Discovery of differentially expressed genes associated with paclitaxel resistance using cDNA array technology: Analysis of interleukin (IL) 6, IL-8, and monocyte chemotactic protein 1 in the paclitaxel-resistant phenotype
Zf. Duan et al., Discovery of differentially expressed genes associated with paclitaxel resistance using cDNA array technology: Analysis of interleukin (IL) 6, IL-8, and monocyte chemotactic protein 1 in the paclitaxel-resistant phenotype, CLIN CANC R, 5(11), 1999, pp. 3445-3453
In an attempt to define the molecular changes associated with the paclitaxe
l-resistant phenotype in human cancer, a paclitaxel-resistant ovarian cance
r cell Line, SKOV-3(TR), was established through stepwise selection in incr
easing paclitaxel concentrations. SROV-3(TR) was cross- resistant to doxoru
bicin and vincristine and overexpressed multidrug resistance gene 1 but not
multidrug resistance associated protein. SKOV-3(TR) and the paclitaxel-sen
sitive SKOV-3 parent line were characterized using human cDNA array technol
ogy that examined expression of a wide variety of genes involved in cell gr
owth, signal transduction, cell death, and immune function. cDNA probes fro
m reverse transcribed mRNAs of both paclitaxel-resistant and parent cells w
ere compared to identify genes differentially expressed in the paclitaxel-r
esistant cells. Of 588 different human cDNA transcripts compared, 6 genes w
ere found to be markedly decreased, and 12 genes increased in the resistant
subline. Northern analysis and/or reverse transcription-PCR confirmed that
12 of these 18 genes were over- or underexpressed in SKOV-3(TR), In additi
on, at Least eight of the genes were found differentially expressed in seve
ral other paclitaxel- and/or doxorubicin-resistant cell lines, both those w
ith increased multidrug resistance expression and those without. Included i
n the set of overexpressed genes were the cytokines/chemokines interleukin
6, interleukin 8, and monocyte chemotactic protein 1, ELISA assays confirm
that mRNA overexpression of these cytokine/chemokines was associated with t
he increased secretion of these molecules in the tissue culture supernatant
. Evaluation of supernatants from an expanded collection of paclitaxel- and
Adriamycin-resistant cell lines demonstrated that all of the resistant lin
es had significant overexpression of at least one cytokine/chemokine as com
pared with their drug-sensitive parent line. The overexpression of these cy
tokines seemed to be stable and associated with a drug-resistant phenotype
with only a modest induction of cytokine expression in the parent line with
short-term paclitaxel exposure. These findings suggest that the developmen
t of paclitaxel resistance is accompanied by multiple changes in gene expre
ssion including stable alterations in selective chemokine and cytokine expr
ession. The role these associated genetic changes have in the drug-resistan
t phenotype is discussed.