Lack of amino acids in mouse hepatocytes in culture induces the selection of preneoplastic cells |
| |
Authors: | Chisari Andrea N Sancho Patricia Caja Laia Bertran Esther Fabregat Isabel |
| |
Institution: | a Biological Clues of the Invasive and Metastatic Phenotype Group, Bellvitge Biomedical Research Institut (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spainb Instituto de Investigaciones Biológicas (IIB), Universidad Nacional de Mar del Plata, Argentinac Departament de Ciències Fisiològiques II, Universitat de Barcelona, L'Hospitalet de Llobregat, Barcelona, Spain |
| |
Abstract: | Protein malnutrition occurs when there is insufficient protein to meet metabolic demands. Previous works have indicated that cycles of protein fasting/refeeding enhance the incidence of early lesions during chemical carcinogenesis in rat liver. The general objective of this work was to study the effect of aminoacids (Aa) deprivation on the proliferation and survival of hepatocytes, to understand its possible involvement in the generation of pre-neoplastic stages in the liver. Lack of Aa in the culture medium of an immortalized mice hepatocyte cell line induced loss in cell viability, correlating with apoptosis. However, a subpopulation of cells was able to survive, which showed a more proliferative phenotype and resistance to apoptotic stimuli. Escaping to Aa deprivation-induced death is coincident with an activated mTOR signaling and higher levels of phospho-AKT and phospho-ERKs, which correlated with increased activation of EGFR/SRC pathway and overexpression of EGFR ligands, such as TGF-α and HB-EGF. Lack of Aa induced a rapid increase in reactive oxygen species (ROS) production. However, cells that survived showed an enhancement in the levels of reduced glutathione and a higher expression of γ-GCS, the regulatory enzyme of glutathione synthesis, which can be interpreted as an adaptation of the cells to counteract the oxidative stress. In conclusion, results presented in this paper indicate that it is possible to isolate a subpopulation of hepatocytes that are able to grow in the absence of Aa, showing higher capacity to proliferate and survive, reminiscent of a preneoplastic phenotype. |
| |
Keywords: | Aa aminoacids EGFR Epidermal growth Factor Receptor FBS fetal bovine serum CM complete medium PM aminoacid-starved medium HCC Hepatocellular carcinoma H2DCFDA 2&prime 7&prime -dichlorodihydro-fluorescein diacetate γ-GCS gamma glutamylcysteine syntethase mTOR mammalian Target Of Rapamycin PTKs Protein Tyrosin Kinases ROS Reactive Oxygen Species TGF-β Transforming Growth Factor-beta |
本文献已被 ScienceDirect PubMed 等数据库收录! |
|