siRNAs targeted against cell cycle related genes as tools to down regulate cell-proliferation in hepatocellular carcinoma and vascular smooth muscle cells.

Farra, Rossella

siRNAs targeted against cell cycle related genes as tools to down regulate cell-proliferation in hepatocellular carcinoma and vascular smooth muscle cells.

Farra, Rossella

2008-04-15

http://hdl.handle.net/10077/2651

Doctoral Thesis

Contributor(s)

Grassi, Gabriele

Abstract

ABSTRACT Exuberant and non-controlled cellular proliferation underlines the ethio-pathogenesis of many human pathological conditions, including tumour and non-tumour diseases. Thus, the possibility to control this complex process can be extremely useful in terms of prevention/control of disease progression, especially in the light of the limited efficacy of current therapeutic approaches. In this project we draw our attention on the down regulation of cell proliferation in the context of two human diseases, namely hepatocellular carcinoma (HCC), as an example of tumour pathology and in stent- restenosis, example of non-tumour pathology. To explore the possibility to down regulate cell growth, we targeted the transcription factor E2F1 and the serum response factor (SRF) and cyclins E1/E2, all genes implicated in cell cycle progression. As tools to down regulate the expression of the target genes, we used small interfering RNAs, short double stranded RNA molecules able to induce the specific degradation of a homologue mRNA. The presented results indicate that SRF depletion impairs cell proliferation, in primary VSMC and in the most differentiated HCC cell line HepG2, but not in the less differentiated HuH7 and JHH6. Additionally, the depletion of CyE1, CyE2 and E2F1 is effective in preventing all HCC cell expansion, regardless of the differentiation status. However, whereas in HepG2 the major mechanism is the induction of apoptosis, in HuH7 and JHH6 it is the down modulation of cell growth. In conclusion, our project based on the inhibition of cell growth in tumour and non tumour cells by means of siRNAs, can contribute to better understand the complex mechanisms regulating cell proliferation in HCC and in vascular smooth muscle cells. Moreover, these data support the rationale to continue the studies for the development of future novel anti HCC and in-stent restenosis approaches based on the use of siRNAs.