3D Tumor Spheroid Model Research Articles

Ultrasmall superparamagnetic iron oxide nanoparticles for enhanced tumor penetration.

The intrinsic pathological characteristics of tumor microenvironments restrict the deep penetration of nanomedicines by passive diffusion. Magnetophoresis is a promising strategy to improve the tumor penetration of nanomedicines aided by the external magnetic propulsive force. However, the research thus far has been focused on large nanoparticles, while ultrasmall superparamagnetic iron oxide (Fe3O4) nanoparticles (<∼20 nm) exhibit better performance in many applications such as cancer diagnosis and treatment. Herein, we aim to determine and understand the penetration of ultrasmall Fe3O4 nanoparticles with various sizes, shapes, surface charges and magnetizations in a 3D tumor spheroid model. The behaviour of the nanoparticles of three sizes (10, 15 and 21 nm), two shapes (spherical and octahedral), and opposite surface charges (negative and positive) was investigated. The results demonstrate that magnetically directed penetration works effectively on ultrasmall Fe3O4 nanoparticles. In the absence of a magnetic field, the shape and the surface charge of the ultrasmall magnetic nanoparticles have a more pronounced effect on their penetration compared to their dimensions. While in the presence of a magnetic field, the advantage of larger magnetic nanoparticles was obvious because they experience higher magnetic driving force due to their higher magnetic moments. Overall, relatively large (21 nm), spherical, and positively charged ultrasmall Fe3O4 nanoparticles showed greater penetration in tumors under a magnetic field. Furthermore, our findings suggest that the penetration efficiency of Fe3O4 nanoparticles is closely related to their cellular internalization ability. Therefore, optimization of the cellular uptake and of the magnetization of magnetic nanoparticles should be considered simultaneously for maximizing their penetration in tumor tissue through magnetophoresis.

Application of a Rhodamine-chromone Schiff base probe for the sensing of Fe3+, Al3+, Cr3+ at low concentration and exploration of the anticancer activity and bio-imaging

Strategic design of fluorescent probe for the recognition of ions/molecules at very low concentration by fluorescence sensing is one of the stimulating current research topics with reference to health and sustainability. Towards this objective, Rhodamine based chemosensors are playing extraordinary protagonist. In this work, a Rhodamine appended chromone Schiff base (RFC), with two fluorogenic motifs, has been characterized through various spectroscopic techniques. The probe exhibits efficient sensitivity towards Analytical Group IIIA ions (Al3+, Cr3+ and Fe3+) in existence of other competitive analytes. The fluorescent intensity is enhanced by 350 fold (Fe3+), 250 fold (Al3+) and 220 fold (Cr3+), respectively in methanol-water (99:1,v/v; HEPES buffer, pH, 7.2) medium. The limits of detection (LOD) (3σ/M method; σ = standard deviation; M = slope) are 0.0051 ppm (Fe3+), 0.0029 ppm (Al3+) and 0.0052 ppm (Cr3+); which are impressive and much below the WHO recommended data. In addition to this, the compound has been utilized for cell imaging in presence of these three cations. The action of probe on MCF-7 (human breast cancer) cell lines demonstrates IC50, 2.53 µM that is far better than activity against WI-38 (normal cell line) (IC50, 393.7 µM). The drug (RFC) minimizes the cellular proliferation and has significant wound healing capacity of the infected tissue with MCF-7 cells. The probe shows significant nuclear fragmentation with increase in the expression of apoptotic markers. Growth inhibition analysis in 3D tumor spheroid model showed the inhibition of breast cancer MCF-7 cells.

Anti-EGFR Targeted Multifunctional I-131 Radio-Nanotherapeutic for Treating Osteosarcoma: In Vitro 3D Tumor Spheroid Model.

The systemic delivery of doxorubicin (DOX) to treat osteosarcoma requires an adequate drug concentration to be effective, but in doing so, it raises the risk of increasing organ off-target toxicity and developing drug resistance. Herein, this study reveals a multiple therapeutic nanocarrier delivery platform that overcomes off-target toxicity by providing good specificity and imparting enhanced tumor penetration in a three-dimensional (3D) human MG-63 spheroid model. By synthesizing PEG-PLGA nanoparticles by the double emulsion method, encapsulating DOX and Na131I in the inner core, and conjugating with an epidermal growth factor receptor (EGFR) antibody, it is intended to specifically target human MG-63 cells. The nanocarrier is biocompatible with blood and has good stability characteristics. Na131I encapsulation efficiency was >96%, and radiochemical purity was >96% over 96 h. A DOX encapsulation efficacy of ~80% was achieved, with a drug loading efficiency of ~3%, and a sustained DOX release over 5 days. The nanocarrier EGFR antibody achieved a ~80-fold greater targeting efficacy to MG-63 cells (EGFR+) than fibroblast cells (EGFR−). The targeted multiple therapeutic DIE-NPs have a higher penetration and uptake of Na131I to the 3D model and a ~3-fold higher cytotoxicity than the DOX monotherapy (D-NPs). The co-administration of DOX and Na131I (DIE-NPs) disrupts DNA repair and generates free radicals resulting in DNA damage, triggering the activation of apoptosis pathways. This leads to inhibition of MG-63 cell proliferation and promotes cell cycle arrest in the G0/G1 phase. Furthermore, the PEGylated anti-EGFR functionalized DIE-NPs were found to be biocompatible with red blood cells and to have no adverse effects. This anti-EGFR targeted multifunctional I-131 radio-nanotherapeutic signifies a customizable specific targeted treatment for osteosarcoma.

Bichromophoric BODIPY and Biotin Tagged Terpyridyl Ruthenium(II) Complexes for Cellular Imaging and Photodynamic Therapy

AbstractA perceived drawback of ruthenium(II) polypyridyl photosensitizers for phototherapeutic applications is their inadequate absorption in the visible region. Ru(II) dyads attached to light‐harvesting organic chromophores are studied to address this issue. Biotin‐appended compounds having one chromophore, namely BODIPY (boron‐dipyrromethene) (1) and Ru(II)‐(tpy)2 (2), or a dyad system containing BODIPY linked to Ru(II)‐(tpy)2 via a diphenylacetylene linker (3) were prepared and studied as photodetection agent and photosensitizes for Photodynamic Therapy (PDT) applications. The bichromophoric 3 with a strong absorption profile (ϵ≈71000 M−1 cm−1 at λmax=503 nm) and high singlet oxygen quantum yield (ΦΔ=0.63 in DMSO) was studied for PDT activity. This complex produced a superoxide anion radical via type‐I and singlet oxygen via type‐II photosensitization processes on light exposure, as evidenced from DNA photo‐cleavage experiments and in vitro DCFDA assay using reactive oxygen species scavengers/quenchers. Dyad 3 displayed an apoptotic photo‐cytotoxic effect against HeLa and H1299 cancer cells with a photocytotoxicity index (PI) value of &gt;625 in HeLa cells with a PDT efficacy much superior to those of its monochromophoric analogs 1 and 2. The intrinsic emission of complex 3, utilized for cellular imaging, showed selectivity towards lysosomes. Finally, the remarkable potential of complex 3 was evidenced using a clinically relevant 3D multicellular tumor spheroid model.

3D Multicellular Tumor Spheroids in a Microfluidic Droplet System for Investigation of Drug Resistance.

A three-dimensional (3D) tumor spheroid model plays a critical role in mimicking tumor microenvironments in vivo. However, the conventional culture methods lack the ability to manipulate the 3D tumor spheroids in a homogeneous manner. To address this limitation, we developed a microfluidic-based droplet system for drug screening applications. We used a tree-shaped gradient generator to control the cell density and encapsulate the cells within uniform-sized droplets to generate a 3D gradient-sized tumor spheroid. Using this microfluidic-based droplet system, we demonstrated the high-throughput generation of uniform 3D tumor spheroids containing various cellular ratios for the analysis of the anti-cancer drug cytotoxicity. Consequently, this microfluidic-based gradient droplet generator could be a potentially powerful tool for anti-cancer drug screening applications.

In vitro 2D and 3D cancer models to evaluate compounds that modulate macrophage polarization

In vitro cancer models that can identify novel immunomodulating compounds are essential. Using a 3D multicellular tumor spheroid (MCTS) model comprising cancer cells, fibroblasts, and macrophages, we tested tumor-associated macrophage (TAM)-inhibiting compounds (CCL2 Ab, CSF1R inhibitor, CSF1R Ab) and TAM-reprograming compounds (poly I:C, CD40 Ab, CD40 ligand) for their effects on monocyte infiltration and polarization in tumor spheroids. For characterization of macrophage polarization, we measured the expression of CD206, CD163, CD86, MHC II, CD40, and CD14 and measured 43 soluble factors in the 3D MCTS cultures. 2D macrophage models were evaluated for comparison. A CSF1R inhibitor prevented infiltration of monocytes into pancreatic cancer spheroids, and macrophages treated with the inhibitor showed decreased expression of M2 markers. Treatment with a CD40 ligand and poly I:C induced M1 macrophage polarization in our models. We propose that these models can be used to improve the drug screening process of anti-cancer immunotherapies targeting macrophages.

Abstract 600: Discovery of a single-domain antibody fragment targeting PD-L1 for cancer immunotherapy

Abstract Immunotherapy has shown enormous promise for cancer treatment. The use of Antibodies to target immune checkpoints, particularly PD-1/PD-L1, has made a profound impact in cancer immunotherapy. Single-domain antibody fragment (sdAb) is an antibody fragment composed of a single variable domain of the heavy chain. sdAb is the smallest antibody fragment (15 kDa) that maintains the similar antigen-binding affinity. sdAbs show many advantages over monoclonal antibodies such as small size, low immunogenicity, ease of production, and ease of modification, making sdAbs promising candidates for cancer immunotherapy. Here, we use a phage display library to identify an anti-PD-L1 sdAb (CLV3) which effectively blocks the PD-1/PD-L1 interaction. The CLV3 sdAb demonstrates high binding affinity and specificity to PD-L1 protein and PD-L1 overexpression DU145 tumor cells. Moreover, the CLV3 sdAb exhibits efficient tumor penetration in a 3D tumor spheroid model, suggesting its good penetration capability in the tumor microenvironment in vivo. CLV3 restores T cell proliferation and reduces T cell apoptosis in the co-culture experiment of peripheral blood mononuclear cells (PBMC) with tumor cells. These data suggest that the CLV3 sdAb can be potentially used as an anti-PD-L1 inhibitor for cancer immunotherapy. Citation Format: Yanli Liu, Hao Liu, Kun Cheng. Discovery of a single-domain antibody fragment targeting PD-L1 for cancer immunotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 600.

Abstract 6029: Long-term three-dimensional (3D) tumor culture models using a universal well-plate platform

Abstract Generating 3D tumor spheroid in vitro has been a straightforward method not only to replicate in vivo like cytoarchitecture and also to study complex interactions to the 3D milieu. Although various approaches have been developed to date, most of the in vitro techniques were hampered by the limitations like small-volume, non-uniformity, irregular sphericity, short-term culture, labor-intensive and studies’ complexities. Here, we have developed very intuitive methods to generate 3D tumor spheroid models and scaffold-based 3D culture models in a single well of universal plate for long-term cultivation. Experimental Procedures: The prototype of 3D printed chamber was designed by Sketchup software (Trimble) and printed at Illinois MakerLab (http://makerlab.illinois.edu) for this study. The human colon cancer cell (HCT116), obtained from American Type Culture Collection (ATCC), were cultured in DMEM medium containing 10% FBS and stored in a humidified incubator of 5% CO 2 at 37 °C. Five universal 96 well plates (Corning, Thermo Scientific, CytoOne, Advangene, and Genesee Scientific), Elisa 96 well strip (Corning), Black 96-well plate (Thermo scientific) were used without any modification (Not a type of ultra-low attachment (ULA) plate). The prototype designs are flexible to be modified and will be utilized to develop a product beyond conceptual frameworks in the market. Results: Recently, microfabricated approaches have been intensively studied for micro 3D tumor models (&amp;lt; 300 µm in diameter) implemented with high-throughput analysis. However, the micro tumor model incubated in a short-term might not effectively develop tumor heterogeneity such as a non-perfusion core, diffusion gradient and increased interstitial pressure. We intentionally generated a tumor spheroid model incubated over 1 month with appropriate media replacement to supply nutrients. The spheroid in the system grew over 1.5mm of diameter with an excellent sphericity (&amp;gt; 0.95). Besides, our methodology can perform various in-situ spheroid assays in basic cancer research and also generate scaffold-free/based 3D tumor culture models in the system. To replicate in vivo like cytoarchitecture more physiologically relevant, decellularized tissue scaffold-based 3D culture was conceptually demonstrated. Conclusions: We developed a simple and effective process that generates 3D tumor culture models in millimeter size and allows long-term incubation to develop local heterogeneity. Importantly, this approach does not require additional hidden costs and any specialized instruments. We believe the present strategy satisfies all essential criteria (i.e., easiness, accessibility, reproducibility, effectiveness, and applicability) to appeal to general researchers compared to other available methods by far. Citation Format: Yoon Jeong, Ashley Tin, Joseph Irudayaraj. Long-term three-dimensional (3D) tumor culture models using a universal well-plate platform [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 6029.

Calcium Electroporation Reduces Viability and Proliferation Capacity of Four Uveal Melanoma Cell Lines in 2D and 3D Cultures.

Simple SummaryCalcium electroporation (CaEP) is an innovative anti-tumor treatment modality that induces cell death by introducing supraphysiological concentrations of calcium into cells with a limited effect on normal cells. The objective of the present study is to assess the effect of CaEP in uveal melanoma (UM) cell lines in comparison to electrochemotherapy (ECT) with bleomycin using 2D monolayer cell cultures as well as 3D tumor spheroid models in four different UM cell lines. The morphological changes of the spheroids, the cell viability, growth rate as well as the cytotoxic effect of electroporation (EP) with calcium chloride and bleomycin were evaluated with various drug concentrations. The results of CaEP and ECT both suggest a comparable dose-dependent reduction in cell viability and proliferation rate in all tested 2D cell lines and 3D tumor spheroids. These data point out that CaEP is an established anticancer treatment causing cell death by ATP depletion in in vitro and in vivo, representing an efficient alternative therapy with a lower cytotoxic potency for the local UM tumor control.Electrochemotherapy (ECT) is the combination of transient pore formation following electric pulse application with the administration of cytotoxic drugs, which enhances the cytotoxic effect of the applied agent due to membrane changes and permeabilization. Although EP represents an established therapeutic option for solid malignancies, recent advances shift to the investigation of non-cytotoxic agents, such as calcium, which can also induce cell death. The present study aims to evaluate the cytotoxic effect, the morphological changes in tumor spheroids, the effect on the cell viability, and the cell-specific growth rate following calcium electroporation (CaEP) in uveal melanoma (UM) 2D monolayer cell cultures as well as in 3D tumor spheroid models. The experiments were conducted in four cell lines, UM92.1, Mel270, and two primary UM cell lines, UPMD2 and UPMM3 (UPM). The 2D and 3D UM cell cultures were electroporated with eight rectangular pulses (100 µs pulse duration, 5 Hz repetition frequency) of a 1000 V/cm pulse strength alone or in combination with 0.11 mg/mL, 0.28 mg/mL, 0.55 mg/mL or 1.11 mg/mL calcium chloride or 1.0 µg/mL or 2.5 µg/mL bleomycin. The application of calcium chloride alone induced an ATP reduction only in the UM92.1 2D cell cultures. Calcium alone had no significant effect on ATP levels in all four UM spheroids. A significant decrease in the intracellular adenosine triphosphate (ATP) level was documented in all four 2D and 3D cell cultures for both CaEP as well as ECT with bleomycin. The results suggest a dose-dependent ATP depletion with a wide range of sensitivity among the tested UM cell lines, control groups, and the applied settings in both 2D monolayer cell cultures and 3D tumor spheroid models. The colony formation capacity of the cell lines after two weeks reduced significantly after CaEP only with 0.5 mg/mL and 1.1 mg/mL, whereas the same effect could be achieved with both applied bleomycin concentrations, 1.0 µg/mL and 2.5 µg/mL, for the ECT group. The specific growth rate on day 7 following CaEP was significantly reduced in UM92.1 cell lines with 0.5 and 1.1 mg/mL calcium chloride, while Mel270 showed a similar effect only after administration of 1.1 mg/mL. UM92.1 and Mel270 spheroids exhibited lower adhesion and density after CaEP on day three in comparison to UPM spheroids showing detachment after day 7 following treatment. CaEP and bleomycin electroporation significantly reduce cell viability at similar applied voltage settings. CaEP may be a feasible and inexpensive therapeutic option for the local tumor control with fewer side effects, in comparison to other chemotherapeutic agents, for the treatment of uveal melanoma. The limited effect on normal cells and the surrounding tissue has already been investigated, but further research is necessary to clarify the effect on the surrounding tissue and to facilitate its application in a clinical setting for the eye.

Efficiency of GrowDex&lt;sup&gt;®&lt;/sup&gt; nanofibrillar cellulosic hydrogel when generating homotypic and heterotypic 3D tumor spheroids

&lt;abstract&gt; &lt;p&gt;In recent times, homotypic and heterotypic 3D tumor spheroid (HTS) models have been receiving increasing attention and come to be widely employed in preclinical studies. The present study is focused on the generation of homotypic (A549 and MDA-MB-231, separately) and heterotypic (A549 + NIH/3T3; MDA-MB-231 + NIH/3T3) 3D tumor spheroids by using GrowDex&lt;sup&gt;®&lt;/sup&gt; nanofibrillar cellulosic (NFC) hydrogel as the scaffold. Light microscopic observations and F-actin staining confirmed the formation of spheroids. The proliferation efficiency indicated an expansion of cell population and an increase in spheroid size over time. The distribution, interaction pattern and influence of fibroblasts on the epithelial cell types were observed in terms of the size and shape of the HTS against homo-spheroids. An interesting observation was that, with an increase in the size of HTSs, many more fibroblast cells were found to occupy the core region, which, perhaps, was due to the faster growth of tumor cells over normal cells. Thus, normal and tumor cells, especially with origins from two different species, can be cultured together in 3D format, and this can potentially enhance our knowledge of tumor microenvironments and cell-cell interaction. These spheroids could be used to improve microphysiological systems for drug discovery and to better understand the tumor microenvironment.&lt;/p&gt; &lt;/abstract&gt;

Oncogenic Activation of YAP Signaling Sensitizes Ferroptosis of Hepatocellular Carcinoma via ALOXE3-Mediated Lipid Peroxidation Accumulation.

Ferroptosis, a form of programmed cell death process driven by iron-dependent lipid peroxidation, plays an important role in tumor suppression. Although previous study showed that intracellular Merlin-Hippo signaling suppresses ferroptosis of epithelial tumor cells through the inactivation of YAP signaling, it remains elusive if the proto-oncogenic transcriptional co-activator YAP could serve as a potential biomarker to predict cancer cell response to ferroptosis-inducing therapies. In this study, we show that both total YAP staining and nuclear YAP staining were more prevalent in HCC tissues than in nontumorous regions. Compared to low-density HCC cells, high-density cells showed decreased nuclear localization of YAP and conferred significant resistance to ferroptosis. Oncogenic activation of YAP signaling by overexpression of YAP(S127A) mutant sensitized ferroptosis of HCC cells cultured in confluent density or in the 3D tumor spheroid model. Furthermore, we validated the lipoxygenase ALOXE3 as a YAP-TEAD target gene that contributed to YAP-promoted ferroptosis. Overexpression of ALOXE3 effectively increased the vulnerability of HCC cells to ferroptotic cell death. In an orthotopic mouse model of HCC, genetic activation of YAP rendered HCC cells more susceptible to ferroptosis. Finally, an overall survival assay further revealed that both a high expression of YAP and a low expression of GPX4 were correlated with increased survival of HCC patients with sorafenib treatment, which had been proven to be an inducer for ferroptosis by inhibition of the xc-amino acid antiporter. Together, this study unveils the critical role of intracellular YAP signaling in dictating ferroptotic cell death; it also suggests that pathogenic alterations of YAP signaling can serve as biomarkers to predict cancer cell responsiveness to future ferroptosis-inducing therapies.

Cold helium plasma jet does not stimulate collagen remodeling in a 3D human dermal substitute

Cold Atmospheric Plasma (CAP) is an emerging physical approach displaying encouraging antitumor and wound healing effects both in vitro and in vivo. In this study, we assessed the potential of direct CAP to remodel skin collagens using an original tissue-engineered human dermal substitute model rich in endogenous extracellular matrix (ECM) covered with 600 µl of culture medium and treated with CAP for 30 and 120 s. Our results indicated that Reactive Oxygen and Nitrogen Species (RONS) such as H2O2, NO3– and NO2– were produced in the medium during treatment. It appeared that in the CAP-treated dermal substitutes 1) cell viability was not altered, 2) pro-collagen I secretion was not modified over 48 h of culture after treatment, 3) global activity of matrix metalloproteinases MMPs was not modulated over 48 h after treatment, and 4) no change in hydroxyproline content was observed over 5 days after treatment. In order to confirm the efficiency of our device, we showed that the plasma-activated culture medium induced cell apoptosis and growth delay using a 3D human tumor spheroid model. In conclusion, no effect of direct CAP treatment was monitored on dermal ECM production and degradation, indicating that CAP does not stimulate collagen remodeling at the tissue scale.

Induction of Apoptosis by Isoalantolactone in Human Hepatocellular Carcinoma Hep3B Cells through Activation of the ROS-Dependent JNK Signaling Pathway.

Isoalantolactone (IALT) is one of the isomeric sesquiterpene lactones isolated from the roots of Inula helenium L. IALT is known to possess various biological and pharmacological activities, but its anti-cancer mechanisms are not well understood. The aim of the present study was to investigate the anti-proliferative effects of IALT in human hepatocellular carcinoma (HCC) cells and to evaluate the potential anti-cancer mechanisms. Our results demonstrated that IALT treatment concentration-dependently suppressed the cell survival of HCC Hep3B cells, which was associated with the induction of apoptosis. IALT increased the expression of death-receptor-related proteins, activated caspases, and induced Bid truncation, subsequently leading to cleavage of poly (ADP-ribose) polymerase. In addition, IALT contributed to the cytosolic release of cytochrome c by destroying mitochondrial integrity, following an increase in the Bax/Bcl-2 expression ratio. However, IALT-mediated growth inhibition and apoptosis were significantly attenuated in the presence of a pan-caspase inhibitor, suggesting that IALT induced caspase-dependent apoptosis in Hep3B cells. Moreover, IALT activated the mitogen-activated protein kinases signaling pathway, and the anti-cancer effect of IALT was significantly diminished in the presence of a potent c-Jun N-terminal kinase (JNK) inhibitor. IALT also improved the generation of intracellular reactive oxygen species (ROS), whereas the ROS inhibitor significantly abrogated IALT-induced growth reduction, apoptosis, and JNK activation. Furthermore, ROS-dependent apoptosis was revealed as a mechanism involved in the anti-cancer activity of IALT in a 3D multicellular tumor spheroid model of Hep3B cells. Taken together, our findings indicate that IALT exhibited anti-cancer activity in HCC Hep3B cells by inducing ROS-dependent activation of the JNK signaling pathway.

A novel design of microfluidic platform for metronomic combinatorial chemotherapy drug screening based on 3D tumor spheroid model.

For treating cancer at various stages, chemotherapy drugs administered in combination provide better treatment results with lower side effects compared to single-drug therapy. However, finding the potential drug combinations has been challenging due to the large numbers of possible combinations from approved drugs and the failure of in vitro 2D well plate-based cancer models. 3D spheroid-based high-throughput microfluidic platforms recapitulate some of the important features of native tumor tissue and offer a promising alternative to evaluate the combinatory effects of the drugs. This study develops a novel polydimethylsiloxane (PDMS) based microfluidic design with a dynamic environment and strategically placed U-shaped wells for testing all seven possible combinations (three single-drug treatments, three pairwise combinations, treatment with all three drugs) of three chemotherapy drugs (Paclitaxel, Vinorelbine, and Etoposide) on lung tumor spheroids. The design of U-shaped wells has been validated with computational results. Firstly, we test all combinations of drugs on the conventional well plate in static conditions with 3D tumor spheroids. Based on static drug testing results, we show a proof-of-concept by testing the most effective drug combination on the microfluidic device in a dynamic environment. The concentration of the drugs used in combination falls below the maximum tolerated dose (MTD) of the individual drugs, towards low dose metronomic (LDM) chemotherapy. LDM combinatorial chemotherapy identified in this study can potentially lower toxicity and provide better treatment results in cancer patients. The device can be further used to culture patient-specific tumor spheroids and identify synergistic drug combinations for personalized medicine.

A Three-Dimensional Spheroid Model to Investigate the Tumor-Stromal Interaction in Hepatocellular Carcinoma.

The aggressiveness and lack of well-tolerated and widely effective treatments for advanced hepatocellular carcinoma (HCC), the predominant form of liver cancer, rationalize its rank as the second most common cause of cancer-related death. Preclinical models need to be adapted to recapitulate the human conditions to select the best therapeutic candidates for clinical development and aid the delivery of personalized medicine. Three-dimensional (3D) cellular spheroid models show promise as an emerging in vitro alternative to two-dimensional (2D) monolayer cultures. Here, we describe a 3D tumor spheroidmodel which exploits the ability of individual cells to aggregate when maintained in hanging droplets, and is more representative of an in vivo environment than standard monolayers. Furthermore, 3D spheroids can be produced by combining homotypic or heterotypic cells, more reflective of the cellular heterogeneity in vivo, potentially enabling the study of environmental interactions that can influence progression and treatment responses. The current research optimized the cell density to form 3D homotypic and heterotypic tumor spheroids by immobilizing cell suspensions on the lids of standard 10 cm3 Petri dishes. Longitudinal analysis was performed to generate growth curves for homotypic versus heterotypic tumor/fibroblasts spheroids. Finally, the proliferative impact of fibroblasts (COS7 cells) and liver myofibroblasts (LX2) on homotypic tumor (Hep3B) spheroids was investigated. A seeding density of 3,000 cells (in 20 µL media) successfully yielded Huh7/COS7 heterotypic spheroids, which displayed a steady increase in size up to culture day 8, followed by growth retardation. This finding was corroborated using Hep3B homotypic spheroids cultured in LX2 (human hepatic stellate cell line) conditioned medium (CM). LX2 CM triggered the proliferation of Hep3B spheroids compared to control tumor spheroids. In conclusion, this protocol has shown that 3D tumor spheroids can be used as a simple, economical, and prescreen in vitro tool to study tumor-stromal interactions more comprehensively.

A Three-Dimensional Spheroid Model to Investigate the Tumor-Stromal Interaction in Hepatocellular Carcinoma

The aggressiveness and lack of well-tolerated and widely effective treatments for advanced hepatocellular carcinoma (HCC), the predominant form of liver cancer, rationalize its rank as the second most common cause of cancer-related death. Preclinical models need to be adapted to recapitulate the human conditions to select the best therapeutic candidates for clinical development and aid the delivery of personalized medicine. Three-dimensional (3D) cellular spheroid models show promise as an emerging in vitro alternative to two-dimensional (2D) monolayer cultures. Here, we describe a 3D tumor spheroid model which exploits the ability of individual cells to aggregate when maintained in hanging droplets, and is more representative of an in vivo environment than standard monolayers. Furthermore, 3D spheroids can be produced by combining homotypic or heterotypic cells, more reflective of the cellular heterogeneity in vivo, potentially enabling the study of environmental interactions that can influence progression and treatment responses. The current research optimized the cell density to form 3D homotypic and heterotypic tumor spheroids by immobilizing cell suspensions on the lids of standard 10 cm3 Petri dishes. Longitudinal analysis was performed to generate growth curves for homotypic versus heterotypic tumor/fibroblasts spheroids. Finally, the proliferative impact of fibroblasts (COS7 cells) and liver myofibroblasts (LX2) on homotypic tumor (Hep3B) spheroids was investigated. A seeding density of 3,000 cells (in 20 µL media) successfully yielded Huh7/COS7 heterotypic spheroids, which displayed a steady increase in size up to culture day 8, followed by growth retardation. This finding was corroborated using Hep3B homotypic spheroids cultured in LX2 (human hepatic stellate cell line) conditioned medium (CM). LX2 CM triggered the proliferation of Hep3B spheroids compared to control tumor spheroids. In conclusion, this protocol has shown that 3D tumor spheroids can be used as a simple, economical, and prescreen in vitro tool to study tumor-stromal interactions more comprehensively.

Tumor-Targeted Fluorescent Proteinoid Nanocapsules Encapsulating Synergistic Drugs for Personalized Cancer Therapy.

Personalized cancer treatment based on specific mutations offers targeted therapy and is preferred over “standard” chemotherapy. Proteinoid polymers produced by thermal step-growth polymerization of amino acids may form nanocapsules (NCs) that encapsulate drugs overcoming miscibility problems and allowing passive targeted delivery with reduced side effects. The arginine-glycine-glutamic acid (RGD) sequence is known for its preferential attraction to αvβ3 integrin, which is highly expressed on neovascular endothelial cells that support tumor growth. Here, tumor-targeted RGD-based proteinoid NCs entrapping a synergistic combination of Palbociclib (Pal) and Alpelisib (Alp) were synthesized by self-assembly to induce the reduction of tumor cell growth in different types of cancers. The diameters of the hollow and drug encapsulating poly(RGD) NCs were 34 ± 5 and 22 ± 3 nm, respectively; thereby, their drug targeted efficiency is due to both passive and active targeting. The encapsulation yield of Pal and Alp was 70 and 90%, respectively. In vitro experiments with A549, MCF7 and HCT116 human cancer cells demonstrate a synergistic effect of Pal and Alp, controlled release and dose dependence. Preliminary results in a 3D tumor spheroid model with cells derived from patient-derived xenografts of colon cancer illustrate disassembly of spheroids, indicating that the NCs have therapeutic potential.

Metabolomic analysis of Viscum album L homeopathic tinctures and antitumor studies in 3D spheroid models

Background The antitumoral efficacy of aqueous Viscum album extracts is attributed to the presence of lectins and viscotoxins. However, previous studies demonstrated an antitumoral activity of European V. album ethanolic homeopathic tinctures (VAHT) prepared according to homeopathic methodology. Aims To investigate the seasonal influences (summer and winter) in the metabolomic profile of V. album ssp. homeopathic mother tinctures (VAHT) and to evaluate the antitumoral activity of some VAHT in 3D tumor spheroid models. Methodology The following VAHT were prepared by ethanolic maceration: V. album ssp. album growing on Malus domestica, Quercus sp. and Ulmus sp.; V. album ssp. austriacum from Pinus sylvestris; V. album ssp. abietis from Abies alba. Chemical analyses were performed using liquid chromatography coupled to high-resolution mass spectrometry. Data was submitted to multivariate statistical analysis using principal component analysis (PCA) and Partial Least Squares Discriminant Analysis (PLSDA) in Metaboanalyst platform. The antitumor potential of VAHT (0.5% v/v) was conducted in 3D tumor spheroid models (MDA-MB-231 cell line) by MTT for 72 hours. Results and discussion The PCA analysis explained 40% of data variation and clustered VAHT samples into 3 groups, emphasizing the chemical similarity between the botanical subspecies of V. album. Some key compounds were mainly responsible for this separation: pinobankasin hexose-pentose (V. album ssp. abietis); citric acid (V. album ssp. austriacum); malic acid (V. album ssp. album). The chemical differences among summer and winter samples, detected by PLSDA, were related to the Viscum album host trees. A significant reduction of 50% and 41% (p

MiR-155 Inhibitor-Laden Exosomes Reverse Resistance to Cisplatin in a 3D Tumor Spheroid and Xenograft Model of Oral Cancer.

Cisplatin resistance is one of the major concerns in the treatment of oral squamous cell carcinoma (OSCC). Accumulating evidence suggests microRNA (miRNA) dysregulation as one of the mediators of chemoresistance. Toward this, our previous study revealed the role of exosomal microRNA-155 (miR-155) in cisplatin resistance via downregulation of FOXO3a, a direct target of miR-155, and induction of epithelial-to-mesenchymal transition in OSCC. In the present study, we demonstrate the therapeutic potential of miR-155 inhibitor-laden exosomes in the sensitization of a cisplatin-resistant (cisRes) OSCC 3D tumor spheroid and xenograft mouse model. The cisRes OSSC 3D tumor spheroid model recapitulated the hallmarks of solid tumors such as enhanced hypoxia, reactive oxygen species, and secretory vascular endothelial growth factor. Further treatment with miR-155 inhibitor-loaded exosomes showed the upregulation of FOXO3a and induction of the mesenchymal-to-epithelial transition with improved sensitization to cisplatin in cisRes tumor spheroids and xenograft mouse model. Moreover, the exosomal miR-155 inhibitor suppressed the stem-cell-like property as well as drug efflux transporter protein expression in cisplatin-resistant tumors. Taken together, our findings, for the first time, established that the miR-155 inhibitor-loaded exosomes reverse chemoresistance in oral cancer, thereby providing an alternative therapeutic strategy for the management of refractory oral cancer patients.

Proteolysis Targeting Chimera (PROTAC) for Macrophage Migration Inhibitory Factor (MIF) Has Anti‐Proliferative Activity in Lung Cancer Cells

AbstractMacrophage migration inhibitory factor (MIF) is involved in protein‐protein interactions that play key roles in inflammation and cancer. Current strategies to develop small molecule modulators of MIF functions are mainly restricted to the MIF tautomerase active site. Here, we use this site to develop proteolysis targeting chimera (PROTAC) in order to eliminate MIF from its protein‐protein interaction network. We report the first potent MIF‐directed PROTAC, denoted MD13, which induced almost complete MIF degradation at low micromolar concentrations with a DC50 around 100 nM in A549 cells. MD13 suppresses the proliferation of A549 cells, which can be explained by deactivation of the MAPK pathway and subsequent induction of cell cycle arrest at the G2/M phase. MD13 also exhibits antiproliferative effect in a 3D tumor spheroid model. In conclusion, we describe the first MIF‐directed PROTAC (MD13) as a research tool, which also demonstrates the potential of PROTACs in cancer therapy.