Mechanism of reversal of gemcitabine resistance by gossypol in high Bcl-2 cell lines.

<p>Immunoblots of apoptotic protein expressions in gemcitabine resistant cell lines (GEM-R) when treated with combination of gossypol and gemcitabine for 48 hours. The results shown are representative of two independent experiments.</p

Gene expression analysis in response to gemcitabine and combined treatment.

<p>Heatmap of 2702 significant differentially expressed genes in gemcitabine resistant, GEM-R and gemcitabine sensitive, GEM-S treated with gemcitabine alone (Gem) or in combination with gossypol (Gem+GOS) relative to untreated matched control cell lines. The expression levels of each gene are higher and lower than control is depicted in red and green, respectively.</p

Sensitivity of breast cell lines to gemcitabine in relationship with Bcl-2 expression.

<p>(A) IC₅₀ of gemcitabine to breast cancer cell lines. Mean IC₅₀±Standard Error (SE) of at least two independent experiments were performed in triplicates. Cells were treated with gemcitabine for 72 hr and cell proliferation was assessed using the MTS assay. (B) Immunoblot of Bcl-2 baseline expression in breast cancer cell lines.</p

Analysis of pairwise linkage disequilibrium (LD) coefficients and statistics (D′) for lung cancer patients (below diagonal) and control (above diagonal) among five SNPs.

<p>Analysis of pairwise linkage disequilibrium (LD) coefficients and statistics (D′) for lung cancer patients (below diagonal) and control (above diagonal) among five SNPs.</p

In vitro functional characterization of UGT1A6 105C>T polymorphism.

<p>UGT1A6*1 and UGT1A6 105TT constructs were stably transfected into HEK293 cells. (<b>A</b>) Cells were harvested upon treatment with ActD at different time point up to 24 hours. The data plotted are time course changes in the remaining amount of UGT1A6 mRNA after ActD treatment. There was significantly higher mRNA level in UGT1A6 105TT than UGT1A6*1 transfected cells at 4 hours (p = 0.039) and 8 hours (p = 0.004) after treatment with ActD. (<b>B</b>) Western blot analysis. Cell lysate used was from 5×10⁵ cells at the indicated times (0, 8, 24 and 48 hours) after treatment with ActD. There was a down-regulation in protein expression in UGT1A6*1 as compared to UGT1A6 variant at 48 hours after treatment with ActD. UGT1A6 activity was assessed by evaluating the production of serotonin glucuronide using lysate from variant UGT1A6 (VT) and UGT1A6*1 (WT) at 0 hour (<b>C</b>) and 48 hours (<b>D</b>) after ActD treatment, with substrate concentrations varied from 0.5 to 30 mM serotonin. Activities are expressed as reaction velocity (nanomoles of serotonin glucuronide formed per minute per milligram of protein).</p

Baseline characteristics of Lung cancer patients and controls.

<p>*Smoking history was not obtained for the 100 controls.</p

IC₅₀ of gossypol in different types of cancer cell lines.

<p>Nasopharyngeal (n = 4), breast (n = 3) and gastric (n = 3) cancer cell lines were tested for their sensitivity to gossypol. Mean IC₅₀ of ±Standard Error (SE) of at least two independent experiments were performed in triplicates. Cells were treated with gossypol for 72 hr and cell proliferation was assessed using the MTS assay.</p

Genotype and allele frequencies of <i>UGT1A6</i> SNPs in both first and second cohorts.

<p>Genotype and allele frequencies of <i>UGT1A6</i> SNPs in both first and second cohorts.</p

Synergistic drug interaction between gossypol and gemcitabine.

<p>Combination treatment of masitinib and gemcitabine was tested on nasopharyngeal (n = 4), breast (n = 3) and gastric (n = 3) cancer cell lines. Combination index (CI) were generated by Calcusyn software for combination of gossypol and gemcitabine. CI <1 is indicated as synergistic of the combination treatment.</p>*<p>indicates gemcitabine resistance cell lines. High/low Bcl-2 expression is defined by the presence or absence of Bcl-2 expression based on immunoblot of the gene.</p

Sensitivity of nasopharyngeal cancer cell lines to gemcitabine in relationship with Bcl-2 expression.

<p>(A) IC₅₀ of gemcitabine to nasopharyngeal cancer cell lines. Mean IC₅₀±Standard Error (SE) of at least two independent experiments were performed in triplicates. Cells were treated with gemcitabine for 72 hr and cell proliferation was assessed using the MTS assay. (B) Immunoblot of Bcl-2 baseline expression in nasopharyngeal cancer cell lines.</p