Slow-turning Lateral Vessel Research Articles

Abstract 4303: Enrichment of nonadherent prostate cancer stem cell populations using simulated microgravity bioreactor

Abstract Prostate cancer is the most prevalent and the leading cause of cancer-related death among men, particularly African Americans. The cellular and molecular mechanisms contributing to this deadly disease remain largely unknown. As such, there are no effective strategies to treat metastatic cancer and improve patient outcomes. Anchorage-independent growth of circulating prostate tumor cell clusters is essential for developing cancer metastasis. However, there is no model system to study the molecular and functional characteristics of prostate tumor cell clusters reminiscent of the bloodstream in a laboratory setting. In addressing this need, we have established nonadherent LNCaP cell clusters, LN-G2 and LN-G3, under androgen-depleted growth conditions in a simulated microgravity bioreactor called Slow Turning Lateral Vessel (STLV). Our quantitative PCR analysis repeatedly demonstrated that LN-G2 and LN-G3 cell populations expressed high levels of the well-characterized CD44 and CXCR4 cancer stem cell maker, respectively, compared to the LNCaP parental. In addition, our functional analysis indicates that, unlike the LNCaP cell, LN-G2 and LN-G3 cells showed superior clonogenic and growth behaviors in response to androgen depletion and enzalutamide-treatment under adherent monolayer and nonadherent conditions. These observations suggest that cancer stem cell-like cell clusters that survived under microgravitational stress confer distinctive molecular and functional properties associated with superior survival and contribute to castration-resistant prostate cancer. Furthermore, the STLV bioreactor could help enrich cancer stem cell populations and enhance our understanding of the underlying mechanisms of lethal cancer, which may lead to novel therapeutics to improve patient outcomes. Citation Format: Kezhan Khazaw, Sebnem Unlu, Abdulrahman M. Dwead, Bekir Cinar. Enrichment of nonadherent prostate cancer stem cell populations using simulated microgravity bioreactor [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4303.

Novel Bioreactor Platform for Scalable Cardiomyogenic Differentiation from Pluripotent Stem Cell-Derived Embryoid Bodies.

Generation of cardiomyocytes from pluripotent stem cells (PSCs) is a common and valuable approach to produce large amount of cells for various applications, including assays and models for drug development, cell-based therapies, and tissue engineering. All these applications would benefit from a reliable bioreactor-based methodology to consistently generate homogenous PSC-derived embryoid bodies (EBs) at a large scale, which can further undergo cardiomyogenic differentiation. The goal of this chapter is to describe a scalable method to consistently generate large amount of homogeneous and synchronized EBs from PSCs. This method utilizes a slow-turning lateral vessel bioreactor to direct the EB formation and their subsequent cardiomyogenic lineage differentiation.

Slow Turning Lateral Vessel Bioreactor Improves Embryoid Body Formation and Cardiogenic Differentiation of Mouse Embryonic Stem Cells

Embryonic stem cells (ESCs) have the ability to form aggregates, which are called embryoid bodies (EBs). EBs mimic early embryonic development and are commonly produced for cardiomyogenesis. Here, we describe a method of EB formation in hydrodynamic conditions using a slow-turning lateral vessel (STLV) bioreactor and the subsequent differentiation of EBs into cardiomyocytes. EBs formed in the STLV were compared with conventional techniques, such as hanging drop (HD) or static suspension cell culture (SSC), for homogeneity of EB size, shape, proliferation, apoptosis, and in vitro cardiac differentiation. After 3 days of culture, a four-fold improvement in the yield of EB formation/mL, a six-fold enhancement in total yield of EB/mL, and a nearly 10-fold reduction of cells that failed to incorporate into EBs were achieved in STLV versus SSC. During cardiac differentiation, a 1.5- to 4.2-fold increase in the area of cardiac troponin T (cTnT) per single EB in STLV versus SSC and HD was achieved. These results demonstrate that the STLV method improves the quality and quantity of ES cells to form EBs and enhances the efficiency of cardiac differentiation. We have demonstrated that the mechanical method of cell differentiation creates different microenvironments for the cells and thus influences their lineage commitments, even when genetic origin and the culture medium are the same. Ascorbic acid (ASC) improved further cardiac commitment in differentiation assays. Hence, this culture system is suitable for the production of large numbers of cells for clinical cell replacement therapies and industrial drug testing applications.

Culturing and Applications of Rotating Wall Vessel Bioreactor Derived 3D Epithelial Cell Models

Cells and tissues in the body experience environmental conditions that influence their architecture, intercellular communications, and overall functions. For in vitro cell culture models to accurately mimic the tissue of interest, the growth environment of the culture is a critical aspect to consider. Commonly used conventional cell culture systems propagate epithelial cells on flat two-dimensional (2-D) impermeable surfaces. Although much has been learned from conventional cell culture systems, many findings are not reproducible in human clinical trials or tissue explants, potentially as a result of the lack of a physiologically relevant microenvironment. Here, we describe a culture system that overcomes many of the culture condition boundaries of 2-D cell cultures, by using the innovative rotating wall vessel (RWV) bioreactor technology. We and others have shown that organotypic RWV-derived models can recapitulate structure, function, and authentic human responses to external stimuli similarly to human explant tissues (1-6). The RWV bioreactor is a suspension culture system that allows for the growth of epithelial cells under low physiological fluid shear conditions. The bioreactors come in two different formats, a high-aspect rotating vessel (HARV) or a slow-turning lateral vessel (STLV), in which they differ by their aeration source. Epithelial cells are added to the bioreactor of choice in combination with porous, collagen-coated microcarrier beads (Figure 1A). The cells utilize the beads as a growth scaffold during the constant free fall in the bioreactor (Figure 1B). The microenvironment provided by the bioreactor allows the cells to form three-dimensional (3-D) aggregates displaying in vivo-like characteristics often not observed under standard 2-D culture conditions (Figure 1D). These characteristics include tight junctions, mucus production, apical/basal orientation, in vivo protein localization, and additional epithelial cell-type specific properties. The progression from a monolayer of epithelial cells to a fully differentiated 3-D aggregate varies based on cell type(1, 7-13). Periodic sampling from the bioreactor allows for monitoring of epithelial aggregate formation, cellular differentiation markers and viability (Figure 1D). Once cellular differentiation and aggregate formation is established, the cells are harvested from the bioreactor, and similar assays performed on 2-D cells can be applied to the 3-D aggregates with a few considerations (Figure 1E-G). In this work, we describe detailed steps of how to culture 3-D epithelial cell aggregates in the RWV bioreactor system and a variety of potential assays and analyses that can be executed with the 3-D aggregates. These analyses include, but are not limited to, structural/morphological analysis (confocal, scanning and transmission electron microscopy), cytokine/chemokine secretion and cell signaling (cytometric bead array and Western blot analysis), gene expression analysis (real-time PCR), toxicological/drug analysis and host-pathogen interactions. The utilization of these assays set the foundation for more in-depth and expansive studies such as metabolomics, transcriptomics, proteomics and other array-based applications. Our goal is to present a non-conventional means of culturing human epithelial cells to produce organotypic 3-D models that recapitulate the human in vivo tissue, in a facile and robust system to be used by researchers with diverse scientific interests.

Enhanced cardiac differentiation of mouse embryonic stem cells by use of the slow-turning, lateral vessel (STLV) bioreactor

Embryoid body (EB) formation is a common intermediate during in vitro differentiation of pluripotent stem cells into specialized cell types. We have optimized the slow-turning, lateral vessel (STLV) for large scale and homogenous EB production from mouse embryonic stem cells. The effects of inoculating different cell numbers, time of EB adherence to gelatin-coated dishes, and rotation speed for optimal EB formation and cardiac differentiation were investigated. Using 3×10(5) cells/ml, 10rpm rotary speed and plating of EBs onto gelatin-coated surfaces three days after culture, were the best parameters for optimal size and EB quality on consequent cardiac differentiation. These optimized parameters enrich cardiac differentiation in ES cells when using the STLV method.

293 MASS PRODUCTION OF Nkx2.5-POSITIVE CARDIAC PROGENITOR CELLS DERIVED FROM MOUSE EMBRYONIC STEM CELLS IN SLOW-TURNING LATERAL VESSEL FOR CELL TRANSPLANTATION AND DRUG TESTING

Regenerative cell therapy against cardiovascular disease would require mass production and purification of specific cell types before transplantation. To enable large-scale production of embryonic stem (ES)-derived pure cardiomyocytes, we developed an animal model for a single-step scalable bioprocess that allows direct embryoid body (EB) formation in a fully controlled slow-turning lateral vessel (STLV, Synthecon, Inc., Houston, TX, USA) bioreactor following inoculation with a single cell suspension of mouse ES cells. To enhance the yield of cardiac progenitor cells, mouse ES cells (HM1; 129Sv/Ola, Magin et al. 1992 Nucl. Acids Res. 20, 3795–3796) were targeted with the cardiac-specific mouse Nkx2.5 promoter driven enhanced fluorescent green protein (EGFP). Among 15 targeted colonies, which were characterised based on morphology, the ability to form EB, EGFP expression, and in vitro differentiation ability toward cardiomyocytes, 3 lines were further evaluated for the efficiency of cardiomyocyte production. The 3 lines were cultured in STLV bioreactor and compared with classical hanging drop (HD) and static suspension culture methods. Embryonic bodies at day 3 to 8 were collected and analysed by using fluorescence-activated cell sorting for markers of pluripotency (e.g. Oct-4, SSEA1, Nanog) and cardiac (e.g. Nkx2.5, Troponin T) lineage commitments. Data was analysed by one-way ANOVA and t-tests. The results showed that both level and kinetics of Nkx2.5 expression was dependent on culture conditions. The STLV and static suspension culture methods produced higher rates of Nkx2.5-positive cells on day 5 than that of HD (70 and 54 v. 30%, respectively). The STLV method produced a highly uniform population of efficiently differentiating EB in large quantities and resulted in the highest, 108 yield of cardiomyocytes in a single 110-mL STLV on day 4. In conclusion, the STLV method provides a technological platform for controlled large-scale generation of ES-cell-derived cardiomyocytes for clinical and industrial applications. In vivo transplantation tests of cardiomyocytes produced via STLV are currently underway. This study was financed by EU FP6 (CLONET, MRTN-CT-2006-035468), EU FP7 (PartnErS, PIAP-GA-2008-218205; InduHeart, PEOPLE-IRG-2008-234390; InduStem, PIAP-GA-2008-230675; PluriSys, HEALTH-2007-B-223485); NKTH-OTKA-EU FP7-HUMAN-2009-MB08-C 80205 and NKTH/KPI (NKFP_07_1-ES2HEART-HU OM-00202-2007), CHE-TRF senior scholarship, No. RTA 5080010 (M.T.), and the Thailand Commission on Higher Education [CHE-PhD-SW-2005-100 (S.R.), CHE-PhD-SW-RG-2007 (N.K.)].

Bioreactor Cultivation Enhances NTEB Formation and Differentiation of NTES Cells into Cardiomyocytes

Autogenic embryonic stem cells established from somatic cell nuclear transfer (SCNT) embryos have been proposed as unlimited cell sources for cell transplantation-based treatment of many genetic and degenerative diseases, which can eliminate the immune rejection that occurs after transplantation. In the present study, pluripotent nuclear transfer ES (NTES) cell lines were successfully established from different strains of mice. One NTES cell line, NT1, with capacity of germline transmission, was used to investigate in vitro differentiation into cardiomyocytes. To optimize differentiation conditions for mass production of embryoid bodies (NTEBs) from NTES cells, a slow-turning lateral vessel (STLV) rotating bioreactor was used for culturing the NTES cells to produce NTEBs compared with a conventional static cultivation method. Our results demonstrated that the NTEBs formed in STLV bioreactor were more uniform in size, and no large necrotic centers with most of the cells in NTEBs were viable. Differentiation of the NTEBs formed in both the STLV bioreactor and static culture into cardiomyocytes was induced by ascorbic acid, and the results demonstrated that STLV-produced NTEBs differentiated into cardiomyocytes more efficiently. Taken together, our results suggested that STLV bioreactor provided a more ideal culture condition, which can facilitate the formation of better quality NTEBs and differentiation into cardiomyocytes more efficiently in vitro.

Creation of Engineered Cardiac Tissue In Vitro From Mouse Embryonic Stem Cells

Embryonic stem (ES) cells can terminally differentiate into all types of somatic cells and are considered a promising source of seed cells for tissue engineering. However, despite recent progress in in vitro differentiation and in vivo transplantation methodologies of ES cells, to date, no one has succeeded in using ES cells in tissue engineering for generation of somatic tissues in vitro for potential transplantation therapy. ES-D3 cells were cultured in a slow-turning lateral vessel for mass production of embryoid bodies. The embryoid bodies were then induced to differentiate into cardiomyocytes in a medium supplemented with 1% ascorbic acid. The ES cell-derived cardiomyocytes were then enriched by Percoll gradient centrifugation. The enriched cardiomyocytes were mixed with liquid type I collagen supplemented with Matrigel to construct engineered cardiac tissue (ECT). After in vitro stretching for 7 days, the ECT can beat synchronously and respond to physical and pharmaceutical stimulation. Histological, immunohistochemical, and transmission electron microscopic studies further indicate that the ECTs both structurally and functionally resemble neonatal native cardiac muscle. Markers related to undifferentiated ES cell contamination were not found in reverse transcriptase-polymerase chain reaction analysis of the Percoll-enriched cardiomyocytes. No teratoma formation was observed in the ECTs implanted subcutaneously in nude mice for 4 weeks. ES cells can be used as a source of seed cells for cardiac tissue engineering. Additional work remains to demonstrate engraftment of the engineered heart tissue in the case of cardiac defects and its functional integrity within the host's remaining healthy cardiac tissue.

Loss of signal transduction and inhibition of lymphocyte locomotion in a ground-based model of microgravity.

Inflammatory adherence to, and locomotion through the interstitium is an important component of the immune response. Conditions such as microgravity and modeled microgravity (MMG) severely inhibit lymphocyte locomotion in vitro through gelled type I collagen. We used the NASA rotating wall vessel bioreactor or slow-turning lateral vessel as a prototype for MMG in ground-based experiments. Previous experiments from our laboratory revealed that when lymphocytes (human peripheral blood mononuclear cells [PBMCs]) were first activated with phytohemaglutinin followed by exposure to MMG, locomotory capacity was not affected. In the present study, MMG inhibits lymphocyte locomotion in a manner similar to that observed in microgravity. Phorbol myristate acetate (PMA) treatment of PBMCs restored lost locomotory capacity by a maximum of 87%. Augmentation of cellular calcium flux with ionomycin had no restorative effect. Treatment of lymphocytes with mitomycin C prior to exposure to MMG, followed by PMA, restored locomotion to the same extent as when nonmitomycin C-treated lymphocytes were exposed to MMG (80-87%), suggesting that deoxyribonucleic acid replication is not essential for the restoration of locomotion. Thus, direct activation of protein kinase C (PKC) with PMA was effective in restoring locomotion in MMG comparable to the normal levels seen in Ig cultures. Therefore, in MMG, lymphocyte calcium signaling pathways were functional, with defects occurring at either the level of PKC or upstream of PKC.

Simulated microgravity conditions enhance differentiation of cultured PC12 cells towards the neuroendocrine phenotype.

We are studying microenvironmental cues which contribute to neuroendocrine organ assembly and tissue-specific differentiation. As our in vitro model, we cultured rat adrenal medullary PC12 pheochromocytoma cells in a novel cell culture system, the NASA rotating wall vessel (RWV) bioreactors. This "simulated microgravity" environment in RWV bioreactors, characterized by randomizing gravitational vectors and minimizing shear stress, has been shown to favor macroscopic tissue assembly and to induce tissue-specific differentiation. We hypothesized that the unique culture conditions in the RWV bioreactors might enhance the in vitro formation of neuroendocrine organoids. To test our hypothesis, we evaluated the expression of several markers of neuroendocrine differentiation in cultures of PC12 cells maintained for up to 20 d in the slow turning lateral vessel (STLV) type RWV. PC12 cell differentiation was assessed by morphological, immunological, biochemical and molecular techniques. PC12 cells, cultured under "simulated microgravity" conditions, formed macroscopic, tissue-like organoids several millimeters in diameter. Concomitantly, the expression of phenylethanolamine-N-methyl transferase (PNMT), but not of other catecholamine synthesizing enzymes, was enhanced. Increased PNMT expression, as verified on both the gene and protein level, was accompanied by an increase in the specific activity of the enzyme. Furthermore, after 20 d in culture in the STLV, we observed altered patterns of protein tyrosine phosphorylation and prolonged activation of c-fos, a member of the AP-1 nuclear transcription factor complex. We conclude that culture conditions in the RWV appear to selectively activate signal transduction pathways leading to enhanced neuroendocrine differentiation of PC12 cells.

Three-dimensional modeling of T-24 human bladder carcinoma cell line: A new simulated microgravity culture vessel

We present a new device and method for culture of cell lines and primary tissues requiring high oxygen tensions. The High Aspect Rotating-Wall Vessel (HARV) described successfully propagated T-24, a human bladder transitional epithelial cell line, on Cytodex-3 microcarriers in three-dimensional cellular aggregates up to 0.5 cm in diameter. The HARV is a horizontally rotated tissue culture vessel with a large surface-area-to-volume ratio silicone membrane oxygenator. This design augments the principle of the rotating-wall vessel termed the Slow-Turning Lateral Vessel (STLV) by providing a low turbulence, low shear, cell growing environment with increased oxygen delivery capability. Comparisons of glucose metabolism, oxygen consumption, and morphology as a function of cell growth for a T-24 bladder carcinoma were performed in the HARV vs. the STLV. The HARV was superior in the culture of a variety of cell types including normal and neoplastic, anchorage-dependent and suspension cells.