scholarly journals Increased Proliferation of Neuroblastoma Cells under Fructose Metabolism Can Be Measured by Isothermal Microcalorimetry

Children ◽  
2021 ◽  
Vol 8 (9) ◽  
pp. 784
Author(s):  
Nicola Pini ◽  
Zihe Huo ◽  
Stefan Holland-Cunz ◽  
Stephanie J. Gros
Keyword(s):  
Energy Efficiency ◽  
Tumor Cells ◽  
Metabolic Activity ◽  
Neuroblastoma Cells ◽  
Nutrient Supply ◽  
Isothermal Microcalorimetry ◽  
Low Oxygen ◽  
Normal Medium ◽  
Fructose Metabolism ◽  
Cancer Types

Neuroblastoma, like other cancer types, has an increased need for energy. This results in an increased thermogenic profile of the cells. How tumor cells optimize their energy efficiency has been discussed since Warburg described the fact that tumor cells prefer an anaerobic to an aerobic metabolism in the 1920s. An important question is how far the energy efficiency is influenced by the substrate. The aim of this study was to investigate how the metabolic activity of neuroblastoma cells is stimulated by addition of glucose or fructose to the medium and if this can be measured accurately by using isothermal microcalorimetry. Proliferation of Kelly and SH-EP Tet-21/N cells was determined in normal medium, in fructose-enriched, in glucose-enriched and in a fructose/glucose-enriched environment. Heat development of cells was measured by isothermal microcalorimetry. The addition of fructose, glucose or both to the medium led to increases in the metabolic activity of the cells, resulting in increased proliferation under the influence of fructose. These changes were reflected in an enhanced thermogenic profile, mirroring the results of the proliferation assay. The tested neuroblastoma cells prefer fructose metabolism over glucose metabolism, a quality that provides them with a survival benefit under unfavorable low oxygen and low nutrient supply when fructose is available. This can be quantified by measuring thermogenesis.

scholarly journals Development of Group B Coxsackievirus as an Oncolytic Virus: Opportunities and Challenges

Viruses ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1082
Author(s):  
Huitao Liu ◽  
Honglin Luo
Keyword(s):  
Tumor Cells ◽  
Current Knowledge ◽  
Oncolytic Viruses ◽  
Human Enterovirus ◽  
Multiple Cancer ◽  
The Family ◽  
Cancer Types ◽  
Group B ◽  
Type 3 ◽  
Genus Enterovirus

Oncolytic viruses have emerged as a promising strategy for cancer therapy due to their dual ability to selectively infect and lyse tumor cells and to induce systemic anti-tumor immunity. Among various candidate viruses, coxsackievirus group B (CVBs) have attracted increasing attention in recent years. CVBs are a group of small, non-enveloped, single-stranded, positive-sense RNA viruses, belonging to species human Enterovirus B in the genus Enterovirus of the family Picornaviridae. Preclinical studies have demonstrated potent anti-tumor activities for CVBs, particularly type 3, against multiple cancer types, including lung, breast, and colorectal cancer. Various approaches have been proposed or applied to enhance the safety and specificity of CVBs towards tumor cells and to further increase their anti-tumor efficacy. This review summarizes current knowledge and strategies for developing CVBs as oncolytic viruses for cancer virotherapy. The challenges arising from these studies and future prospects are also discussed in this review.

scholarly journals Hypoxic tumor microenvironment: Implications for cancer therapy

2020 ◽  
Vol 245 (13) ◽  
pp. 1073-1086
Author(s):  
Sukanya Roy ◽  
Subhashree Kumaravel ◽  
Ankith Sharma ◽  
Camille L Duran ◽  
Kayla J Bayless ◽  
...  
Keyword(s):  
Tumor Microenvironment ◽  
Cancer Cells ◽  
Metabolic Regulation ◽  
Molecular Mechanisms ◽  
Hypoxia Inducible Factor ◽  
Tumor Vasculature ◽  
Therapeutic Strategies ◽  
Therapeutic Resistance ◽  
Low Oxygen ◽  
Cancer Types

Hypoxia or low oxygen concentration in tumor microenvironment has widespread effects ranging from altered angiogenesis and lymphangiogenesis, tumor metabolism, growth, and therapeutic resistance in different cancer types. A large number of these effects are mediated by the transcription factor hypoxia inducible factor 1⍺ (HIF-1⍺) which is activated by hypoxia. HIF1⍺ induces glycolytic genes and reduces mitochondrial respiration rate in hypoxic tumoral regions through modulation of various cells in tumor microenvironment like cancer-associated fibroblasts. Immune evasion driven by HIF-1⍺ further contributes to enhanced survival of cancer cells. By altering drug target expression, metabolic regulation, and oxygen consumption, hypoxia leads to enhanced growth and survival of cancer cells. Tumor cells in hypoxic conditions thus attain aggressive phenotypes and become resistant to chemo- and radio- therapies resulting in higher mortality. While a number of new therapeutic strategies have succeeded in targeting hypoxia, a significant improvement of these needs a more detailed understanding of the various effects and molecular mechanisms regulated by hypoxia and its effects on modulation of the tumor vasculature. This review focuses on the chief hypoxia-driven molecular mechanisms and their impact on therapeutic resistance in tumors that drive an aggressive phenotype. Impact statement Hypoxia contributes to tumor aggressiveness and promotes growth of many solid tumors that are often resistant to conventional therapies. In order to achieve successful therapeutic strategies targeting different cancer types, it is necessary to understand the molecular mechanisms and signaling pathways that are induced by hypoxia. Aberrant tumor vasculature and alterations in cellular metabolism and drug resistance due to hypoxia further confound this problem. This review focuses on the implications of hypoxia in an inflammatory TME and its impact on the signaling and metabolic pathways regulating growth and progression of cancer, along with changes in lymphangiogenic and angiogenic mechanisms. Finally, the overarching role of hypoxia in mediating therapeutic resistance in cancers is discussed.

Increased MAGEC2 Expression Renders Resistance to Apoptotic Death Through Sustained Activation of STAT3 in Suspension Cultured Tumor Cells

2020 ◽  
Author(s):  
Doyeon Park ◽  
Sora Han ◽  
Hyun Jeong Joo ◽  
Hye In Ka ◽  
Su Jung Soh ◽  
...  
Keyword(s):  
Tumor Cells ◽  
Circulating Tumor Cells ◽  
Apoptotic Cell ◽  
Annexin V ◽  
Underlying Mechanism ◽  
Proliferation Rate ◽  
Suspension Cells ◽  
Protein Levels ◽  
Proliferation And Apoptosis ◽  
Cancer Types

Abstract Background Melanoma-associated antigen C2 (MAGEC2) is an oncogene associated with various cancer types. However, the biological function of MAGEC2 in circulating tumor cells is unclear. In this study, we investigated the role of MAGEC2 using adapted suspension cells (ASCs), which were previously developed to study circulating tumor cells (CTCs).Methods Differential gene expression between adherent cells (ADs) and ASCs was examined using RNA-seq analysis. MAGEC2 expression was assessed using RT-qPCR, immunoblotting, and ChIP-seq analysis. Depletion of MAGEC2 expression was carried out using siRNA. MAGEC2-depleted ADs and ASCs were used to investigate the change in proliferation rate and cell cycle. Then, the protein levels of STAT3, phosphorylated STAT3, and downstream of STAT3 were measured using control and MAGEC2-depleted ADs and ASCs. The direct effect of active STAT3 inhibition with Stattic in ASCs was also assessed in terms of proliferation and apoptosis. Finally, an Annexin V/7-AAD assay was performed to determine the percentage of apoptotic cells in Stattic-treated cells. Results MAGEC2 was highly expressed in ASCs compared to ADs. Depletion of MAGEC2 reduced the proliferation rate and viability of ASCs. To elucidate the underlying mechanism, the level of STAT3 was examined because of its oncogenic properties. Tyrosine-phosphorylated active STAT3 was highly expressed in ASCs and decreased in MAGEC2-depleted ASCs. In addition, when ASCs were treated with Stattic, an active STAT3 inhibitor, they were more sensitive to intrinsic pathway-mediated apoptosis.Conclusions High expression of MAGEC2 may play an important role in the survival of ASCs by maintaining the expression of activated STAT3 to prevent apoptotic cell death.

scholarly journals MYCN and PRC1 cooperatively repress docosahexaenoic acid synthesis in neuroblastoma via ELOVL2

2019 ◽  
Vol 38 (1) ◽  
Author(s):  
Yi Ding ◽  
Jie Yang ◽  
Yawen Ma ◽  
Tengteng Yao ◽  
Xingyu Chen ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Cell Growth ◽  
Docosahexaenoic Acid ◽  
Tumor Cells ◽  
Target Gene ◽  
Bioinformatics Analysis ◽  
Neuroblastoma Cells ◽  
Single Copy ◽  
Rt Pcr ◽  
Clinical Bioinformatics

Abstract Background The MYCN amplification is a defining hallmark of high-risk neuroblastoma. Due to irregular oncogenes orchestration, tumor cells exhibit distinct fatty acid metabolic features from non-tumor cells. However, the function of MYCN in neuroblastoma fatty acid metabolism reprogramming remains unknown. Methods Gas Chromatography-Mass Spectrometer (GC-MS) was used to find the potential target fatty acid metabolites of MYCN. Real-time PCR (RT-PCR) and clinical bioinformatics analysis was used to find the related target genes. The function of the identified target gene ELOVL2 on cell growth was detected through CCK-8 assay, Soft agar colony formation assay, flow Cytometry assay and mouse xenograft. Chromatin immunoprecipitation (ChIP) and Immunoprecipitation-Mass Spectrometer (IP-MS) further identified the target gene and the co-repressor of MYCN. Results The fatty acid profile of MYCN-depleted neuroblastoma cells identified docosahexaenoic acid (DHA), an omega-3 polyunsaturated fatty acid with anti-tumor activity, significantly increased after MYCN depletion. Compared with MYCN single-copy neuroblastoma cells, DHA level was significantly lower in MYCN-amplified neuroblastoma cells. RT-PCR and clinical bioinformatics analysis discovered that MYCN interfered DHA accumulation via ELOVL fatty acid elongase 2 (ELOVL2) which is a rate-limiting enzyme of cellular DHA synthesis. Enforced ELOVL2 expression in MYCN-amplified neuroblastoma cells led to decreased cell growth and counteracted the growth-promoting effect of MYCN overexpression both in vitro and vivo. ELOVL2 Knockdown showed the opposite effect in MYCN single-copy neuroblastoma cells. In primary neuroblastoma, high ELOVL2 transcription correlated with favorable clinical tumor biology and patient survival. The mechanism of MYCN-mediated ELOVL2 inhibition contributed to epigenetic regulation. MYCN recruited PRC1 (Polycomb repressive complex 1), catalysed H2AK119ub (histone 2A lysine 119 monoubiquitination) and inhibited subsequent ELOVL2 transcription. Conclusions The tumor suppressive properties of DHA and ELOVL2 are repressed by the MYCN and PRC1 jointly, which suggests a new epigenetic mechanism of MYCN-mediated fatty acid regulation and indicates PRC1 inhibition as a potential novel strategy to activate ELOVL2 suppressive functions.

Effects of varying silage quality for dry cows on feed intake, weight change and performance in the subsequent lactation

2000 ◽  
Vol 2000 ◽  
pp. 142-142
Author(s):  
R. J. Dewhurst ◽  
D. W. R. Davies ◽  
W. J. Fisher
Keyword(s):  
Milk Production ◽  
Metabolic Activity ◽  
Feed Intake ◽  
Nutrient Supply ◽  
Current Experiment ◽  
High Quality ◽  
Grass Silage ◽  
Silage Quality ◽  
Voluntary Intake ◽  
And Performance

Earlier studies (e.g. Dewhurst et al., 1996, 1999) have shown marked declines in forage voluntary intake as calving approaches. The resultant reduction in nutrient supply may compromise performance in the next lactation, because it coincides with a period of intense metabolic activity in preparation for the next lactation. Feeding concentrates to dry cows did not overcome this problem (Dewhurst et al., 1999). The objective of the current experiment was to investigate alternative dry cow strategies, using only high-quality grass silage, to minimise the severity and consequences for subsequent milk production of the reduction in nutrient supply in this period.

scholarly journals High Expression of Pd-1 in Circulating Cells of Patients With Advanced Colorectal Cancer Receiving Adjuvant Therapy

2020 ◽  
Vol 19 ◽  
pp. 153303382096944
Author(s):  
Muhammed A. Bakhrebah ◽  
Mohammad Nasrullah ◽  
Wesam H. Abdulaal ◽  
Mohammed A. Hassan ◽  
Halima Siddiqui ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Immune Response ◽  
Adjuvant Therapy ◽  
Tumor Cells ◽  
Immune Cells ◽  
Human Leukocyte ◽  
Genetic Alterations ◽  
Programmed Death ◽  
Programmed Death 1 ◽  
Cancer Types

Among all cancer types, colorectal cancer is the third most common in men and the second most common in women globally. Generally, the risk of colorectal cancer increases with age, and colorectal cancer is modulated by various genetic alterations. Alterations in the immune response serve a significant role in the development of colorectal cancer. In primary cancer types, immune cells express a variety of inhibitory molecules that dampen the immune response against tumor cells. Additionally, few reports have demonstrated that classical chemotherapy promotes the immunosuppressive microenvironment in both tissues and immune cells. This study assessed the expression levels of genes using RT-qPCR associated with the immune system, including interferon-γ, programmed death-1, β2-microglobulin, human leukocyte antigen-A, CD3e, CD28 and intracellular adhesion molecule 1, in patients with colorectal cancer, as these genes are known to serve important roles in immune regulation during cancer incidence. Gene expression analysis was performed with the whole blood cells of patients with colorectal cancer and healthy volunteers. Compared with the normal controls, programmed death-1was highly expressed in patients with advanced-stage colorectal cancer. Furthermore, the expression of programmed death-1 was higher in patients receiving adjuvant therapy, which suggests the therapy dampened the immune response against tumor cells. The results of the present study indicate that classical adjuvant therapies, which are currently used for patients with colorectal cancer, should be modulated, and a combination of classical therapy with anti-programmed death-1 antibody should be conducted for improved management of patients with colorectal cancer.

PD-L1 expression on tumor cells and tumor infiltrating immune cells in Chinese colorectal cancer patients.

2020 ◽  
Vol 38 (15_suppl) ◽  
pp. e16111-e16111
Author(s):  
Jianjun Yang ◽  
Guanghui Xu ◽  
Jiyang Zheng ◽  
Kunli Du ◽  
Wei Zhou ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Tumor Cells ◽  
Immune Cells ◽  
Checkpoint Inhibitors ◽  
Cancer Treatments ◽  
Targeted Next Generation Sequencing ◽  
Biomarker Analysis ◽  
Programmed Death 1 ◽  
Cancer Types ◽  
Colorectal Cancer Patients

e16111 Background: Nowadays, immune checkpoint inhibitors (ICIs) targeting programmed death-1/ligand-1 (PD-1/PD-L1) have been an alternative in cancer treatments. Previous biomarker analysis found that response to anti-PD1/PD-L1 was associated with PD-L1 expression on tumor cells and/or tumor infiltrating immune cells in some cancer types. Explorations of IMblaze370 study demonstrated better survival outcome in colorectal cancer (CRC) patients with positive PD-L1 expression compared with those with negative PD-L1 expression in the atezolizumab group. Our study investigated PD-L1 expression profile in Chinese CRC population. Methods: PD-L1 expression on tumor cells or tumor infiltrating immune cells in 816 CRC tumors between January 01, 2017 and December 02, 2019 in 3D Medicines database was assessed by immunohistochemistry assay (SP263 or 22C3). We defined percentage of PD-L1 expression on tumor cells as tumor proportion score (TPS) strong positive ≥50%, moderate positive ≥5% and < 50%, weak positive ≥1% and < 5%, and negative < 1%. Similarly, we defined percentage of PD-L1 expression on infiltrating immune cells as immune proportion score (IPS) strong positive ≥10%, moderate positive ≥5% and < 10%, weakly positive ≥1% and < 5%, and negative < 1%. In addition, MSI status was evaluated with targeted next-generation sequencing covering 100 MSI loci. Results: 12 (1.5%) individuals had TPS as strong positive, 63 (7.7%) as moderate positive, 95 (11.6%) as weak positive and 646 (79.2%) as negative. Meanwhile, TPS of patients were 55 (6.7%) for strong positive, 49 (6.0%) for moderate positive, 34 (4.2%) for weak positive and 678 (83.0%) for negative, respectively. 16.9% in Chinese CRC patients here were defined as positive PD-L1 expression (IPS ≥1%), which is lower than the positive proportion of CRC in IMblaze370 study (39.9% for IPS ≥1%, P < 0.0001). The PD-L1 expression on tumor cells and on tumor infiltrating immune cells showed minimal overlap. In detail, only 29 (3.6%) patients exhibited simultaneously TPS positive (≥1%) and IPS positive (≥1%). Furthermore, IPS was not associated with MSI status (P = 0.9153), while TPS showed an association with MSI-H (P < 0.0001). In detail, 45.5% of MSI-H CRC patients were TPS positive. Conclusions: Chinese CRC patients express PD-L1 with 20.8% TPS positive and 17.0% IPS positive, and TPS positive were related to MSI-H. When studying the connection between the efficacy of PD1/PD-L1 inhibitors and PD-L1 expression, TPS and IPS detection would be both considered to engage.

scholarly journals Identification of a Posttranslational Mechanism for the Regulation of hERG1 K+ Channel Expression and hERG1 Current Density in Tumor Cells

2008 ◽  
Vol 28 (16) ◽  
pp. 5043-5060 ◽  
Author(s):  
Leonardo Guasti ◽  
Olivia Crociani ◽  
Elisa Redaelli ◽  
Serena Pillozzi ◽  
Simone Polvani ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Tumor Cells ◽  
Molecular Mechanisms ◽  
Neuroblastoma Cells ◽  
Surface Expression ◽  
K Channel ◽  
Aberrant Expression ◽  
Channel Surface ◽  
Channel Expression ◽  
Herg1 Channel

ABSTRACT A common feature of tumor cells is the aberrant expression of ion channels on their plasma membrane. The molecular mechanisms regulating ion channel expression in cancer cells are still poorly known. K+ channels that belong to the human ether-a-go-go-related gene 1 (herg1) family are frequently misexpressed in cancer cells compared to their healthy counterparts. We describe here a posttranslational mechanism for the regulation of hERG1 channel surface expression in cancer cells. This mechanism is based on the activity of hERG1 isoforms containing the USO exon. These isoforms (i) are frequently overexpressed in human cancers, (ii) are retained in the endoplasmic reticulum, and (iii) form heterotetramers with different proteins of the hERG family. (iv) The USO-containing heterotetramers are retained intracellularly and undergo ubiquitin-dependent degradation. This process results in decreased hERG1 current (IhERG1) density. We detailed such a mechanism in heterologous systems and confirmed its functioning in tumor cells that endogenously express hERG1 proteins. The silencing of USO-containing hERG1 isoforms induces a higher IhERG1 density in tumors, an effect that apparently regulates neurite outgrowth in neuroblastoma cells and apoptosis in leukemia cells.

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