Stem Cell Characteristics Research Articles

Abstract 4250: Adherent and spheroid cell models of patient-derived xenograft for drug development and translational research

Abstract Introduction: The development of new drugs in cancer therapy comprises toxicity and efficacy tests with increasing complexity. First and foremost, in vitro experiments are performed with well-established cancer cell lines, which are subsequently validated in animal experiments as prerequisite for clinical trials. Until a few years ago, there were gaps in the complexity chain between in vitro and in vivo experiments. Ethical considerations have led to use of systems like organ on a chip or mini-organ 3D in vitro models. In cancer research, cell cultures or organoids are generated from patient tumor material. However, these cultures only reflect the tumor of one patient, which is why panels of patient tumors should be used to evaluate the effectiveness of drugs on different patients. In vivo panel screens of patient derived xenografts (PDX) mouse models need high numbers of animals and takes several months. A pre-screen with in vitro models generated from in vivo PDX tissues allows large scale and faster pre-screens complementing in vivo systems for more focused in vivo analyses. Methods: Currently we have a pool of more than 600 established PDX models of 21 tumor entities. From this pool, cancer tissues of glioblastoma, mesothelioma, gastric, head/neck, lung and breast cancer were processed in single cell suspensions and cultured under defined conditions to obtain adherent cells or spheroids. The generated PDX in vitro cultures were analyzed for cellular impurities, cancer stem cell content and perpetuation of in vivo PDX characteristics. FACS analyses for tumor specific markers, chemo sensitivity assays and growth characteristics of the PDX derived cell lines (especially for glioblastoma) were analyzed. Results: From PDX tissues used, 90% grew as adherent and/or spheroid PDX derived in vitro cultures, in which mouse cells were entirely depleted. A high percentage of these cultures showed enriched cancer stem cell features and stem cell marker expression. Tumor marker expression and standard drug sensitivity data correlate to the in vivo PDX and derived in vitro cell culture models. RNAseq data were used to predict drug sensitivities in silico for untested drugs and drug combinations on our newly established PDX derived glioblastoma cell lines. Initial screens with predicted candidates were performed. Promising conditions were successfully repeated in corresponding animal PDX models. Conclusion: The newly developed technology for establishment if in vitro cell cultures from PDX efficiently generates stably growing cell lines possessing all key features of the original PDX. These cell lines can be used for initial pre-screens to optimize and improve selection of pharmacologically active drugs or drug combinations before initiating in vivo PDX studies. Citation Format: Lars Winkler, Joshua Alcaniz, Maria Stecklum, Wolfgang Walther, Jens Hoffmann. Adherent and spheroid cell models of patient-derived xenograft for drug development and translational research [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 4250.

Abstract 6395: Metabolic dysregulation as a determinant of prognosis and response to sorafenib in liver cancer

Abstract Background & Aims: Elevated metabolic activity is a defining characteristic of liver cancer. Nevertheless, our understanding of the molecular underpinnings of high metabolic activity in liver cancer and its impact on clinical outcomes and treatment responses remains limited. We aimed to elucidate the metabolic features of liver cancer associated with clinical outcomes, particularly overall survival and responsiveness to sorafenib treatment. Methods: Utilizing cross-species comparisons of genomic data, we integrated gene expression profiles from liver tissues in metabolically challenged mice and from patients with cirrhosis and liver cancer. To categorize patients, we developed a genomic predictor and applied it to gene expression data from a cirrhosis cohort (n=216) and large liver cancer cohorts (n=1390). Comprehensive statistical and informatics analyses were conducted to evaluate clinical significance, including overall survival and responses to standard treatments. Moreover, we integrated genomic data derived from patient-derived xenograft (PDX) models into our analytical framework. Results: Our integrated data analysis unveiled three distinct metabolic subtypes of tissues: high, moderate, and low metabolic subtypes. In the cirrhosis cohort, the high metabolic subtype was significantly associated with early liver cancer development. Among liver cancer cohorts, the high metabolic subtype exhibited characteristics such as poor survival, heightened hepatic stem cell features, increased genomic instability, and elevated expression of AFP, KRT19, EPCAM, and SALL4. Notably, when liver cancer patients undergoing systemic sorafenib treatment were stratified using our genomic predictor, those with low and moderate metabolic activity derived significant benefits from sorafenib therapy. Conversely, the high metabolic subtype displayed substantial resistance to sorafenib, suggesting that metabolic activity may dictate the response of liver cancer cells to sorafenib treatment. Gene network analysis of the metabolic expression signature identified multiple signaling pathways that potentially contribute to sorafenib resistance in liver cancer cells. Our analysis predicted the activation of pathways such as the TGF-β pathway (TGFB1), consistent with previous findings of TGF-β pathway activation in highly metabolic cancer cells. Additionally, our analysis identified YAP1, HIF1A, and MAPK pathways as activated pathways in sorafenib-resistant liver cancer. Conclusions: This study identifies clinically and metabolically distinct subtypes of liver cancer, biomarkers associated with these subtypes, and mechanisms underlying metabolic-mediated resistance of liver cancer cells to sorafenib. Furthermore, the metabolic subtypes observed in PDX models provide valuable tools for selecting appropriate preclinical models for future research endeavors. Citation Format: Hyewon Park, Sowon Park, Sung-Hwan Lee, Yun Seong Jeong, Bohwa Sohn, Sun Young Yim, Ju-Seog Lee. Metabolic dysregulation as a determinant of prognosis and response to sorafenib in liver cancer [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 6395.

The role of lipids in genome integrity and pluripotency.

Pluripotent stem cells (PSCs), comprising embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs), offer immense potential for regenerative medicine due to their ability to differentiate into all cell types of the adult body. A critical aspect of harnessing this potential is understanding their metabolic requirements during derivation, maintenance, and differentiation in vitro. Traditional culture methods using fetal bovine serum often lead to issues such as heterogeneous cell populations and diminished pluripotency. Although the chemically-defined 2i/LIF medium has provided solutions to some of these challenges, prolonged culturing of these cells, especially female ESCs, raises concerns related to genome integrity. This review discusses the pivotal role of lipids in genome stability and pluripotency of stem cells. Notably, the introduction of lipid-rich albumin, AlbuMAX, into the 2i/LIF culture medium offers a promising avenue for enhancing the genomic stability and pluripotency of cultured ESCs. We further explore the unique characteristics of lipid-induced pluripotent stem cells (LIP-ESCs), emphasizing their potential in regenerative medicine and pluripotency research.

Retracted: Development of a 5-Gene Signature to Evaluate Lung Adenocarcinoma Prognosis Based on the Features of Cancer Stem Cells.

[This retracts the article DOI: 10.1155/2022/4404406.].

Isolation, Biological Characterization, and Quality Inspection of Human Umbilical Cord-derived Mesenchymal Stem Cells for Clinical Research

Background: Human umbilical cord mesenchymal stem cells (hUCMSCs) represent a valuable and versatile cell type derived from the umbilical cord tissue of newborns. These cells exhibit diverse characteristics, including multipotent differentiation potential and low immunogenicity. hUCMSCs hold promise for clinical applications, yet concerns persist regarding their chromosomal stability. This study employs short tandem repeat (STR) analysis to assess genomic integrity. By focusing on chromosomal stability, the study aims to enhance confidence in the clinical viability of hUCMSCs, contributing to their safe and effective use in regenerative medicine. hUCMSCs were extracted from healthy newborn umbilical cords using tissue block adherence and enzyme digestion. The third generation of hUCMSCs undergoes biological characterization and quality checks, including examinations of cell morphology, viability, growth curves, surface markers, cell cycle, and multi-lineage differentiation potential. The result of the present study shows that hUCMSCs exhibit mesenchymal stem cell characteristics, with robust growth and high viability. Positive surface markers are expressed at rates exceeding 95%, while negative markers are ≤2%. Cell karyotyping analysis, STR spectrum identification, and chromosomal microarray analysis confirm genetic stability. Microbial testing shows the absence of contaminants, and immunological studies demonstrate the immunomodulatory capabilities of hUCMSCs. Specific residues, such as trypsin, were not detected. In conclusion, hUCMSCs produced under strict GLP and GMP conditions meet the quality guidelines for clinical application in various stem cell therapies. The findings support the clinical application of hUCMSCs in various medical contexts.

Deciphering "Immaturity-Stemness" in Human Epidermal Stem Cells at the Levels of Protein-Coding and Non-Coding Genomes: A Prospective Computational Approach.

The epidermis hosts populations of epithelial stem cells endowed with well-documented renewal and regenerative functions. This tissue thus constitutes a model for exploring the molecular characteristics of stem cells, which remain to date partially characterized at the molecular level in human skin. Our group has investigated the regulatory functions of the KLF4/TGFB1 and the MAD4/MAX/MYC signaling pathways in the control of the immaturity-stemness versus differentiation fate of keratinocyte stem and precursor cells from human interfollicular epidermis. We described that down-modulation of either KLF4 or MXD4/MAD4 using RNA interference tools promoted an augmented stemness cellular status; an effect which was associated with significant transcriptional changes, as assessed by RNA-sequencing. Here, we have implemented a computational approach aimed at integrating the level of the coding genome, comprising the transcripts encoding conventional proteins, and the non-coding genome, with a focus on long non-coding RNAs (lncRNAs). In addition, datasets of micro-RNAs (miRNAs) with validated functions were interrogated in view of identifying miRNAs that could make the link between protein-coding and non-coding transcripts. Putative regulons comprising both coding and long non-coding transcripts were built, which are expected to contain original pro-stemness candidate effectors available for functional validation approaches. In summary, interpretation of our basic functional data together with in silico biomodeling gave rise to a prospective picture of the complex constellation of transcripts regulating the keratinocyte stemness status.

Establishment of an induced pluripotent stem cell (iPSC) line (INNDSUi005-A) from a healthy female Chinese Han

We obtained skin fibroblasts from a 34-year-old healthy woman and established a human induced pluripotent stem cell (hiPSC) line (INDSUi005-A) using a non-integrated reprogramming approach. The obtained cells have typical characteristics of embryonic stem cells, can express specific pluripotency markers and have the ability to differentiate into three germ layers in vitro. This iPSC cell line can be used as an in vitro model for studying disease mechanisms and developing novel therapies.

Analysis of the differences in the characteristics of mesenchymal stem cells derived from jaw and long bones based on single-cell RNA-sequencing

Objective: To study the whole bone marrow cellular composition of jaw and long bones, and further analyze the heterogeneity of mesenchymal stem cells (MSCs) derived from these two tissue, aiming at exploring the differences in functional characteristics of bone MSCs from different lineage sources. Methods: The Seurat package of R language was used to analyze the mandibular and femur whole bone marrow single-cell RNA-sequencing (scRNA-seq) datasets in the literature, and the subpopulations were annotated by reference to the marker genes reported by previous studies. The differentially expressed genes between mandible-derived MSCs (M-MSCs) and femur-derived MSCs (F-MSCs) were calculated, and cell-cell communication analysis between M-MSCs or F-MSCs with other cell populations was performed. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed on up-regulated and down-regulated differentially expressed genes of M-MSCs, and Gene Set Enrichment Analysis (GSEA) was performed on M-MSCs or F-MSCs. Results: cRNA-seq analysis showed that the mandible and femur had the same bone marrow cell composition, but there were differences in the proportion of specific cell populations. Also, there were significantly differentially expressed genes between M-MSCs and F-MSCs. In addition, cell-cell communication analysis revealed differences in numbers of ligand-receptor pairs between M-MSCs or F-MSCs with other cell populations. Furthermore, GO, KEGG and GSEA analysis showed that M-MSCs had higher extracellular matrix production potential than F-MSCs, but had lower ability to regulate other cells in the bone marrow, especially immune cells. Conclusions: M-MSCs and F-MSCs showed distinct differences in the gene expression pattern and up-regulated signaling pathways, which may be closely related to the developmental sources and functional characteristics of jaw and long bones.

Characteristics of Cancer Stem Cells and Their Potential Role in Endometrial Cancer.

Endometrial cancer is one of most common types of gynaecological tumours in developing countries. It has been suggested that cancer stem cells play an important role in the development of endometrial cancer. These are a subset of highly tumorigenic cells with similar features to normal stem cells (unlimited proliferation, multi-potential differentiation, self-renewal, aggressiveness, invasion, recurrence, and chemo- and endocrine therapy resistance). Wnt/β-catenin, Hedghog, and Notch1 are the most frequently activated pathways in endometrial cancer stem cells. The presence of cancer stem cells is associated with the resistance to chemotherapy caused by different mechanisms. Various markers, including CD24, CD40, CD44, CD9, CD133, and CD 166, have been identified on the surface of these cells. A higher expression of such markers translates into enhanced tumorigenicity. However, there is no strong evidence showing that any of these identified markers can be used as the universal marker for endometrial cancer stem cells. Growing data from genomic and proteomic profiling shed some light on the understanding of the molecular basis of cancers in humans and the role of cancer stem cells. However, there is much left to discover. Therefore, more studies are needed to fully uncover their functional mechanisms in order to prevent the development and recurrence of cancer, as well as to enhance treatment effectiveness.

Platelet-Activating Factor Receptor (PAFR) Regulates Retinal Progenitor/Stem Cells Profile in Ciliary Epithelium Cells.

The retina is a central nervous tissue essential to visual perception and highly susceptible to environmental damage. Lower vertebrate retinas activate intrinsic regeneration mechanisms in response to retinal injury regulated by a specialized population of progenitor cells. The mammalian retina does not have populations of progenitor/stem cells available to activate regeneration, but contains a subpopulation of differentiated cells that can be reprogrammed into retinal stem cells, the ciliary epithelium (CE) cells. Despite the regenerative potential, stem cells derived from CE exhibit limited reprogramming capacity probably associated with the expression of intrinsic regulatory mechanisms. Platelet-activating factor (PAF) is a lipid mediator widely expressed in many cells and plays an important role in stem cell proliferation and differentiation. During mammalian development, PAF receptor signaling showed important effects on retinal progenitors' cell cycle regulation and neuronal differentiation that need to be further investigated. In this study, our findings suggested a dynamic role for PAF receptor signaling in CE cells, impacting stem cell characteristics and neurosphere formation. We showed that PAF receptors and PAF-related enzymes are downregulated in retinal progenitor/stem cells derived from PE cells. Blocking PAFR activity using antagonists increased the expression of specific progenitor markers, revealing potential implications for retinal tissue development and maintenance.

270 Radiologic diagnosis of Extranodal Extension (ENE) in patients with HPV-positive oropharyngeal cancer: consensus diagnosis and influence on prognosis

Tumor often progresses through the weakest part of any surrounding tissues. The extent of tumor invasion depends on: a. Aggressiveness of the tumor cells (e.g. number and invasive character of stem cells), b. robustness of the surrounding tissues and their composition (e.g. vessels), and c. time to allow the tumor to proliferate. The lymph node (LN) capsule comprises dense connective tissue stroma and collagenous fibers, and is a natural barrier that generally prevents further tumor progression. Permeation of tumor through the nodal capsule into surrounding tissues is termed “extranodal extension”. The idiosyncratic and inconsistent mechanism of ENE is imprecisely understood, but it is thought to be due to either tumor cell proliferation that outpaces the capacity of nodal capsular expansion (“ruptures” the LN capsule), or factors within the tumor or tumor microenvironment that facilitate the “breach” of the capsule. The latter might explain ENE in small LNs, or a “neglected” tumor (lengthy intranodal tumor growth with eventual “rupture” through an expanded nodal capsule). Several biomarkers (e.g. podoplanin) that are often associated with tumor aggressiveness have been reported to have a high expression in ENE+ LN. ENE represents a spectrum of tumor nodal invasion. The early sign of ENE can only be visible under the microscope (pathologic ENE); when ENE progresses further, the radiographic signal changes become apparent, making it visible on imaging (iENE). Most advanced ENE causes emergence of clinical surrogates (e.g. peau d'orange, or a “fixed” nodal mass), rendering it detectable by regular clinical examination (ENEc). iENE has been reported to be one of the strongest anatomic prognostic factors for overall survival (mainly due to increased risk of distant metastasis) in HPV-positive oropharyngeal carcinoma (HPV+ OPC), and is able to identify a subgroup of stage I disease with poor prognosis. Several deintensification trials (NRG-HN002, ORATOR, ORATOR2, E3311) have excluded HPV+ OPC with some form of iENE from trial enrolment. Several authors have proposed that iENE be included in future clinical N classification for HPV+ OPC. However, adoption of iENE in clinical care remains challenging because it is not a well-defined radiologic feature among the radiology community. Various definitions / descriptions of iENE have been used in literature. There is also insufficient awareness of the prognostic importance of this parameter in head and neck oncology community. The international iENE Expert Panel was convened under the HNCIG comprised expert internationally renowned neuroradiologists and clinicians. Several rounds of Delphi process were conducted to consolidate iENE definition. The consensus recommendations on the terminology and diagnostic criteria for iENE were generated. The experts in the consensus process recognized the following as criteria for the diagnosis of iENE: clear evidence of irregular or indistinct nodal margin/border; extension into perinodal fat; extension into adjacent structures, and conglomerate/matted/coalescent nodes. These recommendations have been endorsed by 19 national organisations, representing 34 countries. With increased awareness and consolidated definition as well as training, iENE could become an important baseline factor for risk stratification and staging in HPV+ OPC.

Identification of TMZ resistance-associated histone post-translational modifications in glioblastoma using multi-omics data.

Glioblastoma multiforme (GBM) is among the most aggressive cancers, with current treatments limited in efficacy. A significant hurdle in the treatment of GBM is the resistance to the chemotherapeutic agent temozolomide (TMZ). The methylation status of the MGMT promoter has been implicated as a critical biomarker of response to TMZ. To explore the mechanisms underlying resistance, we developed two TMZ-resistant GBM cell lines through a gradual increase in TMZ exposure. Transcriptome sequencing of TMZ-resistant cell lines revealed that alterations in histone post-translational modifications might be instrumental in conferring TMZ resistance. Subsequently, multi-omics analysis suggests a strong association between histone H3 lysine 9 acetylation (H3K9ac) levels and TMZ resistance. We observed a significant correlation between the expression of H3K9ac and MGMT, particularly in the unmethylated MGMT promoter samples. More importantly, our findings suggest that H3K9ac may enhance MGMT transcription by facilitating the recruitment of the SP1 transcription factor to the MGMT transcription factor binding site. Additionally, by analyzing single-cell transcriptomics data from matched primary and recurrent GBM tumors treated with TMZ, we modeled the molecular shifts occurring upon tumor recurrence. We also noted a reduction in tumor stem cell characteristics, accompanied by an increase in H3K9ac, SP1, and MGMT levels, underscoring the potential role of H3K9ac in tumor relapse following TMZ therapy. The increase in H3K9ac appears to enhance the recruitment of the transcription factor SP1 to its binding sites within the MGMT locus, consequently upregulating MGMT expression and driving TMZ resistance in GBM.

Interplay of p62-mTORC1 and EGFR signaling promotes cisplatin resistance in oral cancer

Cisplatin resistance poses a major challenge in the treatment of oral squamous cell carcinoma (OSCC). Deeper investigations into the mechanisms underlying this drug resistance is of great importance. Here, we used cellular assays and clinical immunohistochemistry to examine molecular pathways involved in both innate and acquired cisplatin resistance. We demonstrated that the p62-mTORC1 signaling complex plays a pivotal role, and is driven by the EGFR signaling network, specifically through the PI3K-Akt axis and the transcription factor C/EBP-β. Elevated p-mTOR expression was associated with cancer relapse and poor prognosis among oral cancer patients. Additionally, we illustrated that mTOR inhibitors enhance the cytotoxic effect of cisplatin, by employing cancer stem cell characteristics. Our work unveils fundamental mechanisms for cisplatin resistance, thereby presenting therapeutic implications for OSCC.

Tumor-derived mesenchymal progenitor cell-related genes in the regulation of breast cancer proliferation.

Breast cancer (BC) is one of the most common malignancies worldwide, and its development is affected in various ways by the tumor microenvironment (TME). Tumor-derived mesenchymal progenitor cells (MPCs), as the most important components of the TME, participate in the proliferation and metastasis of BC in several ways. In this study, we aimed to characterize the genes associated with tumor-derived MPCs and determine their effects on BC cells. Tumor-derived MPCs and normal breast tissue-derived mesenchymal stem cells (MSCs) were isolated from tissues specimens of patients with BC. We conducted culture and passage, phenotype identification, proliferation and migration detection, inflammatory factor release detection, and other experiments on isolated MPCs from tumors and MSCs from normal breast tissues. Three paired tumor-derived MPCs and normal breast tissue-derived MSCs were then subjected to transcriptome analysis to determine the expression profiles of the relevant genes, and quantitative real-time polymerase chain reaction (qRT-PCR) was used to further confirm gene expression. Subsequently, the overexpression plasmids were transfected into tumor-derived MPCs, and the expression of various inflammatory factors of tumor-derived MPCs and their proliferation were characterized with a cell viability test reagent (Cell Counting Kit 8). Subsequently, the transfected tumor-derived MPCs were cocultured with BC cells using a conditioned medium coculture method to clarify the role of tumor-derived MSCs in BC. Tumor-derived MPCs expressed stem cell characteristics including CD105, CD90, and CD73 and exhibited adipogenic and osteogenic differentiation in vitro. The proliferation of tumor-derived MPCs was significantly lower than that of normal breast tissue-derived MSCs, and the invasive metastatic ability was comparable; however, MPCs were found to release inflammatory factors such as interleukin 6 (IL-6) and transforming growth factor β (TGF-β). Transcriptome analysis showed that stomatin (STOM), collagen and calcium binding EGF domains 1 (CCBE1), and laminin subunit alpha 5 (LAMA5) were significantly upregulated in tumor-derived MPCs. Among them, STOM was highly expressed in tumor-derived MPCs, which mediated the slow proliferation of MPCs and promoted the proliferation of BC cells. STOM, CCBE1, and LAMA5 were highly expressed in tumor-derived MPCs, with STOM being found to retard the proliferation of MPCs but promote the proliferation of BC cells. There findings present new possibilities in targeted microenvironmental therapy for BC.

Lactate-driven type I collagen deposition facilitates cancer stem cell-like phenotype of head and neck squamous cell carcinoma

Lactate is known to play a crucial role in the progression of malignancies. However, its mechanism in regulating the malignant phenotype of head and neck squamous cell carcinoma (HNSCC) remains unclear. This study found that lactate increases cancer stem cell (CSC) characteristics of HNSCC by influencing the deposition of type I collagen (Col I). Lactate promotes Col I deposition through two distinct pathways. One is to convert lactate to pyruvate, a substrate for Col I hydroxylation. The other is the activation of HIF1-α and P4HA1, the latter being a rate-limiting enzyme for Col I synthesis. Inhibition of these two pathways effectively counteracts lactate-induced enhanced cell stemness. Further studies revealed that Col I affects CSC properties by regulating cell cycle dynamics. In conclusion, our research proposes that lactate-driven Col I deposition is essential for the acquisition of CSC properties, and lactate-centric Col I deposition may be an effective target for CSCs.

Discrete Mechanistic Target of Rapamycin Signaling Pathways, Stem Cells, and Therapeutic Targets.

The mechanistic target of rapamycin (mTOR) is a serine/threonine kinase that functions via its discrete binding partners to form two multiprotein complexes, mTOR complex 1 and 2 (mTORC1 and mTORC2). Rapamycin-sensitive mTORC1, which regulates protein synthesis and cell growth, is tightly controlled by PI3K/Akt and is nutrient-/growth factor-sensitive. In the brain, mTORC1 is also sensitive to neurotransmitter signaling. mTORC2, which is modulated by growth factor signaling, is associated with ribosomes and is insensitive to rapamycin. mTOR regulates stem cell and cancer stem cell characteristics. Aberrant Akt/mTOR activation is involved in multistep tumorigenesis in a variety of cancers, thereby suggesting that the inhibition of mTOR may have therapeutic potential. Rapamycin and its analogues, known as rapalogues, suppress mTOR activity through an allosteric mechanism that only suppresses mTORC1, albeit incompletely. ATP-catalytic binding site inhibitors are designed to inhibit both complexes. This review describes the regulation of mTOR and the targeting of its complexes in the treatment of cancers, such as glioblastoma, and their stem cells.

The Use of Human Platelet Lysate as a Coating Substance for Adipose-Derived Stem Cell Expansion.

Large-scale production of mesenchymal stromal cells is essential for sufficient therapeutic doses in regenerative medicine. However, long-term cultivation encounters limited cell growth and cellular aging. Therefore, an alternative cell culture approach that promotes proliferation and attenuates cell senescence is required. Human platelet lysate (HPL) is a potent supplement for in vitro cell expansion. Applying HPL as a coating material can potentially improve mesenchymal stromal cell cultures. To examine the capacity of HPL, it was used to pre-coat a tissue culture plate for in vitro adipose-derived mesenchymal stromal cell expansion. Alterations in biological features of adipose-derived stem cells (ADSCs) were investigated, including cell adhesion assays, cell proliferation, population doubling time, and cellular senescence. ADSCs cultured on HPL-coated plates significantly increased cell adhesion rate, shortened population doubling time, and stimulated cell growth. The senescent cells were significantly decreased in ADSCs cultured in an HPL-coated plate, and the expression levels of senescence-associated genes, including p16, p21, and p53, were downregulated. Furthermore, Western blotting analysis revealed that HPL was enriched with fibronectin and vitronectin, essential cell adhesive proteins. HPL was effectively used as a coating material for ADSC expansions. Cellular cultivation on the HPL coating is an alternative approach for producing mesenchymal stromal cells.

Estrogen-related receptor alpha (ERRα) promotes the migration, invasion and angiogenesis of breast cancer stem cell-like cells.

Breast cancer progression, metastasis and recurrence are largely driven by breast cancer stem cells (BCSCs), which constitute a subset of tumor cells exhibiting stem cell characteristics. In this study, we evaluated the role of estrogen-related receptor alpha (ERRα) in the migration, invasion and angiogenesis of BCSCs. The inhibition of ERRα using XCT790 or knockdown of ERRα using shRNA inhibited the mammosphere formation efficiency, as well as the migration and invasion of BCSCs derived from the mammospheres of MCF7 and MDA-MB-231 (MB231) cells. Conversely, the overexpression of ERRα significantly increased the migration and invasion of BCSCs derived from the mammosphere. In addition, the XCT790 treatment or shERRα significantly downregulated the epithelial-mesenchymal transition (EMT), as evidenced by the downregulation in the expression of vimentin, Snail, Slug and N-cadherin in the mammospheres of MCF7 and MB231 cells. The chorioallantoic membrane assay showed that the conditioned media from XCT790-treated and shERRα cells significantly inhibited blood vessel formation and vessel length. Furthermore, XCT790 treatment or shERRα also downregulated the expression of molecular markers of angiogenesis, such as VEGF-A and Ang-2 in the mammospheres. Conversely, the overexpression of ERRα in MCF7 cells significantly increased both EMT and angiogenesis. These findings suggest that ERRα inhibits the migration, invasion and angiogenesis of BCSCs, suggesting as a potential target for breast cancer therapy.

MFAP5 Strengthened the Stem Cell Features of Non-small Cell Lung Cancer Cells by Regulating the FBW/Sox9 Axis.

Non-small cell lung cancer (NSCLC) is a type of malignant tumor with high morbidity as well as mortality. The process of lung cancer may be driven by cancer stem cells. It was known that MFAP5 enhanced the occurrence of diverse types of cancer. Also, MFAP5 has the potential to induce the degradation of FBW7 which is a tumor suppressor. Lower levels of FBW7 enhance the stability of Sox9, which is the cancer stem cell-related protein. However, whether the MFAP5 can modulate the stem cell features of NSCLC cells by modulating the FBW7/Sox9 axis is unclear. Therefore, this study aimed to explore the role of MFAP5/FBW7/Sox9 axis on the stem cell features of NSCLC cells and develop a new treatment of this carcinoma. In this study, we explored the effects of MFAP5 on the stem cell features of NSCLC cells for the first time. We established MFAP5 overexpression and knockdown NSCLC cells. Clone formation assays and cell sphere culture assays were conducted for the exploration of the growth and stem cell features of these cells. Western blotting was applied for the detection of Sox9 and FBW7 expression in these cells. CHX was applied for the treatment of these cells for the detection of degradation of Sox9. Finally, we overexpressed the Sox9 in MFAP5 knockdown NSCLC cells. MFAP5 promoted the growth and stem cell features of these cells. Knockdown of MFAP5 induced higher levels of FBW7 while restricting the expression of Sox9. Knockdown of MFAP5 aggravated the degradation of Sox9. Overexpression of Sox9 abrogated the efficacy of MFAP5 inhibition on the growth as well as stem cell features of these cells. The results of this study clarified the role of MFAP5/FBW7/Sox9 axis on the development of non-small cell lung cancer cells, providing the potential therapeutic target for the clinical treatment of NSCLC. MFAP5 maintained the stem cell features of non-small cell lung cancer cells by modulating FBW7/Sox9 axis.

Comparison of the effects of EGF, FGF-b, and NGF on the proliferation, migration, and reprogramming of primary rat Müller cells.

During the healing process of full-thickness macular holes (FTMHs), the closure and recovery of the hole depend on the migration, proliferation, and activation of Müller cells to promote the closure of holes and restoration of the photosensitive layer. In this study, we investigated the ability of the epidermal growth factor (EGF), fibroblast growth factor-basic (FGF-b), and nerve growth factor (NGF) to influence this process by regulating proliferation, migration, and reprogramming of primary rat Müller cells. Cell proliferation was measured using CCK8 [2- (2-Methoxy-4-nitrophenyl)-3- (4-nitrophenyl)-5- (2,4-disulfophenyl)-2H-tetrazolium Sodium Salt] colorimetric assays and EdU [5-Ethynyl-2'-deoxyuridine] assays over 48 h. Cell migration was measured using scratch-wound assays and transwell migration assays over 48 h. In addition, we conducted Western blot assays and immunofluorescence assays on cells that were specially treated for 1, 3, and 5 days for cell reprogramming. The percentage of EdU-positive cells in Nestin-positive have also been tested by co-immunofluorescence (Co-IF) staining. EGF and FGF-b significantly promoted the proliferation of Müller cells (p < 0.05) at a concentration of 0-50 ng/mL, but NGF did not (p > 0.05), compared to untreated controls. Exogenous FGF-b and EGF promote the reprogramming of primary rat Müller cells, significantly enhancing the neural stem cell marker Nestin after stimulation on the 1st, 3rd, and 5th days, respectively. The expression of Müller cell marker Vimentin was significantly (p < 0.05) reduced during this period compared to the control group. However, there was no significant difference between the NGF and control groups. Furthermore, the EGF group expressed stronger Nestin expression than the SCM group. The Co-IF staining showed that early 50% of activated cells came from newly proliferating cells on the 5th day. These observations suggest that FGF-b can promote the activation of Müller cells in a short time and enhance the possessive features of neural stem cells, while EGF may act for a longer period of time. This may further the understanding of growth factor therapy in treating FTMHs, and Müller glia may be promising candidates for cell replacement therapy.