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Cellular levels of oxidative stress affect the response of cervical cancer cells to chemotherapeutic agents.

Filippova M, Filippov V, Williams VM, Zhang K, Kokoza A, Bashkirova S, Duerksen-Hughes P - Biomed Res Int (2014)

Bottom Line: We then extended these findings by comparing the expression level of genes involved in reactive oxygen species (ROS) metabolism through the use of a RT-PCR array.The analyses demonstrated that the resistant SiHa cells expressed higher levels of antioxidant enzymes.Decreasing or increasing oxidative stress led to protection or sensitization, respectively, in both cell lines, supporting the idea that cellular levels of oxidative stress affect responsiveness to treatment.

View Article: PubMed Central - PubMed

Affiliation: Department of Basic Sciences, Loma Linda University School of Medicine, 11021 Campus Street, 101 Alumni Hall, Loma Linda, CA 92354, USA.

ABSTRACT
Treatment of advanced and relapsed cervical cancer is frequently ineffective, due in large part to chemoresistance. To examine the pathways responsible, we employed the cervical carcinoma-derived SiHa and CaSki cells as cellular models of resistance and sensitivity, respectively, to treatment with chemotherapeutic agents, doxorubicin, and cisplatin. We compared the proteomic profiles of SiHa and CaSki cells and identified pathways with the potential to contribute to the differential response. We then extended these findings by comparing the expression level of genes involved in reactive oxygen species (ROS) metabolism through the use of a RT-PCR array. The analyses demonstrated that the resistant SiHa cells expressed higher levels of antioxidant enzymes. Decreasing or increasing oxidative stress led to protection or sensitization, respectively, in both cell lines, supporting the idea that cellular levels of oxidative stress affect responsiveness to treatment. Interestingly, doxorubicin and cisplatin induced different profiles of ROS, and these differences appear to contribute to the sensitivity to treatment displayed by cervical cancer cells. Overall, our findings demonstrate that cervical cancer cells display variable profiles with respect to their redox-generating and -adaptive systems, and that these different profiles have the potential to contribute to their responses to treatments with chemotherapy.

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SiHa cells are more resistant than CaSki cells to treatment with the chemotherapeutic drugs DOX (a and c) and cisplatin (b and d). (a and b) SiHa and CaSki cells (1.5 × 104 cells per well) were seeded into a 96-well plate, allowed to incubate overnight, and then treated with the indicated concentrations of drugs for 20 h. (c and d) SiHa and CaSki cells (0.5 × 104 cells per well) were seeded into a 96-well plate, allowed to incubate overnight, and then treated with the indicated concentrations of drugs for 72 h. Viability was measured by crystal violet and the viability of untreated cells was set at 100%. Each measurement was done in triplicate and error bars indicate the standard deviations of the means.
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fig1: SiHa cells are more resistant than CaSki cells to treatment with the chemotherapeutic drugs DOX (a and c) and cisplatin (b and d). (a and b) SiHa and CaSki cells (1.5 × 104 cells per well) were seeded into a 96-well plate, allowed to incubate overnight, and then treated with the indicated concentrations of drugs for 20 h. (c and d) SiHa and CaSki cells (0.5 × 104 cells per well) were seeded into a 96-well plate, allowed to incubate overnight, and then treated with the indicated concentrations of drugs for 72 h. Viability was measured by crystal violet and the viability of untreated cells was set at 100%. Each measurement was done in triplicate and error bars indicate the standard deviations of the means.

Mentions: Doxorubicin (DOX) and cisplatin are chemotherapeutic agents used to treat solid tumors, including cervical carcinomas [3]. To evaluate and compare the sensitivity of CaSki and SiHa cells to these chemotherapeutic drugs, cells were treated with increasing concentrations of DOX and cisplatin. For the initial set of experiments, relatively high concentrations were applied (10–40 μM for DOX and 16–128 μM for cisplatin) and crystal violet staining was used to monitor cell viability following treatment for 20 h (Figures 1(a) and 1(b)). With both treatments, we found that SiHa cells were more resistant to treatment than were the CaSki cells. For example, cisplatin at a concentration of ~30 μM killed 50% of CaSki cells, while a loss of 50% viability for SiHa cells was observed at 128 μM cisplatin (Figure 1(b)). Similar results were observed for DOX (Figure 1(a)). These experiments were then repeated using lower, more physiologically relevant concentrations (0.05 μM to 2 μM for DOX and 0.2 μM to 5 μM for cisplatin) [11], for a longer period of time (72 h) (Figures 1(c) and 1(d)). Again, we found that SiHa cells were more resistant to treatment than were CaSki cells.


Cellular levels of oxidative stress affect the response of cervical cancer cells to chemotherapeutic agents.

Filippova M, Filippov V, Williams VM, Zhang K, Kokoza A, Bashkirova S, Duerksen-Hughes P - Biomed Res Int (2014)

SiHa cells are more resistant than CaSki cells to treatment with the chemotherapeutic drugs DOX (a and c) and cisplatin (b and d). (a and b) SiHa and CaSki cells (1.5 × 104 cells per well) were seeded into a 96-well plate, allowed to incubate overnight, and then treated with the indicated concentrations of drugs for 20 h. (c and d) SiHa and CaSki cells (0.5 × 104 cells per well) were seeded into a 96-well plate, allowed to incubate overnight, and then treated with the indicated concentrations of drugs for 72 h. Viability was measured by crystal violet and the viability of untreated cells was set at 100%. Each measurement was done in triplicate and error bars indicate the standard deviations of the means.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4248402&req=5

fig1: SiHa cells are more resistant than CaSki cells to treatment with the chemotherapeutic drugs DOX (a and c) and cisplatin (b and d). (a and b) SiHa and CaSki cells (1.5 × 104 cells per well) were seeded into a 96-well plate, allowed to incubate overnight, and then treated with the indicated concentrations of drugs for 20 h. (c and d) SiHa and CaSki cells (0.5 × 104 cells per well) were seeded into a 96-well plate, allowed to incubate overnight, and then treated with the indicated concentrations of drugs for 72 h. Viability was measured by crystal violet and the viability of untreated cells was set at 100%. Each measurement was done in triplicate and error bars indicate the standard deviations of the means.
Mentions: Doxorubicin (DOX) and cisplatin are chemotherapeutic agents used to treat solid tumors, including cervical carcinomas [3]. To evaluate and compare the sensitivity of CaSki and SiHa cells to these chemotherapeutic drugs, cells were treated with increasing concentrations of DOX and cisplatin. For the initial set of experiments, relatively high concentrations were applied (10–40 μM for DOX and 16–128 μM for cisplatin) and crystal violet staining was used to monitor cell viability following treatment for 20 h (Figures 1(a) and 1(b)). With both treatments, we found that SiHa cells were more resistant to treatment than were the CaSki cells. For example, cisplatin at a concentration of ~30 μM killed 50% of CaSki cells, while a loss of 50% viability for SiHa cells was observed at 128 μM cisplatin (Figure 1(b)). Similar results were observed for DOX (Figure 1(a)). These experiments were then repeated using lower, more physiologically relevant concentrations (0.05 μM to 2 μM for DOX and 0.2 μM to 5 μM for cisplatin) [11], for a longer period of time (72 h) (Figures 1(c) and 1(d)). Again, we found that SiHa cells were more resistant to treatment than were CaSki cells.

Bottom Line: We then extended these findings by comparing the expression level of genes involved in reactive oxygen species (ROS) metabolism through the use of a RT-PCR array.The analyses demonstrated that the resistant SiHa cells expressed higher levels of antioxidant enzymes.Decreasing or increasing oxidative stress led to protection or sensitization, respectively, in both cell lines, supporting the idea that cellular levels of oxidative stress affect responsiveness to treatment.

View Article: PubMed Central - PubMed

Affiliation: Department of Basic Sciences, Loma Linda University School of Medicine, 11021 Campus Street, 101 Alumni Hall, Loma Linda, CA 92354, USA.

ABSTRACT
Treatment of advanced and relapsed cervical cancer is frequently ineffective, due in large part to chemoresistance. To examine the pathways responsible, we employed the cervical carcinoma-derived SiHa and CaSki cells as cellular models of resistance and sensitivity, respectively, to treatment with chemotherapeutic agents, doxorubicin, and cisplatin. We compared the proteomic profiles of SiHa and CaSki cells and identified pathways with the potential to contribute to the differential response. We then extended these findings by comparing the expression level of genes involved in reactive oxygen species (ROS) metabolism through the use of a RT-PCR array. The analyses demonstrated that the resistant SiHa cells expressed higher levels of antioxidant enzymes. Decreasing or increasing oxidative stress led to protection or sensitization, respectively, in both cell lines, supporting the idea that cellular levels of oxidative stress affect responsiveness to treatment. Interestingly, doxorubicin and cisplatin induced different profiles of ROS, and these differences appear to contribute to the sensitivity to treatment displayed by cervical cancer cells. Overall, our findings demonstrate that cervical cancer cells display variable profiles with respect to their redox-generating and -adaptive systems, and that these different profiles have the potential to contribute to their responses to treatments with chemotherapy.

Show MeSH
Related in: MedlinePlus