title: Molecular mechanisms of the increased glucose transport in transformed FRTL-5 rat thyroid cells.
abstract: We investigated the molecular mechanisms involved in the glucose carrier (Glut 1) regulation in FRTL-5 cells and two derived transformed clones (SRC and Ki-Mol cells). When compared to the wild-type strain, SRC and Ki-Mol cells showed an increase in both glucose consumption and uptake (about 60 fold), associated with 6-8 fold higher Glut 1 mRNA levels. Transcriptional studies revealed a 2- to 3 fold increased activation of the gene in the transformed cells, suggesting that transcription alone cannot fully account for the higher Glut 1 gene expression. Western blot studies showed an increase of the Glut 1 protein in SRC and Ki-Mol cells, associated with a different gel migration pattern and a disparate distribution rate between the plasma membrane and the microsomal fraction. These data indicate that the higher rate of glucose uptake observed in SRC and Ki-Mol cells is associated to an increase in Glut 1 gene expression, and that also changes in the subcellular distribution and probably in the structure of Glut 1 protein are present.
authors.affiliation: Dipartimento di Medicina Clinica e Sperimentale, Università di Reggio Calabria, Catanzaro, Italy.
authors.forename: D
authors.initials: D
authors.lastname: Foti
authors.forename: G
authors.initials: G
authors.lastname: Damante
authors.forename: D
authors.initials: D
authors.lastname: Russo
authors.forename: M
authors.initials: M
authors.lastname: Distefano
authors.forename: G
authors.initials: G
authors.lastname: Grasso
authors.forename: A
authors.initials: A
authors.lastname: Fusco
authors.forename: S
authors.initials: S
authors.lastname: Filetti
mesh_terms: D000818:Animals; D001692:Biological Transport; D015152:Blotting, Northern; D002461:Cell Line, Transformed; D002467:Cell Nucleus / Q000378:metabolism; D002999:Clone Cells; D003847:Deoxyglucose / Q000378:metabolism; D015870:Gene Expression; D005947:Glucose / Q000378:metabolism*; D007700:Kinetics; D009004:Monosaccharide Transport Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D013347:Subcellular Fractions / Q000378:metabolism; D013961:Thyroid Gland / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: D009004:Monosaccharide Transport Proteins; D012333:RNA, Messenger; D003847:Deoxyglucose; D005947:Glucose