Three-Dimensional (3D) in vitro cell culture protocols to enhance glioblastoma research

Pentagalloyl glucose targets the JAK1/JAK3-STAT3 pathway to inhibit cancer stem cells and epithelial-mesenchymal transition in 5-fluorouracil-resistant colorectal cancer

BACKGROUND

Colorectal cancer (CRC) resistance to 5-fluorouracil (5-FU), primarily driven by cancer stem cells (CSCs) and epithelial-mesenchymal transition (EMT), remains a major clinical challenge, necessitating novel therapeutic strategies.

PURPOSE

This study aims to evaluate the therapeutic potential of pentagalloyl glucose (PGG), a bioactive compound derived from Bouea macrophylla seeds, in overcoming 5-FU resistance in CRC.

METHOD

Anti-tumor effects of PGG were investigated using two- and three-dimensional (2D and 3D) cell culture models and subcutaneous xenograft and metastatic mouse models. Transcriptome sequencing, western blotting, and pharmacological inhibitors were employed to elucidate the underlying molecular mechanisms.

RESULTS

PGG demonstrated potent anti-CSC activity; suppressed EMT-driven invasion and metastasis; and induced apoptosis in 2D monolayers, 3D spheroid models, and xenograft tumor models. Mechanistically, PGG selectively inhibited the JAK1/JAK3-STAT3 signaling pathway, considerably reducing STAT3 phosphorylation. This disruption downregulated the expression of CSC markers (CD133 and CD44), EMT regulators (N-cadherin and vimentin), and anti-apoptotic proteins (Bcl-2), effectively sensitizing 5-FU-resistant CRC to therapy.

CONCLUSION

PGG inhibit dual-target of CSCs and EMT via JAK1/JAK3-STAT3 signaling pathway in 5-FU-resistant CRC, providing a novel therapeutic approach to overcome chemoresistance.

High-throughput non-homogenous 3D polycaprolactone scaffold for cancer cell and cancer-associated fibroblast mini-tumors to evaluate drug treatment response

High-throughput screening (HTS) three-dimensional (3D) tumor models are a promising approach for cancer drug discovery, as they more accurately replicate in vivo cell behavior than two-dimensional (2D) models. However, assessing and comparing current 3D models for drug efficacy remains essential, given the significant influence of cellular conditions on treatment response. To develop in vivo mimicking 3D models, we evaluated two HTS 3D models established in 96-well plates with 3D polycaprolactone (PCL) scaffolds fabricated using two distinct methods, resulting in scaffolds with either homogenous or non-homogenous fiber networks. These models, based on human HeLa cervical cancer cells and cancer-associated fibroblasts (CAFs) cultured as mono- or co-cultures within the 3D scaffolds, revealed that anticancer drug paclitaxel (PTX) exhibited consistently higher inhibitory concentration 50 (IC50) in 3D (≥ 1000 nM) compared to 2D (≥ 100 nM), indicating reduced toxicity on cells cultured in 3D. Interestingly, the toxicity of PTX was significantly lower on mini-tumors in non-homogenous 3D (IC50: 600 or 1000 nM) than in homogenous 3D cultures (IC50 exceeding 1000 nM). Microscopic studies revealed that the non-homogenous scaffolds closely resemble the tumor collagen network than their homogeneous counterpart. Both 3D scaffolds offer optimal pore size, facilitating efficient cell infiltration into the depth of 58.1 ± 1.2 µm (homogenous) and 86.4 ± 9.8 µm (non-homogenous) within 3D cultures. Cells cultured in the 3D non-homogenous systems exhibited drug treatment responses closer to in vivo conditions, highlighting the role of scaffold structure and design on cellular response to drug treatment. The PCL-based 3D models provide a robust, tunable, and efficient approach for the HTS of anti-cancer drugs compared to conventional 2D systems.

Recent progress on the organoids: Techniques, advantages and applications

Organoids are a cutting-edge technology in the life sciences field, with applications in precision medicine, bionic organs, and toxicological evaluations of chemicals. Their 3D structure closely resembles that of real organs, allowing more accurate functional mimicry. The 3D organoid culture system can simulate the growth state of cells in vivo and establish a suspension culture system for organoid 3D culture by using scaffold-less or scaffold technology to avoid direct contact between cells and plastic culture vessels. Furthermore, organoids can simulate the pathophysiological state of tissues and organs in vitro. This paper primarily discusses the construction methodologies, as well as the advantages and disadvantages of 3D culture systems for both scaffold-free organoids and scaffolded organoids. This review also summarizes the application of organoid models in chemical toxicology evaluation, drug screening and functional evaluation, establishment of in vitro disease models, and research on disease occurrence and potential mechanisms. The aim is to provide a reference for the research and practical applications of organoid-related scientific fields.

HDAC6 inhibition through WT161 synergizes with temozolomide, induces apoptosis, reduces cell motility, and decreases β-catenin levels in glioblastoma cells

Glioblastoma multiforme (GBM) accounts for 70% of all primary malignancies of the central nervous system. Current treatment strategies involve surgery followed by chemotherapy with temozolomide (TMZ); however, the median survival after treatment is approximately 15 months. Many GBM cases develop resistance to TMZ, resulting in a poor prognosis for patients, which underscores the urgent need for novel therapeutic approaches. One promising avenue is the inhibition of histone deacetylase 6 (HDAC6), an enzyme that deacetylates α-tubulin and is increasingly recognized as a potential pharmacological target in cancer. In GBM specifically, HDAC6 overexpression has been linked to poor prognosis and chemoresistance. In this study, we demonstrate that HDAC6 protein levels are elevated in GBM and evaluate the effects of the novel selective HDAC6 inhibitor, WT161, on U251, U87, and T98G cells to assess its potential to revert the malignant phenotype. Our results show a significant increase in acetylated α-tubulin levels, suppression of cell growth, cell cycle arrest at the G2/M phase, and decreased clonogenicity of 2D-cultured GBM cells. Additionally, WT161 acted synergistically with TMZ, induced apoptosis and enhanced TMZ-induced apoptosis. Notably, HDAC6 inhibition resulted in reduced cell migration and invasion, associated with decreased β-catenin levels. When cultured in 3D conditions, WT161-treated T98G spheroids were sensitized to TMZ and exhibited reduced migration. Finally, HDAC6 inhibition altered the metabolome, particularly affecting metabolites associated with lipid peroxidation. In conclusion, our data reveal, for the first time, the efficacy of the selective HDAC6 inhibitor WT161 in a preclinical GBM setting.

Live-cell imaging and analysis of 3D spheroids in hypoxia- and radiotherapy-related research

3D spheroids are a valuable tool for investigating the interplay between hypoxia and radioresistance. However, standardized methods for visualizing normoxic and hypoxic regions within spheroids and assessing treatment responses are lacking. We developed a straightforward workflow for the analysis of spheroids based on image processing using a novel custom-written script, and flow cytometry.

Lung cancer organoid-based drug evaluation models and new drug development application trends

Lung cancer is a malignant tumor with high incidence and mortality rates in both men and women worldwide. Although anticancer drugs are prescribed to treat lung cancer patients, individual responses to these drugs vary, making it crucial to identify the most suitable treatment for each patient. Therefore, it is necessary to develop an anticancer drug efficacy prediction model that can analyze drug efficacy before patient treatment and establish personalized treatment strategies. Unlike two-dimensional (2D) cultured lung cancer cells, lung cancer organoid (LCO) models have a three-dimensional (3D) structure that effectively mimics the characteristics and heterogeneity of lung cancer cells. Lung cancer patient-derived organoids (PDOs) also have the advantage of recapitulating histological and genetic characteristics similar to those of patient tissues under in vitro conditions. Due to these advantages, LCO models are utilized in various fields, including cancer research, and precision medicine, and are especially employed in various new drug development processes, such as targeted therapies and immunotherapy. LCO models demonstrate potential applications in precision medicine and new drug development research. This review discusses the various methods for implementing LCO models, LCO-based anticancer drug efficacy analysis models, and new trends in lung cancer-targeted drug development.

Cell-Based Glioma Models for Anticancer Drug Screening: From Conventional Adherent Cell Cultures to Tumor-Specific Three-Dimensional Constructs

Gliomas are a group of primary brain tumors characterized by their aggressive nature and resistance to treatment. Infiltration of surrounding normal tissues limits surgical approaches, wide inter- and intratumor heterogeneity hinders the development of universal therapeutics, and the presence of the blood-brain barrier reduces the efficiency of their delivery. As a result, patients diagnosed with gliomas often face a poor prognosis and low survival rates. The spectrum of anti-glioma drugs used in clinical practice is quite narrow. Alkylating agents are often used as first-line therapy, but their effectiveness varies depending on the molecular subtypes of gliomas. This highlights the need for new, more effective therapeutic approaches. Standard drug-screening methods involve the use of two-dimensional cell cultures. However, these models cannot fully replicate the conditions present in real tumors, making it difficult to extrapolate the results to humans. We describe the advantages and disadvantages of existing glioma cell-based models designed to improve the situation and build future prospects to make drug discovery comprehensive and more effective for each patient according to personalized therapy paradigms.

Investigation of Biological Activity of Fucoidan and Laminarin as Bioactive Polysaccharides from Irish Brown Macroalgae

This study aimed to investigate the biological activity of crude and purified laminarin and fucoidan samples extracted from Irish brown macroalgae species Laminaria digitata and Fucus vesiculosus. The antioxidant capacity of the samples was evaluated using the 2,2-diphenyl-1-picrylhydrazyl and ferric-reducing antioxidant power assays. The anti-inflammatory potential of the samples was analysed using the cyclooxygenases inhibition activity, and the antidiabetic activity was evaluated using a dipeptidyl peptidase-4 inhibitor screening assay. The cytotoxicity of the samples was measured using the Alamar Blue™ assay with different types of cancer cell lines. The crude laminarin and fucoidan samples exhibited higher antioxidant activity (p < 0.05) than the purified samples and commercial standards. Similarly, the crude extracts showed stronger anti-inflammatory and antidiabetic effects compared to the purified samples. Additionally, the crude laminarin and fucoidan samples showed higher cytotoxic activity. Specifically, as confirmed in the flow cytometry analysis, 3D tumour spheres using different cancer cell lines showed significantly higher resistance to bioactive compounds compared to 2D monolayer cells. The laminarin and fucoidan polysaccharide samples investigated are suitable for potential nutraceutical applications based on the biological activity values observed. Future research is necessary to purify the bioactive compounds investigated and improve their selectivity for targeted therapeutic uses in food and biomedical applications.

Ultrasensitive Dual Fluorophore-Conjugated Carbon Dots for Intracellular pH Sensing in 3D Tumor Models

The dysregulation of pH has been linked to the onset of chronic conditions, such as cancer and neurological diseases. Consequently, the development of a highly sensitive tool for intracellular pH sensing is imperative to investigate the interplay between pH and the biochemical changes accompanying disease pathogenesis. Here, we present the development of a ratiometric fluorescent nanoprobe, NpRhoDot, designed for precisely measuring pH levels. We demonstrate its efficacy in sensitively reporting intracellular pH in monolayer A549 lung cancer cells, primary fibroblast cells, and 3D tumor spheroids derived from the DLD-1 colorectal adenocarcinoma cell line. NpRhoDot leverages a novel design, where stable carbon dots are functionalized with a pH-responsive ratiometric fluorescent probe comprising a naphthalimide-rhodamine moiety, NpRho1. This design confers NpRhoDot with the high pH sensitivity characteristics of organic fluorescent probes, along with excellent photostability up to 1 h and biocompatibility of carbon dots. Through one-photon and two-photon fluorescence microscopy, we validate the reliability of NpRhoDot for biosensing intracellular pH in monolayer and three-dimensional tumor models from pH 4 to 7.

Novel half Salphen cobalt(III) complexes: synthesis, DNA binding and anticancer studies

While platinum(II)-based drugs continue to be employed in cancer treatments, the escalating occurrence of severe side effects has spurred researchers to explore novel sources for potential therapeutic agents. Notably, cobalt(III) has emerged as a subject of considerable interest due to its ubiquitous role in human physiology. Several studies investigating the anticancer effects of Salphen complexes derived from cobalt(III) have unveiled intriguing antiproliferative properties. In a bid to enhance our understanding of this class of compounds, we synthesized and characterized two novel half Salphen cobalt(III) complexes. Both compounds exhibited notable stability, even in the presence of physiologically relevant concentrations of glutathione. The application of spectroscopic and computational methodologies unravelled their interactions with duplex and G4-DNAs, suggesting an external binding affinity for these structures, with preliminary indications of selectivity trends. Importantly, antiproliferative assays conducted on 3D cultured SW-1353 cancer cells unveiled a compelling anticancer activity at low micromolar concentrations, underscoring the potential therapeutic efficacy of this novel class of cobalt(III) complexes.

3D tumor spheroids: morphological alterations a yardstick to anti-cancer drug response

Tumor spheroids are one of the well-characterized 3D culture systems bearing close resemblance to the physiological tissue organization and complexity of avascular solid tumor stage with hypoxic core. They hold a wide-spread application in the field of pharmaceutical science and anti-cancer drug research. However, the difficulty in determining optimal technique for the generation of spheroids with uniform size and shape, evaluation of experimental outputs, or mass production often limits their usage in anti-cancer research and in high-throughput drug screening. In recent times, several studies have demonstrated various simple techniques for generating uniform-size 3D spheroids, including the hanging drop (HD), liquid overlay technique (LOT), and microfluidic approaches. Morphological alterations apart from biochemical assays, and staining techniques are suitably employed for the evaluation of experimental outcomes within 3D spheroid models. Morphological alterations in response to effective anti-cancer drug treatment in 3D tumor spheroids such as reduced spheroid size, loss of spheroid compactness and integrity or smooth surface, are highly reliable. These alterations can significantly reduce the need for biochemical assays and staining techniques, resulting in both time and cost savings. The present article specifically covers a variety of available procedures in spheroid generation. For practical applicability, we have supplemented our review study with the generation of glioblastoma U87 spheroids using HD and LOT methods. Additionally, we have also incorporated the outcome of U87 spheroid treatment with doxorubicin on spheroid morphology.

In vivo antiangiogenic effect of nimbolide, trans-chalcone and piperine for use against glioblastoma

BACKGROUND

Angiogenesis is an important hallmark of Glioblastoma (GBM) marked by elevated vascular endothelial growth factor-A (VEGF-A) and its receptor 2 (VEGFR-2). As previously reported nimbolide (NBL), trans-chalcone (TC) and piperine (PPR) possess promising antiangiogenic activity in several cancers however, their comparative efficacy and mechanism of antiangiogenic activity in GBM against VEGFR-2 has not been elucidated.

METHODS

2D and 3D spheroids cultures of U87 (Uppsala 87 Malignant Glioma) were used for evaluation of non-cytotxoic dose for anti-angiogenic activity. The antiangiogenic effect was investigated by the GBM U87 cell line bearing chick CAM model. Excised U87 xenografts were histologically examined for blood vascular density by histochemistry. Reverse transcriptase polymerase chain reaction (RT-PCR) was used to detect the presence of avian and human VEGF-A and VEGFR-2 mRNA transcripts.

RESULTS

Using 2D and 3D spheroid models, the non-cytotoxic dose of NBL, TC and PPR was ≤ 11 µM. We found NBL, TC and PPR inhibit U87-induced neoangiogenesis in a dose-dependent manner in the CAM stand-alone model as well as in CAM U87 xenograft model. The results also indicate that these natural compounds inhibit the expression of notable angiogenic factors, VEGF-A and VEGFR-2. A positive correlation was found between blood vascular density and VEGF-A as well as VEGFR-2 transcripts.

CONCLUSION

Taken together, NBL, TC and PPR can suppress U87-induced neoangiogenesis via a reduction in VEGF-A and its receptor VEGFR-2 transcript expression at noncytotoxic concentrations. These phytochemicals showed their utility as adjuvants to GBM therapy, with Piperine demonstrating superior effectiveness among them all.

Fabrication of a Three-Dimensional Spheroid Culture System for Oral Squamous Cell Carcinomas Using a Microfabricated Device

Cancer stem cells (CSCs) are considered to be responsible for recurrence, metastasis, and resistance to treatment in many types of cancers; therefore, new treatment strategies targeting CSCs are attracting attention. In this study, we fabricated a polyethylene glycol-tagged microwell device that enabled spheroid formation from human oral squamous carcinoma cells. HSC-3 and Ca9-22 cells cultured in the microwell device aggregated and generated a single spheroid per well within 24-48 h. The circular shape and smooth surface of spheroids were maintained for up to five days, and most cells comprising the spheroids were Calcein AM-positive viable cells. Interestingly, the mRNA expression of CSC markers (Cd44, Oct4, Nanog, and Sox2) were significantly higher in the spheroids than in the monolayer cultures. CSC marker-positive cells were observed throughout the spheroids. Moreover, resistance to cisplatin was enhanced in spheroid-cultured cells compared to that in the monolayer-cultured cells. Furthermore, some CSC marker genes were upregulated in HSC-3 and Ca9-22 cells that were outgrown from spheroids. In xenograft model, the tumor growth in the spheroid implantation group was comparable to that in the monolayer culture group. These results suggest that our spheroid culture system may be a high-throughput tool for producing uniform CSCs in large numbers from oral cancer cells.

Encapsulation of Human Spinal Cord Progenitor Cells in Hyaluronan-Gelatin Hydrogel for Spinal Cord Injury Treatment

Transplanting human induced pluripotent stem cells (iPSCs)-derived spinal cord progenitor cells (SCPCs) is a promising approach to treat spinal cord injuries. However, stem cell therapies face challenges in cell survival, cell localization to the targeted site, and the control of cell differentiation. Here, we encapsulated SCPCs in thiol-modified hyaluronan-gelatin hydrogels and optimized scaffold mechanical properties and cell encapsulation density to promote cell viability and neuronal differentiation in vitro and in vivo. Different compositions of hyaluronan-gelatin hydrogels formulated by varying concentrations of poly(ethylene glycol) diacrylate were mechanically characterized by using atomic force microscopy. In vitro SCPC encapsulation study showed higher cell viability and proliferation with lower substrate Young's modulus (200 Pa vs 580 Pa) and cell density. Moreover, the soft hydrogels facilitated a higher degree of neuronal differentiation with extended filament structures in contrast to clumped cellular morphologies obtained in stiff hydrogels (p < 0.01). When transplanted in vivo, the optimized SCPC-encapsulated hydrogels resulted in higher cell survival and localization at the transplanted region as compared to cell delivery without hydrogel encapsulation at 2 weeks postimplantation within the rat spinal cord (p < 0.01). Notably, immunostaining demonstrated that the hydrogel-encapsulated SCPCs differentiated along the neuronal and oligodendroglial lineages in vivo. The lack of pluripotency and proliferation also supported the safety of the SCPC transplantation approach. Overall, the injectable hyaluronan-gelatin hydrogel shows promise in supporting the survival and neural differentiation of human SCPCs after transplantation into the spinal cord.

Research Methods and New Advances in Drug-Drug Interactions Mediated by Renal Transporters

The kidney is critical in the human body's excretion of drugs and their metabolites. Renal transporters participate in actively secreting substances from the proximal tubular cells and reabsorbing them in the distal renal tubules. They can affect the clearance rates (CLr) of drugs and their metabolites, eventually influence the clinical efficiency and side effects of drugs, and may produce drug-drug interactions (DDIs) of clinical significance. Renal transporters and renal transporter-mediated DDIs have also been studied by many researchers. In this article, the main types of in vitro research models used for the study of renal transporter-mediated DDIs are membrane-based assays, cell-based assays, and the renal slice uptake model. In vivo research models include animal experiments, gene knockout animal models, positron emission tomography (PET) technology, and studies on human beings. In addition, in vitro-in vivo extrapolation (IVIVE), ex vivo kidney perfusion (EVKP) models, and, more recently, biomarker methods and in silico models are included. This article reviews the traditional research methods of renal transporter-mediated DDIs, updates the recent progress in the development of the methods, and then classifies and summarizes the advantages and disadvantages of each method. Through the sorting work conducted in this paper, it will be convenient for researchers at different learning stages to choose the best method for their own research based on their own subject's situation when they are going to study DDIs mediated by renal transporters.