Chitosan-hyaluronan based 3D co-culture platform for studying the crosstalk of lung cancer cells and mesenchymal stem cells

A Pump-Free Strategy for the Controllable Generation of Alginate Microgels as Cellular Microcarriers

Microgels are advanced scaffolds for tissue engineering due to their proper biodegradability, good biocompatibility, and high specific surface area for effective oxygen and nutrient transfer. However, most of the current monodispersed microgel fabrication systems rely heavily on various precision pumps, which highly increase the cost and complexity of their downstream application. In this work, we developed a simple and facile system for the controllable generation of uniform alginate microgels by integrating a gas-shearing strategy into a glass microfluidic device. Importantly, the cell-laden microgels can be rapidly prepared in a pump-free manner under an all-aqueous environment. The three-dimensional cultured green fluorescent protein-human A549 cells in alginate microgels exhibited enhanced stemness and drug resistance compared to those under two-dimensional conditions. The pancreatic cancer organoids in alginate microgels exhibited some of the key features of pancreatic cancer. The proposed microgels showed decent monodispersity, biocompatibility, and versatility, providing great opportunities in various biomedical applications such as microcarrier fabricating, organoid engineering, and high-throughput drug screening.

Mesenchymal Stem Cells Increase Drug Tolerance of A431 Cells Only in 3D Spheroids, Not in 2D Co-Cultures

Mesenchymal stem cells (MSCs) are an integral part of the tumor microenvironment (TME); however, their role is somewhat controversial: conflicting reports suggest that, depending on the stage of tumor development, MSCs can either support or suppress tumor growth and spread. Additionally, the influence of MSCs on drug resistance is also ambiguous. Previously, we showed that, despite MSCs proliferating significantly more slowly than cancer cells, there are chemotherapeutic drugs which proved to be similarly toxic to both cell types. Here we established 2D co-cultures and 3D co-culture spheroids from different ratios of GFP-expressing, adipose tissue-derived MSCs and A431 epidermoid carcinoma cells tagged with mCherry to investigate the effect of MSCs on cancer cell growth, survival, and drug sensitivity. We examined the cytokine secretion profile of mono- and co-cultures, explored the inner structure of the spheroids, applied MSC-(nutlin-3) and cancer cell-targeting (cisplatin) treatments separately, monitored the response with live-cell imaging and identified a new, double-fluorescent cell type emerging from these cultures. In 2D co-cultures, no effect on proliferation or drug sensitivity was observed, regardless of the changes in cytokine secretion induced by the co-culture. Conversely, 3D spheroids developed a unique internal structure consisting of MSCs, which significantly improved cancer cell survival and resilience to treatment, suggesting that physical proximity and cell-cell connections are required for MSCs to considerably affect nearby cancer cells. Our results shed light on MSC-cancer cell interactions and could help design new, better treatment options for tumors.

The Nexus of Inflammation-Induced Epithelial-Mesenchymal Transition and Lung Cancer Progression: A Roadmap to Pentacyclic Triterpenoid-Based Therapies

Lung cancer is the leading cause of cancer-related death worldwide. Its high mortality is partly due to chronic inflammation that accompanies the disease and stimulates cancer progression. In this review, we analyzed recent studies and highlighted the role of the epithelial-mesenchymal transition (EMT) as a link between inflammation and lung cancer. In the inflammatory tumor microenvironment (iTME), fibroblasts, macrophages, granulocytes, and lymphocytes produce inflammatory mediators, some of which can induce EMT. This leads to increased invasiveness of tumor cells and self-renewal of cancer stem cells (CSCs), which are associated with metastasis and tumor recurrence, respectively. Based on published data, we propose that inflammation-induced EMT may be a potential therapeutic target for the treatment of lung cancer. This prospect is partially realized in the development of EMT inhibitors based on pentacyclic triterpenoids (PTs), described in the second part of our study. PTs reduce the metastatic potential and stemness of tumor cells, making PTs promising candidates for lung cancer therapy. We emphasize that the high diversity of molecular mechanisms underlying inflammation-induced EMT far exceeds those that have been implicated in drug development. Therefore, analysis of information on the relationship between the iTME and EMT is of great interest and may provide ideas for novel treatment approaches for lung cancer.

Zebrafish in Lung Cancer Research

Zebrafish is increasingly used as a model organism for cancer research because of its genetic and physiological similarities to humans. Modeling lung cancer (LC) in zebrafish has received significant attention. This review focuses on the insights gained from using zebrafish in LC research. These insights range from investigating the genetic and molecular mechanisms that contribute to the development and progression of LC to identifying potential drug targets, testing the efficacy and toxicity of new therapies, and applying zebrafish for personalized medicine studies. This review provides a comprehensive overview of the current state of LC research performed using zebrafish, highlights the advantages and limitations of this model organism, and discusses future directions in the field.

A Microfluidic Experimental Method for Studying Cell-to-Cell Exosome Delivery-Taking Stem Cell-Tumor Cell Interaction as a Case

Cell-to-cell communication must occur through molecular transport in the intercellular fluid space. Nanoparticles, such as exosomes, diffuse or move more slowly in fluids than small molecules. To find a microfluidic technology for real-time exosome experiments on intercellular communication between living cells, we use the microfluidic culture dish's quaternary ultra-slow microcirculation flow field to accumulate nanoparticles in a specific area. Taking stem cell-tumor cell interaction as an example, the ultra-slow microcirculatory flow field controls stem cell exosomes to interfere with tumor cells remotely. Under static coculture conditions (without microfluidics), the tumor cells near stem cells (<200 µm) show quick breaking through from its Matrigel drop to meet stem cells, but this 'breaking through' quickly disappears with increasing distance. In programmed ultra-slow microcirculation, stem cells induce tumor cells 5000 μm far at the site of exosome deposition (according to nanoparticle simulations). After 14 days of programmed coculture, the glomeration and migration of tumor cells were observed in the exosome deposition area. This example shows that the ultra-slow microcirculation of the microfluidic culture dish has good prospects in quantitative experiments to study exosome communication between living cells and drug development of cancer metastasis.

Advances in tissue engineering of cancer microenvironment-from three-dimensional culture to three-dimensional printing

Cancer treatment development is a complex process, with tumor heterogeneity and inter-patient variations limiting the success of therapeutic intervention. Traditional two-dimensional cell culture has been used to study cancer metabolism, but it fails to capture physiologically relevant cell-cell and cell-environment interactions required to mimic tumor-specific architecture. Over the past three decades, research efforts in the field of 3D cancer model fabrication using tissue engineering have addressed this unmet need. The self-organized and scaffold-based model has shown potential to study the cancer microenvironment and eventually bridge the gap between 2D cell culture and animal models. Recently, three-dimensional (3D) bioprinting has emerged as an exciting and novel biofabrication strategy aimed at developing a 3D compartmentalized hierarchical organization with the precise positioning of biomolecules, including living cells. In this review, we discuss the advancements in 3D culture techniques for the fabrication of cancer models, as well as their benefits and limitations. We also highlight future directions associated with technological advances, detailed applicative research, patient compliance, and regulatory challenges to achieve a successful bed-to-bench transition.

The interplay of cells, polymers, and vascularization in three-dimensional lung models and their applications in COVID-19 research and therapy

Millions of people have been affected ever since the emergence of the corona virus disease of 2019 (COVID-19) outbreak, leading to an urgent need for antiviral drug and vaccine development. Current experimentation on traditional two-dimensional culture (2D) fails to accurately mimic the in vivo microenvironment for the disease, while in vivo animal model testing does not faithfully replicate human COVID-19 infection. Human-based three-dimensional (3D) cell culture models such as spheroids, organoids, and organ-on-a-chip present a promising solution to these challenges. In this report, we review the recent 3D in vitro lung models used in COVID-19 infection and drug screening studies and highlight the most common types of natural and synthetic polymers used to generate 3D lung models.

Advances in Tumor Organoids for the Evaluation of Drugs: A Bibliographic Review

Tumor organoids are defined as self-organized three-dimensional assemblies of heterogeneous cell types derived from patient samples that mimic the key histopathological, genetic, and phenotypic characteristics of the original tumor. This technology is proposed as an ideal candidate for the evaluation of possible therapies against cancer, presenting advantages over other models which are currently used. However, there are no reports in the literature that relate the techniques and material development of tumor organoids or that emphasize in the physicochemical and biological properties of materials that intent to biomimicry the tumor extracellular matrix. There is also little information regarding the tools to identify the correspondence of native tumors and tumoral organoids (tumoroids). Moreover, this paper relates the advantages of organoids compared to other models for drug evaluation. A growing interest in tumoral organoids has arisen from 2009 to the present, aimed at standardizing the process of obtaining organoids, which more accurately resemble patient-derived tumor tissue. Likewise, it was found that the characteristics to consider for the development of organoids, and therapeutic responses of them, are cell morphology, physiology, the interaction between cells, the composition of the cellular matrix, and the genetic, phenotypic, and epigenetic characteristics. Currently, organoids have been used for the evaluation of drugs for brain, lung, and colon tumors, among others. In the future, tumor organoids will become closer to being considered a better model for studying cancer in clinical practice, as they can accurately mimic the characteristics of tumors, in turn ensuring that the therapeutic response aligns with the clinical response of patients.

Cancer metastasis is related to normal tissue stemness

The occurrence of cancer metastasis may be related to stem cells in normal tissues. We searched for patient IDs with both normal tissue stem cell values and TCGA (The Cancer Genome Atlas) clinical data for pairing and obtained 639 sets of data (stemness index of normal tissue, stemness index of tumor tissue, cancer stage, distant metastasis, tumor size) and invasion, and lymph node involvement). However, clinical data on cancer metastasis are of only four stages (e.g., Stage I, II, III, and IV), which cannot show subtle changes continuously. We need to find an effective data mining method to transform this four-valued clinical description into a numerical curve. We data-mine this data through numericalization, sorting, and noise reduction filtering. The results showed that: as the normal tissue stemness value (NS) increased, the tumor tissue stemness value (TS) increased proportionally (1.26 times NS). When NS >0.5, the rate of change in TS decelerated (0.43 times NS), and tumor metastasis began to occur. Clinical indicators, such as cancer stage, distant metastasis, tumor size and invasion, and lymph node involvement, showed that tumor metastasis became more and more severe with the increase of NS. This study suggests that tumor metastasis is triggered when the NS in the patient's body is more significant than 0.5.

The Anti-Proliferative Effect of PI3K/mTOR and ERK Inhibition in Monolayer and Three-Dimensional Ovarian Cancer Cell Models

Simple Summary

In ovarian cancer patients the PI3K/AKT/mTOR and RAS/RAF/MEK/ERK kinase signaling pathways are frequently dysregulated, making them potential targets of therapeutic inhibitors. In this study, we used four human ovarian cancer cell lines grown in two- and three-dimensional models to investigate the potential efficacy of combining two inhibitors, which target these pathways, against ovarian cancer. The inhibitor combination was found to have cell line- and model-dependent synergistic antiproliferative effect.

Abstract

Most ovarian cancer patients are diagnosed with advanced stage disease, which becomes unresponsive to chemotherapeutic treatments. The PI3K/AKT/mTOR and the RAS/RAF/MEK/ERK kinase signaling pathways are attractive targets for potential therapeutic inhibitors, due to the high frequency of mutations to PTEN, PIK3CA, KRAS and BRAF in several ovarian cancer subtypes. However, monotherapies targeting one of these pathways have shown modest effects in clinical trials. This limited efficacy of the agents could be due to upregulation and increased signaling via the adjacent alternative pathway. In this study, the efficacy of combined PI3K/mTOR (BEZ235) and ERK inhibition (SCH772984) was investigated in four human ovarian cancer cell lines, grown as monolayer and three-dimensional cell aggregates. The inhibitor combination reduced cellular proliferation in a synergistic manner in OV-90 and OVCAR8 monolayers and in OV-90, OVCAR5 and SKOV3 aggregates. Sensitivity to the inhibitors was reduced in three-dimensional cell aggregates in comparison to monolayers. OV-90 cells cultured in large spheroids were sensitive to the inhibitors and displayed a robust synergistic antiproliferative response to the inhibitor combination. In contrast, OVCAR8 spheroids were resistant to the inhibitors. These findings suggest that combined PI3K/mTOR and ERK inhibition could be a useful strategy for overcoming treatment resistance in ovarian cancer and warrants further preclinical investigation. Additionally, in some cell lines the use of different three-dimensional models can influence cell line sensitivity to PI3K/mTOR and RAS/RAF/MEK/ERK pathway inhibitors.

Recent advances of 3D hydrogel culture systems for mesenchymal stem cell-based therapy and cell behavior regulation

Mesenchymal stem cells (MSCs) have been increasingly recognized as resources for disease treatments and regenerative medicine. Meanwhile, the unique chemical and physical properties of hydrogels provide innate advantages to achieve...

Development of Breast Cancer Spheroids to Evaluate Cytotoxic Response to an Anticancer Peptide

Breast cancer (BC) is the most commonly diagnosed cancer in women and one of the most common causes of cancer-related deaths. Despite intense research efforts, BC treatment still remains challenging. Improved drug development strategies are needed for impactful benefit to patients. Current preclinical studies rely mostly on cell-based screenings, using two-dimensional (2D) cell monolayers that do not mimic in vivo tumors properly. Herein, we explored the development and characterization of three-dimensional (3D) models, named spheroids, of the most aggressive BC subtypes (triple-negative breast cancer-TNBC; and human-epidermal growth receptor-2-HER2+), using the liquid overlay technique with several selected cell lines. In these cell line-derived spheroids, we studied cell density, proliferation, ultrastructure, apoptosis, reactive oxygen species (ROS) production, and cell permeabilization (live/dead). The results showed a formation of compact and homogeneous spheroids on day 7 after seeding 2000 cells/well for MDA-MB-231 and 5000 cells/well for BT-20 and BT-474. Next, we compared the efficacy of a model anticancer peptide (ACP) in cell monolayers and spheroids. Overall, the results demonstrated spheroids to be less sensitive to treatment than cell monolayers, revealing the need for more robust models in drug development.

Polycaprolactone Electrospun Scaffolds Produce an Enrichment of Lung Cancer Stem Cells in Sensitive and Resistant EGFRm Lung Adenocarcinoma

Simple Summary

The culture of lung cancer stem cells (LCSCs) is not possible using traditional flat polystyrene surfaces. The study of these tumor-initiating cells is fundamental due to their key role in the resistance to anticancer therapies, tumor recurrence, and metastasis. Hence, we evaluated the use of polycaprolactone electrospun (PCL-ES) scaffolds for culturing LCSC population in sensitive and resistant EGFR-mutated lung adenocarcinoma models. Our findings revealed that both cell models seeded on PCL-ES structures showed a higher drug resistance, enhanced levels of several genes and proteins related to epithelial-to-mesenchymal process, stemness, and surface markers, and the activation of the Hedgehog pathway. We also determined that the non-expression of CD133 was associated with a low degree of histological differentiation, disease progression, distant metastasis, and worse overall survival in EGFR-mutated non-small cell lung cancer patients. Therefore, we confirmed PCL-ES scaffolds as a suitable three-dimensional cell culture model for the study of LCSC niche.

Abstract

The establishment of a three-dimensional (3D) cell culture model for lung cancer stem cells (LCSCs) is needed because the study of these stem cells is unable to be done using flat surfaces. The study of LCSCs is fundamental due to their key role in drug resistance, tumor recurrence, and metastasis. Hence, the purpose of this work is the evaluation of polycaprolactone electrospun (PCL-ES) scaffolds for culturing LCSCs in sensitive and resistant EGFR-mutated (EGFRm) lung adenocarcinoma cell models. We performed a thermal, physical, and biological characterization of 10% and 15%-PCL-ES structures. Several genes and proteins associated with LCSC features were analyzed by RT-qPCR and Western blot. Vimentin and CD133 tumor expression were evaluated in samples from 36 patients with EGFRm non-small cell lung cancer through immunohistochemistry. Our findings revealed that PC9 and PC9-GR3 models cultured on PCL-ES scaffolds showed higher resistance to osimertinib, upregulation of ABCB1, Vimentin, Snail, Twist, Sox2, Oct-4, and CD166, downregulation of E-cadherin and CD133, and the activation of Hedgehog pathway. Additionally, we determined that the non-expression of CD133 was significantly associated with a low degree of histological differentiation, disease progression, and distant metastasis. To sum up, we confirmed PCL-ES scaffolds as a suitable 3D cell culture model for the study of the LCSC niche.

Tumor microenvironment-based screening repurposes drugs targeting cancer stem cells and cancer-associated fibroblasts

The tumorous niche may drive the plasticity of heterogeneity and cancer stemness, leading to drug resistance and metastasis, which is the main reason of treatment failure in most cancer patients. The aim of this study was to establish a tumor microenvironment (TME)-based screening to identify drugs that can specifically target cancer stem cells (CSCs) and cancer-associated fibroblasts (CAFs) in the TME. Methods: Lung cancer patient-derived cancer cell and CAFs were utilized to mimic the TME and reproduce the stemness properties of CSCs in vitro and develop a high-throughput drug screening platform with phenotypical parameters. Limiting dilution assay, sphere-forming and ALDH activity assay were utilized to measure the cancer stemness characteristics. In vivo patient-derived xenograft (PDX) models and single-cell RNA sequencing were used to evaluate the mechanisms of the compounds in CSCs and CAFs. Results: The TME-based drug screening platform could comprehensively evaluate the response of cancer cells, CSCs and CAFs to different treatments. Among the 1,524 compounds tested, several drugs were identified to have anti-CAFs, anticancer and anti-CSCs activities. Aloe-emodin and digoxin both show anticancer and anti-CSCs activity in vitro and in vivo, which was further confirmed in the lung cancer PDX model. The combination of digoxin and chemotherapy improved therapeutic efficacy. The single-cell transcriptomics analysis revealed that digoxin could suppress the CSCs subpopulation in CAFs-cocultured cancer cells and cytokine production in CAFs. Conclusions: The TME-based drug screening platform provides a tool to identify and repurpose compounds targeting cancer cells, CSCs and CAFs, which may accelerate drug development and therapeutic application for lung cancer patients.

A Novel Orthotopic Liver Cancer Model for Creating a Human-like Tumor Microenvironment

Simple Summary

Hepatocellular carcinoma is the most common form of liver cancer. The lack of models that resemble actual tumor development in patients, limits the research to improve the diagnosis rate and develop new treatments. This study describes a novel mouse model that involves organoid formation and an implantation technique. This mouse model shares human genetic profiles and factors around the tumor, resembling the actual tumor development in patients. We demonstrate the roles of different cell types around the tumor, in promoting tumor growth, using this model. This model will be useful to understand the tumor developmental process, drug testing, diagnosis, prognosis, and treatment development.

Abstract

Hepatocellular carcinoma (HCC) is the most common form of liver cancer. This study aims to develop a new method to generate an HCC mouse model with a human tumor, and imitates the tumor microenvironment (TME) of clinical patients. Here, we have generated functional, three-dimensional sheet-like human HCC organoids in vitro, using luciferase-expressing Huh7 cells, human iPSC-derived endothelial cells (iPSC-EC), and human iPSC-derived mesenchymal cells (iPSC-MC). The HCC organoid, capped by ultra-purified alginate gel, was implanted into the disrupted liver using an ultrasonic homogenizer in the immune-deficient mouse, which improved the survival and engraftment rate. We successfully introduced different types of controllable TME into the model and studied the roles of TME in HCC tumor growth. The results showed the role of the iPSC-EC and iPSC-MC combination, especially the iPSC-MC, in promoting HCC growth. We also demonstrated that liver fibrosis could promote HCC tumor growth. However, it is not affected by non-alcoholic fatty liver disease. Furthermore, the implantation of HCC organoids to humanized mice demonstrated that the immune response is important in slowing down tumor growth at an early stage. In conclusion, we have created an HCC model that is useful for studying HCC development and developing new treatment options in the future.

Specificity of 3D MSC Spheroids Microenvironment: Impact on MSC Behavior and Properties

Mesenchymal stem cells (MSC) have been considered the promising candidates for the regenerative and personalized medicine due to their self-renewal potential, multilineage differentiation and immunomodulatory capacity. Although these properties have encouraged profound MSC studies in recent years, the majority of research has been based on standard 2D culture utilization. The opportunity to resemble in vivo characteristics of cells native niche has been provided by implementation of 3D culturing models such as MSC spheroid formation assesed through cells self-assembling. In this review, we address the current literature on physical and biochemical features of 3D MSC spheroid microenvironment and their impact on MSC properties and behaviors. Starting with the reduction in the cells' dimensions and volume due to the changes in adhesion molecules expression and cytoskeletal proteins rearrangement resembling native conditions, through the microenvironment shifts in oxygen, nutrients and metabolites gradients and demands, we focus on distinctive and beneficial features of MSC in spheroids compared to cells cultured in 2D conditions. By summarizing the data for 3D MSC spheroids regarding cell survival, pluripotency, differentiation, immunomodulatory activities and potential to affect tumor cells growth we highlighted advantages and perspectives of MSC spheroids use in regenerative medicine. Further detailed analyses are needed to deepen our understanding of mechanisms responsible for modified MSC behavior in spheroids and to set future directions for MSC clinical application.

3D Co-cultured Endothelial Cells and Monocytes Promoted Cancer Stem Cells' Stemness and Malignancy

Cancer stem cells (CSCs) are self-renewing and constitute the primary cause of cancer relapse post-cancer therapy. The CSC niche is composed of various nonmalignant stromal cells that support CSCs' survival during cancer chemoradiotherapy. Understanding the cross-talk between CSCs and stromal cells could pave the way for developing therapeutic strategies to eradicate CSCs. Traditionally, CSC research has been relying on animal models, which can give rise to complications and poor translation in clinical practice. An efficient model to co-culture CSCs and stromal cells is urgently needed. Hence, we leveraged our expertise in enriching CSCs from in vitro cell lines with a 3D alginate-based platform, as reported previously. We established a 3D co-culture system that allowed us to study the interactions between stromal cells and CSCs over an extended period. We showed that the self-renewal capacity and stemness of CSCs were significantly enhanced when co-cultured with 3D cultured human umbilical vein endothelial cells (HUVECs) or a human monocyte cell line (THP1). Strikingly, the expression of MDR1 in 3D co-cultured CSCs was upregulated, leading to enhanced chemotoxic drug tolerance. We suggest that our in vitro co-culture model can impact CSC research and clinical practice when the goal is to develop therapeutics that target and eradicate CSCs by targeting stromal cells.

Three-Dimensional Culture System of Cancer Cells Combined with Biomaterials for Drug Screening

Simple Summary

For the research and development of drug discovery, it is of prime importance to construct the three-dimensional (3D) tissue models in vitro. To this end, the enhancement design of cell function and activity by making use of biomaterials is essential. In this review, 3D culture systems of cancer cells combined with several biomaterials for anticancer drug screening are introduced.

Abstract

Anticancer drug screening is one of the most important research and development processes to develop new drugs for cancer treatment. However, there is a problem resulting in gaps between the in vitro drug screening and preclinical or clinical study. This is mainly because the condition of cancer cell culture is quite different from that in vivo. As a trial to mimic the in vivo cancer environment, there has been some research on a three-dimensional (3D) culture system by making use of biomaterials. The 3D culture technologies enable us to give cancer cells an in vitro environment close to the in vivo condition. Cancer cells modified to replicate the in vivo cancer environment will promote the biological research or drug discovery of cancers. This review introduces the in vitro research of 3D cell culture systems with biomaterials in addition to a brief summary of the cancer environment.

ZenoFishDb v1.1: A Database for Xenotransplantation Studies in Zebrafish

Rapidly accumulating literature has proven feasibility of the zebrafish xenograft models in cancer research. Nevertheless, online databases for searching the current zebrafish xenograft literature are in great demand. Herein, we have developed a manually curated database, called ZenoFishDb v1.1 (https://konulab.shinyapps.io/zenofishdb), based on R Shiny platform aiming to provide searchable information on ever increasing collection of zebrafish studies for cancer cell line transplantation and patient-derived xenografts (PDXs). ZenoFishDb v1.1 user interface contains four modules: DataTable, Visualization, PDX Details, and PDX Charts. The DataTable and Visualization pages represent xenograft study details, including injected cell lines, PDX injections, molecular modifications of cell lines, zebrafish strains, as well as technical aspects of the xenotransplantation procedures in table, bar, and/or pie chart formats. The PDX Details module provides comprehensive information on the patient details in table format and can be searched and visualized. Overall, ZenoFishDb v1.1 enables researchers to effectively search, list, and visualize different technical and biological attributes of zebrafish xenotransplantation studies particularly focusing on the new trends that make use of reporters, RNA interference, overexpression, or mutant gene constructs of transplanted cancer cells, stem cells, and PDXs, as well as distinguished host modifications.

Effect of RGD content in poly(ethylene glycol)-crosslinked poly(methyl vinyl ether-alt-maleic acid) hydrogels on the expansion of ovarian cancer stem-like cells

The extracellular matrix (ECM) affects cell behaviors, such as survival, proliferation, motility, invasion, and differentiation. The arginine-glycine-aspartic acid (RGD) sequence is present in several ECM proteins, such as fibronectin, collagen type I, fibrinogen, laminin, vitronectin, and osteopontin. It is very critical to develop ECM-like substrates with well-controlled features for the investigation of influence of RGD on the behavior of tumor cells. In this study, poly(ethylene glycol) (PEG)-crosslinked poly(methyl vinyl ether-alt-maleic acid) (P(MVE-alt-MA)) hydrogels (PEMM) with different RGD contents were synthesized, fully characterized, and established as in vitro culture platforms to investigate the effects of RGD content on cancer stem cell (CSC) enrichment. The morphology, proliferation, and viability of SK-OV-3 ovarian cancer cells cultured on hydrogels with different RGD contents, the expression of CSC markers and malignant signaling pathway-related genes, and drug resistance were systematically evaluated. The cell aggregates formed on the hydrogel surface with a lower RGD content acquired certain CSC-like properties, thus drug resistance was enhanced. In contrast, the drug sensitivity of cells on the higher RGD content surface increased because of less CSC-like properties. However, the presence of RGD in the stiff hydrogels (PEMM2) had less effect on the stemness expression than did its presence in the soft hydrogels (PEMM1). The results suggest that RGD content and matrix stiffness can lead to synergetic effects on the expression of cancer cell stemness and the epithelial-mesenchymal transition (EMT), interleukin-6 (IL-6), and Wnt pathways.

Biomaterial substrate-derived compact cellular spheroids mimicking the behavior of pancreatic cancer and microenvironment

Pancreatic stromal cells especially pancreatic stellate cells (PSCs) play a critical role in the progression of human pancreatic ductal adenocarcinoma (PDAC). However, the exact interaction between cancer cells and PSCs remains to be elucidated in order to develop more effective therapeutic approaches to treat PDAC. The microenvironment of PDAC shows higher hyaluronan (HA) levels, which is associated with poor prognosis of PDAC patients. In the current study, an efficient three-dimensional tumor spheroid model for PDAC was established. The pancreatic cancer cells and PSCs were co-cultured on hyaluronan grafted chitosan (CS-HA) coated plates to generate 3D tumor-like co-spheroids. The pancreatic cancer cells and PSCs (1:9 ratio) co-cultured on CS-HA coated plates were assembled into tumor-like co-spheroids with 3D core-shell structure in 48 h. These spheroids displayed potent in vitro tumorigenicity such as up-regulated expression of stemness and migration markers. The migration rate of cancer cells in spheroids (from 1:9 cell ratio) was much faster (3.2-fold) than that of cancer cells alone. Meanwhile, this unique co-spheroidal cancer cell structure with the outer wrap of PSCs contributed to the chemo-resistance of pancreatic cancer cells to gemcitabine as well as sensitivity to the combined gemcitabine and Abraxane treatment in vitro. The metastatic nature of the spheroids was confirmed by the zebrafish xenograft model in vivo. The compact and dynamic pancreatic cancer-PSC co-spheroids generated by the unique 3D co-culture platform on CS-HA biomaterials can mimic the PSC-constituting microenvironment of PDAC and demonstrate the chemo-resistant, invasive, and metastatic phenotypes. They have potential applications in personalized and high-throughput drug screening.

Cellular Spheroids of Mesenchymal Stem Cells and Their Perspectives in Future Healthcare

Intrinsic cellular properties of several types of cells are dramatically altered as the culture condition shifts from two-dimensional (2D) to three-dimensional (3D) environment. Currently, several lines of evidence have demonstrated the therapeutic potential of mesenchymal stem cells (MSCs) in regenerative medicine. MSCs not only replenish the lost cells, they also promote the regeneration of impaired tissues by modulating the immune responses. Following the development of 3D cell culture, the enhanced therapeutic efficacy of spheroid-forming MSCs have been identified in several animal disease models by promoting differentiation or trophic factor secretion, as compared to planar-cultured MSCs. Due to the complicated and multifunctional applications in the medical field, MSCs are recently named as medicinal signaling cells. In this review, we summarize the predominant differences of cell–environment interactions for the MSC spheroids formed by chitosan-based substrates and other scaffold-free approaches. Furthermore, several important physical and chemical factors affecting cell behaviors in the cell spheroids are discussed. Currently, the understanding of MSCs spheroid interactions is continuously expanding. Overall, this article aims to review the broad advantages and perspectives of MSC spheroids in regenerative medicine and in future healthcare.

Bioinstructive microparticles for self-assembly of mesenchymal stem Cell-3D tumor spheroids

3D multicellular tumor spheroids (3D-MCTS) that closely mimic in vitro the complex lung tumor microenvironment (TME) are highly desirable for screening innovative anti-cancer therapeutics. Despite significant improvements in mimicking lung TME, few models have combined tumor-infiltrating mesenchymal stem cells from bone marrow (hBM-MSCs) with heterotypic 3D tumor spheroid models containing ECM mimetic components. Herein, we engineered hybrid 3D-MCTS that combine, for the first time, A549:fibroblasts:hBM-MSCs in heterotypic tri-culture, with bioinstructive hyaluronan microparticles that act as tumor-ECM mimetics and as cell-anchoring hotspots. The obtained results indicated that 3D microspheres provided proper support for cells to self-assemble into compact 3D microtissues and promoted an increase in CD44 expression, emulating the presence of native-ECM hyaluronan. 3D-MCTS size and sphere-like morphology was reproducible and tri-culture models presented the characteristic solid tumors necrotic core. Mesenchymal stem cells tracking demonstrated that hBM-MSCs migrate to different regions in 3D microtumors mass exhibiting dynamic interactions with cancer cells and stromal fibroblasts, alike in human tumors. Importantly, doxorubicin administration revealed hBM-MSCs effect on cytotoxic responses in 3D tri-culture models and in dual cultures of hBM-MSCs:A549 at 10:1 ratio. Such findings evidence the relevance of including hBM-MSCs in combination with cancer-stromal fibroblasts in 3D in vitro tumor models and the importance to test different cell-to-cell ratios to mimic tumor heterogeneity. In addition, bioinstructive hyaluronan-microparticles were also effective as cell-agglomerating scaffolds and showed potential to be used as an enabling technology for including different ECM components in 3D in vitro models in the future.

Design of spherically structured 3D in vitro tumor models -Advances and prospects

Three-dimensional multicellular tumor models are receiving an ever-growing focus as preclinical drug-screening platforms due to their potential to recapitulate major physiological features of human tumors in vitro. In line with this momentum, the technologies for assembly of 3D microtumors are rapidly evolving towards a comprehensive inclusion of tumor microenvironment elements. Customized spherically structured platforms, including microparticles and microcapsules, provide a robust and scalable technology to imprint unique biomolecular tumor microenvironment hallmarks into 3D in vitro models. Herein, a comprehensive overview of novel advances on the integration of tumor-ECM components and biomechanical cues into 3D in vitro models assembled in spherical shaped platforms is provided. Future improvements regarding spatiotemporal/mechanical adaptability, and degradability, during microtumors in vitro 3D culture are also critically discussed considering the realistic potential of these platforms to mimic the dynamic tumor microenvironment. From a global perspective, the production of 3D multicellular spheroids with tumor ECM components included in spherical models will unlock their potential to be used in high-throughput screening of therapeutic compounds. It is envisioned, in a near future, that a combination of spherically structured 3D microtumor models with other advanced microfluidic technologies will properly recapitulate the flow dynamics of human tumors in vitro.

STATEMENT OF SIGNIFICANCE

The ability to correctly mimic the complexity of the tumor microenvironment in vitro is a key aspect for the development of evermore realistic in vitro models for drug-screening and fundamental cancer biology studies. In this regard, conventional spheroid-based 3D tumor models, combined with spherically structured biomaterials, opens the opportunity to precisely recapitulate complex cell-extracellular matrix interactions and tumor compartmentalization. This review provides an in-depth focus on current developments regarding spherically structured scaffolds engineered into in vitro 3D tumor models, and discusses future advances toward all-encompassing platforms that may provide an improved in vitro/in vivo correlation in a foreseeable future.

Looking into the Future: Toward Advanced 3D Biomaterials for Stem-Cell-Based Regenerative Medicine

Stem-cell-based therapies have the potential to provide novel solutions for the treatment of a variety of diseases, but the main obstacles to such therapies lie in the uncontrolled differentiation and functional engraftment of implanted tissues. The physicochemical microenvironment controls the self-renewal and differentiation of stem cells, and the key step in mimicking the stem cell microenvironment is to construct a more physiologically relevant 3D culture system. Material-based 3D assemblies of stem cells facilitate the cellular interactions that promote morphogenesis and tissue organization in a similar manner to that which occurs during embryogenesis. Both natural and artificial materials can be used to create 3D scaffolds, and synthetic organic and inorganic porous materials are the two main kinds of artificial materials. Nanotechnology provides new opportunities to design novel advanced materials with special physicochemical properties for 3D stem cell culture and transplantation. Herein, the advances and advantages of 3D scaffold materials, especially with respect to stem-cell-based therapies, are first outlined. Second, the stem cell biology in 3D scaffold materials is reviewed. Third, the progress and basic principles of developing 3D scaffold materials for clinical applications in tissue engineering and regenerative medicine are reviewed.

How to Hit Mesenchymal Stromal Cells and Make the Tumor Microenvironment Immunostimulant Rather Than Immunosuppressive

Experimental evidence indicates that mesenchymal stromal cells (MSCs) may regulate tumor microenvironment (TME). It is conceivable that the interaction with MSC can influence neoplastic cell functional behavior, remodeling TME and generating a tumor cell niche that supports tissue neovascularization, tumor invasion and metastasization. In addition, MSC can release transforming growth factor-beta that is involved in the epithelial-mesenchymal transition of carcinoma cells; this transition is essential to give rise to aggressive tumor cells and favor cancer progression. Also, MSC can both affect the anti-tumor immune response and limit drug availability surrounding tumor cells, thus creating a sort of barrier. This mechanism, in principle, should limit tumor expansion but, on the contrary, often leads to the impairment of the immune system-mediated recognition of tumor cells. Furthermore, the cross-talk between MSC and anti-tumor lymphocytes of the innate and adaptive arms of the immune system strongly drives TME to become immunosuppressive. Indeed, MSC can trigger the generation of several types of regulatory cells which block immune response and eventually impair the elimination of tumor cells. Based on these considerations, it should be possible to favor the anti-tumor immune response acting on TME. First, we will review the molecular mechanisms involved in MSC-mediated regulation of immune response. Second, we will focus on the experimental data supporting that it is possible to convert TME from immunosuppressive to immunostimulant, specifically targeting MSC.

Collagen-based three-dimensional culture microenvironment promotes epithelial to mesenchymal transition and drug resistance of human ovarian cancerin vitro

OV-NC and OV-206 cells cultured in collagen I hydrogel scaffolds, could gradually generate multicellular spheroids.

Mesenchymal Stem Cells Relevance in Multicellular Bioengineered 3D In Vitro Tumor Models

In vitro 3D tumor microenvironment mimicking models are gathering momentum as alternatives to traditional 2D flat monolayer cultures due to their potential for recapitulating major cancer hallmarks. To fulfill such potential, it is crucial that 3D tumor testing platforms completely emulate in vitro the complex in vivo tumor niche and its cellular constituents. Mesenchymal stem cells (MSCs) are recognized to play a pivotal multi-modulatory role in cancer, generating interest as biological targets and as key tumor suppressing, or tumor promoting effectors. This review discusses the biological influence of different types of MSCs in the tumor microenvironment and showcases recent studies that engineer 3D MSCs-cancer cells co-cultures as advanced in vitro therapy testing platforms. A special focus is given to MSCs-cancer 3D co-culture set-up parameters, challenges, and future opportunities. Understanding cancer-MSCs crosstalk and their underlying effects is envisioned to support the development of advanced 3D in vitro disease models for discovery of forefront cancer treatments.

Application of multifunctional targeting epirubicin liposomes in the treatment of non-small-cell lung cancer

Chemotherapy for aggressive non-small-cell lung cancer (NSCLC) usually results in a poor prognosis due to tumor metastasis, vasculogenic mimicry (VM) channels, limited killing of tumor cells, and severe systemic toxicity. Herein, we developed a kind of multifunctional targeting epirubicin liposomes to enhance antitumor efficacy for NSCLC. In the liposomes, octreotide was modified on liposomal surface for obtaining a receptor-mediated targeting effect, and honokiol was incorporated into the lipid bilayer for inhibiting tumor metastasis and eliminating VM channels. In vitro cellular assays showed that multifunctional targeting epirubicin liposomes not only exhibited the strongest cytotoxic effect on Lewis lung tumor cells but also showed the most efficient inhibition on VM channels. Action mechanism studies showed that multifunctional targeting epirubicin liposomes could downregulate PI3K, MMP-2, MMP-9, VE-Cadherin, and FAK and activate apoptotic enzyme caspase 3. In vivo results exhibited that multifunctional targeting epirubicin liposomes could accumulate selectively in tumor site and display an obvious antitumor efficacy. In addition, no significant toxicity of blood system and major organs was observed at a test dose. Therefore, multifunctional targeting epirubicin liposomes may provide a safe and efficient therapy strategy for NSCLC.

In vitro design of mesenchymal to epithelial transition of prostate cancer metastasis using 3D nanoclay bone-mimetic scaffolds

Nanocomposite scaffolds show extensive applications in regenerative medicine and have shown promise as in vitro analogues of human tissue that can be used for the study of diseases. The complex nature of cancer metastasis is recently investigated using several 3D scaffold models. Herein, we report a polymer-nanoclay-based in vitro tumour model that recapitulates early stage of prostate cancer (PCa) colonization during skeletal metastasis on bone mimetic scaffolds. A unique cell culture system termed as "sequential culture (SC)" has been applied to create a bone-mimetic niche for colonization of PCa cells. Human mesenchymal stem cells (MSCs) were seeded on the bone-mimetic scaffolds, where they differentiated into bone cells and then formed mineralized bone matrix without osteogenic supplements. Further, PCa was seeded on MSCs-seeded scaffolds. Sequentially cultured PCa cells with MSCs formed self-organized multicellular tumoroids with distinct tight cellular junctions and hypoxic core regions. Extensive quantitative reverse transcription-polymerase chain reaction experiments were performed to evaluate the expressions of genes related to osteotropic bone metastasis of PCa. On the nanoclay scaffolds, the MSCs differentiated to mature osteoblasts and epithelial to mesenchymal transition was inhibited whereas mesenchymal to epithelial transition was enhanced, as also the hypoxia increased angiogenesis, and finally, PCa cells initiated osteoblastic lesion. Further, the SC technique has significant effects on expression of key metastasis-related genes. Therefore, the SC-based tumour model can be applied to recapitulate more consistent osteotropic cancer cell behavior in understanding tumour biology. This model also can be implemented for drug screening to target colonization stage of PCa cells in the bone microenvironment.

PTD modified paclitaxel anti-resistant liposomes for treatment of drug-resistant non-small cell lung cancer

CONTEXT

Non-small cell lung carcinoma (NSCLC) is a type of epithelial lung cancer that accounts for approximately 80-85% of lung carcinoma cases. Chemotherapy for the NSCLC is unsatisfactory due to multidrug resistance, nonselectively distributions and the accompanying side effects.

OBJECTIVE

The objective of this study was to develop a kind of PTD modified paclitaxel anti-resistant liposomes to overcome these chemotherapy limitations.

METHOD

The studies were performed on LLT cells and resistant LLT cells in vitro and on NSCLC xenograft mice in vivo, respectively.

RESULTS AND DISCUSSION

In vitro results showed that the liposomes with suitable physicochemical characteristics could significantly increase intracellular uptake in both LLT cells and resistant LLT cells, evidently inhibit the growth of cancer cells, and clearly induce the apoptosis of resistant LLT cells. Studies on resistant LLT cells xenograft mice demonstrated that the liposomes magnificently enhanced the anticancer efficacy in vivo. Involved action mechanisms were down-regulation of adenosine triphosphate binding cassette transporters on resistant LLT cells, and activation of the apoptotic enzymes (caspase 8/9/3).

CONCLUSION

The PTD modified paclitaxel anti-resistant liposomes may provide a promising strategy for treatment of the drug-resistant non-small cell lung cancer.

Copolymer-Mediated Cell Aggregation Promotes a Proangiogenic Stem Cell Phenotype In Vitro and In Vivo

Material-induced cell aggregation drives a proangiogenic expression profile. Copolymer substrates containing cell-repellent and cell-adhesive domains force the aggregation of human mesenchymal stem cells, which results in enhanced tubulogenesis in vitro and stabilization of vasculature in vivo. These findings can be used to design instructive biomaterial scaffolds for clinical use.