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Intracellular GSH Alterations and Its Relationship to Level of Resistance following Exposure to Cisplatin in Cancer Cells.

Jamali B, Nakhjavani M, Hosseinzadeh L, Amidi S, Nikounezhad N, H Shirazi F - Iran J Pharm Res (2015)

Bottom Line: Our results indicate that there are significant differences between GSHi content of A2780CP and U373MGCP cells compared to other cell lines.As a conclusion, it seems that resistance to cisplatin in different cell lines is more related with the diverse patterns of GSHi variations following cisplatin exposure than its original level, and/or its cellular increase or decrease.It is also suggested that GSH (mean)90 may be used as a factor for the prediction of cellular resistance to cisplatin.

View Article: PubMed Central - PubMed

Affiliation: Chemical Injuries Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran.

ABSTRACT
One of the major complications in cancer chemotherapy with cisplatin as one of the important medicines in treatment regimens of different cancers is the development of resistance. One of the most described cellular defense mechanisms involved in resistance is glutathione (GSH), thus in this study, the effects of cisplatin on the total intracellular GSH level (GSHi) in some sensitive and resistant variants of human cell lines (hepatocarcinoma HepG2, skin A375, cisplatin sensitive glioblastoma U373MG and cisplatin resistant glioblastoma U373MGCP, cisplatin sensitive ovary A2780S and cisplatin resistant A2780CP cells) were studied. MTT assay was performed to measure cytotoxicity of cisplatin (33.3 µM for 1 hour). Following cisplatin exposure, GSHi (per million cells) was evaluated using a photometrical assay up to 90 minutes. Our results indicate that there are significant differences between GSHi content of A2780CP and U373MGCP cells compared to other cell lines. Moreover, IC50 of cisplatin in different cells seems to have a relation with mean of GSH level in 90 minutes (GSH (mean)90). As a conclusion, it seems that resistance to cisplatin in different cell lines is more related with the diverse patterns of GSHi variations following cisplatin exposure than its original level, and/or its cellular increase or decrease. It is also suggested that GSH (mean)90 may be used as a factor for the prediction of cellular resistance to cisplatin.

No MeSH data available.


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Comparing the IC50 (ug/mL) of cisplatin exposed to cisplatin sensitive or resistant cell line after 1 hour.
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Figure 2: Comparing the IC50 (ug/mL) of cisplatin exposed to cisplatin sensitive or resistant cell line after 1 hour.

Mentions: The role of GSH in the regulation of resistance to cisplatin has been explained by many researchers (18-20). Although it is stated that alteration in GSH level might not be the primary mechanism of resistance to cisplatin (21, 22), it is generally believed that high resistance to cisplatin is associated with increased synthesis of GSH (9, 23, 24). Yet, controversies in this area exist and all the cell lines do not have a similar pattern of resistance to this medicine. For example, Sandrine and coworkers showed that increase in GSHi did not influence resistance to cisplatin in Hela cell line (25). In the present study, the correlation between resistance to cisplatin and the pattern of intracellular GSH alterations was studied on some cisplatin resistant and sensitive cell lines. The clinical Minimum Residence Time (MRT) of cisplatin, after the injection of clinical doses is about 15 minutes and that is the exposure time we had selected for the observation of intracellular GSH variations. However, this exposure time is not enough to distinguish the level of resistance of this cell lines in-vitro. That is why the minimum more repeated exposure time in literatures of one hour has been selected to present statistically significant variations in these cell lines’ resistance to cisplatin. Ninety minutes is the length of observation for intracellular GSH that we could manage in the lab. Therefore, these timings are independent to each other. The selection of 15 minutes is to mimic the most relevant timing to the clinical exposure of tumor cells to cisplatin, 90 minutes observation was to follow the intracellular GSH alterations based on the general belief in clinical pharmacokinetics that the effect of a drug lasts for a minimum of 6 to 7 half lives (15 × 6 = 90). Sixty minutes exposure was the minimum time to observe the level of cellular resistance in the lab using MTT assay. To compare the intensity of resistance against cisplatin, MTT assay reveled IC50s of 0.9±0.1 µg/mL, 2±0.1 µg/mL, 2.3±0.1 µg/mL, 4.5±0.1 µg/mL, 2.8±0.1 µg/mL and 1.6±0.1 µg/mL for A2780S, A2780CP, U373MGS, U373MGCP, HepG2 and A375, respectively (Figure 2). These data confirm U373MGCP as the most resistant cell line in this study.


Intracellular GSH Alterations and Its Relationship to Level of Resistance following Exposure to Cisplatin in Cancer Cells.

Jamali B, Nakhjavani M, Hosseinzadeh L, Amidi S, Nikounezhad N, H Shirazi F - Iran J Pharm Res (2015)

Comparing the IC50 (ug/mL) of cisplatin exposed to cisplatin sensitive or resistant cell line after 1 hour.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4403068&req=5

Figure 2: Comparing the IC50 (ug/mL) of cisplatin exposed to cisplatin sensitive or resistant cell line after 1 hour.
Mentions: The role of GSH in the regulation of resistance to cisplatin has been explained by many researchers (18-20). Although it is stated that alteration in GSH level might not be the primary mechanism of resistance to cisplatin (21, 22), it is generally believed that high resistance to cisplatin is associated with increased synthesis of GSH (9, 23, 24). Yet, controversies in this area exist and all the cell lines do not have a similar pattern of resistance to this medicine. For example, Sandrine and coworkers showed that increase in GSHi did not influence resistance to cisplatin in Hela cell line (25). In the present study, the correlation between resistance to cisplatin and the pattern of intracellular GSH alterations was studied on some cisplatin resistant and sensitive cell lines. The clinical Minimum Residence Time (MRT) of cisplatin, after the injection of clinical doses is about 15 minutes and that is the exposure time we had selected for the observation of intracellular GSH variations. However, this exposure time is not enough to distinguish the level of resistance of this cell lines in-vitro. That is why the minimum more repeated exposure time in literatures of one hour has been selected to present statistically significant variations in these cell lines’ resistance to cisplatin. Ninety minutes is the length of observation for intracellular GSH that we could manage in the lab. Therefore, these timings are independent to each other. The selection of 15 minutes is to mimic the most relevant timing to the clinical exposure of tumor cells to cisplatin, 90 minutes observation was to follow the intracellular GSH alterations based on the general belief in clinical pharmacokinetics that the effect of a drug lasts for a minimum of 6 to 7 half lives (15 × 6 = 90). Sixty minutes exposure was the minimum time to observe the level of cellular resistance in the lab using MTT assay. To compare the intensity of resistance against cisplatin, MTT assay reveled IC50s of 0.9±0.1 µg/mL, 2±0.1 µg/mL, 2.3±0.1 µg/mL, 4.5±0.1 µg/mL, 2.8±0.1 µg/mL and 1.6±0.1 µg/mL for A2780S, A2780CP, U373MGS, U373MGCP, HepG2 and A375, respectively (Figure 2). These data confirm U373MGCP as the most resistant cell line in this study.

Bottom Line: Our results indicate that there are significant differences between GSHi content of A2780CP and U373MGCP cells compared to other cell lines.As a conclusion, it seems that resistance to cisplatin in different cell lines is more related with the diverse patterns of GSHi variations following cisplatin exposure than its original level, and/or its cellular increase or decrease.It is also suggested that GSH (mean)90 may be used as a factor for the prediction of cellular resistance to cisplatin.

View Article: PubMed Central - PubMed

Affiliation: Chemical Injuries Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran.

ABSTRACT
One of the major complications in cancer chemotherapy with cisplatin as one of the important medicines in treatment regimens of different cancers is the development of resistance. One of the most described cellular defense mechanisms involved in resistance is glutathione (GSH), thus in this study, the effects of cisplatin on the total intracellular GSH level (GSHi) in some sensitive and resistant variants of human cell lines (hepatocarcinoma HepG2, skin A375, cisplatin sensitive glioblastoma U373MG and cisplatin resistant glioblastoma U373MGCP, cisplatin sensitive ovary A2780S and cisplatin resistant A2780CP cells) were studied. MTT assay was performed to measure cytotoxicity of cisplatin (33.3 µM for 1 hour). Following cisplatin exposure, GSHi (per million cells) was evaluated using a photometrical assay up to 90 minutes. Our results indicate that there are significant differences between GSHi content of A2780CP and U373MGCP cells compared to other cell lines. Moreover, IC50 of cisplatin in different cells seems to have a relation with mean of GSH level in 90 minutes (GSH (mean)90). As a conclusion, it seems that resistance to cisplatin in different cell lines is more related with the diverse patterns of GSHi variations following cisplatin exposure than its original level, and/or its cellular increase or decrease. It is also suggested that GSH (mean)90 may be used as a factor for the prediction of cellular resistance to cisplatin.

No MeSH data available.


Related in: MedlinePlus