Insights into spheroids formation in cellulose nanofibrils and Matrigel hydrogels using AFM-based techniques

The recent FDA decision to eliminate animal testing requirements emphasises the role of cell models, such as spheroids, as regulatory test alternatives for investigations of cellular behaviour, drug responses, and disease modelling. The influence of environment on spheroid formation are incompletely understood, leading to uncertainty in matrix selection for scaffold-based 3D culture. This study uses atomic force microscopy-based techniques to quantify cell adhesion to Matrigel and cellulose nanofibrils (CNF), and cell-cell adhesion forces, and their role in spheroid formation of hepatocellular carcinoma (HepG2) and induced pluripotent stem cells (iPS(IMR90)-4). Results showed different cell behaviour in CNF and Matrigel cultures. Both cell lines formed compact spheroids in CNF but loose cell aggregates in Matrigel. Interestingly, the type of cell adhesion protein, and not the bond strength, appeared to be a key factor in the formation of compact spheroids. The gene expression of E- and N-cadherins, proteins on cell membrane responsible for cell-cell interactions, was increased in CNF culture, leading to formation of compact spheroids while Matrigel culture induced integrin-laminin binding and downregulated E-cadherin expression, resulting in looser cell aggregates. These findings enhance our understanding of cell-biomaterial interactions in 3D cultures and offer insights for improved 3D cell models, culture biomaterials, and applications in drug research.

Principles of Hanging Drop Method (Spheroid Formation) in Cell Culture

A type of three-dimensional (3D) cell culture models which is simple and easy is hanging drop method. The hanging drop method emerges as a pivotal technique with diverse applications in cancer research and cell biology. This method facilitates the formation of multicellular spheroids, providing a unique environment for studying cell behavior dynamics. The hanging drop method's theoretical underpinning relies on gravity-enforced self-assembly, allowing for cost-effective, reproducible 3D cell cultures with controlled spheroid sizes. The advantages of this approach include its efficiency in producing cellular heterogeneity, particularly in non-adherent 3D cultures, and its ability to create hypoxic spheroids, making it a suitable model for studying cancer. Moreover, the hanging drop method has proven valuable in investigating various aspects such as tissue structure, signaling pathways, immune activation of cancer cells, and notably, cell proliferation. Researchers have utilized the hanging drop method to explore the dynamics of cell proliferation, studying the effects of mesenchymal stem cells (MSC) secretome on cancer cells. The method's application involves co-culturing different cell lines, assessing spheroid formations, and quantifying their sizes over time. These studies have unveiled intricate cell behavior dynamics, demonstrating how the MSC secretome influences cancer cell growth and viability within a three-dimensional co-culture paradigm.

MNRR1 is a driver of ovarian cancer progression

Cancer progression requires the acquisition of mechanisms that support proliferative potential and metastatic capacity. MNRR1 (also CHCHD2, PARK22, AAG10) is a bi-organellar protein that in the mitochondria can bind to Bcl-xL to enhance its anti-apoptotic function, or to respiratory chain complex IV (COX IV) to increase mitochondrial respiration. In the nucleus, it can act as a transcription factor and promote the expression of genes involved in mitochondrial biogenesis, migration, and cellular stress response. Given that MNRR1 can regulate both apoptosis and mitochondrial respiration, as well as migration, we hypothesize that it can modulate metastatic spread. Using ovarian cancer models, we show heterogeneous protein expression levels of MNRR1 across samples tested and cell-dependent control of its stability and binding partners. In addition to its anti-apoptotic and bioenergetic functions, MNRR1 is both necessary and sufficient for a focal adhesion and ECM repertoire that can support spheroid formation. Its ectopic expression is sufficient to induce the adhesive glycoprotein THBS4 and the type 1 collagen, COL1A1. Conversely, its deletion leads to significant downregulation of these genes. Furthermore, loss of MNRR1 leads to delay in tumor growth, curtailed carcinomatosis, and improved survival in a syngeneic ovarian cancer mouse model. These results suggest targeting MNRR1 may improve survival in ovarian cancer patients.

Preventive cancer stem cell-based vaccination modulates tumor development in syngeneic colon adenocarcinoma murine model

BACKGROUND

Cancer stem cells (CSCs), a rare sub-fraction of tumor cells, with the capability of self-renewal and strong oncogenicity are tightly responsible for chemo and radio resistance and tumor metastasis in colorectal cancer. Hence, CSCs targeting would improve the efficacy of therapeutic strategies and clinical outcomes.

METHODS

Here, using three-dimensional CSC spheroids and syngeneic mice model, we evaluated the cancer preventive impact of CSCs-based vaccination. CSCs enrichment was performed via colonosphere formation from CT-26 cell line and CT-26-derived tumor biopsy and characterized by confirming high expression of key stemness genes (OCT4, SOX2, and NANOG) and CSC-related surface biomarkers (CD166, DCLK1, and CD133) via real-time PCR and flow cytometry, respectively. Then, the stemness phenotype and self-renewal in CSC-enriched spheroids were further confirmed by showing serial sphere formation capacity, clonogenicity potential, and enhanced in vivo tumorigenic capacity compared to their parental counterparts. CSCs lysates were used as vaccines in prophylactic settings compared to the parental cell lysate and PBS groups.

RESULT

Immunization of syngeneic mice with CSCs lysates was effective in the prevention of tumor establishment and significantly decreased tumor growth rate accompanied by an improvement in survival rate in tumor-bearing mice compared to groups subjected to parental cells lysate and PBS. These results, for the first time, showed that mice immunized with cell lysate from tumor biopsy-derived spheroids are resistant to tumor induction. Immunofluorescence staining indicated that only the serum antibodies from CSC-vaccinated mice reacted with colonospheres.

CONCLUSIONS

These findings represent CSCs lysate-based vaccination as a potential approach to hampering immunotherapy failure of colorectal cancer which along with other traditional therapies may effectively apply to prevent the establishment of aggressive tumors harboring stemness features.

Structure and Function of Potential Glycosylation Sites of Dynactin-Associated Protein dynAP

Overexpression of human dynactin-associated protein (dynAP) transforms NIH3T3 cells. DynAP is a single-pass transmembrane protein with a carboxy-terminal region (amino acids 135-210) exposed to the outside of the cell possessing one potential N-glycosylation site (position 143) and a distal C-terminal region (residues 173-210) harboring a Thr/Ser-rich (T/S) cluster that may be O-glycosylated. In SDS-PAGE, dynAP migrates anomalously at ~ 45 kDa, much larger than expected (22.5 kDa) based on the amino acid composition. Using dynAP mutants, we herein showed that the T/S cluster region is responsible for the anomalous migration. The T/S cluster region is required for transport to the cytoplasmic membrane and cell transformation. We produced and purified the extracellular fragment (dynAP135-210) in secreted form and analyzed the attached glycans. Asn143 displayed complex-type glycosylation, suggesting that oligosaccharide transferase may recognize the NXT/S sequon in the secretory form, but not clearly in full-length dynAP. Core I-type O-glycosylation (Gal-GalNAc) was observed, but the mass spectrometry signal was weak, clearly indicating that further studies are needed to elucidate modifications in this region.

HΜGB1/sRAGE levels differ significantly between transudates and exudates

High mobility group box 1(HMGB1) protein operates as an alarmin with multiple roles in immunity and cell homeostasis. It is highly expressed in epithelial barrier sites and acts via the binding to the receptor for advanced glycation end products (RAGE). Production of HMGB1 and soluble RAGE (sRAGE), a decoy receptor for HMGB1, has been implicated in several pulmonary diseases, but both have been scarcely investigated in pleural diseases. The aim of this study was to determine the levels of HMGB1 and sRAGE in transudative, malignant and parapneumonic pleural effusions (PEs) and to investigate the effect of low and high HMGB1 pleural fluid levels on MeT-5A cell adhesion, migration and spheroid formation, in each group. HMGB1 and sRAGE levels were significantly lower and higher in transudative PEs compared to malignant and parapneumonic PEs, respectively. Patients above 65 years of age had significantly lower HMGB1 and higher sRAGE levels compared to patients below 65 years old. Furthermore, incubation of MeT-5A cells with malignant or parapneumonic PEs bearing low or high levels of HMGB1 yielded significant differential effects on MeT-5A cell adhesion, migration and spheroid formation. In all types of effusions, high HMGB1 levels correlated with more adherence compared to low HMGB1 levels. In transudative and malignant PEs high HMGB1 levels correlated with decreased migration of MeT-5A cells while in parapneumonic ones the effect was the opposite. Only samples from parapneumonic PEs high in HMGB1 achieved uniform spheroid formation. These results reveal a clinical context-dependent effect of the HMGB1/sRAGE axis in PEs.

A novel Golgi mannosidase inhibitor: Molecular design, synthesis, enzyme inhibition, and inhibition of spheroid formation

Effective chemotherapy for solid cancers is challenging due to a limitation in permeation that prevents anticancer drugs from reaching the center of the tumor, therefore unable to limit cancer cell growth. To circumvent this issue, we planned to apply the drugs directly at the center by first collapsing the outer structure. For this, we focused on cell-cell communication (CCC) between N-glycans and proteins at the tumor cell surface. Mature N-glycans establish CCC; however, CCC is hindered when numerous immature N-glycans are present at the cell surface. Inhibition of Golgi mannosidases (GMs) results in the transport of immature N-glycans to the cell surface. This can be employed to disrupt CCC. Here, we describe the molecular design and synthesis of an improved GM inhibitor with a non-sugar mimic scaffold that was screened from a compound library. The synthesized compounds were tested for enzyme inhibition ability and inhibition of spheroid formation using cell-based methods. Most of the compounds designed and synthesized exhibited GM inhibition at the cellular level. Of those, AR524 had higher inhibitory activity than a known GM inhibitor, kifunensine. Moreover, AR524 inhibited spheroid formation of human malignant cells at low concentration (10 µM), based on the disruption of CCC by GM inhibition.

Interleukin-8 Induces Proliferation of Ovarian Cancer Cells in 3D Spheroids

Ovarian cancer (OC) is the most common cause of cancer deaths among gynecological malignancies. OC ascites contain multicellular spheroid aggregates, which exhibit increased pro-survival signaling, invasive behavior, and chemotherapeutic resistance. OC cells are characterized by an increased expression of the pro-inflammatory and pro-angiogenic chemokine interleukin-8 (IL-8, CXCL8), which increases their survival and migration, thus contributing to OC metastasis and angiogenesis. While previous studies have shown that IL-8 increases proliferation of OC cells grown in monolayer cultures, the effect of IL-8 on proliferation of OC cells grown in 3D spheroids has not been investigated. The spheroid 3D culture assays have been particularly useful in translational research since they allow cell-to-cell interactions that resemble tumor growth in vivo, while allowing easy cell manipulations and visualization. Here, we used the 3D spheroid culture assay to investigate the effect of IL-8 on OC cell proliferation. Using this assay, our results show that IL-8 significantly increases proliferation of OC cells grown in 3D spheroids.

Scaffold-free bioprinting of mesenchymal stem cells using the Regenova printer: Spheroid characterization and osteogenic differentiation

Limitations in scaffold material properties, such as sub-optimal degradation time, highlight the need for alternative approaches to engineer de novo tissues. One emerging solution for fabricating tissue constructs is scaffold-free tissue engineering. To facilitate this approach, three-dimensional (3D) bioprinting technology (Regenova Bio 3D Printer) has been developed to construct complex geometric shapes from discrete cellular spheroids without exogenous scaffolds. Optimizing spheroid fabrication and characterizing cellular behavior in the spheroid environment are important first steps prior to printing larger constructs. Here, we characterized spheroids of immortalized mouse bone marrow stromal cells (BMSCs) that were differentiated to the osteogenic lineage. Immortalized BMSCs were seeded in low attachment 96-well plates in various numbers to generate self-aggregated spheroids either under the force of gravity or centrifugation. Cells were cultured in control or osteogenic media for up to 28 days. Spheroid diameter, roundness and smoothness were measured. Cell viability, DNA content and alkaline phosphatase activity were assessed at multiple time points. Additionally, expression of osteogenic markers was determined using real time qPCR. Spheroids formed under gravity with 20 K, 30 K and 40 K cells had average diameters of 498.5 ± 8.3 μm, 580.0 ± 32.9 μm and 639.2 ± 54.0 μm, respectively, while those formed under 300G centrifugation with the same numbers of cells had average diameters of 362.3 ± 3.5 μm, 433.1 ± 6.4 μm and 491.2 ± 8.0 μm. Spheroids formed via centrifugation were superior to those formed by gravity, as evidenced by better roundness and smoothness and double the retention of DNA (cellular) content. Cells in spheroids exhibited a robust osteogenic response to the differentiation medium, including higher mRNA expression of alkaline phosphatase, collagen type I, and osteocalcin than those cultured in control medium, as well as greater alkaline phosphatase activity. The optimal spheroid fabrication technique from this study was to aggregate 40K cells under 150-300G centrifugation. In future investigations, these spheroids will be 3D printed into larger tissue constructs.

Angiotensin II promotes ovarian cancer spheroid formation and metastasis by upregulation of lipid desaturation and suppression of endoplasmic reticulum stress

Background

Angiotensin II (ANGII) and its receptor (AGTR1) have been proposed as significant contributors to metastasis in multiple cancers. Further, high AGTR1 levels are associated with poor epithelial ovarian cancer (EOC) outcomes. However, the mechanistic basis for these effects is unknown. Recent studies have suggested that ovarian cancer metastasis is highly dependent on the formation of multicellular spheroids (MCS). To understand the associations between the ANGII/AGTR1 pathway and cancer outcomes, we evaluated the effects of ANGII on MCS formation by ovarian cancer cells and used a proteomic approach to analyze the mechanistic basis.

Methods

We used the data from the GENT database and immunohistochemistry staining to assess the AGTR1 expression in epithelial ovarian cancer (EOC) patients and to assess its role in cancer progression. Colony formation assay, 3D culture assay, and transwell assays were used to analyze the effect of ANGII on the MCS formation and cell migration. The signaling pathways of AGTR1 and transactivation of epidermal growth factor receptor (EGFR) transactivation were investigated by the western blotting analysis. Xenograft models were used to determine the role of AGTR1 in ovarian cancer metastasis. ANGII release from ovarian cancer cells and ANGII levels in the EOC ascites fluid were measured by immunoassay. A shotgun proteomic approach was used to explore the detail molecular mechanism. Modulation of lipid desaturation and endoplasmic reticulum stress were verified by the in vitro and in vivo functional assays.

Results

AGTR1 expression was negatively correlated with EOC prognosis. AGTR1activation significantly enhanced the MCS formation and cell migration. ANGII triggered both of the classical AGTR1 pathway and the EGFR transactivation. ANGII administration increased peritoneal metastasis. In addition, ovarian cancer cells secreted ANGII and enhanced cancer metastasis in a positive feedback manner. Based on the proteomic data, lipid desaturation was activated by induction of stearoyl-CoA desaturase-1 (SCD1), which suggests that inhibition of SCD1 may significantly reduce MCS formation by increasing endoplasmic reticulum stress.

Conclusions

ANGII promotes MCS formation and peritoneal metastasis of EOC cells. AGTR1 activation increases the lipid desaturation via SCD1 upregulation, which ultimately reduces endoplasmic reticulum stress in MCS. This mechanism explained the association between high levels of AGTR1 and poor clinical outcomes in EOC patients.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1127-x) contains supplementary material, which is available to authorized users.

The FAK inhibitor BI 853520 inhibits spheroid formation and orthotopic tumor growth in malignant pleural mesothelioma

No tyrosine kinase inhibitors are approved for malignant pleural mesothelioma (MPM). Preclinical studies identified focal adhesion kinase (FAK) as a target in MPM. Accordingly, we assessed the novel, highly selective FAK inhibitor (BI 853520) in 2D and 3D cultures and in vivo. IC50 values were measured by adherent cell viability assay. Cell migration and 3D growth were quantified by video microscopy and spheroid formation, respectively. Phosphorylation of FAK, Akt, S6, and Erk was measured by immunoblot. The mRNA expression of the putative tumor stem cell markers SOX2, Nanog, CD44, ALDH1, c-myc, and Oct4 was analyzed by qPCR. Cell proliferation, apoptosis, and tumor tissue microvessel density (MVD) were investigated in orthotopic MPM xenografts. In all 12 MPM cell lines, IC50 exceeded 5 μM and loss of NF2 did not correlate with sensitivity. No synergism was found with cisplatin in adherent cells. BI 853520 decreased migration in 3 out of 4 cell lines. FAK phosphorylation was reduced upon treatment but activation of Erk, Akt, or S6 remained unaffected. Nevertheless, BI 853520 inhibited spheroid growth and significantly reduced tumor weight, cell proliferation, and MVD in vivo. BI 853520 has limited effect in adherent cultures but demonstrates potent activity in spheroids and in orthotopic tumors in vivo. Based on our findings, further studies are warranted to explore the clinical utility of BI 853520 in human MPM. KEY MESSAGES: Response to FAK inhibition in MPM is independent of NF2 expression or histotype. FAK inhibition strongly interfered with MPM spheroid formation. BI 853520 has been shown to exert anti-tumor effect in MPM.

The oncogene KRAS promotes cancer cell dissemination by stabilizing spheroid formation via the MEK pathway

Background

Peritoneal dissemination is a critical prognostic factor in ovarian cancer. Although stabilized spheroid formation promotes cancer cell peritoneal dissemination in ovarian cancer, the associated oncogenes are unknown. In this study, we assessed the role of the KRAS oncogene in ovarian cancer cell dissemination, focusing on the stability of cells in spheroid condition, as well as the modulation of intracellular signaling following spheroid transformation.

Methods

We used ID8, a murine ovarian cancer cell line, and ID8-KRAS, an oncogenic KRAS (G12 V)-transduced ID8 cell line in this study. Spheroid-forming (3D) culture and cell proliferation assays were performed to evaluate the growth characteristics of these cells. cDNA microarray analysis was performed to identify genes involved in KRAS-associated signal transduction in floating condition. A MEK inhibitor was used to evaluate the effect on cancer peritoneal dissemination.

Results

Cell viability and proliferation in monolayer (2D) cultures did not differ between ID8 and ID8-KRAS cells. However, the proportions of viable and proliferating ID8-KRAS cells in 3D culture were approximately 2-fold and 5-fold higher than that of ID8, respectively. Spheroid-formation was increased in ID8-KRAS cells. Analysis of peritoneal floating cells obtained from mice intra-peritoneally injected with cancer cells revealed that the proportion of proliferating cancer cells was approximately 2-fold higher with ID8-KRAS than with ID8 cells. Comprehensive cDNA microarray analysis revealed that pathways related to cell proliferation, and cell cycle checkpoint and regulation were upregulated specifically in ID8-KRAS cells in 3D culture, and that some genes partially regulated by the MEK-ERK pathway were upregulated only in ID8-KRAS cells in 3D culture. Furthermore, a MEK inhibitor, trametinib, suppressed spheroid formation in 3D culture of ID8-KRAS cells, although trametinib did not affect 2D-culture cell proliferation. Finally, we demonstrated that trametinib dramatically improved the prognosis for mice with ID8-KRAS tumors in an in vivo mouse model.

Conclusions

Our data indicated that KRAS promoted ovarian cancer dissemination by stabilizing spheroid formation and that the MEK pathway is important for stabilized spheroid formation. Disruption of spheroid formation by a MEK inhibitor could be a therapeutic target for cancer peritoneal dissemination.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4922-4) contains supplementary material, which is available to authorized users.

Spontaneous formation of tumor spheroid on a hydrophilic filter paper for cancer stem cell enrichment

Emerging evidence has demonstrated that cancer stem cells (CSCs) play critical roles in tumor invasion, metastasis and recurrence. The specific targeting capability on CSCs is of high importance for the development of effective anti-tumor therapeutics. However, isolation, enrichment and cultivation of these special and rare groups of tumor cells for in vitro analyses is a nontrivial job and requires particular culture medium and environmental control. Herein, we established a low-cost and efficient method for CSC enrichment by culturing prostate cancer cells on a hydrophilic filter paper. We found that tumor spheroids could form spontaneously on a pristine filter paper solely with regular cell culture medium. The paper-grown cells had elevated expression of putative CSC markers, indicating increased stemness of the cancer cells. Moreover, increased resistance of the chemotherapeutic drug doxorubicin was observed on the formed CSC spheroids compared to regular culture. The properties of the filter paper were characterized to investigate the underlying mechanism behind the promoted tumor spheroid formation. The obtained results suggested that the excellent hydrophilicity of the cellulose fibers retarded the hydrophobic interaction-mediated cell anchoring on the cellulose fibers, while the limited space/niche between fibers promoted the aggregation of cells. In addition, biocompatible paper-based materials are able to realize convenient assembly of tissue-like structures for developing in vitro disease models or organs-on-paper applications. Therefore, hydrophilic filter papers could be a low-cost material for construction of various assay platforms for isolating and enriching CSCs, screening anti-tumor drugs, and constructing tumor models in vitro.

Effects of three-dimensional spheroid culture on equine mesenchymal stem cell plasticity

Mesenchymal stem cells (MSCs) are useful candidates for tissue engineering and cell therapy fields. We optimize culture conditions of equine adipose tissue-derived MSCs (eAD-MSCs) for treatment of horse fractures. To investigate enhancing properties of three-dimensional (3D) culture system in eAD-MSCs, we performed various sized spheroid formation and determined changes in gene expression levels to obtain different sized spheroid for cell therapy. eAD-MSCs were successfully isolated from horse tailhead. Using hanging drop method, spheroid formation was generated for three days. Quantitative real-time PCR was performed to analyze gene expression. As results, expression levels of pluripotent markers were increased depending on spheroid size and the production of PGE₂ was increased in spheroid formation compared to that in monolayer. Ki-67 showed a remarkable increase in the spheroid formed with 2.0 × 10⁵ cells/drop as compared to that in the monolayer. Expression levels of angiogenesis-inducing factors such as VEGF, IL-6, IL-8, and IL-18 were significantly increased in spheroid formation compared to those in the monolayer. Expression levels of bone morphogenesis-inducing factors such as Cox-2 and TGF-β1 were also significantly increased in spheroid formation compared to those in the monolayer. Expression levels of osteocyte-specific markers such as RUNX2, osteocalcin, and differentiation potential were also significantly increased in spheroid formation compared to those in the monolayer. Therefore, spheroid formation of eAD-MSCs through the hanging drop method can increases the expression of angiogenesis-inducing and bone morphogenesis-inducing factors under optimal culture conditions.

Characterization of isolated liver sinusoidal endothelial cells for liver bioengineering

BACKGROUND

The liver sinusoidal capillaries play a pivotal role in liver regeneration, suggesting they may be beneficial in liver bioengineering. This study isolated mouse liver sinusoidal endothelial cells (LSECs) and determined their ability to form capillary networks in vitro and in vivo for liver tissue engineering purposes.

METHODS AND RESULTS

In vitro LSECs were isolated from adult C57BL/6 mouse livers. Immunofluorescence labelling indicated they were LYVE-1⁺/CD32b⁺/FactorVIII⁺/CD31^-. Scanning electron microscopy of LSECs revealed the presence of characteristic sieve plates at 2 days. LSECs formed tubes and sprouts in the tubulogenesis assay, similar to human microvascular endothelial cells (HMEC); and formed capillaries with lumens when implanted in a porous collagen scaffold in vitro. LSECs were able to form spheroids, and in the spheroid gel sandwich assay produced significantly increased numbers (p = 0.0011) of capillary-like sprouts at 24 h compared to HMEC spheroids. Supernatant from LSEC spheroids demonstrated significantly greater levels of vascular endothelial growth factor-A and C (VEGF-A, VEGF-C) and hepatocyte growth factor (HGF) compared to LSEC monolayers (p = 0.0167; p = 0.0017; and p < 0.0001, respectively), at 2 days, which was maintained to 4 days for HGF (p = 0.0017) and VEGF-A (p = 0.0051). In vivo isolated mouse LSECs were prepared as single cell suspensions of 500,000 cells, or as spheroids of 5000 cells (100 spheroids) and implanted in SCID mouse bilateral vascularized tissue engineering chambers for 2 weeks. Immunohistochemistry identified implanted LSECs forming LYVE-1⁺/CD31^- vessels. In LSEC implanted constructs, overall lymphatic vessel growth was increased (not significantly), whilst host-derived CD31⁺ blood vessel growth increased significantly (p = 0.0127) compared to non-implanted controls. LSEC labelled with the fluorescent tag DiI prior to implantation formed capillaries in vivo and maintained LYVE-1 and CD32b markers to 2 weeks.

CONCLUSION

Isolated mouse LSECs express a panel of vascular-related cell markers and demonstrate substantial vascular capillary-forming ability in vitro and in vivo. Their production of liver growth factors VEGF-A, VEGF-C and HGF enable these cells to exert a growth stimulus post-transplantation on the in vivo host-derived capillary bed, reinforcing their pro-regenerative capabilities for liver tissue engineering studies.

3D Co-culture System of Tumor-associated Macrophages and Ovarian Cancer Cells

Ovarian cancer is fairly unique in that ovarian carcinoma cells can detach and spread directly through peritoneal cavity. It has been unclear, however, how detached cancer cells survive in the peritoneum and form spheroid structure. We have recently reported that there is a strong correlation between Tumor-associated macrophages (TAMs)-associated spheroid and clinical pathology of ovarian cancer, and that TAMs promote spheroid formation and tumor growth at early stages of transcoelomic metastasis in orthotopic mouse models. We have established an in vitro spheroid formation assay using a 3D co-culture system in which mouse GFP⁺F4/80⁺CD206⁺ TAMs isolated from spheroids of ovarian cancer-bearing donor tomato^lysM-cre mice were mixed with ID8 cells (TAM:ID8 at a ratio of 1:10) in medium containing 2% Matrigel and seeded onto the 24-well plate precoated with Matrigel. As transcoelomic metastasis is also associated with many other cancers such as pancreatic and colon cancers, TAM-mediated spheroid formation assay would provide a useful approach to define the molecular mechanism and therapeutic targets for ovarian cancer and other transcoelomic metastasis cancers.

Enhanced viability and neural differential potential in poor post-thaw hADSCs by agarose multi-well dishes and spheroid culture

Human adipose-derived stem cells (hADSCs) are potential adult stem cells source for cell therapy. But hADSCs with multi-passage or cryopreservation often revealed poor growth performance. The aim of our work was to improve the activity of poor post-thaw hADSCs by simple and effective means. We describe here a simple method based on commercially available silicone micro-wells for creating hADSCs spheroids to improve viability and neural differentiation potential on poor post-thaw hADSCs. The isolated hADSCs positively expresse d CD29, CD44, CD105, and negatively expressed CD34, CD45, HLA-DR by flow cytometry. Meanwhile, they had adipogenic and osteogenic differentiation capacity. The post-thaw and post-spheroid hADSCs from poor growth status hADSCs showed a marked increase in cell proliferation by CKK-8 analysis, cell cycle analysis and Ki67/P27 quantitative polymerase chain reaction (qPCR) analysis. They also displayed an increase viability of anti-apoptosis by annexin v and propidium iodide assays and mitochondrial membrane potential assays. After 3 days of neural induction, the neural differentiation potential of post-thaw and post-spheroid hADSCs could be enhanced by qPCR analysis and western blotting analysis. These results suggested that the spheroid formation could improve the viability and neural differentiation potential of bad growth status hADSCs, which is conducive to ADSCs research and cell therapy.