Cellular Levels of Oxidative Stress Affect the Response of Cervical Cancer Cells to Chemotherapeutic Agents

Figure 2

SiHa and CaSki cells differ in expression levels of proteins involved in the regulation of ROS. (a) Differential regulation of nine pathways in SiHa and CaSki cells. The percentage of genes downregulated in SiHa as compared to CaSki cells is shown in black, upregulated in grey. (b) Immunoblot analysis confirms differential expression. Lysates prepared from 10⁶ CaSki and SiHa cells using Laemmli lysis buffer were subjected to SDS-PAGE. Immunoblots were performed using antibodies directed against the indicated proteins. Loading was normalized by blotting for -actin. (c and d) Transcription levels of genes related to oxidative stress as determined by semiquantitative RT-PCR (c) and by quantitative qRT-PCR (d) differ between SiHa and CaSki cells. Total RNA was isolated from 10⁶ cells of each cell line using Trizol Reagent (Sigma Aldrich) and cDNA was synthetized using oligo-dT. PCR and qPCR were performed using specific primers for the genes of interest. The PCR and qPCR products obtained using primers for the PGK1 transcript were used to normalize to cDNA input. (d) Differences in gene expression are presented as fold changes (SiHa versus CaSki). Each measurement was done in triplicate and error bars indicate the standard deviations of the means.

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