Heterogeneous Cell Cultures Research Articles

A device for studying heterogeneous tumor cell cultures based on a hybrid microfluidic system

A device for studying heterogeneous tumor cell cultures based on a hybrid microfluidic system

Apoptosis-Cell Cycle-Autophagy Molecular Mechanisms Network in Heterogeneous Aggressive Phenotype Prostate Hyperplasia Primary Cell Cultures Have a Prognostic Role.

Our study highlights the apoptosis, cell cycle, DNA ploidy, and autophagy molecular mechanisms network to identify prostate pathogenesis and its prognostic role. Caspase 3/7 expressions, cell cycle, adhesion glycoproteins, autophagy, nuclear shrinkage, and oxidative stress by flow-cytometry analysis are used to study the BPH microenvironment's heterogeneity. A high late apoptosis expression by caspases 3/7 activity represents an unfavorable prognostic biomarker, a dependent predictor factor for cell adhesion, growth inhibition by arrest in the G2/M phase, and oxidative stress processes network. The heterogeneous aggressive phenotype prostate adenoma primary cell cultures present a high S-phase category (>12%), with an increased risk of death or recurrence due to aneuploid status presence, representing an unfavorable prognostic biomarker, a dependent predictor factor for caspase 3/7 activity (late apoptosis and necrosis), and cell growth inhibition (G2/M arrest)-linked mechanisms. Increased integrin levels in heterogenous BPH cultures suggest epithelial-mesenchymal transition (EMT) that maintains an aggressive phenotype by escaping cell apoptosis, leading to the cell proliferation necessary in prostate cancer (PCa) development. As predictor biomarkers, the biological mechanisms network involved in apoptosis, the cell cycle, and autophagy help to establish patient prognostic survival or target cancer therapy development.

Utilizing convolutional neural networks for discriminating cancer and stromal cells in three-dimensional cell culture images with nuclei counterstain.

Accurate cell segmentation and classification in three-dimensional (3D) images are vital for studying live cell behavior and drug responses in 3D tissue culture. Evaluating diverse cell populations in 3D cell culture over time necessitates non-toxic staining methods, as specific fluorescent tags may not be suitable, and immunofluorescence staining can be cytotoxic for prolonged live cell cultures. We aim to perform machine learning-based cell classification within a live heterogeneous cell culture population grown in a 3D tissue culture relying only on reflectance, transmittance, and nuclei counterstained images obtained by confocal microscopy. In this study, we employed a supervised convolutional neural network (CNN) to classify tumor cells and fibroblasts within 3D-grown spheroids. These cells are first segmented using the marker-controlled watershed image processing method. Training data included nuclei counterstaining, reflectance, and transmitted light images, with stained fibroblast and tumor cells as ground-truth labels. Our results demonstrate the successful marker-controlled watershed segmentation of 84% of spheroid cells into single cells. We achieved a median accuracy of 67% (95% confidence interval of the median is 65-71%) in identifying cell types. We also recapitulate the original 3D images using the CNN-classified cells to visualize the original 3D-stained image's cell distribution. This study introduces a non-invasive toxicity-free approach to 3D cell culture evaluation, combining machine learning with confocal microscopy, opening avenues for advanced cell studies.

Improving the Efficacy of Common Cancer Treatments via Targeted Therapeutics towards the Tumour and Its Microenvironment.

Cancer is defined as the uncontrolled proliferation of heterogeneous cell cultures in the body that develop abnormalities and mutations, leading to their resistance to many forms of treatment. Left untreated, these abnormal cell growths can lead to detrimental and even fatal complications for patients. Radiation therapy is involved in around 50% of cancer treatment workflows; however, it presents significant recurrence rates and normal tissue toxicity, given the inevitable deposition of the dose to the surrounding healthy tissue. Chemotherapy is another treatment modality with excessive normal tissue toxicity that significantly affects patients' quality of life. To improve the therapeutic efficacy of radiotherapy and chemotherapy, multiple conjunctive modalities have been proposed, which include the targeting of components of the tumour microenvironment inhibiting tumour spread and anti-therapeutic pathways, increasing the oxygen content within the tumour to revert the hypoxic nature of the malignancy, improving the local dose deposition with metal nanoparticles, and the restriction of the cell cycle within radiosensitive phases. The tumour microenvironment is largely responsible for inhibiting nanoparticle capture within the tumour itself and improving resistance to various forms of cancer therapy. In this review, we discuss the current literature surrounding the administration of molecular and nanoparticle therapeutics, their pharmacokinetics, and contrasting mechanisms of action. The review aims to demonstrate the advancements in the field of conjugated nanomaterials and radiotherapeutics targeting, inhibiting, or bypassing the tumour microenvironment to promote further research that can improve treatment outcomes and toxicity rates.

Intratumor genetic heterogeneity and head and neck cancer relapse

BackgroundHead and neck squamous cell carcinomas are treated by surgery, radiotherapy (RT), chemoradiotherapy (CRT) or combinations thereof, but locoregional recurrences (LRs) occur in 30–40% of treated patients. We have previously shown that in approximately half of the LRs after CRT, cancer driver mutations are not shared with the index tumor. AimTo investigate two possible explanations for these genetically unrelated relapses, treatment-induced genetic changes and intratumor genetic heterogeneity. MethodsTo investigate treatment-induced clonal DNA changes, we compared copy number alterations (CNAs) and mutations between primary and recurrent xenografted tumors after treatment with (C)RT. Intratumor genetic heterogeneity was studied by multi-region sequencing on DNA from 31 biopsies of 11 surgically treated tumors. ResultsInduction of clonal DNA changes by (C)RT was not observed in the xenograft models. Multi-region sequencing demonstrated variations in CNA profiles between paired biopsies of individual tumors, with copy number heterogeneity scores varying from 0.027 to 0.333. In total, 32 cancer driver mutations could be identified and were shared in all biopsies of each tumor. Remarkably, multi-clonal mutations in these same cancer driver genes were observed in 6 of 11 tumors. Genetically distinct heterogeneous cell cultures could also be established from single tumors, with different biomarker profiles and drug sensitivities. ConclusionIntratumor genetic heterogeneity at the level of the cancer driver mutations might explain the discordant mutational profiles in LRs after CRT, while there are no indications in xenograft models that these changes are induced by CRT.

Rapid and Live-Cell Detection of Senescence in Mesenchymal Stem Cells by Micro Magnetic Resonance Relaxometry.

Detection of cellular senescence is important quality analytics of cell therapy products, including mesenchymal stromal cells (MSCs). However, its detection is critically limited by the lack of specific markers and the destructive assays used to read out these markers. Here, we establish a rapid, live-cell assay for detecting senescent cells in heterogeneous mesenchymal stromal cell (MSC) cultures. We report that the T2 relaxation time measured by microscale Magnetic Resonance Relaxometry, which is related to intracellular iron accumulation, correlates strongly with senescence markers in MSC cultures under diverse conditions, including different passages and donors, size-sorted MSCs by inertial spiral microfluidic device, and drug-induced senescence. In addition, the live-cell and non-destructive method presented here has general applicability to other cells and tissues and can critically advance our understanding of cellular senescence.

Chicken CSF2 and IL-4-, and CSF2-dependent bone marrow cultures differentiate into macrophages over time.

Chicken bone marrow-derived macrophages (BMMΦ) and dendritic cells (BMDC) are utilized as models to study the mononuclear phagocytic system (MPS). A widely used method to generate macrophages and DC in vitro is to culture bone marrow cells in the presence of colony-stimulating factor-1 (CSF1) to differentiate BMMΦ and granulocyte-macrophage-CSF (GM-CSF, CSF2) and interleukin-4 (IL-4) to differentiate BMDC, while CSF2 alone can lead to the development of granulocyte-macrophage-CSF-derived DC (GMDC). However, in chickens, the MPS cell lineages and their functions represented by these cultures are poorly understood. Here, we decipher the phenotypical, functional and transcriptional differences between chicken BMMΦ and BMDC along with examining differences in DC cultures grown in the absence of IL-4 on days 2, 4, 6 and 8 of culture. BMMΦ cultures develop into a morphologically homogenous cell population in contrast to the BMDC and GMDC cultures, which produce morphologically heterogeneous cell cultures. At a phenotypical level, all cultures contained similar cell percentages and expression levels of MHCII, CD11c and CSF1R-transgene, whilst MRC1L-B expression decreased over time in BMMΦ. All cultures were efficiently able to uptake 0.5 µm beads, but poorly phagocytosed 1 µm beads. Little difference was observed in the kinetics of phagosomal acidification across the cultures on each day of analysis. Temporal transcriptomic analysis indicated that all cultures expressed high levels of CSF3R, MERTK, SEPP1, SPI1 and TLR4, genes associated with macrophages in mammals. In contrast, low levels of FLT3, XCR1 and CAMD1, genes associated with DC, were expressed at day 2 in BMDC and GMDC after which expression levels decreased. Collectively, chicken CSF2 + IL-4- and CSF2-dependent BM cultures represent cells of the macrophage lineage rather than inducing conventional DC.

Three-dimensional Collagen Scaffolds in Cultures of Olfactory Ensheathing Cells Used for Severed Spinal Cord Regeneration.

The regeneration of a completely damaged spinal cord is still a challenge in modern medicine. A promising treatment method is autologous transplantation of olfactory ensheathing cells (OECs). This study aimed primarily to test methods of culturing OECs with the use of materials and reagents that are certified for pharmaceutical use in the production of an advanced cell therapy product intended for humans. The culture of OECs was performed using various modifications of the surface of the culture vessels (with fibronectin and poly-D-lysine). The number of cells was assessed after immunofluorescence staining using anti-fibronectin and anti-p75 NGF receptor antibodies. The study compared, in terms of surgical manipulations, scaffolds with OECs prepared based on 3 types of collagen: Acid Solubilized Telo Collagen and Pepsin Solubilized Atelocollagen, and the popular Corning collagen. We have shown that when suspending OECs in collagen gel, it is much better to use acid-solubilized collagen (ASC) than pepsin-solubilized collagen (PSC) because the 3D collagen scaffold from ASC provides much easier handling of the product during a surgical procedure. We also found that the OEC cultures should be grown on the surface modified with fibronectin. Furthermore, we have also shown that the optimal concentration of fetal bovine serum (FBS) for culturing these cells should be around 10%. The culture of OECs based on reagents intended for human use can be successfully carried out, obtaining sufficient OECs content in the heterogeneous cell culture to produce a functional advanced therapy medicinal product.

Image-based cell subpopulation identification through automated cell tracking, principal component analysis, and partitioning around medoids clustering.

In vitro cell culture model systems often employ monocultures, despite the fact that cells generally exist in a diverse, heterogeneous microenvironment in vivo. In response, heterogeneous cultures are increasingly being used to study how cell phenotypes interact. However, the ability to accurately identify and characterize distinct phenotypic subpopulations within heterogeneous systems remains a major challenge. Here, we present the use of a computational, image analysis-based approach-comprising automated contour-based cell tracking for feature identification, principal component analysis for feature reduction, and partitioning around medoids for subpopulation characterization-to non-destructively and non-invasively identify functionally distinct cell phenotypic subpopulations from live-cell microscopy image data. Using a heterogeneous model system of endothelial and smooth muscle cells, we demonstrate that this approach can be applied to both mono and co-culture nuclear morphometric and motility data to discern cell phenotypic subpopulations. Morphometric clustering identified minimal difference in mono- versus co-culture, while motility clustering revealed that a portion of endothelial cells and smooth muscle cells adopt increased motility rates in co-culture that are not observed in monoculture. We anticipate that this approach using non-destructive and non-invasive imaging can be applied broadly to heterogeneous cell culture model systems to advance understanding of how heterogeneity alters cell phenotype. This work presents a computational, image-analysis-based approach-comprising automated contour-based cell tracking for feature identification, principle component analysis for feature reduction, and partitioning around medoids for subpopulation characterization-to non-destructively and non-invasively identify functionally distinct cell phenotypic subpopulations from live-cell microscopy image data.

Long-term live imaging and multiscale analysis identify heterogeneity and core principles of epithelial organoid morphogenesis

BackgroundOrganoids are morphologically heterogeneous three-dimensional cell culture systems and serve as an ideal model for understanding the principles of collective cell behaviour in mammalian organs during development, homeostasis, regeneration, and pathogenesis. To investigate the underlying cell organisation principles of organoids, we imaged hundreds of pancreas and cholangiocarcinoma organoids in parallel using light sheet and bright-field microscopy for up to 7 days.ResultsWe quantified organoid behaviour at single-cell (microscale), individual-organoid (mesoscale), and entire-culture (macroscale) levels. At single-cell resolution, we monitored formation, monolayer polarisation, and degeneration and identified diverse behaviours, including lumen expansion and decline (size oscillation), migration, rotation, and multi-organoid fusion. Detailed individual organoid quantifications lead to a mechanical 3D agent-based model. A derived scaling law and simulations support the hypotheses that size oscillations depend on organoid properties and cell division dynamics, which is confirmed by bright-field microscopy analysis of entire cultures.ConclusionOur multiscale analysis provides a systematic picture of the diversity of cell organisation in organoids by identifying and quantifying the core regulatory principles of organoid morphogenesis.

Impedance flow cytometry allows the early prediction of embryo yields in wheat (Triticum aestivum L.) microspore cultures

Haplomethods are key biotechnological tools that make it possible to rapidly produce perfectly homozygous lines, speeding up plant breeding programs. Under specific stress conditions, microspores are reprogrammed toward sporophytic pathways, leading to embryo formation. Various endogenous and exogenous factors affect embryo yield in androgenesis, so the improvement of androgenesis efficiency requires the development of early, reliable and robust reactivity markers. During the last decade, numerous cytological, cellular and biochemical approaches were carried out to finely characterize microspore development and fate during androgenesis. However, the different available markers are often species-dependent, and their development and application are time-consuming and cumbersome. In this study, we show the suitable use of impedance flow cytometry (IFC) to develop new robust, reliable and strong markers of androgenesis reactivity in wheat, leading to: (i) routine monitoring of the viability of heterogeneous cell cultures; (ii) quick and simple evaluation of stress treatment efficiency; and (iii) early prediction of embryo yields from microspore suspensions. IFC can therefore provide the fine characterization of all of the microspore developmental pathways that occur in a cell suspension, for embryogenic microspores as well as pollen-like microspores. IFC technology has become a very useful tool to track and characterize wheat microspores in androgenesis, but can also be adapted to other species and other in vitro cell culture systems.

Graphene oxide nanofilm and the addition of l-glutamine can promote development of embryonic muscle cells

BackgroundFormation of muscular pseudo-tissue depends on muscle precursor cells, the extracellular matrix (ECM)-mimicking structure and factors stimulating cell differentiation. These three things cooperate and can create a tissue-like structure, however, their interrelationships are relatively unknown. The objective was to study the interaction between surface properties, culture medium composition and heterogeneous cell culture. We would like to demonstrate that changing the surface properties by coating with graphene oxide nanofilm (nGO) can affect cell behaviour and especially their need for the key amino acid l-glutamine (L-Glu).ResultsChicken embryo muscle cells and their precursors, cultured in vitro, were used as the experimental model. The mesenchymal stem cell, collected from the hind limb of the chicken embryo at day 8 were divided into 4 groups; the control group and groups treated with nGO, L-Glu and nGO supplied with L-Glu (nGOxL-Glu). The roughness of the surface of the plastic plate covered with nGO was much lower than a standard plate. The test of nGO biocompatibility demonstrated that the cells were willing to settle on the nGO without any toxic effects. Moreover, nGO by increasing hydrophilicity and reducing roughness and presumably through chemical bonds available on the GO surface stimulated the colonisation of primary stromal cells that promote embryonic satellite cells. The viability significantly increased in cells cultured on nGOxL-Glu. Observations of cell morphology showed that the most mature state of myogenesis was characteristic for the group nGOxL-Glu. This result was confirmed by increasing the expression of MYF5 genes at mRNA and protein levels. nGO also increased the expression of MYF5 and also very strongly the expression of PAX7 at mRNA and protein levels. However, when analysing the expression of PAX7, a positive link was observed between the nGO surface and the addition of L-Glu.ConclusionsThe use of nGO and L-Glu supplement may improve myogenesis and also the myogenic potential of myocytes and their precursors by promoting the formation of satellite cells. Studies have, for the first time, demonstrated positive cooperation between surface properties nGO and L-Glu supplementation to the culture medium regarding the myogenic potential of cells involved in muscle formation.

A Human Skeletal Muscle Atlas Identifies the Trajectories of Stem and Progenitor Cells across Development and from Human Pluripotent Stem Cells.

The developmental trajectory of human skeletal myogenesis and the transition between progenitor and stem cell states are unclear. We used single-cell RNA sequencing to profile human skeletal muscle tissues from embryonic, fetal, and postnatal stages. In silico, we identified myogenic as well as other cell types and constructed a "roadmap" of human skeletal muscle ontogeny across development. In a similar fashion, we also profiled the heterogeneous cell cultures generated from multiple human pluripotent stem cell (hPSC) myogenic differentiation protocols and mapped hPSC-derived myogenic progenitors to an embryonic-to-fetal transition period. We found differentially enriched biological processes and discovered co-regulated gene networks and transcription factors present at distinct myogenic stages. This work serves as a resource for advancing our knowledge of human myogenesis. It also provides a tool for a better understanding of hPSC-derived myogenic progenitors for translational applications in skeletal muscle-based regenerative medicine.

Motility-Based Single-Cell Capture and Expansion from a Heterogeneous Cell Culture

Motility-Based Single-Cell Capture and Expansion from a Heterogeneous Cell Culture

Isolation and Culture of Oculomotor, Trochlear, and Spinal Motor Neurons from Prenatal Islmn:GFP Transgenic Mice.

Oculomotor neurons (CN3s) and trochlear neurons (CN4s) exhibit remarkable resistance to degenerative motor neuron diseases such as amyotrophic lateral sclerosis (ALS) when compared to spinal motor neurons (SMNs). The ability to isolate and culture primary mouse CN3s, CN4s, and SMNs would provide an approach to study mechanisms underlying this selective vulnerability. To date, most protocols use heterogeneous cell cultures, which can confound the interpretation of experimental outcomes. To minimize the problems associated with mixed-cell populations, pure cultures are indispensable. Here, the first protocol describes in detail how to efficiently purify and cultivate CN3s/CN4s alongside SMNs counterparts from the same embryos using embryonic day 11.5 (E11.5) IslMN:GFP transgenic mouse embryos. The protocol provides details on the tissue dissection and dissociation, FACS-based cell isolation, and in vitro cultivation of cells from CN3/CN4 and SMN nuclei. This protocol adds a novel in vitro CN3/CN4 culture system to existing protocols and simultaneously provides a pure species- and age-matched SMN culture for comparison. Analyses focusing on the morphological, cellular, molecular, and electrophysiological characteristics of motor neurons are feasible in this culture system. This protocol will enable research into the mechanisms that define motor neuron development, selective vulnerability, and disease.

Chemically induced neurite-like outgrowth reveals a multicellular network function in patient-derived glioblastoma cells.

Tumor stem cells and malignant multicellular networks have been separately implicated in the therapeutic resistance of glioblastoma multiforme (GBM), the most aggressive type of brain cancer in adults. Here, we show that small-molecule inhibition of RHO-associated serine/threonine kinase proteins (ROCKi) significantly promoted the outgrowth of neurite-like cell projections in cultures of heterogeneous patient-derived GBM stem-like cells. These projections formed de novo-induced cellular network (iNet) 'webs', which regressed after withdrawal of ROCKi. Connected cells within the iNet web exhibited long range Ca2+ signal transmission, and significant lysosomal and mitochondrial trafficking. In contrast to their less-connected vehicle control counterparts, iNet cells remained viable and proliferative after high-dose radiation. These findings demonstrate a link between ROCKi-regulated cell projection dynamics and the formation of radiation-resistant multicellular networks. Our study identifies means to reversibly induce iNet webs ex vivo, and may thereby accelerate future studies into the biology of GBM cellular networks.

Abstract LB-137: Three-dimensional cytotoxicity assay using magnetic 3D bioprinting for measuring CAR T cell function in heterogeneous solid tumor microenvironments

Abstract Chromium release assays are routinely utilized to assess cytotoxic activity and function of tumor targeting T cells expressing chimeric antigen receptors (CAR T cells). Although these assays can predict the activity of CAR T cells targeting hematological malignancies, results of such assays do not accurately reflect the limited efficacy of T cell therapy observed against solid tumors. This limitation may be due to the disparity between the in vitro cell culture setting and the complex nature of solid tumor microenvironments and their vascular structure. To this end, we have developed a cytotoxicity assay based on a three-dimensional (3D) cell culture model, facilitated by magnetic 3D bioprinting, to more precisely mimic the complexity of solid tumor microenvironments in vitro. This model can be customized to reflect the heterogeneity of solid tumors by incorporating multiple cell types and immune cells. In these studies, we have demonstrated the feasibility of this assay using CD19-specific CAR T cells specifically targeting CD19+ leukemia cells in a heterogeneous 3D cell culture. We also show the CAR T cells infiltrating and targeting glioblastoma (U87) 3D cultures in real-time with fluorescence microscopy. Incorporation of this assay as a routine cytotoxicity assay will provide new dimensions to rapid immune function assessments by revealing the kinetics of cell killing through time-lapse microscopy, the persistence and targeting patterns of CAR T cells, and cell-specific killing by multicolor fluorescence imaging. This assay is being adapted into a 96-, 384- and 1,536-well formats for high-throughput applications. Citation Format: Glauco R. Souza, Amer Najjar. Three-dimensional cytotoxicity assay using magnetic 3D bioprinting for measuring CAR T cell function in heterogeneous solid tumor microenvironments [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr LB-137.

Double-layer perfusable collagen microtube device for heterogeneous cell culture

In vitro perfusable 3D tissue models mimic in vivo tissues and have several benefits in drug testing. However, processes used to fabricate these models often tend to be complicated. Here, we present a double-layer perfusable collagen tube device for multilayered in vitro 3D cell culture. The device is simply made by the repetition of a molding process. The thicknesses of the collagen layers in the tube device can be flexibly designed, and heterogeneous cell types can be co-cultured in/on each collagen layer. Moreover, while our collagen tube is directly attached to silicone tubes, the collagen tube can easily be connected to an external pump system for perfusion culture. We fabricated six different sizes of collagen devices (inner diameter approximately 300–1000 μm) using different molds, and successfully controlled the coefficients of variation to be below 5% for the diameters of each layer for all six device sizes. The device is strong enough to manipulate with tweezers, and can remain stable for more than 3 months in a medium. For the cell culture, we successfully and correctly encapsulated cells in the layer shape at the desired position, and confirmed cell migration. Using the perfusion culture, we demonstrated that the alignments of the HUVEC actin filaments become parallel to the flow direction. We believe that our device could advance the easy fabrication of various tissue models (that is, models mimicking in vivo tissues). In particular, the device could help fabricate vascularized tissue models, and contribute to the development of pharmacokinetic testing platforms and regenerative medicine.

Modeling the impact of drug interactions on therapeutic selectivity

Combination therapies that produce synergistic growth inhibition are widely sought after for the pharmacotherapy of many pathological conditions. Therapeutic selectivity, however, depends on the difference between potency on disease-causing cells and potency on non-target cell types that cause toxic side effects. Here, we examine a model system of antimicrobial compound combinations applied to two highly diverged yeast species. We find that even though the drug interactions correlate between the two species, cell-type-specific differences in drug interactions are common and can dramatically alter the selectivity of compounds when applied in combination vs. single-drug activity—enhancing, diminishing, or inverting therapeutic windows. This study identifies drug combinations with enhanced cell-type-selectivity with a range of interaction types, which we experimentally validate using multiplexed drug-interaction assays for heterogeneous cell cultures. This analysis presents a model framework for evaluating drug combinations with increased efficacy and selectivity against pathogens or tumors.

PO-084 Ascorbic acid selectively targets glucose metabolism of osteosarcoma stem cells

IntroductionThere is increasing evidence that cancer stem cells (CSCs) could mediate resistance to chemo- and radiotherapy, metastasis and recurrence in a wide range of solid tumours. Notch signalling pathway is involved in CSCs maintenance. Notch influences intra- and intercellular communications of various cell types in embryogenesis and adult organs. The oncogenic role of Notch signalling in survival, proliferation, self-renewal, differentiation and migration of cancer cells is demonstrated in most solid tumours and leukaemia. This study aims to explore the effect of Notch1 suppression on CSCs in human lung (A549) and colorectal (HCT116) adenocarcinoma cell lines.Material and methodsKnockdown of Notch1 by shRNA was confirmed by PCR and western-blot analyses. PCR was used for estimation of stemness, epithelia-to-mesenchyma transition (EMT) markers and proto-oncogene c-MYC expression. The proportion of CD133+ cells in different subpopulations was identified by Flow cytometry. Cell migration potential was examined by Boyden chamber assay. The effect of Notch1 inhibition on CSCs was established using classical detection methods of CSCs in heterogeneous cancer cell cultures: tumourisphere formation, tumourigenicity in vivo and quantitative assessment of ABC-transporter activity assays.Results and discussionsNotch1 inhibition resulted in stemness (SOX2, OCT3/4, NES), EMT (TWIST1, HES1, SNAIL1), CSCs (CD133) markers, c-MYC expression decrease and CDH1 (E-cadherin) expression increase suggesting that Notch pathway is involved in EMT. Loss of Notch1 did not influence cell proliferation in vitro but reduced migration potential. It was confirmed that Notch signalling interruption leads to reduction of stemness features: decreased drug resistance (A549 but not HCT116), ability to form tumourispheres and tumourigenic potential in vivo. ABC-transporter activity in HCT116 could be upregulated by TAZ/YAP signalling pathway and not by Notch. Moreover, reduced Notch1 expression increased the minimum inoculum cell dose for xenograft formation. The xenograft vascularisation assay revealed that Notch1 inhibition is not necessary for neovascularizaton but it is essential for angiogenesis but in tumour.ConclusionThe Notch signalling pathway is important for maintaining the CSCs population, stemness and migration so Notch1 could be considered as a potential therapeutic target in lung and colorectal cancer. The study was supported Russian Science Foundation (RSCF), grant No. 14-15-00467.