Cell Cycle Arrest and Cytotoxic Effects of SAHA and RG7388 Mediated through p21<sup>WAF1/CIP1</sup> and p27<sup>KIP1</sup> in Cancer Cells
<i>Background and Objective</i>: Alterations in gene expressions are often due to epigenetic modifications that can have a significant influence on cancer development, growth, and progression. Lately, histone deacetylase inhibitors (HDACi) such as suberoylanilide hydroxamic acid (SAHA, o...
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| Format: | Article |
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MDPI AG
2019-01-01
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| Series: | Medicina |
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| Online Access: | https://www.mdpi.com/1010-660X/55/2/30 |
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| author | Umamaheswari Natarajan Thiagarajan Venkatesan Vijayaraghavan Radhakrishnan Shila Samuel Periannan Rasappan Appu Rathinavelu |
| author_facet | Umamaheswari Natarajan Thiagarajan Venkatesan Vijayaraghavan Radhakrishnan Shila Samuel Periannan Rasappan Appu Rathinavelu |
| author_sort | Umamaheswari Natarajan |
| collection | DOAJ |
| description | <i>Background and Objective</i>: Alterations in gene expressions are often due to epigenetic modifications that can have a significant influence on cancer development, growth, and progression. Lately, histone deacetylase inhibitors (HDACi) such as suberoylanilide hydroxamic acid (SAHA, or vorinostat, MK0683) have been emerging as a new class of drugs with promising therapeutic benefits in controlling cancer growth and metastasis. The small molecule RG7388 (idasanutlin, R05503781) is a newly developed inhibitor that is specific for an oncogene-derived protein called MDM2, which is also in clinical trials for the treatment of various types of cancers. These two drugs have shown the ability to induce p21 expression through distinct mechanisms in MCF-7 and LNCaP cells, which are reported to have wild-type TP53. Our understanding of the molecular mechanism whereby SAHA and RG7388 can induce cell cycle arrest and trigger cell death is still evolving. In this study, we performed experiments to measure the cell cycle arrest effects of SAHA and RG7388 using MCF-7 and LNCaP cells. <i>Materials and Methods</i>: The cytotoxicity, cell cycle arrest, and apoptosis/necroptosis effects of the SAHA and RG7388 treatments were assessed using the Trypan Blue dye exclusion (TBDE) method, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, fluorescence assay with DEVD-<i>amc</i> substrate, and immunoblotting methods. <i>Results:</i> The RG7388 treatment was able to induce cell death by elevating p21<sup>WAF1/CIP1</sup> through inhibition of MDM2 in LNCaP, but not in MCF-7 cells, even though there was evidence of p53 elevation. Hence, we suspect that there is some level of uncoupling of p53-mediated transcriptional induction of p21<sup>WAF1/CIP1</sup> in MCF-7 cells. <i>Conclusion</i>: Our results from MCF-7 and LNCaP cells confirmed that SAHA and RG7388 treatments were able to induce cell death via a combination of cell cycle arrest and cytotoxic mechanisms. We speculate that our findings could lead to the development of newer treatments for breast and prostate cancers with drug combinations including HDACi. |
| first_indexed | 2024-03-12T11:08:27Z |
| format | Article |
| id | doaj.art-4e4c55f08dc845328efa2a964e036fa0 |
| institution | Directory Open Access Journal |
| issn | 1010-660X |
| language | English |
| last_indexed | 2024-03-12T11:08:27Z |
| publishDate | 2019-01-01 |
| publisher | MDPI AG |
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| spelling | doaj.art-4e4c55f08dc845328efa2a964e036fa02023-09-02T03:26:55ZengMDPI AGMedicina1010-660X2019-01-015523010.3390/medicina55020030medicina55020030Cell Cycle Arrest and Cytotoxic Effects of SAHA and RG7388 Mediated through p21<sup>WAF1/CIP1</sup> and p27<sup>KIP1</sup> in Cancer CellsUmamaheswari Natarajan0Thiagarajan Venkatesan1Vijayaraghavan Radhakrishnan2Shila Samuel3Periannan Rasappan4Appu Rathinavelu5Rumbaugh-Goodwin Institute for Cancer Research, Nova Southeastern University, Fort Lauderdale, FL 33314, USARumbaugh-Goodwin Institute for Cancer Research, Nova Southeastern University, Fort Lauderdale, FL 33314, USAVRR Institute of Biomedical Science, Kattupakkam, Chennai 600056, IndiaVRR Institute of Biomedical Science, Kattupakkam, Chennai 600056, IndiaVRR Institute of Biomedical Science, Kattupakkam, Chennai 600056, IndiaRumbaugh-Goodwin Institute for Cancer Research, Nova Southeastern University, Fort Lauderdale, FL 33314, USA<i>Background and Objective</i>: Alterations in gene expressions are often due to epigenetic modifications that can have a significant influence on cancer development, growth, and progression. Lately, histone deacetylase inhibitors (HDACi) such as suberoylanilide hydroxamic acid (SAHA, or vorinostat, MK0683) have been emerging as a new class of drugs with promising therapeutic benefits in controlling cancer growth and metastasis. The small molecule RG7388 (idasanutlin, R05503781) is a newly developed inhibitor that is specific for an oncogene-derived protein called MDM2, which is also in clinical trials for the treatment of various types of cancers. These two drugs have shown the ability to induce p21 expression through distinct mechanisms in MCF-7 and LNCaP cells, which are reported to have wild-type TP53. Our understanding of the molecular mechanism whereby SAHA and RG7388 can induce cell cycle arrest and trigger cell death is still evolving. In this study, we performed experiments to measure the cell cycle arrest effects of SAHA and RG7388 using MCF-7 and LNCaP cells. <i>Materials and Methods</i>: The cytotoxicity, cell cycle arrest, and apoptosis/necroptosis effects of the SAHA and RG7388 treatments were assessed using the Trypan Blue dye exclusion (TBDE) method, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, fluorescence assay with DEVD-<i>amc</i> substrate, and immunoblotting methods. <i>Results:</i> The RG7388 treatment was able to induce cell death by elevating p21<sup>WAF1/CIP1</sup> through inhibition of MDM2 in LNCaP, but not in MCF-7 cells, even though there was evidence of p53 elevation. Hence, we suspect that there is some level of uncoupling of p53-mediated transcriptional induction of p21<sup>WAF1/CIP1</sup> in MCF-7 cells. <i>Conclusion</i>: Our results from MCF-7 and LNCaP cells confirmed that SAHA and RG7388 treatments were able to induce cell death via a combination of cell cycle arrest and cytotoxic mechanisms. We speculate that our findings could lead to the development of newer treatments for breast and prostate cancers with drug combinations including HDACi.https://www.mdpi.com/1010-660X/55/2/30SAHARG7388MDM2p53p21cell cycle arrestcell death |
| spellingShingle | Umamaheswari Natarajan Thiagarajan Venkatesan Vijayaraghavan Radhakrishnan Shila Samuel Periannan Rasappan Appu Rathinavelu Cell Cycle Arrest and Cytotoxic Effects of SAHA and RG7388 Mediated through p21<sup>WAF1/CIP1</sup> and p27<sup>KIP1</sup> in Cancer Cells Medicina SAHA RG7388 MDM2 p53 p21 cell cycle arrest cell death |
| title | Cell Cycle Arrest and Cytotoxic Effects of SAHA and RG7388 Mediated through p21<sup>WAF1/CIP1</sup> and p27<sup>KIP1</sup> in Cancer Cells |
| title_full | Cell Cycle Arrest and Cytotoxic Effects of SAHA and RG7388 Mediated through p21<sup>WAF1/CIP1</sup> and p27<sup>KIP1</sup> in Cancer Cells |
| title_fullStr | Cell Cycle Arrest and Cytotoxic Effects of SAHA and RG7388 Mediated through p21<sup>WAF1/CIP1</sup> and p27<sup>KIP1</sup> in Cancer Cells |
| title_full_unstemmed | Cell Cycle Arrest and Cytotoxic Effects of SAHA and RG7388 Mediated through p21<sup>WAF1/CIP1</sup> and p27<sup>KIP1</sup> in Cancer Cells |
| title_short | Cell Cycle Arrest and Cytotoxic Effects of SAHA and RG7388 Mediated through p21<sup>WAF1/CIP1</sup> and p27<sup>KIP1</sup> in Cancer Cells |
| title_sort | cell cycle arrest and cytotoxic effects of saha and rg7388 mediated through p21 sup waf1 cip1 sup and p27 sup kip1 sup in cancer cells |
| topic | SAHA RG7388 MDM2 p53 p21 cell cycle arrest cell death |
| url | https://www.mdpi.com/1010-660X/55/2/30 |
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