ETD

Archivio digitale delle tesi discusse presso l'Università di Pisa

Tesi etd-08272014-115155


Tipo di tesi
Tesi di laurea magistrale
Autore
TANTILLO, ELENA
URN
etd-08272014-115155
Titolo
sviluppo di un sistema d'immortalizzazione cellulare ex vivo
Dipartimento
BIOLOGIA
Corso di studi
BIOTECNOLOGIE MOLECOLARI E INDUSTRIALI
Relatori
relatore Prof. Pistello, Mauro
Parole chiave
  • espressione genica inducibile
  • inducible gene expression
  • reversione fenotipica
  • phenotypic reversion
  • cellule primarie
  • metabolic alterations
  • alterazioni metaboliche
  • cellular protein
  • proteine cellulari
  • primary cells
Data inizio appello
18/09/2014
Consultabilità
Completa
Riassunto
Generation of cells with unlimited replication capacity yet maintaining their normal features is matter of intense research. An unlimited supply of normal cells is useful to produce biological tissues, study metabolic pathways, test drugs, produce biomolecules, etc. Strategies currently available transform rather than merely immortalize cells.
Immortalization and tumor transformation are two distinct, yet partly overlapping processes. Normal cells work on a biological clock that controls timing and number of replication cycles. Once the maximum number is reached, cells come to age and die.
During immortalization, cells undergo continuous replication but maintain morphology and metabolism of normal cells. Cells that replicate continuously has a higher probability to accumulate gene mutations and genomic alterations, therefore, immortalized cells may eventually acquire irreversible changes such as tumor features. As a result, tumor cells have little in common with normal cells and this makes transformed cells unusable for most of the studies.
During my dissertation internship I have developed a system to induce normal cells to replicate and live beyond physiological lifespan without altering their normal phenotype. The idea derives from previous observations showing that specific genes induced in normal cells and expressed constantly and at high levels transform at high efficiency. The system developed delivers the same group of genes but their expression is controlled by an inducible promoter activated by a doxicicline induced transactivator. Transient expression of these genes induces cells to replicate and cell cycling continues as long as these genes are expressed. The cells retain their normal phenotype and capacity to replicate in time. I’ve tested the immortalization system in human fibroblasts and I have found that replication can be induced in time. During treatment, cells tend to form cellular aggregates as tumor cells. These cells return to normal morphology within two days after removal of activator. The induced immortalization did not change genomic, morphological and metabolic features compared to normal cells.
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