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PubMed1999

The pH-partition profile of the anti-ischemic drug trimetazidine may explain its reduction of intracellular acidosis.

PURPOSE: The anti-ischemic drug trimetazidine (TMZ) acts by a combination of molecular mechanisms which begin to be understood. Thus, it acts in the micromolar range to significantly reduce intracellular acidification during ischemia. To search for a possible physicochemical explanation of this phenomenon, we investigated the transfer mechanisms of the various electrical forms of this dibasic drug. METHODS: The transfer characteristics of TMZ were studied by electrochemistry at the water/1,2-dichloroethane interface. Cyclic voltammetry was used to measure the formal transfer potentials of singly and doubly protonated forms of TMZ (noted TH+ and TH(2)2+, respectively) as a function of aqueous pH, and the partition coefficient of neutral TMZ (log P(T)) was measured by two-phase titration. RESULTS: log P(T) was measured to be 1.04 +/- 0.06, and the acid-base dissociation constants in water were deduced to be pK(w)a1 = 4.54 +/- .02 and pK(w)a2 = 9.14 +/- 0.02. The partition coefficients of TH+ and TH(2)2+ were found to be respectively log P0'TH+ = -3.78 +/- 0.16 and log P0'TH(2)2+ = -9.84 +/- 0.30, which agrees well with the charge being delocalized on two nitrogen atoms in TH+. The pH-partition profile of TMZ was then established in the form of its ionic partition diagram, which showed that the affinity of the ions for the organic phase is pH-dependent and strongly increased by the interfacial potential. CONCLUSIONS: This behavior suggests a physicochemical mechanism whereby efflux of protonated TMZ out of an acidified cell is facilitated, in effect exporting protons to extracellular space.

Acid-Base Equilibrium↗
PubMed2004

Temozolomide for the treatment of recurrent supratentorial glioma: results of a compassionate use program in Belgium.

Temozolomide (TMZ) has demonstrated activity and acceptable toxicity for the treatment of recurrent high-grade gliomas in prospective phase II studies. Limited information is available on TMZ when prescribed outside a clinical trial. We conducted a retrospective study to evaluate the activity and safety of TMZ that was prescribed for the treatment of recurrent glioma in the context of a compassionate use program in Belgium. Data were obtained on 117 adult patients (from five hospitals) who received TMZ as first or second line chemotherapy. The recommended starting dose of TMZ was 200 mg/m2 x5d q28d for chemonaive patients and 150 mg/m2 x5d q28d for pre-treated patients. Toxicity was generally mild. Thrombocytopenia was the most frequent treatment related adverse event (grade 3/4 in 17% of patients). Its occurrence was correlated with a starting dose of 200 mg/m2/d and stresses the need to monitor toxicity. The overall objective response rate (complete and partial response) was 29 and 34% of patients achieved an objective disease stabilization. The median progression-free survival was 104 days (95% CI: 85-123) and the median overall survival was 215 days (95% CI: 161 269). In multivariate analysis a 'deep localization' of the glioma (as opposed to a cortico-subcortical localization) and 'the preceding history of a low-grade glioma' were respectively identified as a negative and positive independent prognostic variable for survival. No significant difference in terms of response or median survival was observed between patients with anaplastic astrocytoma or oligo-astrocytoma and chemonaive glioblastoma multiforme. This retrospective study indicates that the reported activity and toxicity profile of TMZ for the treatment of patients with recurrent glioma is reproducible outside the setting of a prospective clinical trial.

Adult↗
PubMed1981

Long-term hemodynamic and metabolic effects of trimazosin in essential hypertension.

The long-term effects of trimazosin (TMZ) were studied in 26 male patients with mild essential hypertension. After a 2 wk single-blind placebo (P) period, 13 patients were randomly selected to receive TMZ and 13 P; they were followed for an additional 8 wk. TMZ was given in incremental doses of 25 to 50, 100 to 200, and finally 300 mg three times a day. The patients were seen at the clinic every 2 wk and their arterial pressures (AP) and heart rates (HRs) were measured in the supine (5 min) and upright (2 min) position. Blood chemistries, blood count, plasma volume (PV), plasma renin activity (PRA), plasma aldosterone (PA), and cardiac output (CO) were determined by ultrasound at the end of P and TMZ periods. TMZ decreased the AP and total peripheral resistance (TPR) at the higher dosages, but had no effect on PV, PRA, PA, CO, HR, or blood chemistry determinations. No effects were observed on any of the above parameters after P. We conclude that (1) TMZ is an effective and safe antihypertensive, (2) it lowers AP through reduction of TPR, and (3) its effect is dose related.

Antihypertensive Agents↗
PubMed2004

Temozolomide in paediatric high-grade glioma: a key for combination therapy?

This report describes a single-centre study with temozolomide (TMZ) (200 mg m(-2) day(-1) x 5 per cycle of 28 days) in children with (recurrent) high-grade glioma. Magnetic resonance imaging was performed every two cycles. In all, 20 patients were treated between 1998 and 2001 after the UKCCSG/SFOP TMZ phase II trial. All patients had measurable disease. Totally, 15 patients had a relapse after surgery+/-radiotherapy+/-chemotherapy. Overall, five patients received TMZ after surgery or biopsy, awaiting radiotherapy. There were one clinically malignant grade II glioma, 11 grade III and eight grade IV gliomas. Seven tumours had oligodendroglial features. Mean age at start of TMZ was 12.0 years (range 3-20.5 years). In total, eight patients had >8 cycles (range 3-30). One VGPR (currently in CR after surgery), three PRs (with a PFS of 4, 4 and 11 months, respectively) and one MR (PFS 14 months) were observed. Three out of five responses occurred after >4 courses. The overall response rate was 20%. Median progression-free survival (PFS) was 2.0 months (range 3 weeks-34+ months). PFS rate was 20% after 6 months. Median overall survival (OS) was 10 months. Nine patients showed a clinical improvement. Three patients vomitted shortly after TMZ administration, eight patients (13 cycles) experienced grade III/IV thrombocytopenia, occurring predominantly during the fourth week of the first two cycles. Five patients experienced neutropenia, and three patients febrile neutropenia. TMZ is a well-tolerated ambulatory treatment for children with malignant glial tumours. This drug warrants further study in these highly chemoresistant tumours and should be studied either as upfront therapy or in combination therapy.

Administration, Oral↗
PubMed2006

Apoptosis in malignant glioma cells triggered by the temozolomide-induced DNA lesion O6-methylguanine.

Methylating drugs such as temozolomide (TMZ) are widely used in the treatment of brain tumours (malignant gliomas). The mechanism of TMZ-induced glioma cell death is unknown. Here, we show that malignant glioma cells undergo apoptosis following treatment with the methylating agents N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and TMZ. Cell death determined by colony formation and apoptosis following methylation is greatly stimulated by p53. Transfection experiments with O(6)-methylguanine-DNA methyltransferase (MGMT) and depletion of MGMT by O(6)-benzylguanine showed that, in gliomas, the apoptotic signal originates from O(6)-methylguanine (O(6)MeG) and that repair of O(6)MeG by MGMT prevents apoptosis. We further demonstrate that O(6)MeG-triggered apoptosis requires Fas/CD95/Apo-1 receptor activation in p53 non-mutated glioma cells, whereas in p53 mutated gliomas the same DNA lesion triggers the mitochondrial apoptotic pathway. This occurs less effectively via Bcl-2 degradation and caspase-9, -2, -7 and -3 activation. O(6)MeG-triggered apoptosis in gliomas is a late response (occurring >120 h after treatment) that requires extensive cell proliferation. Stimulation of cell cycle progression by the Pasteurella multocida toxin promoted apoptosis whereas serum starvation attenuated it. O(6)MeG-induced apoptosis in glioma cells was preceded by the formation of DNA double-strand breaks (DSBs), as measured by gammaH2AX formation. Glioma cells mutated in DNA-PK(cs), which is involved in non-homologous end-joining, were more sensitive to TMZ-induced apoptosis, supporting the involvement of DSBs as a downstream apoptosis triggering lesion. Overall, the data demonstrate that cell death induced by TMZ in gliomas is due to apoptosis and that determinants of sensitivity of gliomas to TMZ are MGMT, p53, proliferation rate and DSB repair.

Antineoplastic Agents, Alkylating↗
PubMed2005

Temozolomide and cisplatin versus temozolomide in patients with advanced melanoma: a randomized phase II study of the Hellenic Cooperative Oncology Group.

PURPOSE: Temozolomide (TMZ) is an oral alkylating agent that produces methyl adducts at the 0.6 position of guanine. The methyl adducts are removed by the DNA repair enzyme AGAT. As demonstrated by in vitro studies, cisplatin (CDDP) is able to down-regulate the AGAT activity, suggesting that CDDP could enhance the antitumor activity of TMZ. We designed a randomized phase II study to evaluate and compare the activity and safety profile of the combination versus single-agent TMZ in patients with advanced melanoma. PATIENTS AND METHODS: From January 2000 to April 2002, 132 patients were enrolled on the study. Patient and tumor characteristics were well balanced between the two arms. Patients with cerebral metastases were included. Patients received TMZ 200 mg/m(2)/day orally for five consecutive days every 4 weeks or TMZ + CDDP 200 mg/m(2) daily on days 1-5 and 75 mg/m(2) of CDDP on day 1. RESULTS: Tumor responses (complete and partial responses) were seen in 16 patients (26%) in arm A and 19 patients (29%) in arm B. The median time to progression (TTP) was 3.8 months in arm A and 5.8 months in arm B. The median overall survival (OS) was 11.5 months in arm A and 12 months in arm B. The difference between treatment arms regarding objective response rates, TTP and OS were not statistically significant. Toxicity was comparable between the two arms for anemia, leukopenia, neutropenia, thrombocytopenia, fatigue, constipation and arthralgias/myalgias. There was significantly more grade 3 and 4 emesis in the combination arm. CONCLUSIONS: No clear benefit in terms of response rates, median TTP or OS was shown with the combination of TMZ + CDDP. Additionally, the combination was associated with higher incidence of grade 3 and 4 emesis.

Adult↗
PubMed2006

Role of O6-methylguanine-DNA methyltransferase in protecting from alkylating agent-induced toxicity and mutations in mice.

The DNA repair protein O(6)-methylguanine-DNA methyltransferase (MGMT) protects from toxicity and mutations incurred following alkylating agents by removing O(6)-alkylguanine lesions. Using Mgmt-/- mice, we examined MGMT's role in protecting from in vivo mutations induced by three different alkylating agents, temozolomide (TMZ), 1,3-bis (2-chloroethyl)-1-nitrosourea (BCNU) and cyclophosphamide. Mutant frequencies were determined in the hypoxanthine-guanine phosphoribosyltransferase gene of splenic T-lymphocytes from C57BL/6 mice (Mgmt+/+ and Mgmt-/-) following TMZ, BCNU or cyclophosphamide. Following TMZ, the mutation frequency was significantly greater in Mgmt-/- mice (5.5 and 9.8 x 10(-6) for 7 and 10 mg/kg TMZ, respectively) compared with vehicle-treated mice (1.0 x 10(-6), P <or= 0.05). In contrast, TMZ-induced mutations were not increased over vehicle in Mgmt+/+ mice. The mutation frequency of mice treated with BCNU (7.5 mg/kg) was the same regardless of Mgmt status. Similarly, pretreatment of Mgmt+/+ mice with 30 mg/kg O(6)-benzylguanine, a potent inactivator of MGMT, prior to BCNU (15 mg/kg) did not result in significantly more mutations than mice treated with BCNU alone. Following cyclophosphamide, mutation frequencies significantly increased from 1.8 x 10(-6) in control-treated mice to 12.9 x 10(-6) in Mgmt+/+ and 18.1 x 10(-6) in Mgmt-/- mice, although the difference in Mgmt-/- compared with Mgmt+/+ was not significant. Acrolein and chloroacetaldehyde, metabolites of cyclophosphamide, were not mutagenic in Mgmt+/+ and Mgmt-/- mice. These results demonstrate that MGMT significantly protects against in vivo TMZ-induced mutations and that MGMT deficiency does not result in greater mutation frequency following cyclophosphamide or BCNU compared with wild-type mice.

Alkylating Agents↗
PubMed1993

Improvement of long-term preservation of isolated arrested rat heart: beneficial effect of the antiischemic agent trimetazidine.

Rat hearts, arrested in situ after intracaval injection of a simple mineral cardioplegic solution (St. Thomas), were preserved for 15 h at 4 degrees C either by simple immersion in the cardioplegic solution or low-flow perfusion by the same liquid (0.3 ml/min). Trimetazidine (TMZ) was added to the cardioplegic solution at a concentration of 10(-6) M in two additional groups corresponding to both preservation conditions. The biochemically determined ventricular ATP content was increased in immersed hearts by TMZ (+ 78%). The [ATP]/[Pi] ratio, as calculated from 31P nuclear magnetic resonance (NMR) spectroscopy, was significantly increased in both preservation conditions by TMZ: 0.08 +/- 0.03 versus 0.04 +/- 0.01 in immersed hearts and 0.53 +/- 0.13 versus 0.26 +/- 0.16 in perfused hearts (mean +/- SD). Intracellular pH was increased when TMZ was administered in perfused hearts (7.02 +/- 0.14 vs. 6.67 +/- 0.14, mean +/- SD). Functional recovery, estimated by the pressure developed by the left ventricle (intraventricular isovolumic balloon) when hearts were reperfused with a physiologic solution, was improved by TMZ in both preservation conditions: +137% in immersed hearts and +54% in perfused hearts. These results demonstrate that both the bioenergetic status of the myocardial cell and the functional capabilities of isolated, arrested, stored rat heart can be significantly improved by addition of the antiischemic drug TMZ to the preservation solution.

Adenosine Triphosphate↗
PubMed2026

ABCB1 Polymorphisms Influence on Temozolomide Resistance and Overall Survival in Glioblastoma Patients: A Systematic Review of Clinical Evidence.

Glioblastoma (GB), defined as IDH-wildtype CNS WHO grade 4 tumour according to the 2021 WHO classification of CNS tumours, remains a uniformly lethal malignancy in which the efficacy of temozolomide (TMZ) continues to be constrained by both intrinsic tumur biology and the pharmacological barrier imposed by the blood-brain barrier (BBB). Given the central role of the ABCB1 (MDR1/P-glycoprotein) efflux transporter in regulating CNS drug disposition, germline variation in ABCB1 has been proposed as a potential determinant of interindividual variability in TMZ response. This systematic review synthesised clinical evidence from four independent studies, encompassing more than 400&#x2009;GB patients, evaluating the association between ABCB1 polymorphisms and TMZ efficacy and patients' survival. Across the available literature, the influence of ABCB1 genetic variation emerged as limited and inconsistent. An early study reported a marked survival advantage for carriers of the ABCB1 C1236T C/C genotype treated with TMZ, suggesting reduced efflux and enhanced drug exposure. However, subsequent investigations, including epigenetic analyses, high-quality multivariate survival modelling and a pharmacokinetic study demonstrating genotype-dependent differences in plasma TMZ concentrations, did not replicate a corresponding survival effect. Across the remaining cohorts, common variants such as 1236C>T, 2677G>T/A, 3435C>T and 1199G>A showed no robust association with clinical outcome, indicating that transporter-mediated modulation is likely overshadowed by dominant prognostic drivers, including MGMT methylation, IDH status and tumour heterogeneity. Collectively, current evidence does not support ABCB1 polymorphisms as reliable predictive biomarkers of TMZ response in GB. Nonetheless, the pharmacokinetic signals observed, together with emerging technologies capable of selectively modulating efflux activity at the tumour-BBB interface, point to a continued role for ABCB1 in future therapeutic strategies. Integration of transporter genomics with spatial pharmacokinetics and molecular stratification will be essential to refine drug delivery and improve outcomes in GB.

Humans↗
PubMed2003

Trimetazidine reduces basal cytosolic Ca2+ concentration during hypoxia in single Xenopus skeletal myocytes.

We tested the hypotheses that: (1) Ca(2+) handling and force production would be irreversibly altered in skeletal muscle during steady-state contractions when subjected to severe, prolonged hypoxia and subsequent reoxygenation; and (2) application of the cardio-protective drug trimetazidine would attenuate these alterations. Single, living skeletal muscle fibres from Xenopus laevis were injected with the Ca(2+) indicator fura 2, and incubated for 1 h prior to stimulation in 100 micro M TMZ-Ringer solution (TMZ; n = 6) or standard Ringer solution (CON; n = 6). Force and relative free cytosolic Ca(2+) concentration ([Ca(2+)](c)) were measured during continuous tetanic contractions produced every 5 s as fibres were sequentially perfused in the following manner: 3 min high extracellular P(O(2)) (159 mmHg), 15 min hypoxic perfusion (3-5 mmHg) then 3 min high P(O(2)). Hypoxia caused a decrease in force and peak [Ca(2+)](c) in both the TMZ and CON fibres, with no significant (P < 0.05) difference between groups. However, basal [Ca(2+)](c) was significantly lower during hypoxia in the TMZ group vs. the CON group. While reoxygenation generated only modest recovery of relative force and peak [Ca(2+)](c) in both groups, basal [Ca(2+)](c) remained significantly less in the TMZ group. These results demonstrated that in contracting, single skeletal muscle fibres, TMZ prevented increases in basal [Ca(2+)](c) generated during a severe hypoxic insult and subsequent reoxygenation, yet failed to protect the cell from the deleterious effects of prolonged hypoxia followed by reoxygenation.

Animals↗
PubMed2003

The effect of O6-alkylguanine-DNA alkyltransferase and mismatch repair activities on the sensitivity of human melanoma cells to temozolomide, 1,3-bis(2-chloroethyl)1-nitrosourea, and cisplatin.

The prognosis of advanced melanoma is generally poor, because this tumor commonly exhibits intrinsic or acquired resistance to chemotherapy. In an attempt to identify the underlying causes of this resistance, we studied the roles played by the DNA repair enzyme O(6)-alkylguanine-DNA alkyltransferase (OGAT) and the mismatch repair (MMR) system in the sensitivity of melanoma cells to temozolomide (TMZ), 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU), or cis-diamminedichloroplatinum(II) (CDDP). To this end, OGAT levels and MMR efficiency of extracts of nine melanoma cell lines and selected clones derived from four of these lines were determined and correlated with the sensitivity of the respective cells to these drugs. The effectiveness of O(6)-benzylguanine (BG), a specific OGAT inhibitor, in potentiating TMZ- or BCNU-mediated cytotoxicity was also evaluated. Our results demonstrate that MMR efficiency and OGAT levels strongly affect melanoma cell sensitivity to TMZ. In MMR-proficient cells, a direct correlation between OGAT levels and TMZ IC(50) values was found. When OGAT activity was inhibited with BG, the sensitivity of these cells to TMZ increased and was then dictated largely by their MMR efficiency. MMR-deficient cells were highly resistant to the drug irrespective of their OGAT levels. Although OGAT activity and MMR status seemed to be the major determinants of melanoma sensitivity to TMZ, this was not the case for BCNU and CDDP; resistance to the latter drugs clearly involves processes other than the two DNA repair pathways analyzed in this study.

Alkyl and Aryl Transferases↗
PubMed2003

Inhibition of telomerase increases resistance of melanoma cells to temozolomide, but not to temozolomide combined with poly (adp-ribose) polymerase inhibitor.

In the present study, we have investigated the influence of telomerase inhibition in chemosensitivity of melanoma cells to temozolomide (TMZ), a methylating agent with promising antitumor activity against metastatic melanoma. In fact, telomerase, a ribonucleoprotein enzyme expressed in the majority of tumors, is presently considered an attractive target for anticancer therapy, with the double aim of reducing tumor growth and increasing chemosensitivity of cancer cells. Susceptibility to TMZ and to other antitumor agents used for treatment of metastatic melanoma was initially assessed in melanoma lines with different basal levels of telomerase activity. Thereafter, chemosensitivity was investigated after inhibition of telomerase by means of stable transfection of a catalytically inactive, dominant-negative mutant of hTERT (DN-hTERT). This study shows for the first time that: a) susceptibility to TMZ of melanoma lines derived from the same patient did not depend on basal telomerase activity; b) inhibition of telomerase by DN-hTERT resulted in reduced growth rate and increased resistance to TMZ and to the chloroethylating agent carmustine, increased sensitivity to cisplatin, and no change in response to tamoxifen or to a selective N3-adenine methylating agent; c) inhibition of poly(ADP-ribose) polymerase (PARP), an enzyme involved in the repair of N-methylpurines, restored sensitivity of DN-hTERT clones to TMZ. These results indicate that a careful selection of the antitumor agent has to be made when antitelomerase therapy is combined with chemotherapy. Moreover, the data presented here suggest that TMZ + PARP inhibitor combination is active against telomerase-suppressed and slowly growing tumors.

Antineoplastic Agents, Alkylating↗
PubMed2006

Trimetazidine in the prevention of contrast-induced nephropathy after coronary procedures.

OBJECTIVE: To evaluate the efficacy of trimetazidine (TMZ) in the prevention of contrast-induced nephropathy (CIN) in patients with high serum creatinine levels undergoing coronary angiography/angioplasty. METHODS: TMZ (20 mg thrice daily) was administered orally for 72 h starting 48 h before the procedure. All patients were given intravenous saline (0.9%) at a rate of 1 ml/kg of body weight per hour for 24 h starting 12 h beforehand. Serum creatinine levels were measured before the procedure, 48 h and 7 days after the procedure. Increase in serum creatinine level exceeding 0.5 mg/day or one quarter of the basal value is considered as CIN. Venous blood samples for serum total antioxidant capacity (TAC) measurement were drawn before and after coronary angiography. RESULTS: Basal serum creatinine levels and TAC were similar in TMZ and control groups. Serum creatinine levels in the control group increased significantly 2 days after the procedure, and returned to the baseline values on the seventh day. However, it did not change significantly on the second day, and even significantly decreased on the seventh day in the TMZ group. CIN developed in 2.5% (1/40) of patients in the TMZ group and in 16.6% (7/42) of patients in the control group (p<0.05). TAC values were not different between treatment groups. CONCLUSION: TMZ along with isotonic saline infusion is more effective than isotonic saline alone in reducing the risk of CIN in patients with pre-existing renal dysfunction.

Administration, Oral↗
PubMed1998

Trimetazidine reverses deleterious effects of ischemia-reperfusion in the isolated perfused pig kidney model.

BACKGROUND: Delayed graft function has remained an important complication after renal transplantation. METHODS: The purpose of this study was to evaluate Euro-Collins (EC) plus trimetazidine (TMZ) in comparison with standard EC solution after 24- or 48-hour cold storage. The normothermic isolated perfused pig kidney technique combined with proton nuclear magnetic spectroscopy was used. RESULTS: The study verified that TMZ plus EC had a beneficial preservation effect over EC in terms of better perfusate flow rate at both 24 and 48 h (p < 0.01 and p < 0.001, respectively). In addition, TMZ also was beneficial in terms of increased glomerular filtration rate, better proximal tubular functions, and less tubular injury markers. Lipid peroxidation, evaluated by malondialdehyde renal tissue levels, was decreased in kidney homogenates preserved with TMZ, particularly after 48-hour cold storage. Citrate excretion which reflects a better intracellular pH regulation was detected in urine from kidneys preserved with TMZ. Histological data paralleled findings of the above when comparing cellular injury factors such as vacuolization, necrosis, tubular structure, and interstitial edema. CONCLUSION: These results indicate that, under the conditions of our experiments, the addition of TMZ to EC solution increased the preservation quality of kidneys particularly after prolonged cold ischemia.

Animals↗
PubMedDate not supplied

Effect of trimetazidine on retinal ischemia/reperfusion injury in rats.

PURPOSE: To investigate the effect of trimetazidine (TMZ), an antioxidant agent, on the ischemia/reperfusion (I/R) injury in rat retina histopathologically. METHODS: The retinal I/R model was carried out by the 4-vessel occlusion method on Wistar albino rats. Twenty-one rats were divided into 7 groups, each comprising 3 rats. The animals in groups 1, 2 and 3 underwent 30 min of ischemia + 4 h of reperfusion and were treated by the administration of saline, TMZ before reperfusion and TMZ before ischemia, respectively. The animals in groups 4, 5 and 6 underwent 90 min of ischemia + 4 h of reperfusion and were treated in the same way as those in groups 1, 2 and 3, respectively. The 7th group was sham operated. RESULTS: Thirty and 90 min of ischemia followed by 4 h of reperfusion induced retinal injury in the rat retina. Histopathologically, the inner plexiform and inner nuclear layers were the most affected parts. TMZ was able to reduce almost all retinal I/R damage when administered before ischemia. A cytoprotective effect of TMZ was partly observed in those animals which were treated before reperfusion. CONCLUSION: TMZ seemed to have a protective effect against retinal I/R injury in rats.

Animals↗
PubMed2005

Patients with high-grade gliomas harboring deletions of chromosomes 9p and 10q benefit from temozolomide treatment.

Surgical cure of glioblastomas is virtually impossible and their clinical course is mainly determined by the biologic behavior of the tumor cells and their response to radiation and chemotherapy. We investigated whether response to temozolomide (TMZ) chemotherapy differs in subsets of malignant glioblastomas defined by genetic lesions. Eighty patients with newly diagnosed glioblastoma were analyzed with comparative genomic hybridization and loss of heterozygosity. All patients underwent radical resection. Fifty patients received TMZ after radiotherapy (TMZ group) and 30 patients received radiotherapy alone (RT group). The most common aberrations detected were gains of parts of chromosome 7 and losses of 10q, 9p, or 13q. The spectrum of genetic aberrations did not differ between the TMZ and RT groups. Patients treated with TMZ showed significantly better survival than patients treated with radiotherapy alone (19.5 vs 9.3 months). Genomic deletions on chromosomes 9 and 10 are typical for glioblastoma and associated with poor prognosis. However, patients with these aberrations benefited significantly from TMZ in univariate analysis. In multivariate analysis, this effect was pronounced for 9p deletion and for elderly patients with 10q deletions, respectively. This study demonstrates that molecular genetic and cytogenetic analyses potentially predict responses to chemotherapy in patients with newly diagnosed glioblastomas.

Adult↗
PubMed1999

[Influence of trimetazidine on echocardiography parameters and free radical stress index in coronary artery disease and end-stage renal failure patients treated by hemodialysis: preliminary communication].

The aim of the study was the assessment of the influence of trimetazidine (TMZ) on echocardiography parameters and oxidative stress markers in hemodialyzed patients with coronary artery disease. The studies were carried out in 9 patients group before and after 3 months of TMZ treatment in doses 3 x 20 mg. Additionally we measured MDA concentration in the blood, as a oxidative stress marker, before and after 2 and 3 months of TMZ treatment. At the start of the study impairment of relaxation as a sign of diastolic dysfunction was detected. This abnormality persisted up to the end of the study. After 3 months of TMZ treatment we observed elevation of ejection fraction from 59.17 +/- 5.99 to 65.33 +/- 8.7% (p = 0.05). Also occurred statistically significant decrease in MDA level after 2 (0.674 +/- 0.029 vs 0.627 +/- 0.034; p < 0.001) and 3 (0.674 +/- 0.029 vs 0.567 +/- 0.063 mumol/L; p = 0.001) months of TMZ treatment. Significant improvement of the left ventricular function and decrease of MDA levels in the blood might be due to intracellular mechanisms of TMZ activity. There were no side effects of the drug in hemodialyzed patients.

Coronary Disease↗
PubMed2000

Future directions in the treatment of malignant gliomas with temozolomide.

Temozolomide (TMZ) is a new, orally administered, second-generation imidazotetrazine prodrug with essentially 100% oral bioavailability that has demonstrated meaningful efficacy and an acceptable safety profile in the treatment of patients with recurrent glioblastoma multiforme. Because of its unique properties and broad spectrum of anticancer activity, preliminary studies are being conducted to evaluate the efficacy of TMZ in combination with other chemotherapeutic agents, radiation, or immunotherapy. The presence of de novo or acquired resistance to alkylating agents exhibited by malignant gliomas represents a serious impediment in the treatment of these tumors. This review discusses the mechanism of action of TMZ and strategies for overcoming pathways of resistance to this promising agent, including the use of TMZ in combination with other chemotherapeutic agents or radiation therapy, and exploration of alternate dosing schedules. Studies that have evaluated some of these strategies indicate that TMZ is a useful therapeutic option in patients with high-grade gliomas. Alternative approaches, including the use of high-dose TMZ with bone marrow transplantation and in combination with gene therapy, will also be discussed.

Antineoplastic Agents, Alkylating↗