Identification of genes involved in the sensitivity to antitumour drug
17-allylamino,17-demethoxygeldanamycin (17AAG).
Barresi V, Fortuna CG, Garozzo R, Musumarra G, Scirč S, Condorelli DF.
Dipartimento di Scienze Chimiche, Universitą di Catania, 95125 Catania, Italy.
In the present study we analysed the gene expression database provided by the
National Cancer Institute in an attempt to correlate activity profiles of
geldanamycin, 17AAG and 11 other analogues in 60 human tumor cell lines with
their gene expression profiles determined by the cDNA microarray technique. On
the basis of the activity profiles two classes of geldanamycin analogues could
be distinguished, having geldanamycin and 17AAG, respectively, as prototype
compounds (denominated as gelda-like and 17AAG-like classes). Application of the
"soft" statistical methodology of PLS (partial least squares modelling in latent
variables or projections to latent structures) allowed us to evaluate the
influence of each gene expression target in determining the therapeutical
responses. The transcript encoding the translocating chain-associated membrane
protein (TRAM) showed a significant statistical correlation with activity
profiles of 17AAG. In order to validate the role of TRAM in determining
sensitivity to 17AAG we induced a selective knocking-down of this transcript by
the RNA interference methodology in H226 non-small cell lung carcinoma cell
line. The efficiency of double-stranded RNA oligonucleotides (short-interfering
RNAs, siRNAs) was determined by measuring TRAM mRNA levels by quantitative
real-time RT-PCR at different times (24-72 hours) after siRNA lipotransfection.
A significant increase in chemosensitivity to 17AAG was observed in
siRNA-silenced cells. Although a number of factors may affect tumour sensitivity
to 17AAG the present methodology allowed us to dissect out a single parameter
which may be partly responsible for its activity.
PMID: 16880941
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