Adherent Cell Cultures Research Articles

Abstract 15 Safety of DUOC-01, Intrathecal Cord Blood-Derived Cellular Therapy, as an Adjunct to Allogeneic Cord Blood Transplantation in Children with Inherited Metabolic Diseases

IntroductionUnrelated donor umbilical cord blood transplantation (CBT) improves function and extends life in children with certain inherited metabolic diseases (IMDs); however, progressive neurologic decline often occurs during the few months post-CBT prior to donor engraftment in the brain, causing residual, irreversible impairments. We previously described donor engraftment in the brain after CBT and developed DUOC-01, a monocyte-derived CB cell product, to attempt to accelerate donor cell delivery to the brain.ObjectiveThe objective of this study was to determine manufacturing feasibility and safety of intrathecal DUOC-01 in a phase I study in children with IMDs undergoing CBT after myeloablative cytoreduction (busulfan/cyclophosphamide/anti-thymocyte globulin).MethodsDUOC-01 was manufactured in adherent cell culture in a GMP lab over 21 days with a target dose of ≤100 × 105 cells. When cell dose permitted, 80% of the CB unit was used for transplant and 20% of the same unit was used to manufacture DUOC-01. Otherwise, DUOC-01 was manufactured from a unique CB unit. On day ≥+28 post-CBT, if there was evidence of hematopoietic engraftment without severe graft versus host disease or morbidity, DUOC-01 cells were harvested and administered intrathecally. Safety was monitored via neurologic exams, neuroimaging, and CSF studies.ResultsForty patients (aged 0-15 years) underwent CBT, 37 engrafted with donor cells. Median infused total nucleated cell count was 6.5 × 107/kg (range 2.9-33.1 × 107/kg); median time to neutrophil engraftment was 20 days (range 13-46 days). Ten patients did not receive DUOC-01 cells for the following reasons: engraftment failure (3), transplant-related morbidity (4), and low manufacturing yield (3). Thirty patients received 0.2-100 × 105 DUOC-01 cells intrathecally for a median of 31 days (range 27-77 days) post-CBT (19 with the same CB donor and 11 with a unique CB donor). Two patients developed transient fever and hypotension hours after unique-donor DUOC-01, consistent with an inflammatory response. Hydrocortisone (HC) was added to the final formulation, and post-validation, seven additional patients received unique-donor DUOC-01+HC without incident. No other DUOC-01-related serious adverse events occurred.DiscussionDUOC-01 is a CB-derived product intended to accelerate donor cell delivery to the brain of children with IMDs undergoing CBT. Intrathecal DUOC-01 administration is well-tolerated post-CBT from the same donor and, with the addition of HC, also from a unique donor. Escalating DUOC doses are being tested for safety and exploration of potential efficacy in a phase Ia trial of adults with multiple sclerosis.

Immunohistochemistry

Immunohistochemistry is an essential technique for the localization and measurement of proteins in cells and tissues. This article describes methods for labeling proteins in adherent and suspension cell cultures and in tissue sections. Choices of antibodies and detection methods are discussed, and detailed troubleshooting guidelines are provided. © 2022 Wiley Periodicals LLC. Basic Protocol 1: Immunofluorescent labeling of cells grown as adherent monolayers Alternate Protocol 1: Immunofluorescent labeling of cells in suspension Basic Protocol 2: Immunofluorescent labeling of tissue sections Alternate Protocol 2: Immunofluorescent labeling using streptavidin-biotin conjugates Alternate Protocol 3: Immunofluorescent double-labeling of tissue sections Alternate Protocol 4: Immunofluorescent double-labeling of tissue sections with two primary antibodies from the same host species.

Vibropolyfection: coupling polymer-mediated gene delivery to mechanical stimulation to enhance transfection of adherent cells

BackgroundWith the success of recent non-viral gene delivery-based COVID-19 vaccines, nanovectors have gained some public acceptance and come to the forefront of advanced therapies. Unfortunately, the relatively low ability of the vectors to overcome cellular barriers adversely affects their effectiveness. Scientists have thus been striving to develop ever more effective gene delivery vectors, but the results are still far from satisfactory. Therefore, developing novel strategies is probably the only way forward to bring about genuine change. Herein, we devise a brand-new gene delivery strategy to boost dramatically the transfection efficiency of two gold standard nucleic acid (NA)/polymer nanoparticles (polyplexes) in vitro.ResultsWe conceived a device to generate milli-to-nanoscale vibrational cues as a function of the frequency set, and deliver vertical uniaxial displacements to adherent cells in culture. A short-lived high-frequency vibrational load (t = 5 min, f = 1,000 Hz) caused abrupt and extensive plasmalemma outgrowths but was safe for cells as neither cell proliferation rate nor viability was affected. Cells took about 1 hr to revert to quasi-naïve morphology through plasma membrane remodeling. In turn, this eventually triggered the mechano-activated clathrin-mediated endocytic pathway and made cells more apt to internalize polyplexes, resulting in transfection efficiencies increased from 10-to-100-fold. Noteworthy, these results were obtained transfecting three cell lines and hard-to-transfect primary cells.ConclusionsIn this work, we focus on a new technology to enhance the intracellular delivery of NAs and improve the transfection efficiency of non-viral vectors through priming adherent cells with a short vibrational stimulation. This study paves the way for capitalizing on physical cell stimulation(s) to significantly raise the effectiveness of gene delivery vectors in vitro and ex vivo.Graphical

Regeneration of Capto Core 700 resin through high throughput and laboratory scale studies and impact on production of a SARS-CoV-2 vaccine candidate.

During the development of a SARS‐CoV‐2 vaccine candidate, at the height of the COVID‐19 pandemic, raw materials shortages, including chromatography resins, necessitated the determination of a cleaning in place (CIP) strategy for a multimodal core‐shell resin both rapidly and efficiently. Here, the deployment of high throughput (HT) techniques to screen CIP conditions for cleaning Capto Core 700 resin exposed to clarified cell culture harvest (CCCH) of a SARS‐CoV‐2 vaccine candidate produced in Vero adherent cell culture are described. The best performing conditions, comprised of 30% n‐propanol and ≥0.75 N NaOH, were deployed in cycling experiments, completed with miniature chromatography columns, to demonstrate their effectiveness. The success of the CIP strategy was ultimately verified at the laboratory scale. Here, its impact was assessed across the entire purification process which also included an ultrafiltration/diafiltration step. It is shown that the implementation of the CIP strategy enabled the re‐use of the Capto Core 700 resin for up to 10 cycles without any negative impact on the purified product. Hence, the strategic combination of HT and laboratory‐scale experiments can lead rapidly to robust CIP procedures, even for a challenging to clean resin, and thus help to overcome supply shortages.

Identification of Stem Cell Related Gene Expression from the Osteosarcoma Cell Core Side

Osteosarcoma is the most frequent primary malignant bone tumor with higher incidences in children and adolescents. Despite clinical evolutions, patients with osteosacoma have had a poor prognosis. There has been increasing evidence that cancer is a stem cell disease. This study sought to isolate and characterize cancer stem cells from human osteosarcoma with relevant literature reviews. Here we show that the emerging evidence suggests osteosarcoma should be regarded as a differentiation disease such as stem cell disease. Two human osteosarcoma cell lines were cultured in non-adherent culture conditions as sarcospheres. Sarcospheres were observed using histomorphology and alkaline phosphatase (ALP) staining. Expression of the embryonic stem cell marker was analyzed with use of reverse transcriptase-PCR. Sarcospheres could be reproduced consistently throughout multiple passages and produced adherent osteosarcoma cell cultures. Expression of stem cell-associated genes such as those encoding Nanog, octamer-binding transcription factor 3/4, sex determining region Y box 2 , c-Myc and ALP indicated pluripotent stem-like cells. These results support the extension of the cancer stem cell theory to include osteosarcoma. Understanding the cancer stem cell derived from human osteosarcoma could lead to the evolution of diagnosis and treatment for osteosarcoma patients.

Abstract 101: JAK-independent STAT5 signaling as a node of therapeutic vulnerability in glioblastoma

Abstract Glioblastoma (GBM), the most common primary brain tumor in adults, comprises all WHO Grade IV gliomas of astrocytic origin. Despite extensive characterization of the molecular and genetic features of GBM, there remains a paucity of viable treatment options, and this disease confers a dismal 5% 5-year survival rate. Genomic amplification of epidermal growth factor receptor (EGFR) occurs in 40-60% of primary GBM. Half of all EGFR-amplified cases of GBM also harbor EGFRvIII, a constitutively active, truncated variant of EGFR. EGFR and EGFRvIII transduce oncogenic signals via cytoplasmic mediators, including the JAK/STAT signal transduction pathway. The oncogenic role of STAT3 has been well-studied in CNS malignancies; STAT3 has been found to induce the expression of target genes involved in the proliferative and invasive phenotypes of GBM. However, little is known about the mechanism and role of STAT5 activation in GBM progression. Microenvironmental cues and EGFRvIII signaling, lost in adherent cell culture, are required for STAT5 activation, making STAT5 difficult to study by conventional cell culture methods. Our recent data from patient-derived xenograft (PDX) cultures demonstrates that activation of STAT5 is important in GBM cell invasion and survival. Further, STAT5 activation is present predominantly at the invasive periphery of the tumor. In this study, we seek to characterize the mechanism and role of STAT5 activation downstream of EGFRvIII in GBM. RNA sequencing of PDX tumors expressing stable shRNA knockdown of STAT3 or STAT5 indicate both redundant and distinct transcriptional changes induced by STAT3 and STAT5 in GBM. We also find that while STAT3 activation is dependent upon JAK1/2, STAT5 activation is JAK-independent downstream of EGFRvIII in GBM. Depletion of JAK1/2 expression by siRNA oligonucleotides and pharmacologic inhibition of JAK1/2 suppressed STAT3 activation but not STAT5. In fact, targeting JAK2 with kinase inhibitor WP1066 suppressed STAT3 activation, but increased activation of STAT5 in GBM cells expressing EGFR/EGFRvIII. Inhibition of Src family kinases (SFK), a family of upstream signaling effectors of the JAK/STAT pathway, attenuates both STAT3 and STAT5 activation. These results suggest that activation of STAT5 may provide a therapeutic escape mechanism to JAK-STAT3 inhibition in GBM, necessitating dual STAT3 and STAT5 inhibition to successfully inhibit the distinct oncogenic signals transmitted by STAT3 and STAT5 to promote GBM cell survival and resistance. Citation Format: Mylan Blomquist, Serdar Tuncali, Christopher Sereduk, Jean Kloss, Joseph Loftus, Nhan Tran. JAK-independent STAT5 signaling as a node of therapeutic vulnerability in glioblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 101.

Abstract 1119: Non-adherent breast and non-small-cell lung cancer cell cultures as a promising CTCs’ model for evaluation of the anti-tumor effects of artesunate

Abstract Background: Artesunate (AS), besides being widely used as an antimalarial agent, has been also suggested to exert anti-tumor activity in a plethora of cancer types, including breast and lung cancer. Recently, AS has been shown to inhibit the expression of JunB, which is associated with metastatic progression. The aim of this study is to examine the effect of AS on the viability of both adherent and non-adherent (resembling circulating tumor cells; CTCs) breast and lung cancer cell cultures. Methods: Prevention of cell attachment and establishment of the CTCs’ model was achieved via polyHEMA [poly(2-hydroxyethyl methacrylate)] treatment. Viability of adherent and non-adherent MDA-MB-231 (triple negative breast cancer) and H1299 (non-small-cell lung cancer) cells was assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-dimethyltetrazolium bromide (MTT) assay, 48 h following treatment with different concentrations of AS (3 μM to 100 μΜ) in serum starvation conditions. Cell migration was examined using the wound healing assay. Results: Optimization involving the duration (20 min vs. overnight) and concentration (10 mg/ml) of polyHEMA coating, as well as the duration of AS treatment (24 h vs. 48 h) were performed. 5-fluorouracil was used as a positive control. AS decreased viability of both cell lines in a concentration-dependent manner with comparable IC50, whether being adherent (pIC50 = 4.6 ± 0.1 and 5.1 ± 0.1 for MDA-MB-231 and H1299, respectively; n = 8) or non-adherent (pIC50 = 4.5 ± 0.1 and 4.9 ± 0.1 for MDA-MB-231 and H1299, respectively; n =8). AS (10 μΜ, 48 h) inhibited proliferation of both adherent MDA-MB-231 (34% ± 5, n = 8) and H1299 (57% ± 4, n = 8) cells. Interestingly, the effect of AS on MDA-MB-231 and H1299 non-adherent cultures was less prominent (15% ± 6 and 26% ± 6, P<0.001, respectively; n = 8), demonstrating resistance to AS. Furthermore, AS (10 μM, 48 h) decreased cell migration, an effect which was more pronounced in H1299 cells. Conclusions: Evidently, non-adherent, free-floating cells seem to respond differently to AS compared to their attached counterparts. These results suggest that antitumor agents might exert different effects in CTCs compared to adherent tumor cells. Acknowledgements: This research has been co-financed by the European Union and Greek national funds through the Operational Program Competitiveness, Entrepreneurship and Innovation, under the call RESEARCH - CREATE - INNOVATE (project code: T2ΕΔΚ-01562). Citation Format: Evangelia Pantazaka, Dafni Graikioti, Constantinos M. Athanassopoulos, Galatea Kallergi. Non-adherent breast and non-small-cell lung cancer cell cultures as a promising CTCs’ model for evaluation of the anti-tumor effects of artesunate [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1119.

Abstract 6018: Expansion of mouse mammary epithelial stem cells in serum-free organoid growth medium

Abstract Growing mammary epithelial cells as organoids in a three-dimensional (3D) cell culture environment represents a more physiological model system than conventional 2D adherent cell culture systems for studying many different aspects of mammary epithelial cell biology. We have developed MammoCult™ Organoid Growth Medium (Mouse), a serum- and phenol red-free medium for the long-term propagation of organoids from mouse mammary tissue. To initiate the cultures, mouse mammary glands are resected and enzymatically dissociated sequentially in Gentle Collagenase/Hyaluronidase, trypsin, and dispase/DNase I to generate a single-cell suspension, and 4.5 x 103 of the liberated cells are then embedded in Corning® Matrigel® and maintained in MammoCult™ Organoid Growth Medium (Mouse). Alternatively, freshly dissociated mammary cells can be expanded in adherent culture in EpiCult™ Plus Medium prior to seeding into Matrigel®. Approximately 8.4 ± 0.6% (mean ± SEM; n=10) of the freshly dissociated cells seeded in the Corning® Matrigel® will proliferate and generate organoids that are typically > 200 µm in diameter and have a highly branched morphology, although organoids with a cystic morphology are also observed. Immunostaining of these branched organoids reveals that they are composed of a polarized epithelium made up of keratin (K) 8-expressing luminal cells and K5/14-expressing basal cells (n=7). Organoids upregulate transcripts for caseins (Csn1s1, Csn2), whey acidic protein (Wap), and lactoferrin (Ltf) upon stimulation with prolactin, hydrocortisone, and insulin (n=4). These multilineage organoids can be established from multiple inbred mouse strains, including C57Bl6/J, FVB, BALB/c, and CD-1. Organoids can be passaged every 10 - 14 days as small fragments at a 1:3 to 1:4 split ratio, and can be maintained for a minimum of 10 passages while still maintaining multilineage potential and a normal karyotype. These results demonstrate that MammoCult™ Organoid Growth Medium (Mouse) efficiently generates and expands mammary epithelial cell-derived organoids and offers researchers a novel tool for in vitro mammary studies. Citation Format: David Rowbotham, Samantha Rothwell, Allen C. Eaves, Sharon A. Louis, John Stingl. Expansion of mouse mammary epithelial stem cells in serum-free organoid growth medium [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 6018.

SERTAD1 Sensitizes Breast Cancer Cells to Doxorubicin and Promotes Lysosomal Protein Biosynthesis.

Acquired chemoresistance of tumor cells is an unwanted consequence of cancer treatment. Overcoming chemoresistance is particularly important for efficiently improving cancer therapies. Here, using multiple lines of evidence, we report the suppressive role of SERTAD1 in apoptosis/anoikis. Among various breast cancer cell lines, higher SERTAD1 expression was found in MCF7 and MDA-MB-231 in suspension than in adherent cell culture. We revealed an unexpected phenomenon that different types of cell deaths were induced in response to different doses of doxorubicin (Dox) in breast cancer cells, presumably via lysosomal membrane permeabilization. A low dose of Dox highly activated autophagy, while a high dose of the chemotherapy induced apoptosis. Inhibition of SERTAD1 promoted the sensitivity of breast cancer cells to Dox and paclitaxel, leading to a significant reduction in tumor volumes of xenograft mice. Simultaneously targeting cancer cells with Dox and autophagy inhibition successfully induced higher apoptosis/anoikis. The novel role of SERTAD1 in maintaining cellular homeostasis has also been suggested in which lysosomal contents, including LAMP1, LAMP2, CTSB, and CTSD, were reduced in SERTAD1-deficient cells.

Analysis of adherent cell culture lysates with low metabolite concentrations using the Biocrates AbsoluteIDQ p400 HR kit

The AbsoluteIDQ p400 HR kit is a commercial product for targeted metabolomics. While the kit has been validated for human plasma and serum, adherent cell lysates have not yet been evaluated. We have optimized the detection of polar and lipid metabolites in cell lysates using the kit to enable robust and repeatable analysis of the detected metabolites. Parameters optimized include total cell mass, loading volume and extraction solvent. We present a cell preparation and analytical method and report on the performance of the kit with regard to detectability of the targeted metabolites and their repeatability. The kit can be successfully used for a relative quantification analysis of cell lysates from adherent cells although validated only for human plasma and serum. Most metabolites are below the limit of the Biocrates’ set quantification limits and we confirmed that this relative quantification can be used for further statistical analysis. Using this approach, up to 45% of the total metabolites in the kit can be detected with a reasonable analytical performance (lowest median RSD 9% and 13% for LC and FIA, respectively) dependent on the method used. We recommend using ethanol as the extraction solvent for cell lysates of osteosarcoma cell lines for the broadest metabolite coverage and 25 mg of cell mass with a loading volume of 20 µL per sample.

Flexible & scalable solutions for AAV viral vector production using a templated platform

Adeno-associated virus (AAV) has become an increasingly popular viral vector for gene therapy. Currently, there are two approved AAV-based gene therapies, and the number of clinical trials is steadily increasing. As with most viral vector-based therapies, production is labor-intensive and expensive due to the use of adherent cell culture production processes. Consequently, for process intensification, the industry has begun to utilize bioreactors. This article explores the development of a suspension-based AAV upstream process to provide a more efficient and cost-effective bioprocessing solution for large-scale production. The use of template tools for upstream process development will be examined, as will development of the clarification and tangential flow filtration unit operations immediately following harvest.

Inkjet‐Patterned Microdroplets as Individual Microenvironments for Adherent Single Cell Culture (Small 19/2022)

Single Cell Culture In article number 2107992, Jin-Ming Lin and co-workers culture adherent single cells in their individual microenvironments patterned by inkjet printing. Adhesion strength is confirmed by the in-situ microfluidic probe assay. Altered morphology among single cells features ultra-low aspect ratio and shows a distinct behavior caused by “singleness.”

A reducible comparison of 2D vs. 3D HepG2 culture‐derived sEV characteristics and cancer pathway‐related miRNA content

Hepatocellular carcinoma cells (HCCs) produce small extracellular vesicles (sEVs or exosomes) to enable tumor survival, including inactivation of anti‐tumor macrophage immune responses. For sEV studies in vitro, 2D adherent culture cells are typically used to manufacture sEVs. In contrast, 3D matrix‐based culture systems closely simulate in vivo tissues but produce difficult to isolate sEVs. To address this issue, we developed a reducible 3D suspension HCC spheroid culture system to generate easily obtainable sEVs for investigations. The objective was to evaluate biophysical and cancer pathway‐focused miRNA content differences between HCC HepG2 sEVs produced in 2D adherent vs. 3D spheroid suspension culture. To summarize methods, sEVs were isolated from 2D and 3D cell culture using differential ultracentrifugation and size and zeta potential biophysical characteristics were determined by nanoparticle tracking analysis. Fold regulation of 2D and 3D derived sEV miRNAs, compared to their source cells and one another, were determined by qRT‐PCR, and statistically significant differences were determined by Student’s t‐test. Results indicated that HepG2 sEVs generated from 2D adherent or 3D spheroid suspension culture do not differ significantly in terms of size (~130 nm) and zeta potential (< ‐30 mV) characteristic of sEVs. A comparison of 2D vs. 3D sEVs revealed differences in the enrichment of let‐7a‐5p (decreased in HCC in vivo), miR‐21‐5p (enables HCC drug resistance), and miR‐126‐3p (impairs HCC tumor volume in vivo). let‐7a‐5p and miR‐21‐5p were downregulated, while miR‐126‐3p was upregulated in 3D sEVs compared to 2D sEVs (control) respectively. Overall, similarities and differences between 2D and 3D sEV miRNA content were observed relevant to HCC pathogenesis. In conclusion, the 3D HepG2 spheroid suspension model provides an additional reducible level of HCC sEV investigation to augment traditional 2D sEV studies while better simulating an in vivo 3D source of easily obtainable HCC sEVs. Our 3D model could be used in conjunction with typical 2D EV culture systems to streamline the identification of candidate sEV‐based biomarkers and therapeutic targets for HCC and other cancers.

High-density adherent culture of CHO cells using rolled scaffold bioreactor.

Rapid expansion of biopharmaceutical market calls for more efficient and reliable platforms to culture mammalian cells on a large scale. Stirred-tank bioreactors have been widely used for large-scale cell culture. However, it requires months of trials and errors to optimize culture conditions for each cell line. In this article, we extend our earlier studies on rolled scaffold (RS) bioreactors for high-density adherent cell culture and report two new implementations of RSs with greatly enhanced mass-manufacturability, termed as Mesh-RS and Fiber-RS. CHO-K1 cells were successfully expanded in Mesh-RS and Fiber-RS bioreactors with an average growth rate of 1.09 ± 0.04 1/day and 0.95 ± 0.07 1/day, which were higher than those reported in similar studies. Fiber-RS bioreactor exhibited a very high cell density of 72.8 × 106 cells/ml. Besides, a dialyzer was integrated into the RS bioreactor to remove cellular waste and to replenish nutrients without disturbing the cells. By collecting the dialyzed media separately, the dialysis efficiency was significantly improved. In conclusion, the developed RS bioreactor has a strong potential to provide a highly reliable and easily scalable platform for large-scale cell culture in the biopharmaceutical industry.

Inkjet-Patterned Microdroplets as Individual Microenvironments for Adherent Single Cell Culture.

Adhesion of single cells is the foundation of manifold cellular behaviors and life processes. However, investigating the function of a specific cell is still challenging due to deficiency of adhesion or interference from surrounding cells. Herein, an open microfluidic system is reported for culturing adherent single cells, implemented by a micrometer-scale droplet matrix on an inkjet-printed polylysine template. The target cells are isolated from any cell from other droplets, and their adhesion strength is determined to be comparable to conventional petri dishes via an in-situ investigation with a microfluidic extractor. On this proposed platform, isolated single cells are observed to display an entirely distinct spreading behavior featuring total absence of elongation, indicating drastic cell behavior change from their "singleness." This system has high versatility and compatibility for various assaying methods, assuring a promising potential in detailed single cell behavior and cell heterogeneity studies.

Cell Culture in Microfluidic Droplets

Cell manipulation in droplets has emerged as one of the great successes of microfluidic technologies, with the development of single-cell screening. However, the droplet format has also served to go beyond single-cell studies, namely by considering the interactions between different cells or between cells and their physical or chemical environment. These studies pose specific challenges linked to the need for long-term culture of adherent cells or the diverse types of measurements associated with complex biological phenomena. Here we review the emergence of droplet microfluidic methods for culturing cells and studying their interactions. We begin by characterizing the quantitative aspects that determine the ability to encapsulate cells, transport molecules, and provide sufficient nutrients within the droplets. This is followed by an evaluation of the biological constraints such as the control of the biochemical environment and promoting the anchorage of adherent cells. This first part ends with a description of measurement methods that have been developed. The second part of the manuscript focuses on applications of these technologies for cancer studies, immunology, and stem cells while paying special attention to the biological relevance of the cellular assays and providing guidelines on improving this relevance.

Rhenium Perrhenate (188ReO4) Induced Apoptosis and Reduced Cancerous Phenotype in Liver Cancer Cells.

Recurrence in hepatocellular carcinoma (HCC) after conventional treatments is a crucial challenge. Despite the promising progress in advanced targeted therapies, HCC is the fourth leading cause of cancer death worldwide. Radionuclide therapy can potentially be a practical targeted approach to address this concern. Rhenium-188 (188Re) is a β-emitting radionuclide used in the clinic to induce apoptosis and inhibit cell proliferation. Although adherent cell cultures are efficient and reliable, appropriate cell-cell and cell-extracellular matrix (ECM) contact is still lacking. Thus, we herein aimed to assess 188Re as a potential therapeutic component for HCC in 2D and 3D models. The death rate in treated Huh7 and HepG2 lines was significantly higher than in untreated control groups using viability assay. After treatment with 188ReO4, Annexin/PI data indicated considerable apoptosis induction in HepG2 cells after 48 h but not Huh7 cells. Quantitative RT-PCR and western blotting data also showed increased apoptosis in response to 188ReO4 treatment. In Huh7 cells, exposure to an effective dose of 188ReO4 led to cell cycle arrest in the G2 phase. Moreover, colony formation assay confirmed post-exposure growth suppression in Huh7 and HepG2 cells. Then, the immunostaining displayed proliferation inhibition in the 188ReO4-treated cells on 3D scaffolds of liver ECM. The PI3-AKT signaling pathway was activated in 3D culture but not in 2D culture. In nude mice, Huh7 cells treated with an effective dose of 188ReO4 lost their tumor formation ability compared to the control group. These findings suggest that 188ReO4 can be a potential new therapeutic agent against HCC through induction of apoptosis and cell cycle arrest and inhibition of tumor formation. This approach can be effectively combined with antibodies and peptides for more selective and personalized therapy.

Augmenting recombinant antibody production in HEK293E cells: optimizing transfection and culture parameters.

BackgroundOptimizing recombinant antibody production is important for cost-effective therapeutics and diagnostics. With impact on commercialization, higher productivity beyond laboratory scales is highly sought, where efficient production can also accelerate antibody characterizations and investigations.MethodsInvestigating HEK293E cells for mammalian antibody production, various transfection and culture parameters were systematically analyzed for antibody light chain production before evaluating them for whole antibody production. Transfection parameters investigated include seeding cell density, the concentration of the transfection reagent and DNA, complexation time, temperature, and volume, as well as culture parameters such as medium replacement, serum deprivation, use of cell maintenance antibiotic, incubation temperature, medium volume, post-transfection harvest day, and common nutrient supplements.ResultsUsing 2 mL adherent HEK293E cell culture transfections with 25 kDa linear polyethylenimine in the most optimized parameters, we demonstrated a ~2-fold production increase for light chain alone and for whole antibody production reaching 536 and 49 μg, respectively, in a cost-effective manner. With the addition of peptone, κ light chain increased by ~4-fold to 1032 μg, whereas whole antibody increased to a lesser extent by ~2.5-fold to 51 μg, with benefits potentially for antibodies limited by their light chains in production.ConclusionsOur optimized findings show promise for a more efficient and convenient antibody production method through transfection and culture optimizations that can be incorporated to scale-up processes and with potential transferability to other mammalian-based recombinant protein production using HEK293E.

Dendritic Polyglycerol Amine: An Enhanced Substrate to Support Long-Term Neural Cell Culture.

Long-term stable cell culture is a critical tool to better understand cell function. Most adherent cell culture models require a polymer substrate coating of poly-lysine or poly-ornithine for the cells to adhere and survive. However, polypeptide-based substrates are degraded by proteolysis and it remains a challenge to maintain healthy cell cultures for extended periods of time. Here, we report the development of an enhanced cell culture substrate based on a coating of dendritic polyglycerol amine (dPGA), a non-protein macromolecular biomimetic of poly-lysine, to promote the adhesion and survival of neurons in cell culture. We show that this new polymer coating provides enhanced survival, differentiation and long-term stability for cultures of primary neurons or neurons derived from human induced pluripotent stem cells (hiPSCs). Atomic force microscopy analysis provides evidence that greater nanoscale roughness contributes to the enhanced capacity of dPGA-coated surfaces to support cells in culture. We conclude that dPGA is a cytocompatible, functionally superior, easy to use, low cost and highly stable alternative to poly-cationic polymer cell culture substrate coatings such as poly-lysine and poly-ornithine. Summary statement Here, we describe a novel dendritic polyglycerol amine-based substrate coating, demonstrating superior performance compared to current polymer coatings for long-term culture of primary neurons and neurons derived from induced pluripotent stem cells.

Culture of Adherent Cancer Cell Lines.

Adherent cell lines grow attached to the surface of a cell culture vessel. Due to the adherent nature of the cells, enzymes, such as trypsin, are required to lift the cells from the cell culture vessel for harvesting or subculturing. Many cancer cell lines are adherent, rendering adherent cell culture a critical experimental method in the fields of cell biology, biochemistry, and cancer research. In this chapter, we outline the protocols for culturing and maintaining adherent cells. We detail the procedures for preparing cell culture medium, thawing and reviving frozen adherent cells, subculturing adherent cells, freezing cells, and counting cells. Most notably, we outline the best techniques and practices for optimal growth of healthy adherent cells while diminishing the risk of contamination.