Can small molecular inhibitors that stop de novo serine synthesis be used in cancer treatment?

AbstractTo sustain their malignancy, tumour cells acquire several metabolic adaptations such as increased oxygen, glucose, glutamine, and lipids uptake. Other metabolic processes are also enhanced as part of tumour metabolic reprogramming, for example, increased serine metabolism. Serine is a non-essential amino acid that supports several metabolic processes that are crucial for the growth and survival of proliferating cells, including protein, DNA, and glutathione synthesis. Indeed, increased activity of D-3-phosphoglycerate dehydrogenase (PHGDH), the enzyme rate-limiting de novo serine synthesis, has been extensively reported in several tumours. Therefore, selective inhibition of PHGDH may represent a new therapeutic strategy for over-expressing PHGDH tumours, owing to its downstream inhibition of essential biomass production such as one-carbon units and nucleotides. This perspective article will discuss the current status of research into small molecular inhibitors against PHGDH in colorectal cancer, breast cancer, and Ewing’s sarcoma. We will summarise recent studies on the development of PHGDH-inhibitors, highlighting their clinical potential as new therapeutics. It also wants to shed a light on some of the key limitations of the use of PHGDH-inhibitors in cancer treatment which are worth taking into account.

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Untangling the Metabolic Reprogramming in Brain Cancer: Discovering Key Molecular Players Using Mass Spectrometry

Current Topics in Medicinal Chemistry ◽

10.2174/1568026619666190729154543 ◽

2019 ◽

Vol 19 (17) ◽

pp. 1521-1534 ◽

Cited By ~ 6

Author(s):

Anatoly Sorokin ◽

Vsevolod Shurkhay ◽

Stanislav Pekov ◽

Evgeny Zhvansky ◽

Daniil Ivanov ◽

...

Keyword(s):

Mass Spectrometry ◽

Brain Cancer ◽

De Novo ◽

Aerobic Glycolysis ◽

Lipid Production ◽

Dietary Fatty Acids ◽

Metabolic Reprogramming ◽

Detection Methods ◽

Malignant Cells ◽

Proliferating Cells

Cells metabolism alteration is the new hallmark of cancer, as well as an important method for carcinogenesis investigation. It is well known that the malignant cells switch to aerobic glycolysis pathway occurring also in healthy proliferating cells. Recently, it was shown that in malignant cells de novo synthesis of the intracellular fatty acid replaces dietary fatty acids which change the lipid composition of cancer cells noticeably. These alterations in energy metabolism and structural lipid production explain the high proliferation rate of malignant tissues. However, metabolic reprogramming affects not only lipid metabolism but many of the metabolic pathways in the cell. 2-hydroxyglutarate was considered as cancer cell biomarker and its presence is associated with oxidative stress influencing the mitochondria functions. Among the variety of metabolite detection methods, mass spectrometry stands out as the most effective method for simultaneous identification and quantification of the metabolites. As the metabolic reprogramming is tightly connected with epigenetics and signaling modifications, the evaluation of metabolite alterations in cells is a promising approach to investigate the carcinogenesis which is necessary for improving current diagnostic capabilities and therapeutic capabilities. In this paper, we overview recent studies on metabolic alteration and oncometabolites, especially concerning brain cancer and mass spectrometry approaches which are now in use for the investigation of the metabolic pathway.

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Anti-Tumor Potential of IMP Dehydrogenase Inhibitors: A Century-Long Story

Cancers ◽

10.3390/cancers11091346 ◽

2019 ◽

Vol 11 (9) ◽

pp. 1346 ◽

Cited By ~ 13

Author(s):

Naffouje ◽

Grover ◽

Yu ◽

Sendilnathan ◽

Wolfe ◽

...

Keyword(s):

Cancer Treatment ◽

Cancer Progression ◽

De Novo ◽

Malignant Tumors ◽

Inosine Monophosphate Dehydrogenase ◽

Variable Response ◽

Purine Nucleotides ◽

Proliferating Cells ◽

Anti Cancer ◽

Impdh Inhibitors

The purine nucleotides ATP and GTP are essential precursors to DNA and RNA synthesis and fundamental for energy metabolism. Although de novo purine nucleotide biosynthesis is increased in highly proliferating cells, such as malignant tumors, it is not clear if this is merely a secondary manifestation of increased cell proliferation. Suggestive of a direct causative effect includes evidence that, in some cancer types, the rate-limiting enzyme in de novo GTP biosynthesis, inosine monophosphate dehydrogenase (IMPDH), is upregulated and that the IMPDH inhibitor, mycophenolic acid (MPA), possesses anti-tumor activity. However, historically, enthusiasm for employing IMPDH inhibitors in cancer treatment has been mitigated by their adverse effects at high treatment doses and variable response. Recent advances in our understanding of the mechanistic role of IMPDH in tumorigenesis and cancer progression, as well as the development of IMPDH inhibitors with selective actions on GTP synthesis, have prompted a reappraisal of targeting this enzyme for anti-cancer treatment. In this review, we summarize the history of IMPDH inhibitors, the development of new inhibitors as anti-cancer drugs, and future directions and strategies to overcome existing challenges.

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The Application of the Cold Atmospheric Plasma-Activated Solutions in Cancer Treatment

Anti-Cancer Agents in Medicinal Chemistry ◽

10.2174/1871520617666170731115233 ◽

2018 ◽

Vol 18 (6) ◽

pp. 769-775 ◽

Cited By ~ 13

Author(s):

Dayun Yan ◽

Jonathan H. Sherman ◽

Michael Keidar

Keyword(s):

Cancer Treatment ◽

Atmospheric Plasma ◽

Current Status ◽

Cold Atmospheric Plasma ◽

Anti Cancer ◽

Long Time ◽

Key Topics ◽

The Common

Background: Over the past five years, the cold atmospheric plasma-activated solutions (PAS) have shown their promissing application in cancer treatment. Similar as the common direct cold plasma treatment, PAS shows a selective anti-cancer capacity in vitro and in vivo. However, different from the direct cold atmospheric plasma (CAP) treatment, PAS can be stored for a long time and can be used without dependence on a CAP device. The research on PAS is gradually becoming a hot topic in plasma medicine. Objectives: In this review, we gave a concise but comprehensive summary on key topics about PAS including the development, current status, as well as the main conclusions about the anti-cancer mechanism achieved in past years. The approaches to make strong and stable PAS are also summarized.

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Amino Acid Transporters on the Guard of Cell Genome and Epigenome

Cancers ◽

10.3390/cancers13010125 ◽

2021 ◽

Vol 13 (1) ◽

pp. 125

Author(s):

Uğur Kahya ◽

Ayşe Sedef Köseer ◽

Anna Dubrovska

Keyword(s):

Amino Acid ◽

Cancer Metabolism ◽

Tumor Imaging ◽

Redox Homeostasis ◽

Amino Acid Uptake ◽

Metabolic Reprogramming ◽

Tumor Evolution ◽

Amino Acid Transporters ◽

Acid Uptake ◽

Growth And Survival

Tumorigenesis is driven by metabolic reprogramming. Oncogenic mutations and epigenetic alterations that cause metabolic rewiring may also upregulate the reactive oxygen species (ROS). Precise regulation of the intracellular ROS levels is critical for tumor cell growth and survival. High ROS production leads to the damage of vital macromolecules, such as DNA, proteins, and lipids, causing genomic instability and further tumor evolution. One of the hallmarks of cancer metabolism is deregulated amino acid uptake. In fast-growing tumors, amino acids are not only the source of energy and building intermediates but also critical regulators of redox homeostasis. Amino acid uptake regulates the intracellular glutathione (GSH) levels, endoplasmic reticulum stress, unfolded protein response signaling, mTOR-mediated antioxidant defense, and epigenetic adaptations of tumor cells to oxidative stress. This review summarizes the role of amino acid transporters as the defender of tumor antioxidant system and genome integrity and discusses them as promising therapeutic targets and tumor imaging tools.

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AAV-Mediated CRISPRi and RNAi Based Gene Silencing in Mouse Hippocampal Neurons

Cells ◽

10.3390/cells10020324 ◽

2021 ◽

Vol 10 (2) ◽

pp. 324

Author(s):

Matthias Deutsch ◽

Anne Günther ◽

Rodrigo Lerchundi ◽

Christine R. Rose ◽

Sabine Balfanz ◽

...

Keyword(s):

Gene Expression ◽

Transcription Initiation ◽

Hippocampal Neurons ◽

De Novo ◽

Protein Biosynthesis ◽

Physiological Role ◽

High Specificity ◽

Hcn Channels ◽

Proliferating Cells ◽

Neuronal Tissues

Uncovering the physiological role of individual proteins that are part of the intricate process of cellular signaling is often a complex and challenging task. A straightforward strategy of studying a protein’s function is by manipulating the expression rate of its gene. In recent years, the Clustered Regularly Interspaced Short Palindromic Repeat (CRISPR)/Cas9-based technology was established as a powerful gene-editing tool for generating sequence specific changes in proliferating cells. However, obtaining homogeneous populations of transgenic post-mitotic neurons by CRISPR/Cas9 turned out to be challenging. These constraints can be partially overcome by CRISPR interference (CRISPRi), which mediates the inhibition of gene expression by competing with the transcription machinery for promoter binding and, thus, transcription initiation. Notably, CRISPR/Cas is only one of several described approaches for the manipulation of gene expression. Here, we targeted neurons with recombinant Adeno-associated viruses to induce either CRISPRi or RNA interference (RNAi), a well-established method for impairing de novo protein biosynthesis by using cellular regulatory mechanisms that induce the degradation of pre-existing mRNA. We specifically targeted hyperpolarization-activated and cyclic nucleotide-gated (HCN) channels, which are widely expressed in neuronal tissues and play essential physiological roles in maintaining biophysical characteristics in neurons. Both of the strategies reduced the expression levels of three HCN isoforms (HCN1, 2, and 4) with high specificity. Furthermore, detailed analysis revealed that the knock-down of just a single HCN isoform (HCN4) in hippocampal neurons did not affect basic electrical parameters of transduced neurons, whereas substantial changes emerged in HCN-current specific properties.

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Phytochemicals Block Glucose Utilization and Lipid Synthesis to Counteract Metabolic Reprogramming in Cancer Cells

Applied Sciences ◽

10.3390/app11031259 ◽

2021 ◽

Vol 11 (3) ◽

pp. 1259

Author(s):

Qiong Wu ◽

Bo Zhao ◽

Guangchao Sui ◽

Jinming Shi

Keyword(s):

Cancer Cells ◽

Metabolic Pathways ◽

De Novo ◽

Aerobic Glycolysis ◽

Structural Characteristics ◽

Natural Compounds ◽

Metabolic Reprogramming ◽

De Novo Lipogenesis ◽

Anticancer Activities ◽

Substrate Analogs

Aberrant metabolism is one of the hallmarks of cancers. The contributions of dysregulated metabolism to cancer development, such as tumor cell survival, metastasis and drug resistance, have been extensively characterized. “Reprogrammed” metabolic pathways in cancer cells are mainly represented by excessive glucose consumption and hyperactive de novo lipogenesis. Natural compounds with anticancer activities are constantly being demonstrated to target metabolic processes, such as glucose transport, aerobic glycolysis, fatty acid synthesis and desaturation. However, their molecular targets and underlying anticancer mechanisms remain largely unclear or controversial. Mounting evidence indicated that these natural compounds could modulate the expression of key regulatory enzymes in various metabolic pathways at transcriptional and translational levels. Meanwhile, natural compounds could also inhibit the activities of these enzymes by acting as substrate analogs or altering their protein conformations. The actions of natural compounds in the crosstalk between metabolism modulation and cancer cell destiny have become increasingly attractive. In this review, we summarize the activities of natural small molecules in inhibiting key enzymes of metabolic pathways. We illustrate the structural characteristics of these compounds at the molecular level as either inhibitor of various enzymes or regulators of metabolic pathways in cancer cells. Our ultimate goal is to both facilitate the clinical application of natural compounds in cancer therapies and promote the development of novel anticancer therapeutics.

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Expression Signatures of microRNAs and Their Targeted Pathways in the Adipose Tissue of Chickens during the Transition from Embryonic to Post-Hatch Development

Genes ◽

10.3390/genes12020196 ◽

2021 ◽

Vol 12 (2) ◽

pp. 196

Author(s):

Julie A. Hicks ◽

Hsiao-Ching Liu

Keyword(s):

Energy Source ◽

Adipose Tissue ◽

De Novo ◽

Lipid Storage ◽

Storage Site ◽

Metabolic Processes ◽

Metabolic Switch ◽

Regulatory Pathways ◽

Main Site ◽

Real Time Quantitative Pcr

As the chick transitions from embryonic to post-hatching life, its metabolism must quickly undergo a dramatic switch in its major energy source. The chick embryo derives most of its energy from the yolk, a lipid-rich/carbohydrate-poor source. Upon hatching, the chick’s metabolism must then be able to utilize a lipid-poor/carbohydrate-rich source (feed) as its main form of energy. We recently found that a number of hepatically-expressed microRNAs (miRNAs) help facilitate this shift in metabolic processes in the chick liver, the main site of lipogenesis. While adipose tissue was initially thought to mainly serve as a lipid storage site, it is now known to carry many metabolic, endocrine, and immunological functions. Therefore, it would be expected that adipose tissue is also an important factor in the metabolic switch. To that end, we used next generation sequencing (NGS) and real-time quantitative PCR (RT-qPCR) to generate miRNome and transcriptome signatures of the adipose tissue during the transition from late embryonic to early post-hatch development. As adipose tissue is well known to produce inflammatory and other immune factors, we used SPF white leghorns to generate the initial miRNome and transcriptome signatures to minimize complications from external factors (e.g., pathogenic infections) and ensure the identification of bona fide switch-associated miRNAs and transcripts. We then examined their expression signatures in the adipose tissue of broilers (Ross 708). Using E18 embryos as representative of pre-switching metabolism and D3 chicks as a representative of post-switching metabolism, we identified a group of miRNAs which work concordantly to regulate a diverse but interconnected group of developmental, immune and metabolic processes in the adipose tissue during the metabolic switch. Network mapping suggests that during the first days post-hatch, despite the consumption of feed, the chick is still heavily reliant upon adipose tissue lipid stores for energy production, and is not yet efficiently using their new energy source for de novo lipid storage. A number of core master regulatory pathways including, circadian rhythm transcriptional regulation and growth hormone (GH) signaling, likely work in concert with miRNAs to maintain an essential balance between adipogenic, lipolytic, developmental, and immunological processes in the adipose tissue during the metabolic switch.

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