3D In Vitro Model (R)evolution: Unveiling Tumor–Stroma Interactions

In vitro integration of a functional vasculature to model endothelial regulation of chemotherapy and T-cell immunotherapy in liver cancer

The complex tumor microenvironment (TME) presents significant challenges to the development of effective therapies against solid tumors, highlighting the need for advanced in vitro models that better recapitulate TME biology. To address this, we developed a vascularized human liver tumor model using a microfluidic platform, designed to test both drug and cell-based therapies. This model mimics critical tumorigenic features such as hypoxia, extracellular matrix (ECM), and perfusable vascular networks. Intravascular administration of Sorafenib demonstrated its ability to disrupt vascular structures significantly, while eliciting heterogeneous responses in two distinct liver tumor cell lines, HepG2 and Hep3b. Furthermore, treatment with engineered T-cells revealed that the tumor vasculature impeded T-cell infiltration into the tumor core but preserved their cytotoxic capacity, albeit with reduced exhaustion levels. Cytokine analysis and spatial profiling of vascularized tumor samples identified proinflammatory factors that may enhance T-cell-mediated antitumor responses. By capturing key TME characteristics, this microfluidic platform provides a powerful tool enabling detailed investigation of tumor-immune and tumor-vascular interactions. Its versatility could serve as a promising bridge between preclinical studies and clinical testing, offering opportunities for developing and optimizing personalized therapeutic strategies for solid tumors.

A vascularized tumors-on-a-chip model for studying tumor-angiogenesis interplay, heterogeneity and drug responses

Current tumor models struggle to replicate the complexity of the tumor microenvironment, particularly endothelial sprouting and vascular-tumor interactions. To address these limitations, we developed a vascularized tumors-on-a-chip model by fusing tumor spheroids with HUVEC spheroids to simulate angiogenesis. The model incorporates hypoxia-driven cytokine secretion and dynamic endothelial penetration, enabling accurate recapitulation of angiogenic processes. Spheroids were optimized for size and viability, and four cancer types were studied, with GBM and A549 exhibiting the highest angiogenic potential, as confirmed by Z-stack imaging and qRT-PCR. Encapsulation in GelMA and integration into PDMS-based microfluidic chips provided a dynamic flow environment, mimicking in vivo drug delivery while enabling high-throughput drug screening. This chip-based system allows simultaneous testing of multiple drugs or tumors under physiologically relevant conditions, enhancing its translational potential. The platform was validated using doxorubicin and bevacizumab, revealing reduced VEGF secretion and dynamic cytokine responses, replicating vascular barriers. Further validation in murine models demonstrated its capacity to promote angiogenesis and mimic tumor-vessel interactions. This advanced tumors-on-a-chip model addresses critical shortcomings of conventional 2D and 3D systems and offers a transformative tool for preclinical drug evaluation and the development of precision oncology strategies, bridging the gap between in vitro testing and in vivo relevance.

Deciphering pericyte-induced temozolomide resistance in glioblastoma with a 3D microphysiological system mimicking the biomechanical properties of brain tissue

Glioblastoma (GBM) is a highly aggressive malignancy with a poor prognosis and frequent resistance to temozolomide (TMZ), the standard-of-care chemotherapy. The complex mechanisms underlying GBM chemoresistance, particularly the role of pericytes, remain poorly understood due to the lack of physiologically relevant in vitro models replicating the complex tumor microenvironment (TME). Here, we present a biomimetic 3D GBM microphysiological system that replicates the biomechanical properties of brain tissue (G'∼800Pa, G"∼100Pa) and enables the study of pericyte-mediated TMZ resistance. GBM spheroids (U87, LN229, PDM140) were cultured alone or co-cultured with pericytes in a composite hydrogel for 14 days and remained viable and proliferative. In response to TMZ, PDM140 was the most sensitive (IC50=73μM), followed by LN229 (IC50=278μM) and U87 (IC50=446μM). Co-culture with pericytes significantly increased GBM spheroid viability by 22.7% (PDM140), 32.5% (LN229), and 22.1% (U87), confirming pericyte-induced TMZ resistance. Notably, pericytes exhibited a 160-fold upregulation of C-C motif chemokine ligand 5 (CCL5) upon TMZ treatment, implicating the CCL5-mediated pathway in chemoresistance. This innovative brain-mimicking 3D GBM model provides a physiologically relevant platform for studying tumor-pericyte interactions and testing therapeutic strategies targeting CCL5-mediated resistance mechanisms in GBM. STATEMENT OF SIGNIFICANCE: We developed a multicellular 3D glioblastoma microphysiological system mimicking the physicochemical properties of brain tissues and pericyte-mediated TMZ resistance that can be used to screen for standard-of-care chemotherapy. This advanced hydrogel-based platform demonstrated the critical role of the glioblastoma tumor microenvironment in modulating chemotherapy sensitivity, particularly the pericyte-induced CCL5-CCR5 paracrine axis that can lead to the identification of therapeutic targets within the CCL5-CCR5 pathway toward more effective treatments disrupting these resistance mechanisms. Overall, the proposed 3D glioblastoma microphysiological system can transform drug screening and personalized treatment for GBM by offering ethical and cost-effective alternatives to animal testing and more effective drug screening and discovery efforts, ultimately improving GBM patient outcomes.

Development and validation of a high-throughput screening pipeline of compound libraries to target EMT

Epithelial to Mesenchymal transitions (EMT) drive cell plasticity and are associated with cell features such as invasiveness, migration and stemness. They are orchestrated by select families of EMT-associated transcription factors, which exhibit pleiotropic roles in the malignant progression of various cancer types, such as breast and colorectal cancer (CRC). This has spurred interest in EMT as a promising target for the development of novel therapeutic strategies. In this study, we developed a phenotypic dual EMT Sensor screening assay, amendable to efficient high-throughput identification of small molecules interfering with EMT. In a proof-of-concept screening we identified anti-EMT repurposing drugs. From these, we validated RepSox, a selective inhibitor of the TGF-β type I receptor ALK5, and demonstrated that it is potently blocking EMT in both breast and colorectal cancer cell lines in vitro. In addition, utilizing a Drosophila melanogaster metastatic CRC model we confirmed the ability of the identified anti-EMT hits to suppress metastatic behavior in vivo.

Single-cell RNA sequencing reveals a fibroblast gene signature that promotes T-cell infiltration in muscle-invasive bladder cancer

Muscle-invasive bladder cancer (MIBC) is characterized by a complex tumor microenvironment (TME) that drives aggressive progression and treatment resistance. Previous studies have highlighted the roles of cancer-associated fibroblasts (CAFs) and exhausted T (Tex) cells in MIBC, but their interactive mechanisms remain poorly understood. Here, single-cell RNA sequencing of 19 tissue samples from 12 patients-7 MIBC, 3 non-muscle-invasive bladder cancer (NMIBC), and 9 normal tissue samples-identified 13 transcriptionally distinct fibroblast clusters and 10 functionally heterogeneous T-cell subsets. Two interferon (IFN)-responsive fibroblast populations, F-ISG15 (inflammatory CAFs) and F-POSTN (myofibroblastic CAFs), were shown to predominate in the MIBC TME. In vivo experiments demonstrated that IFN-γ secreted by Tex cells polarizes CAFs to secrete CXCL12, which recruits CXCR4-expressing T cells via the CXCL12-CXCR4 chemotactic axis. Spatial analysis revealed a bidirectional loop: Tex-derived IFN-γ sustains CAF activation, whereas CAF-secreted CXCL12 amplifies Tex infiltration. Clinically, activated CAF signatures correlate with advanced disease stages and reduced patient survival in MIBC. These findings establish CXCL12 and IFN signaling as critical therapeutic targets, offering new strategies to disrupt immunosuppressive TME crosstalk and improve outcomes for MIBC patients.

3D Bioprinting Models for Glioblastoma: From Scaffold Design to Therapeutic Application

Conventional in vitro models fail to accurately mimic the tumor in vivo characteristics, being appointed as one of the causes of clinical attrition rate. Recent advances in 3D culture techniques, replicating essential physical and biochemical cues such as cell-cell and cell-extracellular matrix interactions, have led to the development of more realistic tumor models. Bioprinting has emerged to advance the creation of 3D in vitro models, providing enhanced flexibility, scalability, and reproducibility. This is crucial for the development of more effective drug treatments, and glioblastoma (GBM) is no exception. GBM, the most common and deadly brain cancer, remains a major challenge, with a median survival of only 15 months post-diagnosis. This review highlights the key components needed for 3D bioprinted GBM models. It encompasses an analysis of natural and synthetic biomaterials, along with crosslinking methods to improve structural integrity. Also, it critically evaluates current 3D bioprinted GBM models and their integration into GBM-on-a-chip platforms, which hold noteworthy potential for drug screening and personalized therapies. A versatile development framework grounded on Quality-by-Design principles is proposed to guide the design of bioprinting models. Future perspectives, including 4D bioprinting and machine learning approaches, are discussed, along with the current gaps to advance the field further.

Matrix Stiffness Regulates the Osteogenic Differentiation of hPDLSCs via DNA Methylation

OBJECTIVES

This study aimed to examine the influence of matrix stiffness on osteogenic differentiation via epigenetic mechanisms in human periodontal ligament stem cells (hPDLSCs), with implications for understanding orthodontic tooth movement.

MATERIALS AND METHODS

hPDLSCs were cultured on substrates with varying stiffness (soft and stiff). Dot blot and immunofluorescence techniques were employed to measure global DNA methylation levels. RT-qPCR and alkaline phosphatase (ALP) activity assays were conducted to assess differences in DNA methylation and osteogenic potential. Additionally, ELISA was used to quantify DNA methyltransferase content and activity.

RESULTS

hPDLSCs on stiffer substrates exhibited increased 5-methylcytosine (5-mC) and higher global DNA methylation levels than those on soft substrates. With increased matrix stiffness, DNMT3A and DNMT3B mRNA expression levels rose. hPDLSCs on stiff matrices also showed elevated DNMT3B enzyme content and osteogenic activity. When global DNA methylation was reduced, mRNA levels of RUNX2, ALP, and Col-1 decreased, along with a notable reduction in ALP staining intensity in the inhibitor group.

CONCLUSIONS

Matrix stiffness is positively associated with global DNA methylation, with DNMT3B likely mediating this regulation in hPDLSCs. Furthermore, DNA methylation levels are positively linked to the osteogenic capability of hPDLSCs.

Microfabricated Organ-Specific Models of Tumor Microenvironments

Despite the advances in detection, diagnosis, and treatments, cancer remains a lethal disease, claiming the lives of more than 600,000 people in the United States alone in 2024. To accelerate the development of new therapeutic strategies with improved responses, significant efforts have been made to develop microfabricated in vitro models of tumor microenvironments (TMEs) that address the limitations of animal-based cancer models. These models incorporate several advanced tissue engineering techniques to better reflect the organ- and patient-specific TMEs. Additionally, microfabricated models integrated with next-generation single-cell omics technologies provide unprecedented insights into patient's cellular and molecular heterogeneity and complexity. This review provides an overview of the recent understanding of cancer development and outlines the key TME elements that can be captured in microfabricated models to enhance their physiological relevance. We highlight the recent advances in microfabricated cancer models that reflect the unique characteristics of their organs of origin or sites of dissemination.

Classification of the LC4 Primarily-like Cell Line-Recapitulating a CDK4 Overexpressing Immune Evasive HIV-HCV-Induced HCC

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related mortality. HCC is characterized by high heterogeneity and, subsequently, adaptation by developing resistance to current treatments. Applying individualized models is crucial to understanding the potential of approved therapies. Therefore, we classify a primary-like cell line derived from the core region of an HCC with underlying HIV-HCV co-infection employing deep analysis on the pathway regulation level.

METHODS

We employed DEG analysis, followed by pathway analysis, to characterize the preservation level of the LC4 cells and the level of adoption. Next, we classify the new model for HCC research by employing healthy donor samples, commonly used HCC cell lines, and global RNAseq datasets.

RESULTS

LC4 cells reflect the characteristics of the parental cancer region, including immunosuppression and metabolic reprogramming, characterized by the downregulation of drug-metabolizing enzymes compared to healthy individuals, indicating a transition to alternate metabolic pathways. Moreover, we identified specific biomarkers equally regulated in the parental tissue, in global datasets of the same entities as well as in LC4 cells.

CONCLUSIONS

We classified LC4 cells as an individual immunosuppressive and highly progressive primary-like HCC cell line. LC4 cells are applicable as a model for preclinical drug testing, minimizing the lack of preclinical models in HCV-HIV-induced HCC research.

SKOV-3 Cell Aggregates on a Microfluidic Chip with a Thermoresponsive Hydrogel as a Culture Scaffold for DOX Assessment

Microfluidic chip technology is very popular in life sciences. Here, ovarian cancer SKOV-3 cell aggregates were formed using thermoresponsive poly(N-isopropylacrylamide-co-acrylic acid) (PNA) hydrogel as a culture scaffold on a microfluidic chip serving as an operating platform. A simple microfluidic chip was designed and fabricated as the three-dimensional (3D) cell culture microplatform. Different concentrations of doxorubicin (DOX) were fed to the obtained SKOV-3 cell aggregates on the chip via a pump. All characterization results indicated that this system could effectively perform 3D cell culture and drug evaluation to a certain extent. In addition, by grafting the RGD sequence, the biocompatibility of the PNA hydrogel was improved. On the one hand, the grafting of the RGD sequence into the hydrogel could significantly improve cell proliferation in this system; on the other hand, it led to an earlier appearance of DOX drug resistance. This versatile model in this study has the potential for further use in in vitro human ovarian cancer physiological models, drug discovery, and toxicology research.

Breast cancer patient-derived scaffolds enhance the understanding of PD-L1 regulation and T cell cytotoxicity

Recent advances as well as obstacles for immune-based cancer treatment strategies, highlight the notable impact of patient cancer microenvironments on the immune cells and immune targets. Here, we use patient-derived scaffolds (PDS) generated from 110 primary breast cancers to monitor the impact of the cancer microenvironment on immune regulators. Pronounced variation in PD-L1 expression is observed in cancer cells adapted to different patient scaffolds. This variation is further linked to clinical observations and correlated with specific proteins detected in the cell-free PDSs using mass spectrometry. When adding T cells to the PDS-based cancer cultures, the killing efficiency of activated T cells vary between the cultures, whereas non-activated T cells modulate the cancer cell PD-L1 expression to treatment-predictive values, matching killing capacities of activated T cells. Surviving cancer cells show enrichment in cancer stem cell and epithelial-to-mesenchymal transition (EMT) features, suggesting that T cells may not efficiently target cells with metastatic potential. We conclude that clinically relevant insights in how to optimally target and guide immune-based cancer therapies can be obtained by including patient-derived scaffolds and cues from the cancer microenvironment in cancer patient handling and drug development.

Engineered Endometrial Clear Cell Cancer-on-a-Chip Reveals Early Invasion-Metastasis Cascade of Cancer Cells

Endometrial clear cell cancer (ECCC) is an extremely rare and highly malignant subtype of endometrial cancer. For most ECCC patients, cancer metastasis is the major cause of death. To date, due to the complexity of cancer evolution and the small number of cases, the metastasis of ECCC at the early stage remains largely unknown. Herein, we modeled the early invasion-metastasis cascade of ECCC by coculturing the ECCC patient-derived tumor cells (PDTCs) and primary human vascular endothelial cells on a microfluidic chip. With the chip, we for the first time replicated the dynamic migration of PDTCs into the surrounding stroma, including the intravasation and extravasation of PDTCs through the capillaries/microvessels, and presented the changes in the morphology and permeability of capillaries, with the decreased diameter and the increased permeability after cancer metastasis. We found that PDTCs were more invasive than the common endometrial adenocarcinoma cells. In addition, we preliminarily explored the inhibition of drugs on the early PDTC infiltration. This study provides new ideas for better understanding of ECCC evolution.

Development of a simplified and scalable hydrogel-based method for 3D cell culture

ObjectiveTo develop a cost-effective and mechanically robust 3D collagen hydrogel system suitable for pressure-based culture, enabling physiologically relevant in vitro modeling of mechanical stress responses in cells.MethodsA rat tail type I collagen-based hydrogel was formulated through optimized component ratios and cast into standard 24-well plates to form uniform gel columns. Endothelial cells was embedded and subjected to 30 mmHg pressure culture for up to 48 h. Gel morphology and fiber architecture were assessed via scanning electron microscopy. Cell viability, proliferation (Ki67 immunostaining), and tube formation ability were evaluated. A custom mechanical compression setup was used to apply and monitor sustained pressure.ResultsThe hydrogel exhibited stable gelation, uniform porosity, and resistance to deformation under mechanical loading. SEM confirmed a consistent nanofiber network, with fiber diameter unaffected by 30 mmHg pressure. After 24-h pressure culture, the gel retained its height and structure. Endothelial cells remained viable but showed reduced proliferation and impaired tube formation under pressure, as indicated by Ki67 staining and angiogenesis assays.ConclusionsThis 3D collagen hydrogel provides a simple, cost-effective, and scalable alternative to complex bioprinting methods, supporting broader application of 3D cell culture in biomedical research.

Host-microbe-cancer interactions on-a-chip

The tumor microbiota has emerged as a pivotal contributor to a variety of cancers, impacting disease development, progression, and therapeutic resistance. Due to the complexity of the tumor microenvironment, reproducing the interactions between the microbes, tumor cells, and the immune system remains a great challenge for both in vitro and in vivo studies. To this end, significant progress has been made toward leveraging tumor-on-a-chip model systems to replicate critical hallmarks of the native disease in vitro. These microfluidic platforms offer the ability to mimic essential components of the tumor microenvironment, including controllable fluid flow conditions, manipulable extracellular matrix dynamics, and intricate 3D multi-cellular communication. The primary objective of this review is to discuss recent challenges and advances in engineering host-microbiota and tumor interactions on-a-chip. Ultimately, overcoming these obstacles will help us gain deeper insights into tumor-microbe interactions and enhance avenues for developing more effective cancer therapies.

Real-time and regional analysis of the efficacy of anticancer drugs in a patient-derived intratumoral heterogeneous tumor microenvironment

Preclinical evaluation of anticancer drug efficacy utilizes 2D cell culture systems, tumoroids or experimental animal models, but it suffers from limitations such as inaccurate simulation of tumor microenvironments in living tumors, difficulty in regional analysis, and low throughput. Therefore, in this study, we developed a system named tumor-microenvironment-on-chip (TMoC) comprising a 3D dynamic tumor tissue culture system, which recreated diverse and heterogeneous cellular tumor microenvironments. In addition to the culture with a dynamic circulation, TMoC allowed users to perform real-time regional analysis, independently assessing the drug response from the normoxic area to the hypoxic area in a gradient manner. Through cell composition analysis and gene analysis, we proved that TMoC has a tumor environment with close resemblance to the original tumor environment. By comparing 15 drug testing results with animal experiments, we proved that TMoC is 93% consistent with the response results of animal experiments. In addition, we confirmed that either mouse- or patient-derived tumor cell lines can be cultured and tested in TMoC, indicating its immense potential for all aspects of preclinical drug evaluation.

A 3D bioprinted potential colorectal tumor model based on decellularized matrix/gelatin methacryloyl/nanoclay/sodium alginate hydrogel

Colorectal cancer (CRC) is now the third most common cancer worldwide. However, the development cycle for anticancer drugs is lengthy and the failure rate is high, highlighting the urgent need for new tumor models for CRC-related research. The decellular matrix (dECM) offers numerous cell adhesion sites, proteoglycan and cytokines. Notably, porcine small intestine is rich in capillaries and lymphatic capillaries, which facilitates nutrient absorption. This study, we utilized dECM, along with methylacryloyl gelatin (GelMA), sodium alginate (SA) and nanoclay (NC) to create a hydrogel scaffold through 3D extrusion bioprinting. Human CRC cells (HCT8) were seeded onto the scaffold and their drug resistance was tested using 5-fluorouracil (5-FU). Our findings indicate that dECM enhances the hydrophilic properties, mechanical strength and biocompatibility of the scaffold. Furthermore, compared to traditional two-dimensional (2D) models, the three-dimensional (3D) scaffold supports the long-term growth of tumor spheres. After 2 days of 5-FU treatment, the cell survival rate reaches 88.06 ± 0.51 %. This suggests that our scaffold provides a promising alternative platform for in vitro research on cancer mechanisms, anti-cancer drug screening and new drug development.

Exploring oncology treatment strategies with tyrosine kinase inhibitors through advanced 3D models (Review)

The limitations of two-dimensional (2D) models in cancer research have hindered progress in fully understanding the complexities of drug resistance and therapeutic failures. However, three-dimensional (3D) models provide a more accurate representation of in vivo environments, capturing critical cellular interactions and dynamics that are essential in evaluating the efficacy and toxicity of tyrosine kinase inhibitors (TKIs). These advanced models enable researchers to explore drug resistance mechanisms with greater precision, optimizing treatment strategies and improving the predictive accuracy of clinical outcomes. By leveraging 3D models, it will be possible to deepen the current understanding of TKIs and drive forward innovations in cancer treatment. The present review discusses the limitations of 2D models and the transformative impact of 3D models on oncology research, highlighting their roles in addressing the challenges of 2D systems and advancing TKI studies.

Biotechnological advances in 3D modeling of cancer initiation. Examples from pancreatic cancer research and beyond

In recent years, biofabrication technologies have garnered significant attention within the scientific community for their potential to create advancedin vitrocancer models. While these technologies have been predominantly applied to model advanced stages of cancer, there exists a pressing need to develop pertinent, reproducible, and sensitive 3D models that mimic cancer initiation lesions within their native tissue microenvironment. Such models hold profound relevance for comprehending the intricacies of cancer initiation, to devise novel strategies for early intervention, and/or to conduct sophisticated toxicology assessments of putative carcinogens. Here, we will explain the pivotal factors that must be faithfully recapitulated when constructing these models, with a specific focus on early pancreatic cancer lesions. By synthesizing the current state of research in this field, we will provide insights into recent advances and breakthroughs. Additionally, we will delineate the key technological and biological challenges that necessitate resolution in future endeavors, thereby paving the way for more accurate and insightfulin vitrocancer initiation models.

Exploring Mechanical Features of 3D Head and Neck Cancer Models

Head and neck squamous cell carcinoma (HNSCC) presents significant challenges in oncology due to its complex biology and poor prognosis. Traditional two-dimensional (2D) cell culture models cannot replicate the intricate tumor microenvironment, limiting their usefulness in studying disease mechanisms and testing therapies. In contrast, three-dimensional (3D) in vitro models provide more realistic platforms that better mimic the architecture, mechanical features, and cellular interactions of HNSCC. This review explores the mechanical properties of 3D in vitro models developed for HNSCC research. It highlights key 3D culture techniques, such as spheroids, organoids, and bioprinted tissues, emphasizing their ability to simulate critical tumor characteristics like hypoxia, drug resistance, and metastasis. Particular attention is given to stiffness, elasticity, and dynamic behavior, highlighting how these models emulate native tumor tissues. By enhancing the physiological relevance of in vitro studies, 3D models offer significant potential to revolutionize HNSCC research and facilitate the development of effective, personalized therapeutic strategies. This review bridges the gap between preclinical and clinical applications by summarizing the mechanical properties of 3D models and providing guidance for developing systems that replicate both biological and mechanical characteristics of tumor tissues, advancing innovation in cancer research and therapy.

Micro Immune Response On-chip (MIRO) models the tumour-stroma interface for immunotherapy testing

Immunotherapies are beneficial for a considerable proportion of cancer patients, but ineffective in others. In vitro modelling of the complex interactions between cancer cells and their microenvironment could provide a path to understanding immune therapy sensitivity and resistance. Here we develop MIRO, a fully humanised in vitro platform to model the spatial organisation of the tumour/stroma interface and its interaction with immune cells. We find that stromal barriers are associated with immune exclusion and protect cancer cells from antibody-dependent cellular cytotoxicity, elicited by targeted therapy. We demonstrate that IL2-driven immunomodulation increases immune cell velocity and spreading to overcome stromal immunosuppression and restores anti-cancer response in refractory tumours. Collectively, our study underscores the translational value of MIRO as a powerful tool for exploring how the spatial organisation of the tumour microenvironment shapes the immune landscape and influences the responses to immunomodulating therapies.

Facilitation of Tumor Stroma-Targeted Therapy: Model Difficulty and Co-Culture Organoid Method

Background: Tumors, as intricate ecosystems, comprise oncocytes and the highly dynamic tumor stroma. Tumor stroma, representing the non-cancerous and non-cellular composition of the tumor microenvironment (TME), plays a crucial role in oncogenesis and progression, through its interactions with biological, chemical, and mechanical signals. This review aims to analyze the challenges of stroma mimicry models, and highlight advanced personalized co-culture approaches for recapitulating tumor stroma using patient-derived tumor organoids (PDTOs). Methods: This review synthesizes findings from recent studies on tumor stroma composition, stromal remodeling, and the spatiotemporal heterogeneities of the TME. It explores popular stroma-related models, co-culture systems integrating PDTOs with stromal elements, and advanced techniques to improve stroma mimicry. Results: Stroma remodeling, driven by stromal cells, highlights the dynamism and heterogeneity of the TME. PDTOs, derived from tumor tissues or cancer-specific stem cells, accurately mimic the tissue-specific and genetic features of primary tumors, making them valuable for drug screening. Co-culture models combining PDTOs with stromal elements effectively recreate the dynamic TME, showing promise in personalized anti-cancer therapy. Advanced co-culture techniques and flexible combinations enhance the precision of tumor-stroma recapitulation. Conclusions: PDTO-based co-culture systems offer a promising platform for stroma mimicry and personalized anti-cancer therapy development. This review underscores the importance of refining these models to advance precision medicine and improve therapeutic outcomes.

Chaotic (bio)printing in the context of drug delivery systems

Chaotic (bio)printing, an innovative fabrication technique that uses chaotic flows to create highly ordered microstructures within materials, may be transformative for drug delivery systems. This review explores the principles underlying chaotic flows and their application in fabricating complex, multi-material constructs designed for advanced drug delivery and controlled release. Chaotic printing enables the precise layering of different active ingredients-a feature that may greatly facilitate the development of polypills with customizable release profiles. Recently, chaos-assisted fabrication has been extended to produce micro-architected hydrogel spheres in a high-throughput manner, potentially enhancing the versatility and efficiency of drug delivery methods. In addition, chaotic bioprinting enables the creation of evolved tissue models that more accurately emulate physiological systems, providing a more relevant platform for drug testing. This review also highlights the unique advantages of chaotic printing, including the ability to fabricate tissues with organized porosity and pre-vascularized structures, addressing critical challenges in tissue engineering. Despite its promising capabilities, challenges remain, particularly in expanding the range of materials compatible with chaotic printing. Continued research and development in this area are essential to fully realize the potential of chaotic (bio)printing in advancing drug delivery, paving the way for the next generation of smart drug delivery systems and functional tissue models for drug testing.

A Thermo-responsive collapse system for controlling heterogeneous cell localization, ratio and interaction for three-dimensional solid tumor modeling

Cancer immunotherapy using engineered cytotoxic effector cells has demonstrated significant potential. The limited spatial complexity of existing in vitro models, however, poses a challenge to mechanistic studies attempting to approve existing approaches of effector cell-mediated cytotoxicity within a three-dimensional, solid tumor-like environment. To gain additional experimental control, we developed an approach for constructing three-dimensional (3D) culture models using smart polymers that form temperature responsive hydrogels. By embedding cells in these hydrogels, we constructed 3D models to organize multiple cell populations at specified ratios on-demand and gently position them by exploiting the hydrogel phase transition. These systems were amenable to imaging at low- and high-resolution to evaluate cell-to-cell interactions, as well as to dissociation to allow for single cell analyses. We have called this approach "thermal collapse of strata" (TheCOS) and demonstrated its use in creating complex cell assemblies on demand in both layers and spheroids. As an application, we utilized TheCOS to evaluate the impact of directionality of degranulation of natural killer (NK) cell lytic granules. Blocking lytic granule convergence and polarization by inhibiting dynein has been shown to induce bystander killing in single cell suspensions. Using TheCOS we showed that lytic granule dispersion induced by dynein inhibition can be sustained in 3D and results in a multi-directional killing including that of non-triggering bystander cells. By imaging TheCOS experiments, we were able to map a "kill zone" associated with multi-directional degranulation in simulated solid tumor environments. TheCOS should allow for the testing of approaches to alter the mechanics of cytotoxicity as well as to generate a wide-array of human tumor microenvironments to assist in the acceleration of tumor immunotherapy.

Ivermectin Strengthens Paclitaxel Effectiveness in High-Grade Serous Carcinoma in 3D Cell Cultures

BACKGROUND

Chemoresistance is a major obstacle in high-grade serous carcinoma (HGSC) treatment. Although many patients initially respond to chemotherapy, the majority of them relapse due to Carboplatin and Paclitaxel resistance. Drug repurposing has surfaced as a potentially effective strategy that works synergically with standard chemotherapy to bypass chemoresistance. In a prior study, using 2D cultures and two HGSC chemoresistant cell lines, it was demonstrated that combining Carboplatin or Paclitaxel with Pitavastatin or Ivermectin resulted in the most notable synergy. Acknowledging that 2D culture systems are limited in reflecting the tumor architecture, 3D cultures were generated to provide insights on treatment efficacy tests in more complex models.

OBJECTIVES

We aimed to investigate whether combining Carboplatin or Paclitaxel with Pitavastatin or Ivermectin offers therapeutic benefits in a Cultrex-based 3D model.

METHODS

Here, the cytotoxicity of Carboplatin and Paclitaxel, both alone and in combination with Pitavastatin or Ivermectin, were analyzed on two chemoresistant tumor cell lines, OVCAR8 and OVCAR8 PTX R C, in 3D cultures. Cellular viability was assessed using CellTiter-Glo® Luminescent assays. Also, it explored synergistic interactions using zero interaction potency, Loewe, Bliss independence, and High-single agent reference models.

RESULTS

Our research indicates combining chemotherapeutic drugs with Pitavastatin or Ivermectin yields significantly more cytotoxic effects than chemotherapy alone. For all the combinations tested, at least one model indicated an additive effect; however, only the combination of Paclitaxel and Ivermectin consistently demonstrated an additive effect across all chemoresistant cell lines cultured in 3D models, as well as in all four synergy reference models used to assess drug interactions.

CONCLUSIONS

Combining Paclitaxel with Ivermectin has the highest cytotoxic and the strongest additive effect for both chemoresistant cell lines compared to Paclitaxel alone.

Solid cancer-directed CAR T cell therapy that attacks both tumor and immunosuppressive cells via targeting PD-L1

Chimeric antigen receptor (CAR) T cell therapy has encountered limited success in solid tumors. The lack of dependable antigens and the immunosuppressive tumor microenvironment (TME) are major challenges. Within the TME, tumor cells along with immunosuppressive cells employ an immune-evasion mechanism that upregulates programmed death ligand 1 (PD-L1) to deactivate effector T cells; this makes PD-L1 a reliable, universal target for solid tumors. We developed a novel PD-L1 CAR (MC9999) using our humanized anti-PD-L1 monoclonal antibody, designed to simultaneously target tumor and immunosuppressive cells. The antigen-specific antitumor effects of MC9999 CAR T cells were observed consistently across four solid tumor models: breast cancer, lung cancer, melanoma, and glioblastoma multiforme (GBM). Notably, intravenous administration of MC9999 CAR T cells eradicated intracranially established LN229 GBM tumors, suggesting penetration of the blood-brain barrier. The proof-of-concept data demonstrate the cytolytic effect of MC9999 CAR T cells against immunosuppressive cells, including microglia HMC3 cells and M2 macrophages. Furthermore, MC9999 CAR T cells elicited cytotoxicity against primary tumor-associated macrophages within GBM tumors. The concept of targeting both tumor and immunosuppressive cells with MC9999 was further validated using CAR T cells derived from cancer patients. These findings establish MC9999 as a foundation for the development of effective CAR T cell therapies against solid tumors.

Targeting breast tumor extracellular matrix and stroma utilizing nanoparticles

Breast cancer is a complicated malignancy and is known as the most common cancer in women. Considerable experiments have been devoted to explore the basic impacts of the tumor stroma, particularly the extracellular matrix (ECM) and stromal components, on tumor growth and resistance to treatment. ECM is made up of an intricate system of proteins, glycosaminoglycans, and proteoglycans, and maintains structural support and controls key signaling pathways involved in breast tumors. ECM can block different drugs such as chemotherapy and immunotherapy drugs from entering the tumor stroma. Furthermore, the stromal elements, such as cancer-associated fibroblasts (CAFs), immune cells, and blood vessels, have crucial impacts on tumor development and therapeutic resistance. Recently, promising outcomes have been achieved in using nanotechnology for delivering drugs to tumor stroma and crossing ECM in breast malignancies. Nanoparticles have various benefits for targeting the breast tumor stroma, such as improved permeability and retention, extended circulation time, and the ability to actively target the area. This review covers the latest developments in nanoparticle therapies that focus on breast tumor ECM and stroma. We will explore different approaches using nanoparticles to target the delivery of anticancer drugs like chemotherapy, small molecule drugs, various antitumor products, and other specific synthetic therapeutic agents to the breast tumor stroma. Furthermore, we will investigate the utilization of nanoparticles in altering the stromal elements, such as reprogramming CAFs and immune cells, and also remodeling ECM.

Crosstalk and communication of cancer-associated fibroblasts with natural killer and dendritic cells: New frontiers and unveiled opportunities for cancer immunotherapy

Natural killer (NK) cells and dendritic cells (DCs) are critical mediators of anti-cancer immune responses. In addition to their individual roles, NK cells and DCs are involved in intercellular crosstalk which is essential for the initiation and coordination of adaptive immunity against cancer. However, NK cell and DC activity is often compromised in the tumor microenvironment (TME). Recently, much attention has been paid to one of the major components of the TME, the cancer-associated fibroblasts (CAFs), which not only contribute to extracellular matrix (ECM) deposition and tumor progression but also suppress immune cell functions. It is now well established that CAFs support T cell exclusion from tumor nests and regulate their cytotoxic activity. In contrast, little is currently known about their interaction with NK cells, and DCs. In this review, we describe the interaction of CAFs with NK cells and DCs, by secreting and expressing various mediators in the TME of adult solid tumors. We also provide a detailed overview of ongoing clinical studies evaluating the targeting of stromal factors alone or in combination with immunotherapy based on immune checkpoint inhibitors. Finally, we discuss currently available strategies for the selective depletion of detrimental CAFs and for a better understanding of their interaction with NK cells and DCs.

Spatially-Resolved Organoid Transfection by Porous Silicon-Mediated Optoporation

Engineering the spatial organisation of organotypic cultures is pivotal for refining tissue models that are useful for gaining deeper insights into complex, non-cell autonomous processes. These advanced models are key to improving the understanding of fundamental biological mechanisms and therapeutic strategies. Controlling gene regulation through spatially-resolved delivery of nucleic acids provides an attractive approach to produce such tissue models. An emerging strategy for spatially-resolved transfection uses photosensitizing nanoparticles coupled with laser pulses to optoporate cells in culture and locally mediate gene delivery. However, localized optoporation in 3D systems remains challenging. Here we propose a solution to this longstanding hurdle, demonstrating that porous silicon nanoparticles are a safe and bioresorbable photosensitising nanomaterial capable of spatially-resolved transfection of mRNA in MCF-7 organoids by near-infrared two-photon optoporation. Functionalization with an azobenzene-lysine photo-switchable moiety enhances the transfection efficiency of the nanoparticles up to 84% in a 2D cell system. Moreover, the nanoparticles enable spatially selective mRNA transfection to MCF-7 spheroids, demonstrating targeted  gene delivery in complex 3D cellular environments. The approach for spatially-resolved 3D optoporation offers a way forward for the design of tailored spheroids and organoids by spatially selective nucleic acids delivery.

Mechanobiology of 3D cell confinement and extracellular crowding

Cells and tissues are often under some level of confinement, imposed by the microenvironment and neighboring cells, meaning that there are limitations to cell size, volume changes, and fluid exchanges. 3D cell culture, increasingly used for both single cells and organoids, inherently impose levels of confinement absent in 2D systems. It is thus key to understand how different levels of confinement influences cell survival, cell function, and cell fate. It is well known that the mechanical properties of the microenvironment, such as stiffness and stress relaxation, are important in activating mechanosensitive pathways, and these are responsive to confinement conditions. In this review, we look at how low, intermediate, and high levels of confinement modulate the activation of known mechanobiology pathways, in single cells, organoids, and tumor spheroids, with a specific focus on 3D confinement in microwells, elastic, or viscoelastic scaffolds. In addition, a confining microenvironment can drastically limit cellular communication in both healthy and diseased tissues, due to extracellular crowding. We discuss potential implications of extracellular crowding on molecular transport, extracellular matrix deposition, and fluid transport. Understanding how cells sense and respond to various levels of confinement should inform the design of 3D engineered matrices that recapitulate the physical properties of tissues.

A heterotypic tumor-on-a-chip platform for user-friendly combinatorial chemotherapeutic testing

BACKGROUND

Three-dimensional (3D) tumor microdevices are promising platform for biomimetic antitumor prediction and high-throughput chemotherapeutic screening and play crucial roles in the exploration of cancer-associated pharmaceutics and therapeutics. Traditional cell manipulation tools (e.g., non-adhesive surfaces and hanging drops) and recent microengineered systems (e.g., microfluidic chips and micropatterned array chips) have progressed in terms of microscale control, substantial tumor production, programmable drug combinations, and throughput analysis. However, establishing a facile 3D tumor microdevice to construct heterotypic tumor-microenvironmental profiles and for throughput, implementable, multi-instrument-compatible analysis of chemotherapies to advance consumer-grade tumor modelling tools is still being explored.

RESULTS

In this study, we present a facilely operated tumor-on-a-chip platform for massive production of heterotypic 3D tumors and diverse investigations of combinatorial chemotherapy screening. Large quantity of heterotypic tumor generation with high geometric controllability (size difference: 19.6 μm) and operational repeatability (n = 10) was achieved using simple-to-fabricate micropatterned chips. Multiple characteristics of solid tumors, including phenotypic gradients (viability and proliferation) and heterogeneous cellular compositions (multi-cell participation and stroma composition), were reproduced in heterotypic tumors, being more biomimetic than homotypic tumors. We completed the user-friendly analytical evaluation of individual and combinatorial drug therapies, and demonstrated the high applicability of the platform in biomimetic tumor-related large-scale manipulation and on-chip analysis, as well as its high compatibility for off-chip detection. The entire operative process during tumor production and chemotherapy only requires the routine and easy-to-master pipetting manipulation.

SIGNIFICANCE

The establishment of a biomimetic and easy-to-use 3D tumor platform and the large-scale screening-like evaluation of combinatorial chemotherapies based on the usage of the micropatterned chip was achieved in a user-friendly manner. This advancement has significant application potential in the fields of oncology, drug discovery, and tissue engineering, and is expected to be valuable for developing accessible and generalizable tumor-on-a-chip microsystems for exploring cancer therapies.

Endothelin-1 receptor blockade impairs invasion patterns in engineered 3D high-grade serous ovarian cancer tumouroids

High-grade serous ovarian cancer (HG-SOC), accounting for 70-80% of ovarian cancer deaths, is characterized by a widespread and rapid metastatic nature, influenced by diverse cell types, cell-cell interactions, and acellular components of the tumour microenvironment (TME). Within this tumour type, autocrine and paracrine activation of the endothelin-1 receptors (ET-1R), expressed in tumour cells and stromal elements, drives metastatic progression. The lack of three-dimensional models that faithfully recapitulate the unique HG-SOC TME has been the bottleneck in performing drug screening for personalized medicine. Herein, we developed HG-SOC tumouroids by engineering a dense central artificial cancer mass (ACM) containing HG-SOC cells, nested within a compressed hydrogel recapitulating the stromal compartment comprising type I collagen, laminin, fibronectin, and stromal cells (fibroblasts and endothelial cells). ET-1-stimulated HG-SOC cells in the tumouroids showed an altered migration pattern and formed cellular aggregates, mimicking micrometastases that invaded the stroma. Compared with control cells, ET-1-stimulated tumouroids showed a higher number of invasive bodies, which were reduced by treatment with the dual ET-1 receptor (ET-1R) antagonist macitentan. In addition, ET-1 increased the size of the invading aggregates compared with control cells. This study establishes an experimental 3D multicellular model eligible for mechanical research, investigating the impact of matrix stiffness and TME interactions, which will aid drug screening to guide therapeutic decisions in HG-SOC patients.

Multicellular Cancer-Stroma Spheres (CSS) for In Vitro Assessment of CAR-T Cell-Associated Toxicity

CAR-T therapy has revolutionized the field of oncology, offering a promising treatment option for cancer patients. However, the significant morbidity associated with therapy-related toxicity presents a major challenge to its widespread use. Despite extensive research into the underlying mechanisms of CAR-T therapy-related toxicity, there are still many unknowns. Furthermore, the lack of adequate in vitro models for assessing immunotoxicity and neurotoxicity further complicates the development of safer cellular therapies. Previously in our laboratory, we developed cancer-stroma spheres (CSS) composed of prostate adenocarcinoma PC3 cells and mesenchymal stem cells (MSC). Herein we present evidence that multicellular CSS could serve as a valuable in vitro model for toxicity studies related to CAR-T therapy. CSS containing CD19-overexpressing PC3M cells exhibited increased secretion of CAR-T cell toxicity-associated IL-8, MCP-1, and IP-10 in the presence of anti-CD19 CAR-T cells, compared to spheres derived from single cell types.

Tunable Hybrid Hydrogels of Alginate and Cell-Derived dECM to Study the Impact of Matrix Alterations on Epithelial-to-Mesenchymal Transition

Epithelial-to-mesenchymal transition (EMT) is crucial for tumor progression, being linked to alterations in the extracellular matrix (ECM). Understanding the ECM's role in EMT can uncover new therapeutic targets, yet replicating these interactions in vitro remains challenging. It is shown that hybrid hydrogels of alginate (ALG) and cell-derived decellularized ECM (dECM), with independently tunable composition and stiffness, are useful 3D-models to explore the impact of the breast tumor matrix on EMT. Soft RGD-ALG hydrogels (200 Pa), used as neutral bulk material, supported mammary epithelial cells morphogenesis without spontaneous EMT, allowing to define the gene, protein, and biochemical profiles of cells at different TGFβ1-induced EMT states. To mimic the breast tumor composition, dECM from TGFβ1-activated fibroblasts (adECM) are generated, which shows upregulation of tumor-associated proteins compared to ndECM from normal fibroblasts. Using hybrid adECM-ALG hydrogels, it is shown that the presence of adECM induces partial EMT in normal epithelial cells, and amplifes TGF-β1 effects compared to ALG and ndECM-ALG. Increasing the hydrogel stiffness to tumor-like levels (2.5 kPa) have a synergistic effect, promoting a more evident EMT. These findings shed light on the complex interplay between matrix composition and stiffness in EMT, underscoring the utility of dECM-ALG hydrogels as a valuable in vitro platform for cancer research.

Advances in tumor stroma-based targeted delivery

The tumor stroma plays a crucial role in tumor progression, and the interactions between the extracellular matrix, tumor cells, and stromal cells collectively influence tumor progression and the efficacy of therapeutic agents. Currently, utilizing components of the tumor stroma for drug delivery is a noteworthy strategy. A number of targeted drug delivery systems designed based on tumor stromal components are entering clinical trials. Therefore, this paper provides a thorough examination of the function of tumor stroma in the advancement of targeted drug delivery systems. One approach is to use tumor stromal components for targeted drug delivery, which includes certain stromal components possessing inherent targeting capabilities like HA, laminin, along with targeting stromal cells homologously. Another method entails directly focusing on tumor stromal components to reshape the tumor stroma and facilitate drug delivery. These drug delivery systems exhibit great potential in more effective cancer therapy strategies, such as precise targeting, enhanced penetration, improved safety profile, and biocompatibility. Ultimately, the deployment of these drug delivery systems can deepen our comprehension of tumor stroma and the advanced development of corresponding drug delivery systems.

Modeling tumor-immune interactions using hybrid spheroids and microfluidic platforms for studying tumor-associated macrophage polarization in melanoma

Tumor-associated macrophages (TAMs), as key components of tumor microenvironment (TME), exhibit phenotypic plasticity in response to environmental cues, causing polarization into either pro-inflammatory M1 phenotypes or immunosuppressive M2 phenotypes. Although TAM has been widely studied for its crucial involvement in the initiation, progression, metastasis, and immune regulation of cancer cells, there have been limited attempts to understand how the metastatic potentials of cancer cells influence TAM polarization within TME. Here, we developed a miniaturized TME model using a 3D hybrid system composed of murine melanoma cells and macrophages, aiming to investigate interactions between cancer cells exhibiting various metastatic potentials and macrophages within TME. The increase in spheroid size within this model was associated with a reduction in cancer cell viability. Examining macrophage surface marker expression and cytokine secretion indicated the development of diverse TMEs influenced by both spheroid size and the metastatic potential of cancer cells. Furthermore, a high-throughput microfluidic platform equipped with trapping systems and hybrid spheroids was employed to simulate the tumor-immune system of complex TMEs and for comparative analysis with traditional 3D culture models. This study provides insight into TAM polarization in melanoma with different heterogeneities by modeling cancer-immune systems, which can be potentially employed for immune-oncology research, drug screening, and personalized therapy. STATEMENT OF SIGNIFICANCE: This study presents the development of a 3D hybrid spheroid system designed to model tumor-immune interactions, providing a detailed analysis of how melanoma cell metastatic potential influences tumor-associated macrophage (TAM) polarization. By utilizing a microfluidic platform, we are able to replicate and investigate the complex tumor-immune system of the tumor microenvironments (TMEs) under continuous flow conditions. Our model holds significant potential for high-throughput drug screening and personalized medicine applications, offering a versatile tool for advancing cancer research and treatment strategies.

Exploring the impact of microfluidic chip structure on the efficacy of three-dimensional tumor microspheres cultivation

Three-dimensional (3D) tumor microspheres can simulate the interaction and growth dynamics of tumor cells, and have been used as a new in vitro model for drug screening and tumor biology related research. The scaffold-free culture of 3D tumor microspheres on microfluidic chips has many advantages, including low cost, high throughput, convenience and flexibility. However, it is still unclear how various factors, such as chip structure, influence the culture effect of tumor microspheres. The lack of standardized evaluation and characterization of the culture effect hinders the further optimization and development of chip function. This study presents numerical simulations of multiple parts or processes of the proposed 3D culture chips with two different structural parameters based on computational fluid dynamics (CFD) methods. An evaluation system for tumor microspheres was established. The prediction of the CFD simulation was consistent with the culture results of the chips, reflecting the important role of the structural parameters of the microtrap in the formation of uniform tumor microspheres. Furthermore, the velocity of cell suspension also had a significant impact on the retention of tumor cells. Additionally, the drug screening results of tumor microspheres indicated that tumor microspheres exhibit greater drug resistance, which may be attributed to their size. These results offer valuable insights into the factors that influence the characteristics of tumor microspheres. This research provides a reference and direction for the optimal design and functional evaluation of scaffold-free 3D culture chips, and holds promise for promoting the development of novel drug research platforms.

Exploring cancer-associated fibroblast-induced resistance to tyrosine kinase inhibitors in hepatoma cells using a liver-on-a-chip model

Liver cancer is a significant global contributor to cancer-related mortality. Despite available targeted therapies, resistance to tyrosine kinase inhibitors (TKIs) like sorafenib and lenvatinib poses a formidable challenge. The tumor microenvironment (TME), inhabited by cancer-associated fibroblasts (CAFs), profoundly influences this resistance. To uncover the mechanisms, a 3D microfluidic chip replicating liver architecture was fabricated to probe the intricate mechanisms of TKI resistance. The chip design mirrors the hexagonal structure of liver lobules, situating liver cancer cells at the core, encircled by fibroblasts, with rigorous assessments confirming biocompatibility and consistent cell growth. After determining the IC50 values of sorafenib and lenvatinib in 2D co-culture, a transwell setup revealed drug resistance development in co-cultured cells. Within the 3D microfluidic chip, live/dead assays highlighted elevated viability under drug exposure, emphasizing fibroblast-driven drug resistance. The study identifies AHSG and CLEC3B as potential mediators of drug resistance in co-culture, significantly upregulated in the co-cultured medium. Functional tests confirmed their roles, as introducing recombinant AHSG and CLEC3B enhanced liver cancer cell resistance to sorafenib and lenvatinib in both 2D and 3D scenarios. In conclusion, by replicating the complex TME using microfluidic technology, this study sheds light on the roles of AHSG and CLEC3B as well as possible approaches for improving the effectiveness of liver cancer treatment.

An integrative alginate-based 3D in vitro model to explore epithelial-stromal cell dynamics in the breast tumor microenvironment

The tumor microenvironment (TME) orchestrates cellular and extracellular matrix (ECM) interactions, playing a key role in tumorigenesis, tumor growth, and metastization. Investigating the interplay between stromal-epithelial cells within the TME is paramount for understanding cancer mechanisms but demands reliable biological models. 3D-models have emerged as powerful in vitro tools, but many fall short in replicating cell-cell/cell-matrix interactions. This study introduces a novel hybrid 3D-model of the breast TME, combining epithelial cells, cancer-associated fibroblasts (CAFs), and their ECM. To build the stromal compartment, porous 3D-printed alginate scaffolds were seeded with CAFs, which proliferated and produced ECM. The pores were infused with oxidized peptide-modified alginate hydrogel laden with MCF10A cells, forming the parenchymal compartment. The hybrid system supported epithelial morphogenesis into acini surrounded by fibroblasts and ECM, and could be readily solubilized to recover cells, their matrix, and sequestered soluble factors. Proteome profiling of the retrieved ECM showed upregulation of proteins associated with matrix assembly/remodeling, epithelial-to-mesenchymal transition (EMT), and cancer. The TME-like microenvironment induced a partial EMT in MCF10A cells, generating a hybrid population with epithelial and mesenchymal features, characteristic of aggressive phenotypes. Our model provided new insights into epithelial-stromal interactions within the TME, offering a valuable tool for cancer research in a physiologically-relevant 3D setting.

Remarks on Selected Morphological Aspects of Cancer Neuroscience: A Microscopic Photo Review

BACKGROUND

This short review and pictorial essay presents a morphological insight into cancer neuroscience, which is a complex and dynamic area of the pathobiology of tumors.

METHODS

We discuss the different methods and issues connected with structural research on tumor innervation, interactions between neoplastic cells and the nervous system, and dysregulated neural influence on cancer phenotypes.

RESULTS

Perineural invasion (PNI), the most-visible cancer-nerve relation, is briefly presented, focusing on its pathophysiology and structural diversity as well as its clinical significance. The morphological approach to cancer neurobiology further includes the analysis of neural density/axonogenesis, neural network topographic distribution, and composition of fiber types and size. Next, the diverse range of neurotransmitters and neuropeptides and the neuroendocrine differentiation of cancer cells are reviewed. Another morphological area of cancer neuroscience is spatial or quantitative neural-related marker expression analysis through different detection, description, and visualization methods, also on experimental animal or cellular models.

CONCLUSIONS

Morphological studies with systematic methodologies provide a necessary insight into the structure and function of the multifaceted tumor neural microenvironment and in context of possible new therapeutic neural-based oncological solutions.

Chemoresistance and the tumor microenvironment: the critical role of cell-cell communication

Resistance of cancer cells to anticancer drugs remains a major challenge in modern medicine. Understanding the mechanisms behind the development of chemoresistance is key to developing appropriate therapies to counteract it. Nowadays, with advances in technology, we are paying more and more attention to the role of the tumor microenvironment (TME) and intercellular interactions in this process. We also know that important elements of the TME are not only the tumor cells themselves but also other cell types, such as mesenchymal stem cells, cancer-associated fibroblasts, stromal cells, and macrophages. TME elements can communicate with each other indirectly (via cytokines, chemokines, growth factors, and extracellular vesicles [EVs]) and directly (via gap junctions, ligand-receptor pairs, cell adhesion, and tunnel nanotubes). This communication appears to be critical for the development of chemoresistance. EVs seem to be particularly interesting structures in this regard. Within these structures, lipids, proteins, and nucleic acids can be transported, acting as signaling molecules that interact with numerous biochemical pathways, thereby contributing to chemoresistance. Moreover, drug efflux pumps, which are responsible for removing drugs from cancer cells, can also be transported via EVs.

Multicellular ovarian cancer spheroids: novel 3D model to mimic tumour complexity

In vitro, spheroid models have become well established in cancer research because they can better mimic certain characteristics of in vivo tumours. However, interaction with the tumour microenvironment, such as cancer-associated fibroblasts, plays a key role in tumour progression. We initially focused on the interaction of tumour cells with fibroblasts. To model this interaction, we developed a spheroid model of ovarian cancer and fibroblasts. To this end, ovarian cancer cell lines and ex vivo primary cells were simultaneously and sequentially seeded with fibroblasts in a scaffold-free system at different ratios and subsequently characterized with respect to changes in morphology, proliferation, and viability. We demonstrated that co-cultures are able to form by far more compact spheroids, especially in cells that form aggregates in mono-culture. In addition, the co-cultures were able to increase proliferation and sensitivity to cisplatin. Simultaneous seeding led fibroblasts invade the core in both cell lines and primary cells. These results show differences in formation, firmness, and size between co-culture and mono-culture. Our model is designed to better represent and characterize the mutual influencing factors of fibroblasts and tumour cells. Fibroblast-supplemented multicellular spheroids are a valuable tool for tumour microenvironment interaction and new drug discovery.

A brain organoid/ALL coculture model reveals the AP-1 pathway as critically associated with CNS involvement of BCP-ALL

ABSTRACT

Central nervous system (CNS) involvement remains a clinical hurdle in treating childhood B-cell precursor acute lymphoblastic leukemia (BCP-ALL). The disease mechanisms of CNS leukemia are primarily investigated using 2-dimensional cell culture and mouse models. Given the variations in cellular identity and architecture between the human and murine CNS, it becomes imperative to seek complementary models to study CNS leukemia. Here, we present a first-of-its-kind 3-dimensional coculture model combining human brain organoids and BCP-ALL cells. We noticed significantly higher engraftment of BCP-ALL cell lines and patient-derived xenograft (PDX) cells in cerebral organoids than non-ALL cells. To validate translatability between organoid coculture and in vivo murine models, we confirmed that targeting CNS leukemia-relevant pathways such as CD79a/Igα or C-X-C motif chemokine receptor 4-stromal cell-derived factor 1 reduced the invasion of BCP-ALL cells into organoids. RNA sequencing and functional validations of organoid-invading leukemia cells compared with the noninvaded fraction revealed significant upregulation of activator protein 1 (AP-1) transcription factor-complex members in organoid-invading cells. Moreover, we detected a significant enrichment of AP-1 pathway genes in PDX ALL cells recovered from the CNS compared with spleen blasts of mice that had received transplantation with TCF3::PBX1+ PDX cells, substantiating the role of AP-1 signaling in CNS disease. Accordingly, we found significantly higher levels of the AP-1 gene, jun proto-oncogene, in patients initially diagnosed as CNS-positive BCP-ALL compared with CNS-negative cases as well as CNS-relapse vs non-CNS-relapse cases in a cohort of 100 patients with BCP-ALL. Our results suggest CNS organoids as a novel model to investigate CNS involvement and identify the AP-1 pathway as a critical driver of CNS disease in BCP-ALL.

Multicompartmentalized Microvascularized Tumor-on-a-Chip to Study Tumor-Stroma Interactions and Drug Resistance in Ovarian Cancer

Introduction

The majority of ovarian cancer (OC) patients receiving standard of care chemotherapy develop chemoresistance within 5 years. The tumor microenvironment (TME) is a dynamic and influential player in disease progression and therapeutic response. However, there is a lack of models that allow us to elucidate the compartmentalized nature of TME in a controllable, yet physiologically relevant manner and its critical role in modulating drug resistance.

Methods

We developed a 3D microvascularized multiniche tumor-on-a-chip formed by five chambers (central cancer chamber, flanked by two lateral stromal chambers and two external circulation chambers) to recapitulate OC-TME compartmentalization and study its influence on drug resistance. Stromal chambers included endothelial cells alone or cocultured with normal fibroblasts or cancer-associated fibroblasts (CAF).

Results

The tumor-on-a-chip recapitulated spatial TME compartmentalization including vessel-like structure, stromal-mediated extracellular matrix (ECM) remodeling, generation of oxygen gradients, and delayed drug diffusion/penetration from the circulation chamber towards the cancer chamber. The cancer chamber mimicked metastasis-like migration and increased drug resistance to carboplatin/paclitaxel treatment in the presence of CAF when compared to normal fibroblasts. CAF-mediated drug resistance was rescued by ECM targeted therapy. Critically, these results demonstrate that cellular crosstalk recreation and spatial organization through compartmentalization are essential to determining the effect of the compartmentalized OC-TME on drug resistance.

Conclusions

Our results present a functionally characterized microvascularized multiniche tumor-on-a-chip able to recapitulate TME compartmentalization influencing drug resistance. This technology holds the potential to guide the design of more effective and targeted therapeutic strategies to overcome chemoresistance in OC.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12195-024-00817-y.

Improving tumor microenvironment assessment in chip systems through next-generation technology integration

The tumor microenvironment (TME) comprises a diverse array of cells, both cancerous and non-cancerous, including stromal cells and immune cells. Complex interactions among these cells play a central role in driving cancer progression, impacting critical aspects such as tumor initiation, growth, invasion, response to therapy, and the development of drug resistance. While targeting the TME has emerged as a promising therapeutic strategy, there is a critical need for innovative approaches that accurately replicate its complex cellular and non-cellular interactions; the goal being to develop targeted, personalized therapies that can effectively elicit anti-cancer responses in patients. Microfluidic systems present notable advantages over conventional in vitro 2D co-culture models and in vivo animal models, as they more accurately mimic crucial features of the TME and enable precise, controlled examination of the dynamic interactions among multiple human cell types at any time point. Combining these models with next-generation technologies, such as bioprinting, single cell sequencing and real-time biosensing, is a crucial next step in the advancement of microfluidic models. This review aims to emphasize the importance of this integrated approach to further our understanding of the TME by showcasing current microfluidic model systems that integrate next-generation technologies to dissect cellular intra-tumoral interactions across different tumor types. Carefully unraveling the complexity of the TME by leveraging next generation technologies will be pivotal for developing targeted therapies that can effectively enhance robust anti-tumoral responses in patients and address the limitations of current treatment modalities.

Decellularized extracellular matrix-based bioengineered 3D breast cancer scaffolds for personalized therapy and drug screening

Breast cancer (BC) is the second deadliest cancer after lung cancer. Similar to all cancers, it is also driven by a 3D microenvironment. The extracellular matrix (ECM) is an essential component of the 3D tumor micro-environment, wherein it functions as a scaffold for cells and provides metabolic support. BC is characterized by alterations in the ECM. Various studies have attempted to mimic BC-specific ECMs using artificial materials, such as Matrigel. Nevertheless, research has proven that naturally derived decellularized extracellular matrices (dECMs) are superior in providing the essential in vivo-like cues needed to mimic a cancer-like environment. Developing in vitro 3-D BC models is not straightforward and requires extensive analysis of the data established by researchers. For the benefit of researchers, in this review, we have tried to highlight all developmental studies that have been conducted by various scientists so far. The analysis of the conclusions drawn from these studies is also discussed. The advantages and drawbacks of the decellularization methods employed for generating BC scaffolds will be covered, and the review will shed light on how dECM scaffolds help develop a BC environment. The later stages of the article will also focus on immunogenicity issues arising from decellularization and the origin of the tissue. Finally, this review will also discuss the biofabrication of matrices, which is the core part of the bioengineering process.

3D layered co-culture model enhances Trastuzumab Deruxtecan sensitivity and reveals the combined effect with G007-LK in HER2-positive non-small cell lung cancer

Human epidermal growth factor receptor 2 (HER2) aberrations are observed in various cancers. In non-small cell lung cancer, genetic alterations activating HER2, mostly exon 20 insertion mutations, occur in approximately 2-4% of cases. Trastuzumab deruxtecan (T-DXd), a HER2-targeted antibody-drug conjugate has been approved as the first HER2-targeted drug for HER2-mutant lung cancer. However, some cases are not responsive to T-DXd and the primary resistant mechanism remains unclear. In this study, we assessed sensitivity to T-DXd in JFCR-007, a patient-derived HER2-mutant lung cancer cell line. Although JFCR-007 was sensitive to HER2 tyrosine kinase inhibitors, it showed resistance to T-DXd in attachment or spheroid conditions. Accordingly, we established a three-dimensional (3D) layered co-culture model of JFCR-007, where it exhibited a lumen-like structure and became sensitive to T-DXd. In addition, an in-house inhibitor library screening revealed that G007-LK, a tankyrase inhibitor, was effective when combined with T-DXd. G007-LK increased the cytotoxicity of topoisomerase-I inhibitor, DXd, a payload of T-DXd and SN-38. This combined effect was also observed in H2170, an HER2-amplified lung cancer cell line. These results suggest that the proposed 3D co-culture system may help in evaluating the efficacy of T-DXd and may recapitulate the tumor microenvironment.

A Novel Ex Vivo Tumor Spheroid-Tissue Model for Investigating Microvascular Remodeling and Lymphatic Blood Vessel Plasticity

Biomimetic tumor microenvironment models bridge the gap between in vitro and in vivo systems and serve as a useful way to address the modeling challenge of how to recreate the cell and system complexity associated with real tissues. Our laboratory has developed an ex vivo rat mesentery culture model, which allows for simultaneous investigation of blood and lymphatic microvascular network remodeling in an intact tissue environment. Given that angiogenesis and lymphangiogenesis are key contributors to the progression of cancer, the objective of this study was to combine tissue and tumor spheroid culture methods to establish a novel ex vivo tumor spheroid-tissue model by verifying its use for evaluating the effects of cancer cell behavior on the local microvascular environment. H1299 or A549 tumor spheroids were formed via hanging drop culture and seeded onto rat mesenteric tissues harvested from adult male Wistar rats. Tissues with transplanted spheroids were cultured in serum-free media for 3 to 5 days. PECAM, NG2, CD11b, and αSMA labeling identified endothelial cells, pericytes, immune cells, and smooth muscle cells, respectively. Time-lapse imaging confirmed cancer cell type specific migration. In addition to increasing PECAM positive capillary sprouting and LYVE-1 positive endothelial cell extensions indicative of lymphangiogenesis, tumor spheroid presence induced the formation of lymphatic/blood vessel connections and the formation of hybrid, mosaic vessels that were characterized by discontinuous LYVE-1 labeling. The results support the application of a novel tumor spheroid microenvironment model for investigating cancer cell-microvascular interactions.

Exploiting Matrix Stiffness to Overcome Drug Resistance

Drug resistance is arguably one of the biggest challenges facing cancer research today. Understanding the underlying mechanisms of drug resistance in tumor progression and metastasis are essential in developing better treatment modalities. Given the matrix stiffness affecting the mechanotransduction capabilities of cancer cells, characterization of the related signal transduction pathways can provide a better understanding for developing novel therapeutic strategies. In this review, we aimed to summarize the recent advancements in tumor matrix biology in parallel to therapeutic approaches targeting matrix stiffness and its consequences in cellular processes in tumor progression and metastasis. The cellular processes governed by signal transduction pathways and their aberrant activation may result in activating the epithelial-to-mesenchymal transition, cancer stemness, and autophagy, which can be attributed to drug resistance. Developing therapeutic strategies to target these cellular processes in cancer biology will offer novel therapeutic approaches to tailor better personalized treatment modalities for clinical studies.

The Interplay between Extracellular Matrix Remodeling and Cancer Therapeutics

The extracellular matrix (ECM) is an abundant noncellular component of most solid tumors known to support tumor progression and metastasis. The interplay between the ECM and cancer therapeutics opens up new avenues in understanding cancer biology. While the ECM is known to protect the tumor from anticancer agents by serving as a biomechanical barrier, emerging studies show that various cancer therapies induce ECM remodeling, resulting in therapy resistance and tumor progression. This review discusses critical issues in this field including how the ECM influences treatment outcome, how cancer therapies affect ECM remodeling, and the challenges associated with targeting the ECM. Significance: The intricate relationship between the extracellular matrix (ECM) and cancer therapeutics reveals novel insights into tumor biology and its effective treatment. While the ECM may protect tumors from anti-cancer agents, recent research highlights the paradoxical role of therapy-induced ECM remodeling in promoting treatment resistance and tumor progression. This review explores the key aspects of the interplay between ECM and cancer therapeutics.

Bioprinted research models of urological malignancy

Urological malignancy (UM) is among the leading threats to health care worldwide. Recent years have seen much investment in fundamental UM research, including mechanistic investigation, early diagnosis, immunotherapy, and nanomedicine. However, the results are not fully satisfactory. Bioprinted research models (BRMs) with programmed spatial structures and functions can serve as powerful research tools and are likely to disrupt traditional UM research paradigms. Herein, a comprehensive review of BRMs of UM is presented. It begins with a brief introduction and comparison of existing UM research models, emphasizing the advantages of BRMs, such as modeling real tissues and organs. Six kinds of mainstream bioprinting techniques used to fabricate such BRMs are summarized with examples. Thereafter, research advances in the applications of UM BRMs, such as culturing tumor spheroids and organoids, modeling cancer metastasis, mimicking the tumor microenvironment, constructing organ chips for drug screening, and isolating circulating tumor cells, are comprehensively discussed. At the end of this review, current challenges and future development directions of BRMs and UM are highlighted from the perspective of interdisciplinary science.