scholarly journals A Developmentally Prometastatic Niche to Hepatoblastoma in Neonatal Liver mediated by the Cxcl1/Cxcr2 Axis

2021 ◽  
Author(s):  
Li Fan ◽  
Qingfei Pan ◽  
Wentao Yang ◽  
Selene C Koo ◽  
Cheng Tian ◽  
...  
Keyword(s):  
Hepg2 Cells ◽  
Tumor Hypoxia ◽  
Metastatic Potential ◽  
Cell Types ◽  
Orthotopic Transplantation ◽  
Pediatric Cancers ◽  
Very Young Children ◽  
Neonatal Liver ◽  
Patient Prognosis ◽  
Development Methods

Background and Rationale: Hepatoblastoma (HB) is the most common pediatric liver cancer. Its predominant occurrence in very young children led us to investigating whether the neonatal liver provides a protumorigenic niche to HB development. Methods: HB development was compared between orthotopic transplantation models established in postnatal day 5 and 60 mice (P5Tx and P60Tx models). Single-cell RNA-sequencing was performed using tumor and liver tissues from both models and the top candidate cell types and genes identified are investigated for their roles in HB cell growth, migration, and survival. Results: We found that various HB cell lines including HepG2 cells were consistently and considerably more tumorigenic and metastatic in the P5Tx model than in the P60Tx models. Sc-RNAseq of the P5Tx and P60Tx HepG2 models revealed that the P5Tx tumor was more hypoxic and had a larger number of activated hepatic stellate cells (aHSCs) in the tumor-surrounding liver which express significantly higher levels of Cxcl1 than those from the P60Tx model. We found these differences were developmentally present in normal P5 and P60 liver. We showed that the Cxcl1/Cxcr2 axis mediated HB cell migration and was critical to HB cell survival under hypoxia. Treating HepG2 P60Tx model with recombinant CXCL1 protein induced intrahepatic and pulmonary metastasis and CXCR2 knockout in HepG2 cells abolished their metastatic potential in the P5Tx model. Lastly, we showed that in metastatic HB patient tumors there was a similar larger population of aHSCs in the tumor-surrounding liver than in localized tumors, and tumor hypoxia was uniquely associated with HB patient prognosis among pediatric cancers. Conclusion: We demonstrated that the neonatal liver provides a prometastatic niche to HB development via the Cxcl1/Cxcr2 axis.

TAp73 opposes tumor angiogenesis by promoting hypoxia-inducible factor 1α degradation

2020 ◽  
Author(s):  
Lungwani Muungo
Keyword(s):  
Cancer Progression ◽  
Hypoxia Inducible Factor ◽  
Tumor Hypoxia ◽  
Human Lung Cancer ◽  
Regulatory Subunit ◽  
Patients With Cancer ◽  
Hypoxia Inducible Factor 1 ◽  
Chemically Induced ◽  
Induced Tumors ◽  
Patient Prognosis

Tumor hypoxia and hypoxia-inducible factor 1 (HIF-1) activationare associated with cancer progression. Here, we demonstrate thatthe transcription factor TAp73 opposes HIF-1 activity through anontranscriptional mechanism, thus affecting tumor angiogenesis.TAp73-deficient mice have an increased incidence of spontaneousand chemically induced tumors that also display enhanced vascularization.Mechanistically, TAp73 interacts with the regulatory subunit(α) of HIF-1 and recruits mouse double minute 2 homolog intothe protein complex, thus promoting HIF-1α polyubiquitination andconsequent proteasomal degradation in an oxygen-independentmanner. In human lung cancer datasets, TAp73 strongly predictsgood patient prognosis, and its expression is associated with lowHIF-1 activation and angiogenesis. Our findings, supported by invivo and clinical evidence, demonstrate a mechanism for oxygenindependentHIF-1 regulation, which has important implicationsfor individualizing therapies in patients with cancer.

scholarly journals B2M overexpression correlates with malignancy and immune signatures in human gliomas

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hao Zhang ◽  
Biqi Cui ◽  
Yulai Zhou ◽  
Xinxing Wang ◽  
Wantao Wu ◽  
...  
Keyword(s):  
Critical Role ◽  
Cell Types ◽  
Potential Candidate ◽  
Egfr Amplification ◽  
Immune Signatures ◽  
Idh Mutations ◽  
Pten Deletion ◽  
R Project ◽  
Patient Prognosis ◽  
Worse Prognosis

AbstractBecause of the limited treatment strategy of gliomas, the key of diagnosis and treatment is finding new molecular biomarkers. Here, we explored the potential of β2-microglobulin (B2M) to serve as a hopeful candidate for immunotherapy or diagnostic biomarker in gliomas. The genomic profiles, clinical characteristics, and immune signatures were analyzed based on TCGA and CGGA databases. We carried out the whole statistical analyses using R project. High B2M expression correlated with worse prognosis. Somatic mutations of gliomas with high B2M expression are associated with PTEN deletion and EGFR amplification. Isocitrate dehydrogenase (IDH) mutations accounted for 82% in gliomas with low B2M expression. In addition, B2M positively correlated with ESTIMATE scores, interacted with infiltrating immune and stromal cell types. B2M also suppressed anti-tumor immunity through immune related processes. Meanwhile, B2M was associated with immune checkpoint molecules and inflammatory activities. Finally, functional annotation of the identified B2M related genes verified that B2M was a potential candidate for immunotherapy. We confirmed that B2M played a critical role in tumor progression, patient prognosis and immunotherapy of gliomas.

scholarly journals Expression of SOX2 and OCT4 in odontogenic cysts and tumors

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Ekarat Phattarataratip ◽  
Tarit Panitkul ◽  
Watunyoo Khodkaew ◽  
Pattarapong Anupuntanun ◽  
Jirapat Jaroonvechatam ◽  
...  
Keyword(s):  
Cell Types ◽  
Odontogenic Cysts ◽  
Positive Staining ◽  
Stem Cell Markers ◽  
Aberrant Expression ◽  
Future Studies ◽  
Sox2 Expression ◽  
Cells Of Origin ◽  
Dentigerous Cysts ◽  
Patient Prognosis

Abstract Background Aberrant expression of stem cell markers has been observed in several types of neoplasms. This trait attributes to the acquired stem-like property of tumor cells and can impact patient prognosis. The objective of this study was to comparatively analyze the expression and significance of SOX2 and OCT4 in various types of odontogenic cysts and tumors. Methods Fifty-five cases of odontogenic cysts and tumors, including 15 ameloblastomas (AM), 5 adenomatoid odontogenic tumors (AOT), 5 ameloblastic fibromas (AF), 5 calcifying odontogenic cysts (COC), 10 dentigerous cysts (DC) and 15 odontogenic keratocysts (OKC) were investigated for the expression of SOX2 and OCT4 immunohistochemically. Results Most OKCs (86.7 %) and all AFs expressed SOX2 in more than 50 % of epithelial cells. Its immunoreactivity was moderate-to-strong in all epithelial cell types in both lesions. In contrast, SOX2 expression was undetectable in AOTs and limited to the ameloblast-like cells in a minority of AM and COC cases. Most DCs showed positive staining in less than 25 % of cystic epithelium. Significantly greater SOX2 expression was noted in OKC compared with DC or AM, and in AF compared with COC or AOT. OCT4 rarely expressed in odontogenic lesions with the immunoreactivity being mild and present exclusively in OKCs. Conclusions SOX2 is differentially expressed in odontogenic cysts and tumors. This could be related to their diverse cells of origin or stages of histogenesis. The overexpression of SOX2 and OCT4 in OKC indicates the acquired stem-like property. Future studies should investigate whether the overexpression of OCT4 and SOX2 contributes to the aggressive behaviors of the tumors.

Differential sensitivity of AS-30D rat hepatoma cells and normal hepatocytes to anoxic cell damage

1992 ◽  
Vol 262 (6) ◽  
pp. C1384-C1387 ◽  
Author(s):  
C. E. Kobryn ◽  
G. Fiskum
Keyword(s):  
Tumor Cells ◽  
Cell Damage ◽  
Metabolic Stress ◽  
Metastatic Potential ◽  
Cell Types ◽  
Hepatoma Cells ◽  
Differential Sensitivity ◽  
Trypan Blue Exclusion ◽  
Lactate Dehydrogenase Release

A substantial fraction of cells present within hard tumors experience extremely hypoxic and hypoglycemic conditions that can lead to phenotypic alterations such as increased metastatic potential and chemotherapeutic drug resistance. Little is known regarding the influence of anoxic aglycemia on tumor cell energy metabolism and viability, and no direct comparisons have been made between the effects of this form of metabolic stress on tumor cells and their tissue of origin. In this study, the effects of in vitro aglycemic incubation under N2 (with or without iodoacetate) on trypan blue exclusion, lactate dehydrogenase release, cell surface blebbing, ATP levels, and mitochondrial respiratory capacity of rat AS-30D ascites hepatoma cells and normal hepatocytes were measured. Under anoxic-aglycemic conditions, the period of incubation during which 50% viability was lost was 2 h for hepatocytes and 6-8 h for AS-30D cells. In contrast, the rate of anoxia-induced loss of ATP was comparable for the two cell types, and mitochondrial damage was actually accelerated in the tumor cells. These findings suggest that tumor cells are more resistant to anoxic cell death because of their greater ability to withstand deenergization and subcellular injury.

scholarly journals Absence of a Universal Mechanism of Mitochondrial Toxicity by Nucleoside Analogs

2007 ◽  
Vol 51 (7) ◽  
pp. 2531-2539 ◽  
Author(s):  
Kaleb C. Lund ◽  
LaRae L. Peterson ◽  
Kendall B. Wallace
Keyword(s):  
Hepg2 Cells ◽  
Nucleoside Analogs ◽  
Cell Types ◽  
Transcriptase Inhibitor ◽  
Positive Control ◽  
H9c2 Cells ◽  
Mtdna Depletion ◽  
Cell Mortality ◽  
Culture Models ◽  
Metabolic Disruption

ABSTRACT Nucleoside analogs are associated with various mitochondrial toxicities, and it is becoming increasingly difficult to accommodate these differences solely in the context of DNA polymerase gamma inhibition. Therefore, we examined the toxicities of zidovudine (AZT) (10 and 50 μM; 2.7 and 13.4 μg/ml), didanosine (ddI) (10 and 50 μM; 2.4 and 11.8 μg/ml), and zalcitabine (ddC) (1 and 5 μM; 0.21 and 1.1 μg/ml) in HepG2 and H9c2 cells without the presumption of mitochondrial DNA (mtDNA) depletion. Ethidium bromide (EtBr) (0.5 μg/ml; 1.3 μM) was used as a positive control. AZT treatment resulted in metabolic disruption (increased lactate and superoxide) and increased cell mortality with decreased proliferation, while mtDNA remained unchanged or increased (HepG2 cells; 50 μM AZT). ddC caused pronounced mtDNA depletion in HepG2 cells but not in H9c2 cells and increased mortality in HepG2 cells, but no significant metabolic disruption in either cell type. ddI caused a moderate depletion of mtDNA in both cell types but showed no other effects. EtBr exposure resulted in metabolic disruption, increased cell mortality with decreased cell proliferation, and mtDNA depletion in both cell types. We conclude that nucleoside analogs display unique toxicities within and between culture models, and therefore, care should be taken when generalizing about the mechanisms of nucleoside reverse transcriptase inhibitor toxicity. Additionally, mtDNA abundance does not necessarily correlate with metabolic disruption, especially in cell culture; careful discernment is recommended in this regard.

scholarly journals Development and pre-clinical testing of a novel hypoxia-activated KDAC inhibitor

2021 ◽  
Author(s):  
Anna Skwarska ◽  
Ewen Calder ◽  
Deborah Sneddon ◽  
Hannah Bolland ◽  
Maria Odyniec ◽  
...  
Keyword(s):  
Single Agent ◽  
Tumor Hypoxia ◽  
Clonogenic Survival ◽  
Therapy Resistance ◽  
Growth Delay ◽  
Pharmacokinetic Analysis ◽  
Lysine Deacetylase ◽  
Oxygen Conditions ◽  
Patient Prognosis ◽  
Induced Apoptosis

Tumor hypoxia is associated with therapy resistance and poor patient prognosis. Hypoxia-activated prodrugs, designed to selectively target hypoxic cells while sparing normal tissue, represent a promising treatment strategy. We report the pre-clinical efficacy of 1-methyl-2-nitroimidazole panobinostat (NI-Pano, CH-03), a novel bioreductive version of the clinically used lysine deacetylase inhibitor, panobinostat. NI-Pano was stable in normoxic (21% oxygen) conditions and underwent NADPH-CYP-mediated enzymatic bioreduction to release panobinostat in hypoxia (<0.1% oxygen). Treatment of cells grown in both 2D and 3D with NI-Pano increased acetylation of histone H3 at lysine 9, induced apoptosis and decreased clonogenic survival. Importantly, NI-Pano exhibited growth delay effects as a single agent in tumor xenografts. Pharmacokinetic analysis confirmed the presence of sub- micromolar concentrations of panobinostat in hypoxic mouse xenografts, but not in circulating plasma or kidneys. Together, our preclinical results provide a strong mechanistic rationale for the clinical development of NI-Pano for selective targeting of hypoxic tumors.<br>

scholarly journals Establishment of human pluripotent stem cell-derived pancreatic β-like cells in the mouse pancreas

2018 ◽  
Vol 115 (15) ◽  
pp. 3924-3929 ◽  
Author(s):  
Haiting Ma ◽  
Katherine J. Wert ◽  
Dmitry Shvartsman ◽  
Douglas A. Melton ◽  
Rudolf Jaenisch
Keyword(s):  
Stem Cell ◽  
Cell Types ◽  
Human Cells ◽  
Β Cells ◽  
Orthotopic Transplantation ◽  
In Vivo Models ◽  
Pancreatic Cell ◽  
Mouse Pancreas ◽  
Ductal Cells ◽  
Neonatal Mice

Type 1 diabetes is characterized by autoimmune destruction of β cells located in pancreatic islets. However, tractable in vivo models of human pancreatic β cells have been limited. Here, we generated xenogeneic human pancreatic β-like cells in the mouse pancreas by orthotopic transplantation of stem cell-derived β (SC-β) cells into the pancreas of neonatal mice. The engrafted β-like cells expressed β cell transcription factors and markers associated with functional maturity. Engrafted human cells recruited mouse endothelial cells, suggesting functional integration. Human insulin was detected in the blood circulation of transplanted mice for months after transplantation and increased upon glucose stimulation. In addition to β-like cells, human cells expressing markers for other endocrine pancreas cell types, acinar cells, and pancreatic ductal cells were identified in the pancreata of transplanted mice, indicating that this approach allows studying other human pancreatic cell types in the mouse pancreas. Our results demonstrate that orthotopic transplantation of human SC-β cells into neonatal mice is an experimental platform that allows the generation of mice with human pancreatic β-like cells in the endogenous niche.

scholarly journals Insulin and Analogue Effects on Protein Degradation in Different Cell Types

2000 ◽  
Vol 276 (15) ◽  
pp. 11552-11558 ◽  
Author(s):  
Janet Fawcett ◽  
Frederick G. Hamel ◽  
Robert G. Bennett ◽  
Zoltan Vajo ◽  
William C. Duckworth
Keyword(s):  
Protein Degradation ◽  
Hepg2 Cells ◽  
Cell Types ◽  
Major Effect ◽  
Cellular Protein ◽  
Experimental Conditions ◽  
L6 Cells ◽  
Different Cell Types

In adult animals, the major effect of insulin on protein turnover is inhibition of protein degradation. Cellular protein degradation is under the control of multiple systems, including lysosomes, proteasomes, calpains, and giant protease. Insulin has been shown to alter proteasome activityin vitroandin vivo. We examined the inhibition of protein degradation by insulin and insulin analogues (LysB28,ProB29-insulin (LysPro), AspB10-insulin (B10), and GluB4,GlnB16,PheB17-insulin (EQF)) in H4, HepG2, and L6 cells. These effects were compared with receptor binding. Protein degradation was examined by release of trichloroacetic acid-soluble radioactivity from cells previously labeled with [3H]leucine. Short- and intermediate-lived proteins were examined. H4 cells bound insulin with an EC50of 4.6 × 10−9m. LysPro was similar. The affinity of B10 was increased 2-fold; that of EQF decreased 15-fold. Protein degradation inhibition in H4 cells was highly sensitive to insulin (EC50= 4.2 × 10−11and 1.6 × 10−10m, short- and intermediate-lived protein degradation, respectively) and analogues. Despite similar binding, LysPro was 11- to 18-fold more potent than insulin at inhibiting protein degradation. Conversely, although EQF showed lower binding to H4 cells than insulin, its action was similar. The relative binding potencies of analogues in HepG2 cells were similar to those in H4 cells. Examination of protein degradation showed insulin, LysPro, and B10 were equivalent while EQF was less potent. L6 cells showed no difference in the binding of the analogues compared with insulin, but their effect on protein degradation was similar to that seen in HepG2 cells except B10 inhibited intermediate-lived protein degradation better than insulin. These studies illustrate the complexities of cellular protein degradation and the effects of insulin. The effect of insulin and analogues on protein degradation vary significantly in different cell types and with different experimental conditions. The differences seen in the action of the analogues cannot be attributed to binding differences. Post-receptor mechanisms, including intracellular processing and degradation, must be considered.

Biotin uptake by human intestinal and liver epithelial cells: role of the SMVT system

2003 ◽  
Vol 285 (1) ◽  
pp. G73-G77 ◽  
Author(s):  
Krishnaswamy Balamurugan ◽  
Alvaro Ortiz ◽  
Hamid M. Said
Keyword(s):  
Epithelial Cells ◽  
Hepg2 Cells ◽  
Pantothenic Acid ◽  
Cell Types ◽  
Uptake System ◽  
Small Interfering Rnas ◽  
Uptake Mechanism ◽  
High Affinity ◽  
Liver Epithelial Cells ◽  
Relative Contribution

It has been well established that human intestinal and liver epithelial cells transport biotin via an Na+-dependent carrier-mediated mechanism. The sodium-dependent multivitamin transport (SMVT), a biotin transporter, is expressed in both cell types. However, the relative contribution of SMVT toward total carrier-mediated uptake of physiological (nanomolar) concentrations of biotin by these cells is not clear. Addressing this issue is important, especially in light of the recent identification of a second human high-affinity biotin uptake mechanism that operates at the nanomolar range. Hence, we employed a physiological approach of characterizing biotin uptake by human-derived intestinal Caco-2 and HepG2 cells at the nanomolar concentration range. We also employed a molecular biology approach of selectively silencing the endogenous SMVT of these cells with specific small interfering RNAs (siRNAs), then examining carrier-mediated biotin uptake. The results showed that in both Caco-2 and HepG2 cells, the initial rate of biotin uptake as a function of concentration over the range of 0.1 to 50 nM to be linear. Furthermore, we found that the addition of 100 nM unlabeled biotin, desthiobiotin, or pantothenic acid to the incubation medium had no effect on the uptake of 2.6 nM [3H]biotin. Pretreatment of Caco-2 and HepG2 cells with SMVT specific siRNAs substantially reduced SMVT mRNA and protein levels. In addition, carrier-mediated [3H]biotin (2.6 nM) uptake by Caco-2 and HepG2 cells was severely ( P 0.01) inhibited by the siRNAs pretreatment. These results demonstrate that the recently described human high-affinity biotin uptake system is not functional in intestinal and liver epithelial cells. In addition, the results provide strong evidence that SMVT is the major (if not the only) biotin uptake system that operates in these cells.

Sign in / Sign up

Export Citation Format

Share Document