui Liang ◽  
Mingo M. H. Yung ◽  
Fangfang He ◽  
Peili Jiao ◽  
Karen K. L. Chan ◽  
...  

Emerging evidence indicates that hypoxia plays a critical role in governing the transcoelomic metastasis of ovarian cancer. Hence, targeting hypoxia may be a promising approach to prevent the metastasis of ovarian cancer. Here, we report that BCL2A1, a BCL2 family member, acts as a hypoxia-inducible gene for promoting tumor progression in ovarian cancer peritoneal metastases. We demonstrated that BCL2A1 was induced not only by hypoxia but also other physiological stresses through NF-κB signaling and then was gradually reduced by the ubiquitin-proteasome pathway in ascites-derived ovarian cancer cells. The upregulated BCL2A1 was frequently found in advanced metastatic ovarian cancer cells, suggesting its clinical relevance in ovarian cancer metastatic progression. Functionally, BCL2A1 enhanced the foci formation ability of ovarian cancer cells in a stress-conditioned medium, colony formation in an ex vivo omental tumor model, and tumor dissemination in vivo. Under stress conditions, BCL2A1 accumulated and colocalized with mitochondria to suppress intrinsic cell apoptosis by interacting with the BH3-only subfamily BCL2 members HRK/BAD/BID in ovarian cancer cells. These findings indicate that BCL2A1 is an early response factor that maintains the survival of ovarian cancer cells in the harsh tumor microenvironment.


2020 ◽  
Vol 38 (4_suppl) ◽  
pp. 211-211
Author(s):  
Yuki Takahashi ◽  
Kei Tsukamoto ◽  
Rii Morimura ◽  
Isana Nada ◽  
Yuki Shimizu ◽  
...  

211 Background: Importance of interaction between cancer and stromal cells has been widely recognized in tumor progression and tolerance against treatment. Although 2D culture and spheroid consisting only cancer cells still remains the preferred platform for most laboratory preclinical studies while these provide only limited information about tumor microenvironment. In order to mimic the patient tumor tissue, ex vivo model which recaptures the tumor microenvironment is required. Methods: Layered 3D stromal tissues comprising microvascular network were produced by culturing fibroblasts and endothelial cells coated with the extra-cellular matrix (ECM) and natural polysaccharide, namely collagen and heparin. The layered 3D stromal tissues and co-cultured tumor were morphologically evaluated by HE stain, immunohistochemistry and immunofluorescence (IF). Their gene expression and secretome profile were characterized by RNA-sequencing and bio-plex suspension array technologies. Furthermore, drug sensitivity assay were conducted using popular colorectal cancer cell lines, and patient-derived cell lines (PDCs) established in the laboratory of JFCR. Remaining cancer cells post drug treatment were quantified by IF and imaging analysis. Results: The 3D stromal tissues including CD31 positive luminal structure were multi-layered (approximately 20 layers), and the tendency that dense microvascular network was formed nearby cancer cells was observed. In comparison with 2D culture or 3D mono-cultured spheroid model, decreased drug sensitivities were represented in the layered 3D co-cultured model. Omics profiles difference among models suggest that our 3D model has some similarity to in vivo tumor. Conclusions: We developed the layered 3D stromal tissue culture system including blood micro-vessels. Drug sensitivity in the co-cultured tumors may reflect the response of cancer cells in in vivo. Our unique 3D ex vivo model appear to be a valuable tool for drug evaluation, and thus testing approved and/or developing compounds with patient-derived cells would enable better prediction their efficacy.


Lab on a Chip ◽  
2017 ◽  
Vol 17 (16) ◽  
pp. 2852-2860 ◽  
Author(s):  
Qihui Fan ◽  
Ruchuan Liu ◽  
Yang Jiao ◽  
Chunxiu Tian ◽  
James D. Farrell ◽  
...  

A 3-D microfluidic system consisting of microchamber arrays embedded in a collagen hydrogel with tunable biochemical gradients was constructed for investigating interactions between invasive breast cancer cells and stromal cells.


Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Laura Graciotti ◽  
Toru Hosoda ◽  
Fumihiro Sanada ◽  
Giulia Borghetti ◽  
Christian Arranto ◽  
...  

The low incidence of cardiac tumors has been attributed to tissue pressure dictated by myocardial mechanics and large coronary blood flow. These variables, however, have failed to consider the possibility that the rare occurrence of heart neoplasms may be dictated by the molecular characteristics of cardiomyocytes. We have shown that miR-1, miR-133a, and miR-499 translocate from myocytes to co-cultured MCF7 breast cancer cells, inhibiting their growth. The transfer of miRs is mediated by gap junction channels and is abolished by Cx43 and Cx45 silencing. Although these in vitro results provided important information on the inhibitory function of miRs in cell proliferation, co-culture of myocytes and cancer cells does not mimic the in vivo organization of the myocardium that allows the formation of multiple sites of coupling between myocytes and tumor cells. To reproduce, at least in part, the in vivo condition, we developed first a physiological model of organ culture. Thick vibratome-cut myocardial slices were placed on a multiwell plate containing an oxygen-saturated sponge. At 24-48 hours, the cultured tissue was viable and myocytes showed a well organized sarcomere structure. Two hours after plating of the organ slices, control MCF7 cells or MCF7 cells in which Cx43 and Cx45 were silenced (MCF7-shCx43-shCx45) were seeded on the myocardium. Control MCF7 cells showed a slower growth rate than MCF7-shCx43-shCx45 cells, a finding consistent with miR translocation and its blockade, respectively. Second, 1 x 106 MCF7 or MCF7 cells overexpressing miR-1, miR-133a, and miR-499 (MCF7-miRs) were injected subcutaneously in NOD-SCID mice; ~45 days later, the tumors developed from MCF7 cells were more than 10-fold larger and 3-fold heavier than those originated from MCF7-miRs cells. Third, these studies were complemented with the intramyocardial injection of 1 x 105 control MCF7 cells. Five weeks later, no neoplastic lesions were identified. However, when an excessive number of MCF7 cells were injected, 1 x 106, tumor formation was apparent. In conclusion, our results indicate that transfer of miR-1, miR-133a, and miR-499 from cardiomyocytes to cancer cells plays a critical role in preventing the generation of tumors in the myocardium.


2021 ◽  
Vol 11 ◽  
Author(s):  
Congjun Zhang ◽  
Shuangyan Ou ◽  
Yuan Zhou ◽  
Pei Liu ◽  
Peiying Zhang ◽  
...  

ObjectivePancreatic cancer is one of the most lethal human malignancies. Gemcitabine is widely used to treat pancreatic cancer, and the resistance to chemotherapy is the major difficulty in treating the disease. N6-methyladenosine (m6A) modification, which regulates RNA splicing, stability, translocation, and translation, plays critical roles in cancer physiological and pathological processes. METTL14, an m6A Lmethyltransferase, was found deregulated in multiple cancer types. However, its role in gemcitabine resistance in pancreatic cancer remains elusive.MethodsThe mRNA and protein level of m6A modification associated genes were assessed by QRT-PCR and western blotting. Then, gemcitabine‐resistant pancreatic cancer cells were established. The growth of pancreatic cancer cells were analyzed using CCK8 assay and colony formation assay. METTL14 was depleted by using shRNA. The binding of p65 on METTL14 promoter was assessed by chromatin immunoprecipitation (ChIP) assay. Protein level of deoxycytidine kinase (DCK) and cytidine deaminase (CDA) was evaluated by western blotting. In vivo experiments were conducted to further confirm the critical role of METTL14 in gemcitabine resistance.ResultsWe found that gemcitabine treatment significantly increased the expression of m6A methyltransferase METTL14, and METTL14 was up-regulated in gemcitabine-resistance human pancreatic cancer cells. Suppression of METTL14 obviously increased the sensitivity of gemcitabine in resistant cells. Moreover, we identified that transcriptional factor p65 targeted the promoter region of METTL14 and up-regulated its expression, which then increased the expression of cytidine deaminase (CDA), an enzyme inactivates gemcitabine. Furthermore, in vivo experiment showed that depletion of METTL14 rescue the response of resistance cell to gemcitabine in a xenograft model.ConclusionOur study suggested that METTL14 is a potential target for chemotherapy resistance in pancreatic cancer.


Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. SCI-44-SCI-44
Author(s):  
Xiaoxia Li

Abstract Low-grade systemic inflammation is often associated with metabolic syndrome, which plays a critical role in the development of the obesity-associated inflammatory diseases, including insulin resistance and atherosclerosis. Here, we investigate how Toll-like receptor-MyD88 signaling in myeloid and endothelial cells coordinately participates in the initiation and progression of high fat diet-induced systemic inflammation and metabolic inflammatory diseases. MyD88 deficiency in myeloid cells inhibits macrophage recruitment to adipose tissue and their switch to an M1-like phenotype. This is accompanied by substantially reduced diet-induced systemic inflammation, insulin resistance, and atherosclerosis. MyD88 deficiency in endothelial cells results in a moderate reduction in diet-induced adipose macrophage infiltration and M1 polarization, selective insulin sensitivity in adipose tissue, and amelioration of spontaneous atherosclerosis. Both in vivo and ex vivo studies suggest that MyD88-dependent GM-CSF production from the endothelial cells might play a critical role in the initiation of obesity-associated inflammation and development of atherosclerosis by priming the monocytes in the adipose and arterial tissues to differentiate into M1-like inflammatory macrophages. Collectively, these results implicate a critical MyD88-dependent interplay between myeloid and endothelial cells in the initiation and progression of obesity-associated inflammatory diseases. Disclosures No relevant conflicts of interest to declare.


2021 ◽  
Vol 8 ◽  
Author(s):  
Fei Xu ◽  
Heshui Wu ◽  
Jiongxin Xiong ◽  
Tao Peng

Gemcitabine (GEM) resistance remains a challenging clinical issue to overcome in chemotherapy against pancreatic cancer. We previously demonstrated that miR-210 derived from pancreatic cancer stem cells enhanced the GEM-resistant properties of pancreatic cancer cells, thus identifying miR-210 as an oncogenic miRNA. Herein, we report the existence of an upstream effector that acts as a competing endogenous RNA (ceRNA) to miR-210. Bioinformatic screening was performed to identify lncRNAs with a binding relationship to miR-210. Overexpression and interference vectors were constructed to demonstrate the effect of ceRNA activity in pancreatic cell behavior, both in vitro and in vivo. DLEU2L (deleted in lymphocytic leukemia 2-like), which is expressed at low levels in pancreatic cancer tissues, was shown to exhibit a binding relationship with miR-210-3p. Overexpression of DLEU2L and silencing of miR-210-3p suppressed the proliferation, migration, and invasion of pancreatic cancer cells while promoting apoptosis. These effects occurred via the inhibition of the Warburg effect (aerobic glycolysis) and AKT/mTOR signaling. In addition, we showed that BRCA2 is a target gene of miR-210-3p, and the downregulation of miR-210-3p by DLEU2L effectively induced an upregulation of BRCA2 via the ceRNA mechanism. In vivo, DLEU2L overexpression and miR-210-3p interference suppressed pancreatic tumor progression, consistent with the results of in vitro studies. The findings of our study establish DLEU2L as a ceRNA to miR-210-3p and reveal the critical role of the DLEU2L/miR-210-3p crosstalk in targeting GEM resistance.


2020 ◽  
Author(s):  
Guillaume Jacquemin ◽  
Annabelle Wurmser ◽  
Mathilde Huyghe ◽  
Wenjie Sun ◽  
Meghan Perkins ◽  
...  

AbstractTumours are complex ecosystems composed of different types of cells that communicate and influence each other. While the critical role of stromal cells in affecting tumour growth is well established, the impact of mutant cancer cells on healthy surrounding tissues remains poorly defined. Here, we uncovered a paracrine mechanism by which intestinal cancer cells reactivate foetal and regenerative Yap-associated transcriptional programs in neighbouring wildtype epithelial cells, rendering them adapted to thrive in the tumour context. We identified the glycoprotein Thrombospondin-1 (Thbs1) as the essential factor that mediates non-cell autonomous morphological and transcriptional responses. Importantly, Thbs1 is associated with bad prognosis in several human cancers. This study reveals the Thbs1-YAP axis as the mechanistic link mediating paracrine interactions between epithelial cells, promoting tumour formation and progression.


2010 ◽  
Vol 42A (2) ◽  
pp. 103-113 ◽  
Author(s):  
Matthew S. Barnabei ◽  
Nathan J. Palpant ◽  
Joseph M. Metzger

Inbred mouse strains play a critical role in biomedical research. Genetic homogeneity within inbred strains and their general amenability to genetic manipulation have made them an ideal resource for dissecting the physiological function(s) of individual genes. However, the inbreeding that makes inbred mice so useful also results in genetic divergence between them. This genetic divergence is often unaccounted for but may be a confounding factor when comparing studies that have utilized distinct inbred strains. Here, we compared the cardiac function of C57BL/6J mice to seven other commonly used inbred mouse strains: FVB/NJ, DBA/2J, C3H/HeJ, BALB/cJ, 129X1/SvJ, C57BL/10SnJ, and 129S1/SvImJ. The assays used to compare cardiac function were the ex vivo isolated Langendorff heart preparation and in vivo real-time hemodynamic analysis using conductance micromanometry. We report significant strain-dependent differences in cardiac function between C57BL/6J and other commonly used inbred strains. C57BL/6J maintained better cardiac function than most inbred strains after ex vivo ischemia, particularly compared with 129S1/SvImJ, 129X1/SvJ, and C57BL/10SnJ strains. However, during in vivo acute hypoxia 129X1/SvJ and 129S1/SvImJ maintained relatively normal cardiac function, whereas C57BL/6J animals showed dramatic cardiac decompensation. Additionally, C3H/HeJ showed rapid and marked cardiac decompensation in response to esmolol infusion compared with effects of other strains. These findings demonstrate the complex effects of genetic divergence between inbred strains on cardiac function. These results may help inform analysis of gene ablation or transgenic studies and further demonstrate specific quantitative traits that could be useful in discovery of genetic modifiers relevant to cardiac health and disease.


2021 ◽  
pp. jclinpath-2020-207357
Author(s):  
Jeehoon Ham ◽  
Bin Wang ◽  
Joseph William Po ◽  
Amandeep Singh ◽  
Navin Niles ◽  
...  

In 1989, Stephen Paget proposed the ‘seed and soil’ theory of cancer metastasis. This theory has led to previous researchers focusing on the role of a tumour as a cancer seed and antiangiogenesis agents as cancer soil fumigant; for the latter to be effective, it is important for them to be able to distinguish cancer cells from stromal cells. However, antiangiogenesis agents have not produced dramatic survival benefits in vivo. This may be related to their inability to destroy the supporting stroma that promote cancer cell growth. Therefore, in order to effectively arrest cancer cell growth for therapeutic purposes, a paradigm shift is required in our fundamental approach to decipher the molecular events and networks in the stromal environment that cancer cells can thrive and proliferate. The pathogenesis of cancer is a multidimensional process of pathological molecular and cellular pathways, influencing different stromal properties and achieving a mutually negotiated crosstalk between cancer cells and stromal cells. This review summarises the clinical presentation of current knowledge of classical papillary thyroid carcinoma (PTC), emerging molecular diagnostics and future directions of classical PTC research.


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