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Progressive metastasis is the primary cause of cancer-related deaths. It has been recognized that many cancers are characterized by long periods of stability followed by subsequent progression. Genes termed metastasis progression suppressors (MPS) are functional gatekeepers of this process, and their loss leads to late-stage progression. Previously, we identified regulator of calcineurin 1, isoform 4 (RCAN1.4) as a functional MPS for several cancers, including thyroid cancer, a tumor type prone to metastatic dormancy. RCAN1.4 knockdown increases expression of the cancer-promoting transcription factor NFE2-like bZIP transcription factor (NFE2L3), and through this mechanism increases cancer cell proliferation and invasion in in vitro and in vivo and promotes metastatic potential to lungs in tail vein models. However, the mechanisms by which RCAN 1.4 regulates specific metastatic steps is incompletely characterized. Studies of the metastatic cascade are limited in mouse systems due to high cost and long duration. Here, we have shown the creation of a thyroid-to-lung metastasis-on-a-chip (MOC) model to address these limitations, allowing invasion analysis and quantification on a single cell level. We then deployed the platform to investigate RCAN1.4 knockdown in fluorescently tagged hTh74 and FTC236 thyroid cancer cell lines. Cells were circulated through microfluidic channels, running parallel to lung hydrogel constructs allowing tumor cell-lung tissue interactions. Similar to studies in mouse models, RCAN1.4 knockdown increased NFE2L3 expression, globally increased invasion distance into lung constructs and had cell line and clonally dependent variations on bulk metastatic burden. In line with previous in vivo observations, RCAN1.4 knockdown had a greater impact on hTh74 metastatic propensity than FTC236. In summary, we have developed and validated a novel MOC system evaluate and quantify RCAN1.4-regulated thyroid cancer cell lung adherence and invasion. This system creates opportunities for more detailed and rapid mechanistic studies the metastatic cascade and creates opportunities for translational assay development., (© 2024 IOP Publishing Ltd. All rights, including for text and data mining, AI training, and similar technologies, are reserved.)

Adrenocortical carcinoma (ACC) has a poor prognosis, and no new drugs have been identified in decades. The absence of drug development can partly be attributed to a lack of preclinical models. Both animal models and 2D cell cultures of ACC fail to accurately mimic the disease, as animal physiology is inherently different than humans, and 2D cultures fail to represent the crucial 3D architecture. Organoids and other small 3D in vitro models of tissues or tumors can model certain complexities of human in vivo biology; however, this technology has largely yet to be applied to ACC. In this study, we describe the generation of 3D tumor constructs from an established ACC cell line, NCI-H295R. NCI-H295R cells were encapsulated to generate 3D ACC constructs. Tumor constructs were assessed for biomarker expression, viability, proliferation, and cortisol production. In addition, matrix metalloproteinase (MMP) functionality was assessed directly using fluorogenic MMP-sensitive biosensors and through infusion of NCI-H295R cells into a metastasis-on-a-chip microfluidic device platform. ACC tumor constructs showed expression of biomarkers associated with ACC, including SF-1, Melan A, and inhibin α. Treatment of ACC tumor constructs with chemotherapeutics demonstrated decreased drug sensitivity compared to 2D cell culture. Since most tumor cells migrate through tissue using MMPs to break down extracellular matrix, we validated the utility of ACC tumor constructs by integrating fluorogenic MMP-sensitive peptide biosensors within the tumor constructs. Lastly, in our metastasis-on-a-chip device, NCI-H295R cells successfully engrafted in a downstream lung cell line-based construct, but invasion distance into the lung construct was decreased by MMP inhibition. These studies, which would not be possible using 2D cell cultures, demonstrated that NCI-H295R cells secreted active MMPs that are used for invasion in 3D. This work represents the first evidence of a 3D tumor constructs platform for ACC that can be deployed for future mechanistic studies as well as development of new targets for intervention and therapies., (© 2023. Springer Nature Limited.)

Primary tumors secrete large quantities of cytokines and exosomes into the bloodstream, which are uptaken at downstream sites and induce a pro-fibrotic, pro-inflammatory premetastatic niche. Niche development is associated with later increased metastatic burden, but the cellular and matrix changes in the niche that facilitate metastasis are yet unknown. Furthermore, there is no current standard model to study this phenomenon. Here, biofabricated collagen and hyaluronic acid hydrogel models were employed to identify matrix changes elicited by pericytes and fibroblasts after exposure to colorectal cancer-secreted factors. Focusing on myofibroblast activation and collagen remodeling, we report fibroblast activation and pericyte stunting in response to tumor signaling. In addition, we characterize contributions of both cell types to matrix dysregulation via collagen degradation, deposition, and architectural remodeling. With these findings, we discuss potential impacts on tissue stiffening and vascular leakiness and suggest pathways of interest for future mechanistic studies of metastatic cell-premetastatic niche interactions., Competing Interests: The authors declare no competing interests., (© 2022 The Author(s).)

Current in vitro three-dimensional (3D) models of liver tissue have been limited by the inability to study the effects of specific extracellular matrix (ECM) components on cell phenotypes. This is in part due to limitations in the availability of chemical modifications appropriate for this purpose. For example, hyaluronic acid (HA), which is a natural ECM component within the liver, lacks key ECM motifs (e.g. arginine-glycine-aspartic acid (RGD) peptides) that support cell adhesion. However, the addition of maleimide (Mal) groups to HA could facilitate the conjugation of ECM biomimetic peptides with thiol-containing end groups. In this study, we characterized a new crosslinkable hydrogel (i.e. HA-Mal) that yielded a simplified ECM-mimicking microenvironment supportive of 3D liver cell culture. We then performed a series of experiments to assess the impact of physical and biochemical signaling in the form of RGD peptide incorporation and transforming growth factor ß (TGF- ß ) supplementation, respectively, on hepatic functionality. Hepatic stellate cells (i.e. LX-2) exhibited increased cell-matrix interactions in the form of cell spreading and elongation within HA-Mal matrices containing RGD peptides, enabling physical adhesions, whereas hepatocyte-like cells (HepG2) had reduced albumin and urea production. We further exposed the encapsulated cells to soluble TGF- ß to elicit a fibrosis-like state. In the presence of TGF- ß biochemical signals, LX-2 cells became activated and HepG2 functionality significantly decreased in both RGD-containing and RGD-free hydrogels. Altogether, in this study we have developed a hydrogel biomaterial platform that allows for discrete manipulation of specific ECM motifs within the hydrogel to better understand the roles of cell-matrix interactions on cell phenotype and overall liver functionality., (© 2022 IOP Publishing Ltd.)