Sequential decitabine and carboplatin treatment increases the DNA repair protein XPC, increases apoptosis and decreases proliferation in melanoma
Abstract Background Melanoma has two key features, an over-representation of UV-induced mutations and resistance to DNA damaging chemotherapy agents. Both of these features may result from dysfunction of the nucleotide excision repair pathway, in particular the DNA damage detection branch, global ge...
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| Format: | Article |
| Language: | English |
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BMC
2018-01-01
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| Series: | BMC Cancer |
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| Online Access: | http://link.springer.com/article/10.1186/s12885-018-4010-9 |
| _version_ | 1819143242546937856 |
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| author | Timothy Budden Andre van der Westhuizen Nikola A. Bowden |
| author_facet | Timothy Budden Andre van der Westhuizen Nikola A. Bowden |
| author_sort | Timothy Budden |
| collection | DOAJ |
| description | Abstract Background Melanoma has two key features, an over-representation of UV-induced mutations and resistance to DNA damaging chemotherapy agents. Both of these features may result from dysfunction of the nucleotide excision repair pathway, in particular the DNA damage detection branch, global genome repair (GGR). The key GGR component XPC does not respond to DNA damage in melanoma, the cause of this lack of response has not been investigated. In this study, we investigated the role of methylation in reduced XPC in melanoma. Methods To reduce methylation and induce DNA-damage, melanoma cell lines were treated with decitabine and carboplatin, individually and sequentially. Global DNA methylation levels, XPC mRNA and protein expression and methylation of the XPC promoter were examined. Apoptosis, cell proliferation and senescence were also quantified. XPC siRNA was used to determine that the responses seen were reliant on XPC induction. Results Treatment with high-dose decitabine resulted in global demethylation, including the the shores of the XPC CpG island and significantly increased XPC mRNA expression. Lower, clinically relevant dose of decitabine also resulted in global demethylation including the CpG island shores and induced XPC in 50% of cell lines. Decitabine followed by DNA-damaging carboplatin treatment led to significantly higher XPC expression in 75% of melanoma cell lines tested. Combined sequential treatment also resulted in a greater apoptotic response in 75% of cell lines compared to carboplatin alone, and significantly slowed cell proliferation, with some melanoma cell lines going into senescence. Inhibiting the increased XPC using siRNA had a small but significant negative effect, indicating that XPC plays a partial role in the response to sequential decitabine and carboplatin. Conclusions Demethylation using decitabine increased XPC and apoptosis after sequential carboplatin. These results confirm that sequential decitabine and carboplatin requires further investigation as a combination treatment for melanoma. |
| first_indexed | 2024-12-22T12:23:08Z |
| format | Article |
| id | doaj.art-a0418f37c4db404190f6036e805af971 |
| institution | Directory Open Access Journal |
| issn | 1471-2407 |
| language | English |
| last_indexed | 2024-12-22T12:23:08Z |
| publishDate | 2018-01-01 |
| publisher | BMC |
| record_format | Article |
| series | BMC Cancer |
| spelling | doaj.art-a0418f37c4db404190f6036e805af9712022-12-21T18:25:55ZengBMCBMC Cancer1471-24072018-01-0118111410.1186/s12885-018-4010-9Sequential decitabine and carboplatin treatment increases the DNA repair protein XPC, increases apoptosis and decreases proliferation in melanomaTimothy Budden0Andre van der Westhuizen1Nikola A. Bowden2Hunter Medical Research Institute and Faculty of Health, University of NewcastleDepartment of Medical Oncology, Calvary Mater HospitalHunter Medical Research Institute and Faculty of Health, University of NewcastleAbstract Background Melanoma has two key features, an over-representation of UV-induced mutations and resistance to DNA damaging chemotherapy agents. Both of these features may result from dysfunction of the nucleotide excision repair pathway, in particular the DNA damage detection branch, global genome repair (GGR). The key GGR component XPC does not respond to DNA damage in melanoma, the cause of this lack of response has not been investigated. In this study, we investigated the role of methylation in reduced XPC in melanoma. Methods To reduce methylation and induce DNA-damage, melanoma cell lines were treated with decitabine and carboplatin, individually and sequentially. Global DNA methylation levels, XPC mRNA and protein expression and methylation of the XPC promoter were examined. Apoptosis, cell proliferation and senescence were also quantified. XPC siRNA was used to determine that the responses seen were reliant on XPC induction. Results Treatment with high-dose decitabine resulted in global demethylation, including the the shores of the XPC CpG island and significantly increased XPC mRNA expression. Lower, clinically relevant dose of decitabine also resulted in global demethylation including the CpG island shores and induced XPC in 50% of cell lines. Decitabine followed by DNA-damaging carboplatin treatment led to significantly higher XPC expression in 75% of melanoma cell lines tested. Combined sequential treatment also resulted in a greater apoptotic response in 75% of cell lines compared to carboplatin alone, and significantly slowed cell proliferation, with some melanoma cell lines going into senescence. Inhibiting the increased XPC using siRNA had a small but significant negative effect, indicating that XPC plays a partial role in the response to sequential decitabine and carboplatin. Conclusions Demethylation using decitabine increased XPC and apoptosis after sequential carboplatin. These results confirm that sequential decitabine and carboplatin requires further investigation as a combination treatment for melanoma.http://link.springer.com/article/10.1186/s12885-018-4010-9MelanomaMethylationDecitabineCarboplatinXPC |
| spellingShingle | Timothy Budden Andre van der Westhuizen Nikola A. Bowden Sequential decitabine and carboplatin treatment increases the DNA repair protein XPC, increases apoptosis and decreases proliferation in melanoma BMC Cancer Melanoma Methylation Decitabine Carboplatin XPC |
| title | Sequential decitabine and carboplatin treatment increases the DNA repair protein XPC, increases apoptosis and decreases proliferation in melanoma |
| title_full | Sequential decitabine and carboplatin treatment increases the DNA repair protein XPC, increases apoptosis and decreases proliferation in melanoma |
| title_fullStr | Sequential decitabine and carboplatin treatment increases the DNA repair protein XPC, increases apoptosis and decreases proliferation in melanoma |
| title_full_unstemmed | Sequential decitabine and carboplatin treatment increases the DNA repair protein XPC, increases apoptosis and decreases proliferation in melanoma |
| title_short | Sequential decitabine and carboplatin treatment increases the DNA repair protein XPC, increases apoptosis and decreases proliferation in melanoma |
| title_sort | sequential decitabine and carboplatin treatment increases the dna repair protein xpc increases apoptosis and decreases proliferation in melanoma |
| topic | Melanoma Methylation Decitabine Carboplatin XPC |
| url | http://link.springer.com/article/10.1186/s12885-018-4010-9 |
| work_keys_str_mv | AT timothybudden sequentialdecitabineandcarboplatintreatmentincreasesthednarepairproteinxpcincreasesapoptosisanddecreasesproliferationinmelanoma AT andrevanderwesthuizen sequentialdecitabineandcarboplatintreatmentincreasesthednarepairproteinxpcincreasesapoptosisanddecreasesproliferationinmelanoma AT nikolaabowden sequentialdecitabineandcarboplatintreatmentincreasesthednarepairproteinxpcincreasesapoptosisanddecreasesproliferationinmelanoma |