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https://ptsldigital.ukm.my/jspui/handle/123456789/460479| Title: | Characterisation of the apoptotic effect of (Z)-6-(3,5-dimethoxystyryl)-5,6-Dihydropyran-2-one in Jurkat T lymphoblastic cancer cells |
| Authors: | Leong Li Hui (P58571) |
| Supervisor: | Chan Kok Meng, Assoc. Prof. Dr. |
| Keywords: | Leukemia Cancer Styryl lactones Dissertations, Academic -- Malaysia |
| Issue Date: | 9-Jan-2017 |
| Description: | Leukemia is the seventh most common cancer found in Malaysia and the most common cancer among children. Styryl lactones are compounds generally isolated from Goniothalamus sp. plant with various biological activities including potent cytotoxicity on cancerous cells. Goniothalamin (GN), the simplest styryl-lactone was shown to induce apoptosis in cancer cells via early DNA damage, up-regulation of p53, generation of oxidative stress and mitochondrial-mediated caspases activation. Thus, a novel styryl lactone derivative, (Z)-6-(3,5-dimethoxystyryl)-5,6-dihydropyran-2-one (DMSP), was synthesized to investigate its antileukemic potential and to elucidate the molecular mechanism of apoptosis induced in Jurkat T lymphoblastic cells as compared to GN. Firstly, the compound of interest was subjected to 1H-NMR and LC-MS analysis and to confirm its structure and purity. Then, DMSP was confirmed to induce a concentrationdependent increase of apoptosis in Jurkat cells after 4 hours treatment with maximal apoptotic cells population (36.07 ± 3.20%, p<0.05) at 50 μM via Annexin V assay. To further confirm upstream signal in this apoptotic model, it was found that intracellular GSH level in 50 μM DMSP-treated cells was decreased from 30 minutes up to 4 hours. However, only marginal increase of reactvie oxygen species level was detected in 50 μM DMSP-treated cells at subapoptotic time points using Mitosox assay. Furthermore, 50 μM DMSP was also found to directly reduce significantly (p<0.05) free GSH in a cellfree system in a time-dependent manner. These results collectively suggested early perturbation of redox status in this DMSP-induced apoptosis model. In addition, DNA damage, a known apoptosis signal, was also being detected at 30 minutes post-50 μM DMSP treatment as assessed using Alkaline Comet Assay, suggesting that DNA damage as an upstream signal in this model. However, detection of significant (p<0.05) loss of mitochondrial membrane potential in 50 μM DMSP-treated cells only occurred at 4 hours using TMRE dye. Further assessment of caspases processing using Western Blotting demonstrated a time-dependant processing of caspase-2, caspase-9 and caspase-8 as early as 2 hours treatment with 50 μM DMSP whereas pro-caspase-3 was cleaved at 3 hours. This further confirmed caspases activation in DMSP-induced apoptosis was independent of MMP loss. Meanwhile, an increase of p73 protein was detected from 2 hours to 4 hours indicating that upregulation of p73 was involved in DMSP-induced apoptosis. In conclusion, DMSP was shown to possess anticancer potential by inducing apoptosis in Jurkat T cells with DNA damage as upstream signal that leads to p73 up regulation and activation of caspases.,Ijazah Sarjana Sains Kesihatan |
| Pages: | 122 |
| Call Number: | WH250.L583c 2017 9 |
| Publisher: | UKM, Kuala Lumpur |
| Appears in Collections: | Faculty of Health Sciences / Fakulti Sains Kesihatan |
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|---|---|---|---|---|
| ukmvital_99087+Source01+Source010.PDF Restricted Access | 2.12 MB | Adobe PDF |  View/Open |
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