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Research Area
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Description
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Cancer |
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Biological Activity
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Description
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Methazolastone (Temozolomide, Temodar, Temodal) is a DNA damage inducer. |
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Targets
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IC50 |
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In Vitro
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Methazolastone causes formation of DNA alkali-labile sites which are present in similar amounts and repaired at a similar rate in L-1210 and L-1210/BCNU. In L-1210 but not in L-1210/BCNU methazolastone induces an arrest of cells in SL-G2-M phases. Methazolastone induces a similar amount of DNA ALS which is also repaired at a similar rate in L-1210 and L-1210/BCNU cell lines. Methazolastone induces a similar amount of DNA ALS which is also repaired at a similar rate in L-1210 and L-1210/BCNU cell lines. [1] Methazolastone sensitivity of both chemo-sensitive and resistant cells (D54-R and U87-R) is enhanced significantly under hyperoxia. Both Methazolastone and hyperoxia are associated with increased phosphorylation of ERK p44/42 MAPK (Erk1/2), but to a lesser extent in D54-R cells, suggesting that Erk1/2 activity may be involved in regulation of hyperoxia and Methazolastone-mediated cell death. Hyperoxia enhances Methazolastone toxicity in GBM cells by induction of apoptosis, possibly via MAPK-related pathways. [2] Methazolastone induces in monocytes the DNA damage response pathways ATM-Chk2 and ATR-Chk1 resulting in p53 activation. [3] Chronic Methazolastone exposure results in acquired Methazolastone-resistance and elevates miR-21 expression. [4] Methazolastone treatment triggers endoplasmic reticula (ER) stress with increased expression of GADD153 and GRP78 proteins, and deceases pro-caspase 12 protein. Methazolastone induces autophagy through mitochondrial damage- and ER stress-dependent mechanisms to protect glioma cells. [5] |
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In Vivo
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After a daily i.p. dose of 40 mg/kg for 5 consecutive days (days 1-5 after tumor transplant), methazolastone increases life-span by 86% in L-1210 and 22% in L-1210/BCNU. In L-1210/BCNU no effect is seen after 100 μM or 200 μM treatment; only 400 μM methazolastone produced an accumulation of cells in premitotic phase but much less than in L-1210. In L-1210/BCNU the maximum accumulation of cells in SL-G2-M is, after 48 hours-72 hours, approximately 30% as compared to 23% in untreated cells. Cells accumulates in SL-G2-M occurred too when L- 1210 leukemia-bearing mice are treated i.v. with methazola stone (40 mg/kg). No such effect is seen on L-1210/BCNU cells from mice given the same drug dose. [1] |
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Clinical Trials
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Methazolastone plus TPI 287 has entered in a phase II clinical trial in the treatment of melanoma. |
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Features
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Methazolastone is a second-generation alkylating agent. |
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Protocol
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Cell Assay
[1]
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| Cell Lines |
L-1210 and L-1210/BCNU cells |
| Concentrations |
0 μM -100 μM |
| Incubation Time |
l hours |
| Methods |
L-1210 and L-1210/BCNU cells are seeded at 0.2 × 104 cells/mL and incubated for 24 hours. The cultures are treated with Methazolastone for l hours at 37oC, then washed twice in PBS by centrifugation and resuspended in fresh medium. Controls and treated samples are diluted in fresh medium 1:4 at 48 hours and 1:2 at 96 hours. Using these dilutions cell concentrations throughout the experiments are between 3 × 105 and 8 × 105/mL. Control growth is logarithmic in this range. |
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Animal Study
[1]
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| Animal Models |
DBA/2 mice with L-1210 and L-1210/BCNU cells |
| Formulation |
95% ethanol |
| Doses |
40 mg/kg |
| Administration |
Administered via i.v. |
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References |
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[1] Catapano CV, et al. Cancer Res. 1987, 47(18), 4884-4889.
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[2] Sun S, et al. J Neurooncol. 2012.
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[3] Bauer M, et al. PLoS One. 2012, 7(6):e39956.
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[4] Wong ST, et al. Anticancer Res. 2012, 32(7), 2835-2841.
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[5] Lin CJ, et al. PLoS One. 2012, 7(6), e38706.
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[6] Gori JL, et al. Cancer Gene Ther. 2012.
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