Matrix-guided embryo-like invasion enables 3D heart organoids with atrioventricular synchrony-like contraction.

We have examined the role of the maternally encoded transcription factor FAST-1 in the establishment of the mesodermal transcriptional program in Xenopus embryos. FAST-1 has been shown to associate with Smad2 and Smad4, transducers of TGFbeta superfamily signals, in response to stimulation by several TGFbeta superfamily ligands. The FAST-1/Smad2/Smad4 complex binds and activates a 50 bp activin responsive element identified in the promoter of the meso-endodermal marker Mix.2. We have now used three complementary approaches to demonstrate that FAST-1 is a central regulator of mesoderm induction by ectopic TGFbeta superfamily ligands and during endogenous patterning: ectopic expression of mutationally activated FAST-1, ectopic expression of dominant inhibitory FAST-1, and injection of a blocking antibody specific for FAST-1. Expression of constitutively transcriptionally active FAST-1 fusion protein (FAST-VP16(A)) in prospective ectoderm can directly induce the same set of general and dorsal mesodermal genes, as well as some endodermal genes, as are induced by activin or Vg1. In intact embryos, this construct can induce secondary axes similar to those induced by activin or Vg1. Conversely, expression of a FAST-1-repressor fusion (FAST-En(R)) in prospective ectoderm blocks induction of mesodermal genes by activin, while expression of FAST-En(R) in intact embryos prevents general/dorsal mesodermal gene expression and axial development. Injection of a blocking antibody specific for FAST-1 prevents induction of mesodermal response genes by activin or Vg1, but not by FGF. In intact embryos, this antibody can prevent the expression of early mesodermal markers and inhibit axis formation, demonstrating that FAST-1 is a necessary component of the first steps in the specification of mesoderm.

The role of maternal CREB in early embryogenesis of Xenopus laevis

Gynecological cancers pose great health threats to women, in which ovarian cancer (OC), cervical cancer (CC) and endometrial cancer (EC) are most common. Conventional treatment modalities for gynecological cancers, such as surgery, chemotherapy and radiotherapy, are usually affected by multiple factors like drug resistance and recurrence. Organoids, a three-dimensional culture system derived from stem cells, have been demonstrated to recapitulate the biological structure and function of human organs and gradually used in the treatment of various cancer types, including gynecological cancers. The organoids established from gynecological cancers have patient tumor-dependent morphology and disease characteristics while retaining the tumor’s marker expression and genomic profiling, and present heterogeneous inter- and intra-patient drug responses, offering novel insights into drug response of the individual patients. This review provides an overview of recent advancements in the development and application of organoids from gynecological cancers, promoting the understanding of the mechanism underlying tumorigenesis, drug screening prediction and personalized treatment application in gynecological cancers.

Breast cancer (BC) is the most frequently diagnosed malignancy among women globally. Although mouse models have been critical in advancing the knowledge of BC tumorigenesis and progression, human breast models comprising the breast tissue microenvironment are needed to help elucidate the underlying mechanisms of BC risk factors. As such, it is essential to identify an ex vivo human breast tissue mimetic model that can accurately pinpoint the effects of these factors in BC development. While two-dimensional models have been invaluable, they are not suitable for studying patient-specific tumor biology and drug response. Recent developments in three-dimensional (3D) models have led to the prominence of organized structures grown in a 3D environment called “organoids.” Breast organoids can accurately recapitulate the in vivo breast microenvironment and have been used to examine factors that affect signaling transduction, gene expression, and tissue remodeling. In this review, the applications, components, and protocols for development of breast organoids are discussed. We summarize studies that describe the utility of breast organoids, including in the study of normal mammary gland development and tumorigenesis. Finally, we provide an overview of protocols for development of breast organoids, and the advantages and disadvantages of different techniques in studies are described. The included studies have shown that breast organoids will continue to serve as a crucial platform for understanding of progression of BC tumors and the testing of novel therapeutics.

The protein p53 is a key regulator of cellular response to a wide variety of stresses. In cancerous cells inhibitory regulators of the p53 protein such as MDM2 and MDMX are often overexpressed. In silico techniques could be used to inform the selection of interactions to target with novel drug molecules to make the drug development process more efficient. This work furthers these efforts in two ways. Firstly by investigating some of the roles of stochasticity in determining system behavior, and secondly by developing a model of p53 MDM2 and MDMX interactions and attempting to use it to predict the best targets for future drugs. Stochasticity is shown to be able to effect system behavior profoundly, with implications for future work in both theory and experiment. Lack of experimental data is found to limit the effectiveness of attempts to theoretically determine good drug targets.

Three-dimensional extracellular matrix culture, on substrata such as Matrigel, restores many aspects of the differentiated state to non-malignant cells from a variety of tissues. We have adapted these techniques to study EGFR (epidermal growth factor receptor) signalling and drug response in breast cancer cell lines. EGFR-dependent breast cancer cell lines undergo a striking reversion of the malignant phenotype upon treatment with inhibitors targeting the receptor, or downstream signalling intermediates such as mitogen-activated protein kinase and PI3K (phosphoinositide 3-kinase). Using this approach, we have recently reported that EGFR signalling in breast cancer can be effectively inhibited by blocking the activity of a key protease, TACE [TNFalpha (tumour necrosis factor alpha)-converting enzyme], which regulates the bioavailability of EGFR ligands. These results suggest a new way to target EGFR signalling in tumours of the breast and other epithelial tissues and underline the value of three-dimensional extracellular matrix culture models for exploring cancer-relevant signalling processes ex vivo.

Organoids derived from stem cells have significantly advanced disease modeling, particularly in neurodegenerative disorders, while advancing personalized and regenerative medicine. These three-dimensional structures reproduce key aspects of human brain organization and functionality, while remaining simplified models that do not yet recapitulate full neural circuitry or disease progression, providing an improved platform for studying disease mechanisms, drug responses, and potential therapeutic strategies. This review explores the methodologies used in organoid development, including the differentiation of stem cells and culture techniques that enable the formation of self-organizing tissues. Organoids have been successfully used to model key cellular and molecular aspects of neurodegenerative diseases such as Alzheimer’s and Parkinson’s, offering insights into early disease mechanisms and potential novel treatment strategies. Key findings highlight that organoids provide more physiologically relevant data than traditional two-dimensional cultures and animal models, making them valuable tools for preclinical research and personalized treatment approaches. However, challenges remain, including variability in organoid generation, lack of vascularization, and difficulties in large-scale production for clinical applications. For the effective integration of organoids into biomedical and clinical applications, future research should prioritize improving reproducibility, standardization, and vascularization methods. Addressing these limitations will enhance their translational potential, leading to more effective treatments for neurodegenerative disorders and broader applications in precision medicine.

Genetic studies have placed the Fgfr1 gene at the top of major ontogenic pathways that enable gastrulation, tissue development and organogenesis. Using genome-wide sequencing and loss and gain of function experiments the present investigation reveals a mechanism that underlies global and direct gene regulation by the nuclear form of FGFR1, ensuring that pluripotent Embryonic Stem Cells differentiate into Neuronal Cells in response to Retinoic Acid. Nuclear FGFR1, both alone and with its partner nuclear receptors RXR and Nur77, targets thousands of active genes and controls the expression of pluripotency, homeobox, neuronal and mesodermal genes. Nuclear FGFR1 targets genes in developmental pathways represented by Wnt/β-catenin, CREB, BMP, the cell cycle and cancer-related TP53 pathway, neuroectodermal and mesodermal programing networks, axonal growth and synaptic plasticity pathways. Nuclear FGFR1 targets the consensus sequences of transcription factors known to engage CREB-binding protein, a common coregulator of transcription and established binding partner of nuclear FGFR1. This investigation reveals the role of nuclear FGFR1 as a global genomic programmer of cell, neural and muscle development.

Cancer is a complex disease caused by multiple factors, which hamper effective drug discovery. Drug combination or multi target agents provide an alternate way to effectively modify disease networks. Synergistic drug pairs have special potential for treatment since they allow a desired effect to be achieved with lower total dose of administered medicine and usually with fewer side effects. However, the major challenge has been the prediction of chemotherapeutic efficacy based on the biological profile of the tumor. Because of the lack of gene expression data treated with drug combinations, in this study, we present a computational approach to identify effective drug combinations by exploiting high throughput data. We constructed tissue specific network pharmacology based on large-scale screening data on drug treatment efficacies of 130 drugs under clinical and preclinical investigation and drug-target binding affinities. We evaluated CNS cancer subset and applied logic based network algorithm to predict effective drug combinations based on drug-target interactions and single drug sensitivity profiles. Cancer cell based target inhibition network analysis in two case studies using glioma cell lines, (U87 and U251) identified distinct cell line survival pathways (p < 0.001), including cell proliferation, adhesion and growth factor signaling. We estimated pairwise drug synergy scores for all the target genes and identified several synergistic pairs with potential clinical relevance. Target inhibition modeling allowed systematic exploration of functional interactions between drugs and their targets to maximally inhibit multiple survival pathways. Citation Format: Uma Shankavaram, Kevin Camphausen. Target inhibitory networks and drug response modeling. [abstract]. In: Proceedings of the AACR Precision Medicine Series: Integrating Clinical Genomics and Cancer Therapy; Jun 13-16, 2015; Salt Lake City, UT. Philadelphia (PA): AACR; Clin Cancer Res 2016;22(1_Suppl):Abstract nr 42.

Nowadays, the use of 3D cultures (organoids) is considered a valuable experimental tool to model physiological and pathological conditions of organs and tissues. Organoids, retaining cellular heterogeneity with the presence of stem, progenitor, and differentiated cells, allow the faithful in vitro reproduction of structures resembling the original tissue. In this context, the growth of endometrial organoids allows the generation of 3D cultures characterized by a hollow lumen, secretory activity, and apicobasal polarity and displaying phenotypical modification in response to hormone stimulation. However, a limitation in currently used models is the absence of stromal cells in their structure; as a result, they miss epithelial–stromal interactions, which are crucial in endometrial physiology. We developed a novel 3D model to generate endometrial organoids grown in floating MatrigelTM droplets in the presence of standard culture medium. From a structural point of view, these novel floating 3D cultures develop as gland-like structures constituted by epithelial cells organized around a central lumen and retain the expression of endometrial and decidual genes, like previously published organoids, although with a phenotype resembling hormonally differentiated structures. Importantly, floating organoids retain stromal cells which grow in close contact with the epithelial cells, localized within the internal or external portion of the organoid structure. In summary, we present a simple and rapid model for generating 3D endometrial organoids that preserve epithelial–stromal cell interactions, promoting the formation of differentiated organoids and enabling the study of reciprocal modulation between epithelium and stroma.Key features• Development of 3D endometrial organoids using 10% FBS-DMEM/F12 complete medium in less than a month.• Preservation of stromal and epithelial cell populations, favoring the study of their interaction.• Development of differentiated endometrial organoids without the need for in vitro hormonal stimulation.

Intracoronary myocardial contrast echocardiography (MCE) can be used to guide the delivery of ethanol during nonsurgical septal reduction therapy for hypertrophic obstructive cardiomyopathy. The echocardiographic contrast agent is injected immediately before the injection of ethanol, down the lumen of the inflated balloon that resides in the target septal coronary artery. This is the artery that supplies the area of the septum involved with the mitral leaflet(s) in causing dynamic outflow tract obstruction. MCE provides a direct visualization of the myocardial territory that should receive ethanol and consequently undergo infarction. In rare instances, the cannulated vessel does not supply the culprit septal segment(s) but supplies instead …

BackgroundPancreatic ductal adenocarcinoma has the lowest survival rate among all major cancers and is the third leading cause of cancer-related mortality. The stagnant survival statistics and dismal response rates to current therapeutics highlight the need for more efficient preclinical models. Patient-derived organoids (PDOs) offer new possibilities as powerful preclinical models able to account for interpatient variability. Organoid development can be divided into four different key phases: establishment, propagation, drug screening and response prediction. Establishment entails tailored tissue extraction and growth protocols, propagation requires consistent multiplication and passaging, while drug screening and response prediction will benefit from shorter and more precise assays, and clear decision-making tools.ConclusionsThis review attempts to outline the most important challenges that remain in exploiting organoid platforms for drug discovery and clinical applications. Some of these challenges may be overcome by novel methods that are under investigation, such as 3D bioprinting systems, microfluidic systems, optical metabolic imaging and liquid handling robotics. We also propose an optimized organoid workflow inspired by all technical solutions we have presented.

Breast cancer is the most common female malignant tumor type globally. The occurrence and development of breast cancer involve ferroptosis, which is closely related to its treatment. The development of breast cancer organoids facilitates the analysis of breast cancer molecular background and tumor biological behavior, including clinical pathological characteristics, drug response, or drug resistance relationship, and promotes the advancement of precision treatment for breast cancer. The three-dimensional (3D) cell culture of breast cancer MCF-7 organoid is more similar to the in vivo environment and thus obtains more realistic results than 2D cell culture. Our study examined the new mechanism of tamoxifen in treating breast cancer through breast cancer MCF-7 organoids. We used 3D cells to culture breast cancer MCF-7 organoid, as well as tamoxifen-treated MCF-7 and tamoxifen-resistant MCF-7 (MCF-7 TAMR) cells. We used transcriptome sequencing. We detected GPX4 and SLC7A11 protein levels using Western blotting and the content of ATP, glutathione, and ferrous ions using the Cell Counting Lite 3D Kit. We assessed cell viability using the Cell Counting Kit-8 (CCK-8) assay. Tamoxifen significantly inhibited the growth of MCF-7 organoids and significantly induced ferroptosis in MCF-7 organoids. The ferroptosis inhibitor reversed the significant tamoxifen-induced MCF-7 organoid inhibition activity. Moreover, the ferroptosis activator enhanced the tamoxifen-induced MCF-7 TAMR cell activity inhibition. Our study revealed that ferroptosis plays an important role in tamoxifen-induced MCF-7 organoid cell death and provides a new research idea for precise treatment of breast cancer through an organoid model.

Cardiomyocytes (CMs) derived from induced pluripotent stem cells (iPSCs) hold great promise for patient-specific disease modeling, drug screening and cell therapy. However, existing protocols for CM differentiation of iPSCs besides being highly dependent on the application of expensive growth factors show low reproducibility and scalability. The aim of this work was to develop a robust and scalable strategy for mass production of iPSC-derived CMs by designing a bioreactor protocol that ensures a hypoxic and mechanical environment. Murine iPSCs were cultivated as aggregates in either stirred tank or WAVE bioreactors. The effect of dissolved oxygen and mechanical forces, promoted by different hydrodynamic environments, on CM differentiation was evaluated. Combining a hypoxia culture (4 % O2 tension) with an intermittent agitation profile in stirred tank bioreactors resulted in an improvement of about 1000-fold in CM yields when compared to normoxic (20 % O2 tension) and continuously agitated cultures. Additionally, we showed for the first time that wave-induced agitation enables the differentiation of iPSCs towards CMs at faster kinetics and with higher yields (60 CMs/input iPSC). In an 11-day differentiation protocol, clinically relevant numbers of CMs (2.3 × 109 CMs/1 L) were produced, and CMs exhibited typical cardiac sarcomeric structures, calcium transients, electrophysiological profiles and drug responsiveness. This work describes significant advances towards scalable cardiomyocyte differentiation of murine iPSC, paving the way for the implementation of this strategy for mass production of their human counterparts and their use for cardiac repair and cardiovascular research.Electronic supplementary materialThe online version of this article (doi:10.1007/s12015-014-9533-0) contains supplementary material, which is available to authorized users.

Chemopreventive agents are derived from edible plants and from ancient time is a part of daily intake for many humans and animals. There are several lines of compelling evidence from epidemiological, clinical and laboratory studies that these dietary constituents are associated in reducing cancer risks. However, developmental toxicity of these natural compounds cannot be excluded. In the present study, we examined the effect of chemopreventive agents on the differentiation of mouse embryonic stem cells (ESCs) as an in vitro embryotoxicity model. We assumed that inhibition of developmentally regulated genes in vitro might predict developmental toxicity also under in vivo conditions. We found that epigallocatechin gallate (EGCG) (20 microM) induced the expression of mesodermal and cardiomyocyte genes and a significant increase in the number and the percentage of cardiomyocytes. The increase of the subpopulation correlated with higher numbers of beating foci and beating frequencies. Curcumin on the other hand at 0.4 mM was seen to enhance expression of ectodermal transcripts. Quercetin (2.5 microM) was found to inhibit several developmentally regulated genes.