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Topic Review
Biography
Topic Review
Polyploidy and Ploidy Alterations in Hepatocytes
Polyploidy, a condition in which more than two sets of chromosomes are present in a cell, is a characteristic feature of hepatocytes. A significant number of hepatocytes physiologically undergo polyploidization at a young age. Polyploidization of hepatocytes is enhanced with age and in a diseased liver. It is worth noting that polyploid hepatocytes can proliferate, in marked contrast to other types of polyploid cells, such as megakaryocytes and cardiac myocytes. Polyploid hepatocytes divide to maintain normal liver homeostasis and play a role in the regeneration of the damaged liver. Furthermore, polyploid hepatocytes have been shown to dynamically reduce ploidy during liver regeneration. Although it is still unclear why hepatocytes undergo polyploidization, accumulating evidence has revealed that alterations in the ploidy in hepatocytes are involved in the pathophysiology of liver cirrhosis and carcinogenesis.
459
28 Sep 2022
Topic Review
Polyphenols in Leukaemia
Leukaemia is a malignant disease of the blood. Current treatments for leukaemia are associated with serious side-effects. Here we discuss the potential therapeutic use of polyphenols in leukaemia. We outline the molecular mechanism of action of polyphenol in leukaemia cell lines, and discuss the pharmacological properties of polyphenols, including their anti-inflammatory, antioxidant, anti-proliferative, and anti-tumour activities, and suggest that polyphenols are potent natural agents that can be useful therapeutically; and discuss why data on bioavailability, toxicity and metabolism is essential to evaluate their clinical use.
594
22 Sep 2021
Topic Review
Polyphenol-Based Nanoparticles
Conventional therapies for the treatment of colorectal cancer induce several side effects that impact the effectiveness of current therapies as well as the quality of patients’ life. Natural compounds with anticancer properties have gained attention as potential therapeutic agents for various cancers including colorectal cancer. However, several natural compounds such as polyphenols are facing obstacles for their use as anticancer drugs, such as intrinsic poor solubility, plasmatic instability, ineffective cellular uptake, and biological barriers. Novel approaches in precision medicine and nanomedicine are being developed. In this context, to harness the full potential of natural compounds, researchers have explored the use of nanoparticles as a drug delivery system for targeted and enhanced therapeutic efficacy as well as limited side effects.
295
03 Sep 2023
Topic Review
POLRMT Inhibition as an Anti-Cancer Strategy
Transcription of the mitochondrial genome is essential for the maintenance of oxidative phosphorylation (OXPHOS) and other functions directly related to this unique genome. Considerable evidence suggests that mitochondrial transcription is dysregulated in cancer and cancer metastasis and contributes significantly to cancer cell metabolism. The inhibitors of the mitochondrial DNA-dependent RNA polymerase (POLRMT) were identified as potentially attractive new anti-cancer compounds. These molecules (IMT1, IMT1B) inactivate cancer cell metabolism through reduced transcription of mitochondrially-encoded OXPHOS subunits such as ND1-5 (Complex I) and COI-IV (Complex IV).
369
08 Jun 2023
Topic Review
Pol II Pausing during Daily Gene Transcription
Clock proteins and their collaborating transcription factors often act as distal enhancers to regulate the rhythmic transcription of gene promoters. Those transcription factors need to interact with the mediator complex and general transcription factors near the transcription start site to finally control transcription. Pol II pausing, which is determined by Pol II recruitment, pause release, and premature transcription termination near the transcription start site, plays a critical role in influencing the final transcription output.
222
17 Aug 2023
Topic Review
Pluripotent Stem Cells
Pluripotent stem cells (PSCs) hold great potential both in studies on developmental biology and clinical practice. Mitochondrial metabolism that encompasses pathways that generate ATP and produce ROS significantly differs between PSCs and somatic cells. Correspondingly, for quite a long time it was believed that the redox homeostasis in PSCs is also highly specific due to the hypoxic niche of their origin – within the pre-implantation blastocyst. However, recent research showed that redox parameters of cultivated PSCs have much in common with that of their differentiated progeny cells. Moreover, it has been proven that similar to somatic cells, maintaining the physiological ROS level is critical for the regulation of PSC identity, proliferation, differentiation, and de-differentiation.
526
28 Oct 2021
Topic Review
Pluripotent Organ-Specific Pericytes in Growth and Maturation
Cells fitting the description of Mesenchymal Stem/Signaling Cells (MSC) have been isolated from a large number of adult tissues. The original characteristics of MSC as defined by Caplan’s group were adherence to plastic, expression of a subset of cell surface antigens, and the cells could be induced in vitro to differentiate towards different cell lineages, including chondrocytes, bone cells, and adipocytes. It has been noted that MSC from most tissues or fluids are very heterogeneous, and some sources appear to have unique features, including unique lectin-binding phenotypes. Interestingly, MSC from bone marrow appear to preferentially respond to osteogenic stimuli, while MSC from synovium respond well to chondrogenic stimuli. Thus, different locations may reflect the needs of different environments.
333
25 May 2022
Topic Review
Pluripotency Factor Lin28
Lin28 is an RNA-binding protein that can function as a pluripotency factor and is enriched in stem and progenitor cells and embryonic tissues. Lin28 can regulate protein synthesis by binding mRNAs to regulate their translation, and by governing microRNA production through binding let-7 family precursor microRNAs to block their processing to mature functional microRNAs. Lin28 was first discovered in C.elegans and is highly evolutionarily-conserved across the animal kingdom. In most vertebrates, including mammals, there are two Lin28 paralogs, termed Lin28A and Lin28B. An appreciation for the complex interactions between the NF-κB transcription factor and the Lin28 RNA binding protein/let-7 microRNA pathways has grown substantially over the past decade. In many biological settings, accumulated evidence has revealed that Lin28 can be upregulated from low basal levels in adult tissues following injury or in plastic responses. Both the NF-κB and Lin28/let-7 pathways are master regulators impacting cell survival, growth and proliferation, and an understanding of how interfaces between these pathways participate in governing pluripotency, progenitor differentiation, and neuroplastic responses remains an emerging area of research.
690
05 Jan 2021
Topic Review
Pluripotency
Following fertilization, in the mammalian embryo, a series of programmed cell divisions occur whereby the arising cells progressively acquire their own cellular and molecular identity, and totipotency narrows until when pluripotency is achieved. The path towards pluripotency involves transcriptome modulation, remodeling of the chromatin epigenetic landscape to which external modulators contribute. Both human and mouse embryos are a source of different types of pluripotent stem cells whose characteristics can be captured and maintained in vitro.
933
03 Sep 2021
Topic Review
Plexins in Cancer Cell Proliferation, Migration, and Invasivity
Plexins are a family of nine single-pass transmembrane receptors with a conserved GTPase activating protein (GAP) domain. The plexin family is divided into four subfamilies: Type-A, type-B, type-C, and type-D plexins. Plexins function as receptors for axon guidance factors of the semaphorin family. The semaphorin gene family contains 22 genes that are divided into eight subclasses of which subclasses three to seven represent vertebrate semaphorins. The plexins and their semaphorin ligands have important roles as regulators of angiogenesis, cancer proliferation, and metastasis. Class 3 semaphorins, with the exception of sema3E, are the only semaphorins that do not bind directly to plexins. In order to transduce their signals, they bind instead to complexes consisting of receptors of the neuropilin family and various plexins. Some plexins also form complexes with tyrosine-kinase receptors such as the epidermal growth factor receptor ErbB2, the mesenchymal epithelial transition factor receptor (MET), and the Vascular endothelial growth factor receptor 2 (VEGFR2) and, as a result, can modulate cell proliferation and tumor progression.
484
24 Aug 2023
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