Publications by authors named "Kim-Cuong Cap"
In the tumor microenvironment (TME), communication between cancer cells and tumor-associated macrophages (TAMs) through secreted extracellular proteins promotes cancer progression. Here, we observed that co-culturing cancer cells (4T1) and macrophage cells (Raw264.7) significantly enhanced superoxide production in both cell types.
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- Insulin boosts cell growth and metabolism while lowering blood sugar levels, mainly by enhancing the activity of pyruvate dehydrogenase (PDH) in the liver.
- In liver cancer cells (HepG2), insulin leads to an increase in phosphorylated PDH (p-PDHA1) levels and promotes cell proliferation.
- The study found that p-PDHA1 forms a complex with pyruvate kinase M2 (PKM2) that moves to the nucleus, affecting gene expression related to cancer progression, specifically through increasing levels of the long intergenic non-protein coding gene LINC00273 and the EMT marker ZEB1.
Article Synopsis
- * PKM2 is highly expressed in cancer cells and embryos, functioning both as a metabolic enzyme and a transcriptional regulator, while its counterpart PKM1 is dominant in differentiated cells.
- * PKM2's posttranslational modifications allow it to relocate to the nucleus to regulate gene transcription and phosphorylate proteins, highlighting its importance in various cells like astrocytes and cancer cells for processes such as lactate production and energy supply.
Both the accumulation of Amyloid-β (Aβ) in plaques and phosphorylation of Tau protein (p-Tau) in neurofibrillary tangles have been identified as two major symptomatic features of Alzheimer's disease (AD). Despite of critical role of Aβ and p-Tau in AD progress, the interconnection of signalling pathways that Aβ induces p-Tau remains elusive. Herein, we observed that a popular AD model mouse (APP/PS1) and Aβ-injected mouse showed an increase in p-Tyr42 Rho in hippocampus of brain.
View Article and Find Full Text PDFP-Tyr42 RhoA GTPase amplifies superoxide formation through p47phox, phosphorylated by ROCK.
Biochem Biophys Res Commun
March 2020
Optimal levels of reactive oxygen species (ROS) play a critical role in cellular physiological function. For production of intracellular superoxide, NADPH oxidase is one of the sources. Rac1/2 and RhoA GTPases are involved in regulation of NADPH oxidase activity and Tyr42 phosphorylation of RhoA (p-Tyr42 RhoA) seems significant in this regard as it was recently shown that hydrogen peroxide was able to increase p-Tyr42 RhoA levels.
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- Insulin lowers blood glucose by affecting pyruvate dehydrogenase (PDH), but its impact on PDH function hasn't been fully understood.
- In normal rat liver cells, insulin decreased the phosphorylation of a specific site on PDH (p-Ser264), while it increased this phosphorylation in liver cancer cells (HepG2 and Huh7).
- Insulin activates RhoA and related proteins, which then influence p-Ser264 levels on PDH, affecting cell growth through the expression of important proteins like c-Myc and cyclin D1, highlighting a connection between insulin signaling and cell proliferation in cancer cells.
RhoA GTPase plays a variety of functions in regulation of cytoskeletal proteins, cellular morphology, and migration along with various proliferation and transcriptional activity in cells. RhoA activity is regulated by guanine nucleotide exchange factors (GEFs), GTPase activating proteins (GAPs), and the guanine nucleotide dissociation factor (GDI). The RhoA-RhoGDI complex exists in the cytosol and the active GTP-bound form of RhoA is located to the membrane.
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