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Triptolide potentiates lung cancer cells to cisplatin-induced apoptosis by selectively inhibiting the NER activity.

Wang G, Wang X, Xu X - Biomark Res (2015)

Bottom Line: The results of our cell growth inhibition studies revealed that the presence of low-levels triptolide itself had little effect on cell growth but greatly enhanced cisplatin-induced cell growth inhibition in both A549 and HTB182 cells.The results of our reef coral-red protein reporter expression studies indicated that the presence of low-levels triptolide did not affect expression of the reef coral-red protein from pDsRed2-C1 plasmid but greatly inhibited expression of the reef coral-red protein from cisplatin-damaged pDsRed2-C1 plasmid DNA in A549 cells.In addition, the results of our protein phosphorylation studies indicated that the presence of low-levels triptolide caused a decrease for cisplatin-induced CHK1 phosphorylation at Ser(317/345) but an increase for cisplatin-induced ATM phosphorylation at Ser(1981) in both HTB182 and A549 cells.

View Article: PubMed Central - PubMed

Affiliation: Institute of Environmental Health Sciences, Wayne State University, 259 Mack Avenue, Detroit, MI 48201 USA.

ABSTRACT

Background: Cisplatin and many other platinum-based compounds are important anticancer drugs that are used in treating many cancer types. The development of cisplatin-resistant cancer cells, however, quickly diminishes the effectiveness of these drugs and causes treatment failure. New strategies that reverse cancer cell drug resistance phenotype or sensitize cancer cells to these drugs, therefore, need to be explored in order to improve platinum drug-based cancer treatment. Triptolide is a bioactive ingredient isolated from Tripterygium wilfordii, a Chinese herbal medicine. Triptolide binds to the TFIIH basal transcription factor and is required for both transcription and nucleotide excision repair (NER), a DNA repair pathway involved in repairing DNA damage generated by the platinum-based anticancer drugs.

Methods: Caspase-3 activation and cell growth inhibition assays were used to determine the effect of triptolide on cisplatin-induced apoptosis and cell growth in lung cancer cells. Real time PCR, immunoblotting, and expression of reef coral red protein were used to determine a mechanism through which the presence of triptolide increased cisplatin-induced apoptosis of the lung cancer cells.

Results: Our caspase-3 activation studies demonstrated that the presence of low-levels of triptolide greatly increased the cisplatin-induced apoptosis of HTB182, A549, CRL5810, and CRL5922 lung cancer cells. The results of our cell growth inhibition studies revealed that the presence of low-levels triptolide itself had little effect on cell growth but greatly enhanced cisplatin-induced cell growth inhibition in both A549 and HTB182 cells. The results of our reef coral-red protein reporter expression studies indicated that the presence of low-levels triptolide did not affect expression of the reef coral-red protein from pDsRed2-C1 plasmid but greatly inhibited expression of the reef coral-red protein from cisplatin-damaged pDsRed2-C1 plasmid DNA in A549 cells. In addition, the results of our protein phosphorylation studies indicated that the presence of low-levels triptolide caused a decrease for cisplatin-induced CHK1 phosphorylation at Ser(317/345) but an increase for cisplatin-induced ATM phosphorylation at Ser(1981) in both HTB182 and A549 cells.

Conclusion: The results of our studies suggest that the presence of low-levels of triptolide potentiates lung cancer cells to cisplatin treatment by selectively inhibiting NER activity, resulting in an increase in apoptosis of the lung cancer cells.

No MeSH data available.


Related in: MedlinePlus

The effect of triptolide on cell proliferation and gene transcription in both A549 and HTB182 lung tumor cells. For cell growth study, cells were collected at 24, 48, and 72 h after the triptolide treatment. For gene transcription study, cells treated with triptolide (5 ng/ml for HTB182 and 10 ng/ml for A549 cells) for 20 h and total RNA isolated from the cells were analyzed by real time PCR assay
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Fig1: The effect of triptolide on cell proliferation and gene transcription in both A549 and HTB182 lung tumor cells. For cell growth study, cells were collected at 24, 48, and 72 h after the triptolide treatment. For gene transcription study, cells treated with triptolide (5 ng/ml for HTB182 and 10 ng/ml for A549 cells) for 20 h and total RNA isolated from the cells were analyzed by real time PCR assay

Mentions: To determine if the presence of low-levels of triptolide has any effect on cell growth, we first performed a cell proliferation study. Both A549 and HTB182 lung tumor cells were seeded onto 100 mm dishes with the same number of cells. The cells were either left untreated or treated with 5 ng/ml and 10 ng/ml triptolide (14nM and 28nM) respectively. At different time points (0, 24, 48, and 72 h), cell numbers were counted for both the untreated and triptolide-treated dishes (Fig. 1a). The results of our cell proliferation studies revealed that the presence of 5 ng/ml triptolide had little effect on inhibiting cell proliferation in both HTB182 and A549 cells; however, the presence of 10 ng/ml has a limited effect in inhibiting cell proliferation in A549 cells but great effect in inhibiting cell proliferation of HTB182 cells (Fig. 1a). Although the mechanism for this inhibition effect was unknown, it was likely that the global transcription inhibition effect of triptolide contributed to this increased cell proliferation inhibition in HTB182 cells.Fig. 1


Triptolide potentiates lung cancer cells to cisplatin-induced apoptosis by selectively inhibiting the NER activity.

Wang G, Wang X, Xu X - Biomark Res (2015)

The effect of triptolide on cell proliferation and gene transcription in both A549 and HTB182 lung tumor cells. For cell growth study, cells were collected at 24, 48, and 72 h after the triptolide treatment. For gene transcription study, cells treated with triptolide (5 ng/ml for HTB182 and 10 ng/ml for A549 cells) for 20 h and total RNA isolated from the cells were analyzed by real time PCR assay
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4496860&req=5

Fig1: The effect of triptolide on cell proliferation and gene transcription in both A549 and HTB182 lung tumor cells. For cell growth study, cells were collected at 24, 48, and 72 h after the triptolide treatment. For gene transcription study, cells treated with triptolide (5 ng/ml for HTB182 and 10 ng/ml for A549 cells) for 20 h and total RNA isolated from the cells were analyzed by real time PCR assay
Mentions: To determine if the presence of low-levels of triptolide has any effect on cell growth, we first performed a cell proliferation study. Both A549 and HTB182 lung tumor cells were seeded onto 100 mm dishes with the same number of cells. The cells were either left untreated or treated with 5 ng/ml and 10 ng/ml triptolide (14nM and 28nM) respectively. At different time points (0, 24, 48, and 72 h), cell numbers were counted for both the untreated and triptolide-treated dishes (Fig. 1a). The results of our cell proliferation studies revealed that the presence of 5 ng/ml triptolide had little effect on inhibiting cell proliferation in both HTB182 and A549 cells; however, the presence of 10 ng/ml has a limited effect in inhibiting cell proliferation in A549 cells but great effect in inhibiting cell proliferation of HTB182 cells (Fig. 1a). Although the mechanism for this inhibition effect was unknown, it was likely that the global transcription inhibition effect of triptolide contributed to this increased cell proliferation inhibition in HTB182 cells.Fig. 1

Bottom Line: The results of our cell growth inhibition studies revealed that the presence of low-levels triptolide itself had little effect on cell growth but greatly enhanced cisplatin-induced cell growth inhibition in both A549 and HTB182 cells.The results of our reef coral-red protein reporter expression studies indicated that the presence of low-levels triptolide did not affect expression of the reef coral-red protein from pDsRed2-C1 plasmid but greatly inhibited expression of the reef coral-red protein from cisplatin-damaged pDsRed2-C1 plasmid DNA in A549 cells.In addition, the results of our protein phosphorylation studies indicated that the presence of low-levels triptolide caused a decrease for cisplatin-induced CHK1 phosphorylation at Ser(317/345) but an increase for cisplatin-induced ATM phosphorylation at Ser(1981) in both HTB182 and A549 cells.

View Article: PubMed Central - PubMed

Affiliation: Institute of Environmental Health Sciences, Wayne State University, 259 Mack Avenue, Detroit, MI 48201 USA.

ABSTRACT

Background: Cisplatin and many other platinum-based compounds are important anticancer drugs that are used in treating many cancer types. The development of cisplatin-resistant cancer cells, however, quickly diminishes the effectiveness of these drugs and causes treatment failure. New strategies that reverse cancer cell drug resistance phenotype or sensitize cancer cells to these drugs, therefore, need to be explored in order to improve platinum drug-based cancer treatment. Triptolide is a bioactive ingredient isolated from Tripterygium wilfordii, a Chinese herbal medicine. Triptolide binds to the TFIIH basal transcription factor and is required for both transcription and nucleotide excision repair (NER), a DNA repair pathway involved in repairing DNA damage generated by the platinum-based anticancer drugs.

Methods: Caspase-3 activation and cell growth inhibition assays were used to determine the effect of triptolide on cisplatin-induced apoptosis and cell growth in lung cancer cells. Real time PCR, immunoblotting, and expression of reef coral red protein were used to determine a mechanism through which the presence of triptolide increased cisplatin-induced apoptosis of the lung cancer cells.

Results: Our caspase-3 activation studies demonstrated that the presence of low-levels of triptolide greatly increased the cisplatin-induced apoptosis of HTB182, A549, CRL5810, and CRL5922 lung cancer cells. The results of our cell growth inhibition studies revealed that the presence of low-levels triptolide itself had little effect on cell growth but greatly enhanced cisplatin-induced cell growth inhibition in both A549 and HTB182 cells. The results of our reef coral-red protein reporter expression studies indicated that the presence of low-levels triptolide did not affect expression of the reef coral-red protein from pDsRed2-C1 plasmid but greatly inhibited expression of the reef coral-red protein from cisplatin-damaged pDsRed2-C1 plasmid DNA in A549 cells. In addition, the results of our protein phosphorylation studies indicated that the presence of low-levels triptolide caused a decrease for cisplatin-induced CHK1 phosphorylation at Ser(317/345) but an increase for cisplatin-induced ATM phosphorylation at Ser(1981) in both HTB182 and A549 cells.

Conclusion: The results of our studies suggest that the presence of low-levels of triptolide potentiates lung cancer cells to cisplatin treatment by selectively inhibiting NER activity, resulting in an increase in apoptosis of the lung cancer cells.

No MeSH data available.


Related in: MedlinePlus