3D Tumor Models Research Articles

Biomimetic 3D bioprinting approaches to engineer the tumor microenvironment

With the increasing incidence and mortality rates, cancer remains a major health challenge in the world. Despite advances in therapies and clinical programs, the efficacy of anti-cancer drugs often fails to translate from pre-clinical models to patient clinical trials. To date, pre-clinical cancer models, including two-dimensional cell cultures and animal models, have limited versatility and accuracy in recapitulating the complexity of human cancer. To address these limitations, a growing focus has fostered the development of three-dimensional (3D) tumor models that closely resemble the in vivo tumor microenvironment and heterogeneity. Recent efforts have leveraged bioengineering technologies, such as biofabrication, to engineer new platforms that mimic healthy and diseased organs, aiming to overcome the shortcomings of conventional models, such as for musculoskeletal tissues. Notably, 3D bioprinting has emerged as a powerful tool in cancer research, offering precise control over cell and biomaterial deposition to fabricate architecturally complex and reproducible functional models. The following review underscores the urgent need for more accurate and relevant 3D tumor models, highlighting the advantages of the use of biofabrication approaches to engineer new biomimetics platforms. We provide an updated discussion on the role of bioengineering technologies in cancer research and modeling with particular focus on 3D bioprinting platforms, as well as a close view on biomaterial inks and 3D bioprinting technologies employed in cancer modeling. Further insights into the 3D bioprinting tissue-specific modeling panorama are presented in this paper, offering a comprehensive overview of the new possibilities for cancer study and drug discovery.  

Trends in Photopolymerizable Bioinks for 3D Bioprinting of Tumor Models.

Three-dimensional (3D) bioprinting technologies involving photopolymerizable bioinks (PBs) have attracted enormous attention in recent times owing to their ability to recreate complex structures with high resolution, mechanical stability, and favorable printing conditions that are suited for encapsulating cells. 3D bioprinted tissue constructs involving PBs can offer better insights into the tumor microenvironment and offer platforms for drug screening to advance cancer research. These bioinks enable the incorporation of physiologically relevant cell densities, tissue-mimetic stiffness, and vascularized channels and biochemical gradients in the 3D tumor models, unlike conventional two-dimensional (2D) cultures or other 3D scaffold fabrication technologies. In this perspective, we present the emerging techniques of 3D bioprinting using PBs in the context of cancer research, with a specific focus on the efforts to recapitulate the complexity of the tumor microenvironment. We describe printing approaches and various PB formulations compatible with these techniques along with recent attempts to bioprint 3D tumor models for studying migration and metastasis, cell-cell interactions, cell-extracellular matrix interactions, and drug screening relevant to cancer. We discuss the limitations and identify unexplored opportunities in this field for clinical and commercial translation of these emerging technologies.

Recent advances in 3D bioprinted tumor models for personalized medicine

Cancerous tumors are among the most fatal diseases worldwide, claiming nearly 10 million lives in 2020. Due to their complex and dynamic nature, modeling tumors accurately is a challenging task. Current models suffer from inadequate translation between in vitro and in vivo results, primarily due to the isotropic nature of tumors and their microenvironment's relationship. To address these limitations, hydrogel-based 3D bioprinting is emerging as a promising approach to mimic cancer development and behavior. It provides precise control over individual elements' size and distribution within the cancer microenvironment and enables the use of patient-derived tumor cells, rather than commercial lines. Consequently, hydrogel bioprinting is expected to become a state-of-the-art technique for cancer research. This manuscript presents an overview of cancer statistics, current modeling methods, and their limitations. Additionally, we highlight the significance of bioprinting, its applications in cancer modeling, and the importance of hydrogel selection. We further explore the current state of creating models for the five deadliest cancers using 3D bioprinting. Finally, we discuss current trends and future perspectives on the clinical use of cancer modeling using hydrogel bioprinting.

X-Ray Nanothermometry of Nanoparticles in Tumor-Mimicking Tissues under Photothermia.

Temperature plays a critical role in regulating body mechanisms and indicating inflammatory processes. Local temperature increments above 42°C are shown to kill cancer cells in tumorous tissue, leading to the development of nanoparticle-mediated thermo-therapeutic strategies for fighting oncological diseases. Remarkably, these therapeutic effects can occur without macroscopic temperature rise, suggesting localized nanoparticle heating, and minimizing side effects on healthy tissues. Nanothermometry has received considerable attention as a means of developing nanothermosensing approaches to monitor the temperature at the core of nanoparticle atoms inside cells. In this study, a label-free, direct, and universal nanoscale thermometry is proposed to monitor the thermal processes of nanoparticles under photoexcitation in the tumor environment. Gold-iron oxide nanohybrids are utilized as multifunctional photothermal agents internalized in a 3D tumor model of glioblastoma that mimics the in vivo scenario. The local temperature under near-infrared photo-excitation is monitored by X-ray absorption spectroscopy (XAS) at the Au L3 -edge (11 919 eV) to obtain their temperature in cells, deepening the knowledge of nanothermal tumor treatments. This nanothermometric approach demonstrates its potential in detecting high nanothermal changes in tumor-mimicking tissues. It offers a notable advantage by enabling thermal sensing of any element, effectively transforming any material into a nanothermometer within biological environments.

Mimicking 3D breast tumor-stromal interactions to screen novel cancer therapeutics

Most of the 3D breast tumor models used in drug screening studies only comprise tumor cells, keeping out other essential cell players of the tumor microenvironment. Tumor-associated macrophages and fibroblasts are frequently correlated with tumor progression and therapy resistance, and targeting these cells at the tumor site has been appointed as a promising therapeutic strategy. However, the translation of new therapies to the clinic has been hampered by the absence of cellular models that more closely mimic the features of in vivo breast tumor microenvironment. Therefore, the development of innovative 3D models able to provide consistent and predictive responses about the in vivo efficacy of novel therapeutics is still an unmet preclinical need.Herein, we have established an in vitro 3D heterotypic spheroid model including MCF-7 breast tumor cells, human mammary fibroblasts and human macrophages. To establish this model, different cell densities have been combined and characterized through the evaluation of the spheroid size and metabolic activity, as well as histological and immunohistochemistry analysis of the 3D multicellular structures. The final optimized 3D model consisted in a multicellular spheroid seeded at the initial density of 5000 cells and cell ratio of 1:2:1 (MCF-7:monocytes:fibroblasts). Our model recapitulates several features of the breast tumor microenvironment, including the formation of a necrotic core, spatial organization, and extracellular matrix production. Further, it was validated as a platform for drug screening studies, using paclitaxel, a currently approved drug for breast cancer treatment, and Gefitinib, a chemotherapeutic approved for lung cancer and in preclinical evaluation for breast cancer. Generally, the impact on the cell viability of the 3D model was less evident than in 2D model, reinforcing the relevance of such complex 3D models in addressing novel treatment approaches. Overall, the use of a 3D heterotypic spheroid of breast cancer could be a valuable tool to predict the therapeutic effect of new treatments for breast cancer patients, by recapitulating key features of the breast cancer microenvironment.

Gelatin methacryloyl and Laponite bioink for 3D bioprinted organotypic tumor modeling

Three-dimensional (3D) in vitro tumor models that can capture the pathophysiology of human tumors are essential for cancer biology and drug development. However, simulating the tumor microenvironment is still challenging because it consists of a heterogeneous mixture of various cellular components and biological factors. In this regard, current extracellular matrix (ECM)-mimicking hydrogels used in tumor tissue engineering lack physical interactions that can keep biological factors released by encapsulated cells within the hydrogel and improve paracrine interactions. Here, we developed a nanoengineered ion-covalent cross-linkable bioink to construct 3D bioprinted organotypic tumor models. The bioink was designed to implement the tumor ECM by creating an interpenetrating network composed of gelatin methacryloyl (GelMA), a light cross-linkable polymer, and synthetic nanosilicate (Laponite) that exhibits a unique ionic charge to improve retention of biological factors released by the encapsulated cells and assist in paracrine signals. The physical properties related to printability were evaluated to analyze the effect of Laponite hydrogel on bioink. Low GelMA (5%) with high Laponite (2.5%–3.5%) composite hydrogels and high GelMA (10%) with low Laponite (1.0%–2.0%) composite hydrogels showed acceptable mechanical properties for 3D printing. However, a low GelMA composite hydrogel with a high Laponite content could not provide acceptable cell viability. Fluorescent cell labeling studies showed that as the proportion of Laponite increased, the cells became more aggregated to form larger 3D tumor structures. Reverse transcription-polymerase chain reaction (RT-qPCR) and western blot experiments showed that an increase in the Laponite ratio induces upregulation of growth factor and tissue remodeling-related genes and proteins in tumor cells. In contrast, cell cycle and proliferation-related genes were downregulated. On the other hand, concerning fibroblasts, the increase in the Laponite ratio indicated an overall upregulation of the mesenchymal phenotype-related genes and proteins. Our study may provide a rationale for using Laponite-based hydrogels in 3D cancer modeling.

Engineering In Vitro Organ‐Structured Tumor Model for Evaluating Neoantigen‐Specific T Cell Responses in Hepatocellular Carcinoma

AbstractNeoantigens derived from somatic mutations in cancer cells can induce antigen‐specific T‐cell immune response for cancer immunotherapy. However, the 3D models for assessing neoepitope immunogenicity and efficacy of anti‐tumor T‐cell immune response to neoantigens are less than perfect. Here, a 3D tumor model based on recellularized liver matrix is leveraged with HepG2 cells to investigate T cell cytotoxic reactivity toward hepatocellular carcinoma (HCC) neoantigens. The whole exome sequencing (WES) data of 364 HCC patients in The Cancer Genome Atlas database are collected and 25 highly potential immunogenic neoantigens to human leukocyte antigen (HLA)‐A*02:01 molecule in silico are predicted. Six of the HCC neoantigen candidates are functionally validated with high immunogenicity by measuring cellular interferon‐γ secretion and cytotoxicity during neoantigen‐specific T‐cell immune responses in vitro. Then, the minigene of six functionally identified neoantigen peptides is constructed and the minigene‐modified GFP‐HepG2 cells are generated. Neoantigen‐specific immune response is observed with highly secreted Granzyme B, IFN‐γ, and PD‐1 when targeting the minigene‐modified GFP‐HepG2 cells in the 3D RLM HCC tumor model. Overall, the 3D RLM tumor model provides a novel strategy for preclinical assessment of the efficacy of neoantigen‐specific T cell immune response, which helps develop personalized cancer vaccines and immunotherapy treatments for HCC patients.

Microporogen-Structured Collagen Matrices for Embedded Bioprinting of Tumor Models for Immuno-Oncology.

Embedded bioprinting enables the rapid design and fabrication of complex tissues that recapitulate in vivo microenvironments. However, few biological matrices enable good print fidelity, while simultaneously facilitate cell viability, proliferation, and migration. Here, we introduce a new microporogen-structured (μPOROS) matrix for embedded bioprinting, in which matrix rheology, printing behavior, and porosity are tailored by adding sacrificial microparticles composed of a gelatin-chitosan complex to a prepolymer collagen solution. To demonstrate its utility, we created a three-dimensional tumor model via embedded printing of a murine melanoma cell ink within the μPOROS collagen matrix at 4°C. The collagen matrix is subsequently crosslinked around the microparticles upon warming to 21°C, followed by their melting and removal at 37°C. This process results in a μPOROS matrix with a fibrillar collagen type-I network akin to that observed in vivo. Printed tumor cells remain viable and proliferate, while antigen-specific cytotoxic T cells incorporated in the matrix migrate to the tumor site, where they induce cell death. The integration of our μPOROS matrix with embedded bioprinting opens new avenues for creating complex tissue microenvironments in vitro that may find widespread use in drug discovery, disease modeling, and tissue engineering for therapeutic use. This article is protected by copyright. All rights reserved.

Advances in three-dimensional tumor models for colorectal cancer

Conventional tumor culture models include two-dimensional tumor cell cultures and xenograft models. The former has disadvantages including lack of tumor heterogeneity and poor clinical relevance, while the latter are limited by the slow growth, low engraftment successful rate, and high cost. In recent years, in vitro three-dimensional (3D) tumor models have emerged as the tool to better recapitulate the spatial structure and the in vivo environment of tumors. In addition, they preserve the pathological and genetic features of tumor cells and reflect the complex intracellular and extracellular interactions of tumors, which have become a powerful tool for investigating the tumor mechanism, drug screening, and personalized cancer treatment. 3D tumor model technologies such as spheroids, organoids, and microfluidic devices are maturing. Application of new technologies such as co-culture, 3D bioprinting, and air-liquid interface has further improved the clinical relevance of the models. Some models recapitulate the tumor microenvironment, and some can even reconstitute endogenous immune components and microvasculature. In recent years, some scholars have combined xenograft models with organoid technology to develop matched in vivo/in vitro model biobanks, giving full play to the advantages of the two technologies, and providing an ideal research platform for individualized precision therapy for specific molecular targets in certain subtypes of tumors. So far, the above technologies have been widely applied in the field of colorectal cancer research. Our research team is currently studying upon the application of patient-derived tumor cell-like clusters, a self-assembly 3D tumor model, in guiding the selection of postoperative chemotherapy regimens for colorectal cancer. A high modeling success rate and satisfactory results in the drug screening experiments have been achieved. There is no doubt that with the advancement of related technologies, 3D tumor models will play an increasingly important role in the research and clinical practice of colorectal cancer.

3D Porous Scaffold-Based High-Throughput Platform for Cancer Drug Screening.

Natural polymer-based porous scaffolds have been investigated to serve as three-dimensional (3D) tumor models for drug screening owing to their structural properties with better resemblance to human tumor microenvironments than two-dimensional (2D) cell cultures. In this study, a 3D chitosan-hyaluronic acid (CHA) composite porous scaffold with tunable pore size (60, 120 and 180 µm) was produced by freeze-drying and fabricated into a 96-array platform for high-throughput screening (HTS) of cancer therapeutics. We adopted a self-designed rapid dispensing system to handle the highly viscous CHA polymer mixture and achieved a fast and cost-effective large-batch production of the 3D HTS platform. In addition, the adjustable pore size of the scaffold can accommodate cancer cells from different sources to better mimic the in vivo malignancy. Three human glioblastoma multiforme (GBM) cell lines were tested on the scaffolds to reveal the influence of pore size on cell growth kinetics, tumor spheroid morphology, gene expression and dose-dependent drug response. Our results showed that the three GBM cell lines showed different trends of drug resistance on CHA scaffolds of varying pore size, which reflects the intertumoral heterogeneity across patients in clinical practice. Our results also demonstrated the necessity to have a tunable 3D porous scaffold for adapting the heterogeneous tumor to generate the optimal HTS outcomes. It was also found that CHA scaffolds can produce a uniform cellular response (CV < 0.15) and a wide drug screening window (Z' > 0.5) on par with commercialized tissue culture plates, and therefore, can serve as a qualified HTS platform. This CHA scaffold-based HTS platform may provide an improved alternative to traditional 2D-cell-based HTS for future cancer study and novel drug discovery.

Characterization of 3D-Bioprinted In Vitro Lung Cancer Models Using RNA-Sequencing Techniques.

To construct an in vitro lung cancer model using 3D bioprinting and evaluate the feasibility of the model. Transcriptome sequencing was used to compare the differential genes and functions of 2D and 3D lung cancer cells. 1. A549 cells were mixed with sodium alginate/gelatine/fibrinogen as 3D-printed biological ink to construct a hydrogel scaffold for the in vitro model of lung cancer; 2. A hydrogel scaffold was printed using a extrusion 3D bioprinter; 3. The printed lung cancer model was evaluated in vitro; and 4. A549 cells cultured in 2D and 3D tumour models in vitro were collected, and RNA-seq conducted bioinformatics analysis. 1. The in vitro lung cancer model printed using 3D-bioprinting technology was a porous microstructure model, suitable for the survival of A549 cells. Compared with the 2D cell-line model, the 3D model is closer to the fundamental human growth environment; 2. There was no significant difference in cell survival rate between the 2D and 3D groups; 3. In the cell proliferation rate measurement, it was found that the cells in the 2D group had a speedy growth rate in the first five days, but after five days, the growth rate slowed down. Cell proliferation showed a declining process after the ninth day of cell culture. However, cells in the 3D group showed a slow growth process at the beginning, and the growth rate reached a peak on the 12th day. Then, the growth rate showed a downward trend; and 4. RNA-seq compared A549 cells from 2D and 3D lung cancer models. A total of 3112 genes were differentially expressed, including 1189 up-regulated and 1923 down-regulated genes, with p-value ≤ 0.05 and |Log2Ratio| ≥ 1 as screening conditions. After functional enrichment analysis of differential genes, these differential genes affect the biological regulation of A549 cells, thus promoting lung cancer progression. This study uses 3D-bioprinting technology to construct a tumour model of lung cancer that can grow sustainably in vitro. Three-dimensional bioprinting may provide a new research platform for studying the lung cancer TME mechanism and anticancer drug screening.

Tumor-neutrophil crosstalk promotes in vitro and in vivo glioblastoma progression.

The tumor microenvironment (TME) of glioblastoma (GB) is characterized by an increased infiltration of immunosuppressive cells that attenuate the antitumor immune response. The participation of neutrophils in tumor progression is still controversial and a dual role in the TME has been proposed. In this study, we show that neutrophils are reprogrammed by the tumor to ultimately promote GB progression. Using in vitro and in vivo assays, we demonstrate the existence of bidirectional GB and neutrophil communication, directly promoting an immunosuppressive TME. Neutrophils have shown to play an important role in tumor malignancy especially in advanced 3D tumor model and Balb/c nude mice experiments, implying a time- and neutrophil concentration-dependent modulation. Studying the tumor energetic metabolism indicated a mitochondria mismatch shaping the TME secretome. The given data suggests a cytokine milieu in patients with GB that favors the recruitment of neutrophils, sustaining an anti-inflammatory profile which is associated with poor prognosis. Besides, glioma-neutrophil crosstalk has sustained a tumor prolonged activation via NETs formation, indicating the role of NFκB signaling in tumor progression. Moreover, clinical samples have indicated that neutrophil-lymphocyte ratio (NLR), IL-1β, and IL-10 are associated with poor outcomes in patients with GB. These results are relevant for understanding how tumor progression occurs and how immune cells can help in this process.

3D porous sodium alginate-silk fibroin composite bead based in vitro tumor model for screening of anti-cancer drug and induction of magneto-apoptosis

The development of 3D scaffold-based in vitro tumor models can help to address the limitations of cell culture and animal models for designing and screening of anticancer drugs. In this study, in vitro 3D tumor models using sodium alginate (SA) and sodium alginate/silk fibroin (SA/SF) porous beads were developed. The beads were non-toxic and A549 cells had a high tendency to adhere, proliferate, and form tumor-like aggregates within SA/SF beads. The 3D tumor model based on these beads had better efficacy for anti-cancer drug screening than the 2D cell culture model. Additionally, the SA/SF porous beads loaded with superparamagnetic iron oxide nanoparticles were used to explore their magneto-apoptosis ability. The cells exposed to a high magnetic field were more likely to undergo apoptosis than those exposed to a low magnetic field. These findings suggest that the SA/SF porous beads and SPIONs loaded SA/SF porous beads-based tumor models could be useful for drug screening, tissue engineering, and mechanobiology studies.

Development and cytotoxicity evaluation of multiple nanoemulsions for oral co-delivery of 5-fluorouracil and short chain triglycerides for colorectal cancer

Colorectal cancer (CRC) is the third most common cancer in the world, but current chemotherapy options are limited due to adverse effects and low oral bioavailability of drugs. In this study, we investigated the obtainment parameters and composition of new multiple nanoemulsions (MN) based on microemulsions for oral co-delivery of 5-fluorouracil (5FU) and short-chain triglycerides (SCT, either tributyrin or tripropionin). The area of microemulsion formation was increased from 14% to 38% when monocaprylin was mixed with tricaprylin as oil phase. Addition of SCT reduced this value to 24–26%. Using sodium alginate aqueous dispersion as internal aqueous phase (to avoid phase inversion) did not further affected the area but increased microemulsion viscosity by 1.5-fold. To obtain the MN, selected microemulsions were diluted in an external aqueous phase; droplet size was 500 nm and stability improved using polyoxyethylene oleyl ether at 1–2.5% as surfactant in the external phase and a dilution ratio of 1:1 (v/v). 5FU in vitro release could be better described by the Korsmeyer-Peppas model. No pronounced changes in droplet size were observed when selected MNs were incubated in buffers mimicking gastrointestinal fluids. The 5FU cytotoxicity in monolayer cell lines presenting various mutations was influenced by its incorporation in the nanocarrier, presence of SCT and cell mutation status. The MNs selected reduced the viability of tumor spheroids (employed as 3D tumor models) by 2.2-fold compared to 5FU solution and did not affect the survival of the G. mellonella, suggesting effectiveness and safety.

Abstract B021: Pan-RAS IMM-1-104 activity in humanized 3D tumor models is independent of specific amino acid substitution

Abstract Introduction: Novel dual-MEK inhibitor IMM-1-104 is under clinical investigation for use in RAS-addicted solid tumors. Approved KRAS G12C inhibitors are available but cover a limited subset of patients. For example, the KRAS G12C substitution occurs in only 1-3% of pancreatic cancers. We assessed response to IMM-1-104 across RAS mutant preclinical models to determine whether a preference was observed for mutation position, or for specific amino acid substitutions. Experimental Procedures: Response to IMM-1-104 was measured in a humanized 3D tumor growth assay across 133 tumor models. Sixty-nine of these models have a reported RAS mutation, and all models are being mutationally profiled by whole exome sequencing, with the majority (~75%) completed to date. The RAS-mutant panel spans 11 tissue types and includes a subset of 30 confirmed KRAS G12 mutated cell lines drawn from three major indications: 12 pancreatic, 11 lung, and 7 colorectal cancer models. Based on the 3D assay, cell lines were classified into sensitive, intermediate, and resistant to IMM-1-104. The distribution of responses was then assessed across mutation position and amino acid substitutions. Summary of New Data: In the full dataset across 69 RAS-mutant models, at least one model displayed response to IMM-1-104 (sensitive or intermediate) for each observed mutation in K/N/HRAS. That is, no particular mutation position or amino acid substitution was exclusively found to be resistant. Association of response with amino acid identity was further evaluated in a subset of lines for the most frequently altered residue in KRAS, G12. A distribution of responses was observed for each amino acid substitution. The G12 substitutions having at least four cell lines each total across the three indications included G12C (8 lines), D (5 lines), R (4 lines), and V (11 lines). Across cell lines for each of these substitutions, multiple response categories were observed. In each case, half or more lines fell into the intermediate category with the rest falling into one or both of the other response categories. For example, out of the 8 KRAS G12C lines, 6 showed intermediate response, 1 showed resistance, and 1 showed sensitivity. Examining these distributions together, no significant statistical relationship was seen between the amino acid substitution and response categories by Fisher’s exact test. Conclusions: Across 69 RAS-mutated cell lines, each mutation position or amino acid substitution was associated with sensitive or intermediate response in at least one line. Looking at the most commonly mutated position in KRAS, across 30 KRAS G12 mutated cell lines from three cancer indications, no significant preference was observed with respect to response to IMM-1-104 for a particular amino acid at G12. These observations suggest potential relevance of IMM-1-104 to a broad RAS-driven patient population. Citation Format: Sarah Kolitz, Praveen Nair, Mai Johnson, Jason Funt, Peter J. King, Kevin D. Fowler, Anna Travesa, Frank Wang, John Brothers II, Amy Axel, Scott Barrett, Benjamin J. Zeskind, Brett Hall. Pan-RAS IMM-1-104 activity in humanized 3D tumor models is independent of specific amino acid substitution [abstract]. In: Proceedings of the AACR Special Conference: Targeting RAS; 2023 Mar 5-8; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Res 2023;21(5_Suppl):Abstract nr B021.

Tumor Organoid and Spheroid Models for Cervical Cancer.

Cervical cancer is one of the most common malignant diseases in women worldwide. Despite the global introduction of a preventive vaccine against the leading cause of cervical cancer, human papillomavirus (HPV) infection, the incidence of this malignant disease is still very high, especially in economically challenged areas. New advances in cancer therapy, especially the rapid development and application of different immunotherapy strategies, have shown promising pre-clinical and clinical results. However, mortality from advanced stages of cervical cancer remains a significant concern. Precise and thorough evaluation of potential novel anti-cancer therapies in pre-clinical phases is indispensable for efficient development of new, more successful treatment options for cancer patients. Recently, 3D tumor models have become the gold standard in pre-clinical cancer research due to their capacity to better mimic the architecture and microenvironment of tumor tissue as compared to standard two-dimensional (2D) cell cultures. This review will focus on the application of spheroids and patient-derived organoids (PDOs) as tumor models to develop novel therapies against cervical cancer, with an emphasis on the immunotherapies that specifically target cancer cells and modulate the tumor microenvironment (TME).

Sophorolipid Candidates Demonstrate Cytotoxic Efficacy against 2D and 3D Breast Cancer Models.

Sophorolipids are biosurfactants derived from the nonpathogenic yeasts such as Starmerella bombicola with potential efficacy in anticancer applications. Simple and cost-effective synthesis of these drugs makes them a promising alternative to traditional chemotherapeutics, pending their success in preliminary drug-screening. Drug-screening typically utilizes 2D cell monolayers due to their simplicity and ease of high-throughput assessment. However, 2D assays fail to capture the complexity and 3D context of the tumor microenvironment and have consequently been implicated in the high percentage of drugs investigated in vitro that later fail in clinical trials. Herein, we screened two sophorolipid candidates and a clinically-used chemotherapeutic, doxorubicin, on in vitro breast cancer models ranging from 2D monolayers to 3D spheroids, employing optical coherence tomography to confirm these morphologies. We calculated corresponding IC50 values for these drugs and found one of the sophorolipids to have comparable toxicities to the chemotherapeutic control. Our findings show increased drug resistance associated with model dimensionality, such that all drugs tested showed that 3D spheroids exhibited higher IC50 values than their 2D counterparts. These findings demonstrate promising preliminary data to support the use of sophorolipids as a more affordable alternative to traditional clinical interventions and demonstrate the importance of 3D tumor models in assessing drug response.

Anti-Cancer Effects of Artesunate in Human 3D Tumor Models of Different Complexity.

The anti-malaria drug Artesunate (ART) shows strong anti-cancer effects in vitro; however, it shows only marginal treatment results in clinical cancer studies. In this study, ART was tested in preclinical 3D cancer models of increasing complexity using clinically relevant peak plasma concentrations to obtain further information for translation into clinical use. ART reduced cell viability in HCT-116 and HT-29 derived cancer spheroids (p < 0.001). HCT-116 spheroids responded dose-dependently, while HT-29 spheroids were affected more strongly by ART than by cytostatics (p < 0.001). HCT-116 spheroids were chemo-sensitized by ART (p < 0.001). In patient-derived cancer spheroids (PDCS), ART led to inhibition of cell viability in 84.62% of the 39 samples tested, with a mean inhibitory effect of 13.87%. Viability reduction of ART was 2-fold weaker than cytostatic monotherapies (p = 0.028). Meanwhile, tumor-stimulation of up to 16.30% was observed in six (15.38%) PDCS-models. In 15 PDCS samples, ART modulated chemotherapies in combined testing, eight of which showed chemo-stimulation (maximum of 36.90%) and seven chemo-inhibition (up to 16.95%). These results demonstrate that ART's anti-cancer efficacy depends on the complexity of the tumor model used. This emphasizes that cancer treatment with ART should be evaluated before treatment of the individual patient to ensure its benefits and prevent unwanted effects.

A GAN-based method for 3D lung tumor reconstruction boosted by a knowledge transfer approach.

Three-dimensional (3D) image reconstruction of tumors has been one of the most effective techniques for accurately visualizing tumor structures and treatment with high resolution, which requires a set of two-dimensional medical images such as CT slices. In this paper we propose a novel method based on generative adversarial networks (GANs) for 3D lung tumor reconstruction by CT images. The proposed method consists of three stages: lung segmentation, tumor segmentation and 3D lung tumor reconstruction. Lung and tumor segmentation are performed using snake optimization and Gustafson-Kessel (GK) clustering. In the 3D reconstruction part first, features are extracted using the pre-trained VGG model from the tumors that detected in 2D CT slices. Then, a sequence of extracted features is fed into an LSTM to output compressed features. Finally, the compressed feature is used as input for GAN, where the generator is responsible for high-level reconstructing the 3D image of the lung tumor. The main novelty of this paper is the use of GAN to reconstruct a 3D lung tumor model for the first time, to the best of our knowledge. Also, we used knowledge transfer to extract features from 2D images to speed up the training process. The results obtained from the proposed model on the LUNA dataset showed better results than state of the art. According to HD and ED metrics, the proposed method has the lowest values ​​of 3.02 and 1.06, respectively, as compared to those of other methods. The experimental results show that the proposed method performs better than previous similar methods and it is useful to help practitioners in the treatment process.

Impact of hydrogel biophysical properties on tumor spheroid growth and drug response

The extracellular matrix (ECM) plays a critical role in regulating cell-matrix interactions during tumor progression. These interactions are due in large part to the biophysical properties responding to cancer cell interactions. Within in vitro models, the ECM is mimicked by hydrogels, which possess adjustable biophysical properties that are integral to tumor development. This work presents a systematic and comparative study on the impact of the biophysical properties of two widely used natural hydrogels, Matrigel and collagen gel, on tumor growth and drug response. The biophysical properties of Matrigel and collagen including complex modulus, loss tangent, diffusive permeability, and pore size, were characterised. Then the spheroid growth rates in these two hydrogels were monitored for spheroids with two different sizes (140 μm and 500 μm in diameters). An increased migratory growth was observed in the lower concentration of both the gels. The effect of spheroid incorporation within the hydrogel had a minimal impact on the hydrogel's complex modulus. Finally, 3D tumor models using different concentrations of hydrogels were applied for drug treatment using paclitaxel. Spheroids cultured in hydrogels with different concentrations showed different drug response, demonstrating the significant effect of the choice of hydrogels and their concentrations on the drug response results despite using the same spheroids. This study provides useful insights into the effect of hydrogel biophysical properties on spheroid growth and drug response and highlights the importance of hydrogel selection and in vitro model design.