Search

The presence of oncogene carrying eccDNAs is strongly associated with carcinogenesis and poor patient survival. Tumour biopsies and in vitro cancer cell lines are frequently utilized as models to investigate the role of eccDNA in cancer. However, eccDNAs are often lost during the in vitro growth of cancer cell lines, questioning the reproducibility of studies utilizing cancer cell line models. Here, we conducted a comprehensive analysis of eccDNA variability in seven cancer cell lines (MCA3D, PDV, HaCa4, CarC, MIA-PaCa-2, AsPC-1, and PC-3). We compared the content of unique eccDNAs between triplicates of each cell line and found that the number of unique eccDNA is specific to each cell line, while the eccDNA sequence content varied greatly among triplicates (∼ 0-1% eccDNA coordinate commonality). In the PC-3 cell line, we found that the large eccDNA (ecDNA) with MYC is present in high-copy number in an NCI cell line isolate but not present in ATCC isolates. Together, these results reveal that the sequence content of eccDNA is highly variable in cancer cell lines. This highlights the importance of testing cancer cell lines before use, and to enrich for subclones in cell lines with the desired eccDNA to get relatively pure population for studying the role of eccDNA in cancer., Competing Interests: B.R. is cofounder of CARE-DNA. All other authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Authors. Published by Elsevier B.V. on behalf of Research Network of Computational and Structural Biotechnology.)

Phosphorus (P) is an essential nutrient for plant growth and reproduction. Plants preferentially absorb P as orthophosphate (Pi), an ion that displays low solubility and that is readily fixed in the soil, making P limitation a condition common to many soils and Pi fertilization an inefficient practice. To cope with Pi limitation, plants have evolved a series of developmental and physiological responses, collectively known as the Pi starvation rescue system (PSR), aimed to improve Pi acquisition and use efficiency (PUE) and protect from Pi-starvation-induced stress. Intensive research has been carried out during the last 20 years to unravel the mechanisms underlying the control of the PSR in plants. Here we review the results of this research effort that have led to the identification and characterization of several core Pi starvation signaling components, including sensors, transcription factors, microRNAs (miRNAs) and miRNA inhibitors, kinases, phosphatases, and components of the proteostasis machinery. We also refer to recent results revealing the existence of intricate signaling interplays between Pi and other nutrients and antagonists, N, Fe, Zn, and As, that have changed the initial single-nutrient-centric view to a more integrated view of nutrient homeostasis. Finally, we discuss advances toward improving PUE and future research priorities., (Copyright © 2021 The Author. Published by Elsevier Inc. All rights reserved.)

Throughout evolution, plants have evolved sophisticated adaptive responses that allow them to grow with a limited supply of phosphate, the preferential form in which the essential macronutrient phosphorus is absorbed by plants. Most of these responses are aimed to increase phosphate availability and acquisition through the roots, to optimize its usage in metabolic processes, and to protect plants from the deleterious effects of phosphate deficiency stress. Regulation of these adaptive responses requires fine perception of the external and internal phosphate levels, and a complex signal transduction pathway that integrates information on the phosphate status at the whole-plant scale. The molecular mechanisms that participate in phosphate homeostasis include transcriptional control of gene expression, RNA silencing mediated by microRNAs, regulatory non-coding RNAs of miRNA activity, phosphate transporter trafficking, and post-translational modification of proteins, such as phosphorylation, sumoylation and ubiquitination. Such a varied regulatory repertoire reflects the complexity intrinsic to phosphate surveying and signaling pathways. Here, we describe these regulatory mechanisms, emphasizing the increasing importance of ubiquitination in the control of phosphate starvation responses., (© 2013 Institute of Botany, Chinese Academy of Sciences.)