ChemInform Abstract: Protein Purification. From Molecular Mechanisms to Large-Scale Processes

AbstractEpigallocatechin gallate (EGCG) from green tea can induce apoptosis in cancerous cells, but the underlying molecular mechanisms remain poorly understood. Using SPR and NMR, here we report a direct, μM interaction between EGCG and the tumor suppressor p53 (KD = 1.6 ± 1.4 μM), with the disordered N-terminal domain (NTD) identified as the major binding site (KD = 4 ± 2 μM). Large scale atomistic simulations (>100 μs), SAXS and AUC demonstrate that EGCG-NTD interaction is dynamic and EGCG causes the emergence of a subpopulation of compact bound conformations. The EGCG-p53 interaction disrupts p53 interaction with its regulatory E3 ligase MDM2 and inhibits ubiquitination of p53 by MDM2 in an in vitro ubiquitination assay, likely stabilizing p53 for anti-tumor activity. Our work provides insights into the mechanisms for EGCG’s anticancer activity and identifies p53 NTD as a target for cancer drug discovery through dynamic interactions with small molecules.

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Integrative cBioPortal Analysis Revealed Molecular Mechanisms That Regulate EGFR-PI3K-AKT-mTOR Pathway in Diffuse Gliomas of the Brain

Cancers ◽

10.3390/cancers13133247 ◽

2021 ◽

Vol 13 (13) ◽

pp. 3247

Author(s):

Petar Brlek ◽

Anja Kafka ◽

Anja Bukovac ◽

Nives Pećina-Šlaus

Keyword(s):

Large Scale ◽

Molecular Mechanisms ◽

In Silico Analysis ◽

Total Sample ◽

Mtor Signaling ◽

Biological Behavior ◽

Mrna Transcription ◽

Diffuse Gliomas ◽

New Treatment ◽

Using Data

Diffuse gliomas are a heterogeneous group of tumors with aggressive biological behavior and a lack of effective treatment methods. Despite new molecular findings, the differences between pathohistological types still require better understanding. In this in silico analysis, we investigated AKT1, AKT2, AKT3, CHUK, GSK3β, EGFR, PTEN, and PIK3AP1 as participants of EGFR-PI3K-AKT-mTOR signaling using data from the publicly available cBioPortal platform. Integrative large-scale analyses investigated changes in copy number aberrations (CNA), methylation, mRNA transcription and protein expression within 751 samples of diffuse astrocytomas, anaplastic astrocytomas and glioblastomas. The study showed a significant percentage of CNA in PTEN (76%), PIK3AP1 and CHUK (75% each), EGFR (74%), AKT2 (39%), AKT1 (32%), AKT3 (19%) and GSK3β (18%) in the total sample. Comprehensive statistical analyses show how genomics and epigenomics affect the expression of examined genes differently across various pathohistological types and grades, suggesting that genes AKT3, CHUK and PTEN behave like tumor suppressors, while AKT1, AKT2, EGFR, and PIK3AP1 show oncogenic behavior and are involved in enhanced activity of the EGFR-PI3K-AKT-mTOR signaling pathway. Our findings contribute to the knowledge of the molecular differences between pathohistological types and ultimately offer the possibility of new treatment targets and personalized therapies in patients with diffuse gliomas.

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Designing Downstream Processes for Large–Scale Protein Purification

Nature Biotechnology ◽

10.1038/nbt0887-789 ◽

1987 ◽

Vol 5 (8) ◽

pp. 789-793 ◽

Cited By ~ 26

Author(s):

Scott M. Wheelwright

Keyword(s):

Protein Purification ◽

Large Scale ◽

Downstream Processes

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Antihyperglycaemic therapies and cancer risk

Diabetes and Vascular Disease Research ◽

10.1177/1479164114549553 ◽

2014 ◽

Vol 11 (6) ◽

pp. 371-389 ◽

Cited By ~ 17

Author(s):

Stefan Z Lutz ◽

Harald Staiger ◽

Andreas Fritsche ◽

Hans-Ulrich Häring

Keyword(s):

Cancer Risk ◽

Large Scale ◽

Tumour Growth ◽

Molecular Mechanisms ◽

Growth Promotion ◽

Protective Effects ◽

Antidiabetic Drug ◽

Safety Issues ◽

Drug Classes ◽

Few Data

Aims: This review is aimed at highlighting the potential mitogenic/tumour growth–promoting or antimitogenic/tumour growth–inhibiting effects of the main antihyperglycaemic drug classes. Methods: We review and discuss the most current studies evaluating the association between antidiabetic medications used in clinical practice and malignancies as described so far. Results: Metformin seems to be the only antidiabetic drug to exert protective effects both on monotherapy and also when combined with other oral antidiabetic drugs or insulins in several site-specific cancers. In contrast, several other drug classes may increase cancer risk. Some reason for concern remains regarding sulphonylureas and also the incretin-based therapies regarding pancreas and thyroid cancers and the sodium glucose cotransporter-2 inhibitors as well as pioglitazone regarding bladder cancer. The majority of meta-analyses suggest that there is no evidence for a causal relationship between insulin glargine and elevated cancer risk, although the studies have been controversially discussed. For α-glucosidase inhibitors and glinides, neutral or only few data upon cancer risk exist. Conclusion: Although the molecular mechanisms are not fully understood, a potential risk of mitogenicity and tumour growth promotion cannot be excluded in case of several antidiabetic drug classes. However, more large-scale, randomized, well-designed clinical studies with especially long follow-up time periods are needed to get reliable answers to these safety issues.

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Sex differences in white adipose tissue expansion: emerging molecular mechanisms

Clinical Science ◽

10.1042/cs20210086 ◽

2021 ◽

Vol 135 (24) ◽

pp. 2691-2708

Author(s):

Simon T. Bond ◽

Anna C. Calkin ◽

Brian G. Drew

Keyword(s):

Sex Differences ◽

Sexual Dimorphism ◽

Gene Networks ◽

Large Scale ◽

Molecular Mechanisms ◽

Association Studies ◽

Tissue Expansion ◽

Economic Systems ◽

Genomic Association ◽

Males And Females

Abstract The escalating prevalence of individuals becoming overweight and obese is a rapidly rising global health problem, placing an enormous burden on health and economic systems worldwide. Whilst obesity has well described lifestyle drivers, there is also a significant and poorly understood component that is regulated by genetics. Furthermore, there is clear evidence for sexual dimorphism in obesity, where overall risk, degree, subtype and potential complications arising from obesity all differ between males and females. The molecular mechanisms that dictate these sex differences remain mostly uncharacterised. Many studies have demonstrated that this dimorphism is unable to be solely explained by changes in hormones and their nuclear receptors alone, and instead manifests from coordinated and highly regulated gene networks, both during development and throughout life. As we acquire more knowledge in this area from approaches such as large-scale genomic association studies, the more we appreciate the true complexity and heterogeneity of obesity. Nevertheless, over the past two decades, researchers have made enormous progress in this field, and some consistent and robust mechanisms continue to be established. In this review, we will discuss some of the proposed mechanisms underlying sexual dimorphism in obesity, and discuss some of the key regulators that influence this phenomenon.

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Current Strategies for Identification of Glioma Stem Cells: Adequate or Unsatisfactory?

Journal of Oncology ◽

10.1155/2012/376894 ◽

2012 ◽

Vol 2012 ◽

pp. 1-10 ◽

Cited By ~ 44

Author(s):

Paola Brescia ◽

Cristina Richichi ◽

Giuliana Pelicci

Keyword(s):

Stem Cells ◽

Stem Cell ◽

Cancer Stem Cells ◽

Large Scale ◽

Molecular Mechanisms ◽

Cell Phenotype ◽

Multiple Tumor ◽

Early Results ◽

Tumorigenic Potential ◽

Tumor Types

Cancer stem cells (CSCs) were isolated in multiple tumor types, including human glioblastomas, and although the presence of surface markers selectively expressed on CSCs can be used to isolate them, no marker/pattern of markers are sufficiently robust to definitively identify stem cells in tumors. Several markers were evaluated for their prognostic value with promising early results, however none of them was proven to be clinically useful in large-scale studies, leading to outstanding efforts to identify new markers. Given the heterogeneity of human glioblastomas further investigations are necessary to identify both cancer stem cell-specific markers and the molecular mechanisms sustaining the tumorigenic potential of these cells to develop tailored treatments. Markers for glioblastoma stem cells such as CD133, CD15, integrin-α6, L1CAM might be informative to identify these cells but cannot be conclusively linked to a stem cell phenotype. Overlap of expression, functional state and morphology of different subpopulations lead to carefully consider the techniques employed so far to isolate these cells. Due to a dearth of methods and markers reliably identifying the candidate cancer stem cells, the isolation/enrichment of cancer stem cells to be therapeutically targeted remains a major challenge.

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Synaptonemal Complex dimerization regulates chromosome alignment and crossover patterning in meiosis

10.1101/2020.09.24.310540 ◽

2020 ◽

Author(s):

Spencer G. Gordon ◽

Lisa E. Kursel ◽

Kewei Xu ◽

Ofer Rog

Keyword(s):

Synaptonemal Complex ◽

Sequence Homology ◽

Genetic Information ◽

Large Scale ◽

Molecular Mechanisms ◽

Homologous Chromosomes ◽

C Elegans ◽

Local Sequence ◽

Chromosome Alignment ◽

Dimerization Interface

AbstractDuring sexual reproduction the parental homologous chromosomes find each other (pair) and align along their lengths by integrating local sequence homology with large-scale contiguity, thereby allowing for precise exchange of genetic information. The Synaptonemal Complex (SC) is a conserved zipper-like structure that assembles between the homologous chromosomes. This phase-separated interface brings chromosomes together and regulates exchanges between them. However, the molecular mechanisms by which the SC carries out these functions remain poorly understood. Here we isolated and characterized two mutations in the dimerization interface in the middle of the SC zipper in C. elegans. The mutations perturb both chromosome alignment and the regulation of genetic exchanges. Underlying the chromosome-scale phenotypes are distinct alterations to the way SC subunits interact with one another. We propose that the SC brings homologous chromosomes together through two biophysical activities: obligate dimerization that prevents assembly on unpaired chromosomes; and a tendency to phase-separate that extends pairing interactions along the entire length of the chromosomes.

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