Therapeutic Effect Of Temozolomide Research Articles

Characterization of inflammatory profiles and endothelial dysfunction in diabetic limb arterial occlusion.

Our study aims to detect the changes of adiponectin (APN), endothelin 1 (ET)-1, nitric oxide (NO), cystatin C (cysC) in diabetic limb arterial occlusion (DLAO) patients and unravel their associations with endothelial function. Total 240 type 2 diabetes mellitus (T2DM) patients were divided into a DM group (n = 80, ankle brachial index (ABI) ≥ 0.9) and a DLAO group (n = 160, ABI < 0.9). ABI, flow-mediated dilation (FMD) and nitroglycerin-mediated dilation (NMD), serum APN, ET-1, NO, and cysC were compared. There were significant increases in cysC and ET-1, and significant decreases in APN, NO, FMD and NMD of DLAO patients compared to T2DM patients. Serum APN and NO were positively correlated with ABI, while serum cysC and ET-1 were negatively correlated with ABI. cysC, ET-1 and diastolic blood pressure (DBP) were independent predictors of the severity of DLAO. Serum APN was positively correlated with FMD, NMD and NO, but was negatively correlated with ET-1 and cysC. FMD and NMD were positively correlated with APN and NO, and negatively correlated with ET-1 and cysC. Our study deciphers opposite roles of APN, NO, cysC and ET-1 in the development of DLAO and maintaining endothelial function.

Consistency of O6-methylguanine-DNA methyltransferase in intracranial and extracranial lesions and the therapeutic effect of temozolomide in patients with advanced lung cancer and brain metastasis.

e14001 Background: Targeted drugs have made a major breakthrough except small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC) of brain metastasis (BM) patients with negative driving gene. Because of the difficulty to obtain pathology of intracranial metastases lesions and the low acceptance of patients, the heterogeneity of O6-methylguanine-DNA methyltransferase (MGMT) between extracranial lesions and intracranial metastatic lesions worth exploring. Methods: 10 patients were administered TMZ after the progression of radiotherapy and chemotherapy and included in one group; the efficacy and safety of TMZ were assessed. Moreover, 15 patients who underwent resection of the lung and brain without neoadjuvant therapy formed another cohort. The promoter methylation status of MGMT was analyzed and compared in the paired primary and BM lesions. Results: The overall response (OS) rate of TMZ was 50% and the disease control rate was 80% in patients with BM lesions. The median progression-free survival was 13.6 months, and the median overall survival was 18.9 months after a median follow-up of 120 months. No grade 3 or higher side effects were reported, but grade 1 or 2 side effects, such as leucopenia, nausea, or vomiting, occurred. However, in another cohort, MGMT promoter methylation was detected in 2 patients (with primary lesions; unmethylation was detected in BM lesions, and the methylation status of MGMT promoter was consistent in paired primary and BM lesions).Conclusions: TMZ was effective against SCLC and NSCLC combined with BM having negative driving genes. Whether primary lesions can replace the MGMT methylation level of BM lesions, as well as the consistency of the promoter methylation status of MGMT in patients with advanced lung cancer, needs exploration.[Table: see text]

Enhanced Copper-Temozolomide Interactions by Protein for Chemotherapy against Glioblastoma Multiforme.

Current treatment of recurrent glioblastoma multiforme (GBM) demands dose-intense temozolomide (TMZ), a prodrug of 5-(3-methyltriazen-1-yl) imidazole-4-carboxamide (MTIC), based on the spontaneous hydrolysis of TMZ at basic pH. However, how to control the activity of MTIC remains unknown, which poses a particular challenge to search a reliable MTIC receptor. We reported that copper, for the first time, is found to recognize and bind MTIC in the process of TMZ degradation, which means copper can play an important role in enhancing the bioavailability of MTIC derived from TMZ. Using apoferritin as a model copper-bound protein, we studied the copper-TMZ interaction in protein and observed efficient MTIC immobilization with high binding efficiency (up to 92.9% based on original TMZ) and capacity (up to 185 MTIC moieties per protein). The system was stable against both alkaline and acidic pH and could be activated by glutathione to liberate MTIC, which paves a way to deliver a DNA-alkylating agent for both TMZ-sensitive and TMZ-resistant GBM chemotherapy. Our study provides a new insight for understanding the potential relationship between the special GBM microenvironment (specific copper accumulation) and the therapeutic effect of TMZ.

Oleuropein modulates glioblastoma miRNA pattern different from Olea europaea leaf extract.

Glioblastoma (GBM) is the most prevalent and deadliest subtype of glioma. Despite current innovations in existing therapeutic modalities, GBM remains incurable, and alternative therapies are required. Previously, we demonstrated that Olea europaea leaf extract (OLE) kills GBM cells by modulating miR-181b, miR-137, miR-153 and Let-7d expression. However, although oleuropein (OL) is the main compound in OLE, its role in the antitumour effect of OLE remains unknown. This study determined the effect of OL on GBM cell line T98G and compared the results with our previous findings regarding the effect of OLE on the same cell line. The antiproliferative activity of OL and its effect on temozolomide (TMZ) response were tested inT98G cells using WST-1 assay. OL inhibition was evaluated using one-way analysis of variance with Tukey's post hoc test. The effect of OL on miR-181b, miR-137, miR-153 and Let-7d expression was assessed using quantitative reverse transcription polymerase chain reaction. Fold differences in expression between untreated, OL or OL + TMZ-treated samples were calculated using 2-ΔCt method. Significance was evaluated using an independent sample t-test. Treatment with 277.5 and 555 µM OL resulted in 39.51% and 75.40% reductions in T98G cells within 24 h. Coadministration of 325 µM TMZ and 277.5 or 555 µM, OL caused 2.08- and 2.83-fold increases, respectively, in the therapeutic effect of TMZ. OL + TMZ significantly increased microRNA expression, particularly Let-7d, than OLE. In conclusion, OL has an antitumour effect on GBM cells mainly via regulation of Let-7d expression. The present results also indicate other minor compounds in OLE play important anticancer roles.

1p/19q codeletion and RET rearrangements in small-cell lung cancer.

The prognosis of small-cell lung cancer (SCLC) is poor despite reports suggesting modest improvement in survival. To date, chemotherapy remains the cornerstone treatment for SCLC patients, and many studies have focused on identifying the molecular characteristics of SCLC, which serve as the basis for precision treatments that improve the prognosis of SCLC. For instance, the therapeutic effect of temozolomide, recommended for patients with relapsed SCLC, is linked to 1p/19q codeletion in anaplastic oligodendroglial tumors. A subpopulation of SCLC patients may derive benefit from tyrosine kinase inhibitors targeting RET. In order to identify 1p/19q codeletion and RET rearrangement in SCLC patients, 32 SCLC resected specimens were retrospectively collected between 2008 and 2014 from the Zhejiang Cancer Hospital in People’s Republic of China. Fluorescence in situ hybridization was used to detect 1p/19q codeletion and RET rearrangement in the specimens. A 1p single deletion was detected in eight specimens, 19q single deletion was detected in three specimens, and only three specimens had a 1p/19q codeletion. None of the specimens had a RET rearrangement. The three patients whose specimens had a 1p/19q codeletion were alive after 58, 50, and 30 months of follow-up care. There was a trend toward prolonged overall survival for the patients with codeletion compared to no codeletion, 1p single deletion, 19q single deletion, and without 1p and 19q deletion (P=0.113, 0.168, 0.116, and 0.122, respectively). Our data showed that RET rearrangement may be not an ideal molecular target for SCLC therapies in People’s Republic of China. Instead, 1p/19q codeletion is a promising marker for a good prognosis and treatment with temozolomide in SCLC.

P17.14 * A PROPOSAL OF A MODIFIED STUPP'S SCHEDULE WITH PROLONGED ADJUVANT TEMOZOLOMIDE: EXPERIENCE OF A SINGLE INSTITUTION IN A SERIES OF 100 CONSECUTIVE GBM PATIENTS

BACKGROUND: Glioblastoma (GBM) is a primary malignant brain tumor and its evolution is generally rapidly fatal. The current standard of care for this disease is surgical resection followed by concomitant radiationtherapy plus chemiotherapy as described by Stupp and Colleagues. In this study we described our experience in a series of 100 consecutive patients affected by GBM treated with modified Stupp regimen at “Fondazione IRCCS Ca' Granda Ospedale Policlinico Maggiore” in Milan, Italy. METHODS: One hundred patients with newly diagnosed, histologically confirmed GBM were submitted to concomitant chemo-radiation therapy. Subjects who were not able to complete the concomitant phase of chemo-radiation therapy were excluded from this study.The diagnosis was obtained after surgical resection or stereotactic biopsy and then all the patients were treated with radiationtherapy plus continuous daily temozolomide (TMZ) according to a modified Stupp's schedule. In the adjuvant phase we administered a modified schedule consisting of 150mg/mq of TMZ, from day 1 to 5 and 75 mg/mq of TMZ from day 6 to 10 for 12 cycles instead of the 6 standard cycles proposed by Stupp and Colleagues. At recurrence, various strategies were chosen according the patients clinical and radiological status. After the concomitant phase, patients underwent a regular follow-up with a clinical examination and a brain MRI with gadolinium every 3 months. MGMT status was assessed according the method described by Hegi et al. in 2005 and was retrospectively re-evaluated with PCR real time (Pyromark Q96ID System). RESULTS: One hundred patients affected by GBM were included (60 males; 40 females; median age 61). The median KPS at presentation was 70 (range= 40- 100) which remained stable after 6 months. Median Ki67 was 10%. In 63 patients MGMT was methylated (38 males; 25 females. Median TTP-1 was of 12 months) and in 32 patients were MGMT un-methylated (male 21; females11; median TTP-1 of 9 months); in 5 cases we have no data. Surgical resection was done in 92 patients whereas only in 8 cases weproceeded with stereotactic biopsy alone. Gross total resection (>95%) was achieved in 57 patients; while 35 patients receibed a sub-total resection (85-95%).Median Overall survival (OS) was 16 months and TTP-1 and time to tumor progression after recurrence (TTP-2) was 11 months in MGMT methylated patients and 4 months in MGMT un-methylated patients. At a median follow up of 12 months, 24 months and 36 months our OS was 81%, 33% and 20% respectively compared to the historical group described by Stupp in 2005 which were 61% at 12 months and 27.5% at 24 months and 16% at 36 months. Data about the comparison of MGMT status assessment will be discussed at the time of the meeting. CONCLUSION: According the data collected, our modified adjuvant schedule can be useful for increasing the therapeutic effect of TMZ and can contribute to prolong the TTP.

Abstract 1801: Lyn and Fyn inhibition as a potential novel treatment for glioblastoma multiforme

Abstract Background: Glioblastoma multiforme (GBM) is the most malignant and most aggressive of the adult brain tumors. The current therapies including surgical resection, radiation therapy and chemotherapy remain palliative with median survival of 14 months. Two of the Src family kinases, Lyn and Fyn, have been reported to be involved in the pathogenesis and aggressiveness of GBM in clinical and laboratory research studies. Specific Aims: We evaluated the effect of Lyn and Fyn kinase inhibition on GBM cell motility and survival by utilizing a clinically relevant Lyn and Fyn kinase inhibitor, bafetinib or formerly INNO-406 (CytRx Corporation, Los Angeles, CA). Bafetinib, a dual Bcr-Abl and Lyn tyrosine kinase inhibitor has been shown to inhibit 4 of the 79 tyrosine kinases, namely Abl, Abl-related gene (Arg), and two of the Src family kinases Lyn and Fyn but not Src. Methodology: We used Lyn- expressing T98G and Fyn-expressing U87MG human GBM cell lines. The effect of bafetinib on the motile activity was evaluated by the wound healing, single cell trajectory, and the trans-well assays. The cell survival and mitochondrial membrane potential were evaluated by Guava Easycyte *HT flowcytometer (Millipore) in cells treated with bafetinib for 24 h. Further, we examined the effect of bafetinib on cell survival in combination with temozolomide (TMZ), a widely used chemotherapy agent for the management of GBM, in U87MG cells using microplate MTT assay. Results: At 16 h post-wounding, bafetinib at 5 µM concentration inhibited the motility of T98G and U87MG cells by 33% (P &amp;lt; 0.01) and 24% (P &amp;lt; 0.01), respectively. This significant inhibition in the wound healing was accompanied by the inhibition of total length of cell trajectory, total length of the final cell displacement and average speed of cell locomotion. Bafetinib induced 62% mitochondrial membrane depolarization in U87MG cells and 20% depolarization in T98G cells. Higher depolarization levels in U87MG cells correlated with higher apoptosis (49.4%). Treatment of U87MG cells for 4 days with a combination of bafetinib and TMZ reduced the IC50 values as much as 60% and 80%, respectively, compared to the values obtained with each of the drugs, suggesting that bafetinib has the potential to improve the therapeutic effect of TMZ in GBM cells. Conclusion: Our preliminary findings suggest that targeting Lyn and Fyn kinase pathways with bafetinib may have a therapeutic potential for GBM. Our in vivo studies in mouse models with bafetinib will further establish the feasibility of targeting Lyn and Fyn kinases as possible therapeutic targets in GBM. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1801. doi:1538-7445.AM2012-1801

Can the therapeutic effects of temozolomide be potentiated by stimulating AMP-activated protein kinase with olanzepine and metformin?

As current treatments for glioblastoma commonly fail to cure, the need for more effective therapeutic options is overwhelming. Here, we summarize experimental evidence in support of the suggestion that metformin and olanzepine have potential to enhance the cytotoxic effects of temozolomide, an alkylating chemotherapeutic agent commonly used to treat glioblastoma. Although the primary path leading to temozolomide-induced cell death is formation of O-6-methylguanine and apoptotic signalling triggered by O-6-methyl G:T mispairs, that apoptotic signalling goes through a step mediated by AMP-activated protein kinase (AMPK). Metformin or olanzapine have been shown independently to enhance AMPK activation. Metformin to treat diabetes and olanzapine to treat psychiatric disorders are well tolerated and have been used clinically for many years. Thus it should be feasible to increase AMPK activation and add to the pro-apoptotic effects of temozolomide, by adding metformin and olanzapine to the therapeutic regimen. Clinical assessment of the potential benefit of such combined therapy against glioblastoma is warranted.

Inhibition of Sonic Hedgehog and Notch Pathways Enhances Sensitivity of CD133+ Glioma Stem Cells to Temozolomide Therapy

Malignant gliomas are currently treated with temozolomide (TMZ), but often exhibit resistance to this agent. CD133(+) cancer stem cells, a population believed to contribute to the tumor's chemoresistance, bear the activation of Notch and Sonic hedgehog (SHH) pathways. In this study, we examined whether inhibition of both pathways enhances the efficacy of TMZ monotherapy in the context of glioma stem cells. Transcriptional analysis of Notch and SHH pathways in CD133(+)-enriched glioma cell populations showed the activity of these pathways. CD133(+) cells were less susceptible to TMZ treatment than the unsorted glioma counterparts. Interestingly, Notch and SHH pathway transcriptional activity in CD133(+) glioma cells was further enhanced by TMZ exposure, which led to NOTCH 1, NCOR2, and GLI1 upregulation (6.64-, 3.73-, and 2.79-fold, respectively) and CFLAR downregulation (4.22-fold). The therapeutic effect of TMZ was enhanced by Notch and SHH pathway pharmacological antagonism with GSI-1 and cyclopamine. More importantly, simultaneous treatment involving TMZ with both of these compounds led to a significant increase in CD133(+) glioma cytotoxicity than treatment with any of these agents alone (P < 0.05). In conclusion, CD133(+) glioma cells overexpress genes involved in Notch and SHH pathways. These pathways contribute to the chemoresistant phenotype of CD133(+) glioma cells, as their antagonism leads to an additive effect when used in combination with TMZ.