Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0017636 (glioblastoma)
 18,345 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Imatinib mesylate is a small molecule inhibitor of the c-Abl, platelet-derived growth factor (PDGF) receptor and c-Kit tyrosine kinases that is approved for the treatment of Philadelphia chromosome-positive chronic myeloid leukemia (CML) and gastrointestinal stromal tumors. Glioblastoma multiforme is a highly malignant primary brain tumor that is usually treated with surgery and/or radiotherapy. Previous studies implicate an autocrine loop caused by high expression of PDGF and its receptor, PDGFR, in the proliferation of some glioblastomas. Here, we demonstrate that pretreatment of a human glioblastoma cell line, RuSi RS1, with imatinib significantly enhanced the cytotoxic effect of ionizing radiation. This effect was not seen in human breast cancer (BT20) and colon cancer (WiDr) cell lines. Whereas c-Abl and c-Kit were expressed about equally in the three cell lines, RuSi RS1 cells showed significantly higher expression of PDGFR-beta protein in comparison to BT20 and WiDr. Imatinib treatment of RuSi RS1 cells decreased overall levels of cellular tyrosine phosphorylation and specifically inhibited phosphorylation of PDGFR-beta, while c-Abl was not prominently activated in these cells. These results suggest that imatinib may have clinical utility as a radiosensitizer in the treatment of human glioblastoma, possibly through disruption of an autocrine PDGF/PDGFR loop.
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PMID:Imatinib mesylate radiosensitizes human glioblastoma cells through inhibition of platelet-derived growth factor receptor. 1572 3

Glioblastoma is a highly angiogenic tumor with a dismal prognosis. Continuous oral low-dose chemotherapy with methotrexate (MTX) and cyclophosphamide (CPM) has modest activity in heavily pretreated patients with breast cancer. We explored the efficacy of 100 mg CPM daily and 5 mg MTX twice weekly in relapsed glioblastoma. Ten patients, 22-59 years old, with a Karnofsky score of 50% or higher who had failed at least two chemotherapies were accrued. No toxicity was observed. No patient showed a complete or partial response. Five of 10 patients progressed within 2 months of therapy. Another five patients progressed after 3-4.5 months. The median time to progression was 2.5 months. The median overall survival after start of MTX/CPM was 6.9 months (range 0.5-18.8 months). Since the progression-free survival rate at 6 months was 0%, the trial was prematurely closed.
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PMID:UKT-04 trial of continuous metronomic low-dose chemotherapy with methotrexate and cyclophosphamide for recurrent glioblastoma. 1573 20

Efaproxiral [RSR 13, GSJ 61, JP 4, KDD 86, RS 4] is a synthetic, small-molecule, radiation-sensitising agent being developed by Allos Therapeutics primarily for the treatment of cancer. It works by binding and allosterically stabilising deoxyhaemoglobin in hypoxic regions of tumour tissue. This increases oxygen uptake of the tumour tissue and restores its sensitivity to radiation therapy, making therapy potentially more successful. This first-of-its-class compound is particularly applicable for the treatment of certain tumour types that lack oxygen, such as brain metastases. In contrast to conventional chemotherapeutic agents or radiation sensitisers, there is no requirement for efaproxiral to be administered directly into tumours or to cross the blood-brain barrier for it to display efficacy. Efaproxiral is under review for approval in the US and EU as an adjunct to whole-brain radiation therapy (WBRT) for the treatment of brain metastases originating from breast cancer. It is also under clinical evaluation for a variety of other cancers, including glioblastoma, non-small cell lung cancer (NSCLC) and cervical cancer. Allos is seeking partnership opportunities for efaproxiral's development and marketing. The company has indicated that the development of efaproxiral would be in cooperation with a corporate partner, according to its 2003 Annual Report. In 1994, Allos Therapeutics acquired exclusive worldwide rights to intellectual property relating to efaproxiral from the Center for Innovative Technology (CIT). Allos has entered into arrangements with two contract manufacturers for the supply of efaproxiral, and a third manufacturer for the supply of the formulated drug product. Hovione FarmaCiencia is the primary supplier of efaproxiral, and is contracted to manufacture sufficient quantities on a commercial scale. In addition, a second manufacturer, Raylo Chemicals, is also producing quantities of efaproxiral. In December 2003, Allos entered into a long-term development and supply agreement with Baxter Healthcare who will formulate the efaproxiral into an injection. Allos is also seeking to establish an alternate supplier of efaproxiral injection. Allos submitted a rolling NDA to the US FDA consisting of three data components. Submission began in the third quarter of 2003 and was completed by the fourth quarter of 2003. The first part of the application containing non-clinical information was submitted on 5 August 2003. The second part of the NDA containing information about efaproxiral's chemistry, manufacture and controls (CMC) was submitted in October 2003. Allos submitted its final component of the rolling NDA in December 2003. In February 2004, Allos announced that the FDA had accepted the company's NDA under priority review status. The FDA granted efaproxiral orphan drug status in August 2004 as an adjunct to WBRT for the treatment of brain metastases among breast cancer patients. Efaproxiral also received fast-track status in November 2000 for the same indication in the US. In February 2004, Allos initiated a phase III trial, called ENRICH (Enhancing Whole Brain Radiation Therapy In Patients with Breast Cancer and Hypoxic Brain Metastases) to investigate efaproxiral as an adjunct to WBRT for the treatment of brain metastases. Median survival time is the primary endpoint of the study. The National Breast Cancer Coalition (NBCC) is collaborating with the company to support trial enrolment and to gain additional insight about ways to improve radiation treatment in this patient population. The ENRICH trial protocol was approved by the FDA under a Special Protocol Assessment process; as part of the protocol, two interim analyses for safety and efficacy will be performed.This multicentre, randomised, open-label study has a target enrolment of approximately 360 patients at >100 medical centres across the US, Canada, Europe and South America. Allos announced in September 2004 that recruitment of clinical sites for the trial is ongoing across the US and Canada. Completion of trial enrolment in North America is anticipated in December 2005. Subsequently, Allos announced in January 2005 that recruitment into the ENRICH trial has commenced and is ongoing in Europe; enrolment at European sites is expected to conclude by the third quarter of 2006. Allos Therapeutics announced in June 2004 that it had filed an MAA with the EMEA for marketing of exaproxiral as an adjunct to WBRT for treatment of patients with brain metastases originating from breast cancer. The application is based on positive data from a pivotal phase III (REACH, RT-009) trial in this indication. The completed REACH trial investigated efaproxiral among patients with brain metastases undergoing WBRT. The trial was conducted at multiple sites in 11 countries, including the US, Canada, Europe and Australia. In August 2002 Allos completed the enrolment of 538 patients in the study. Initially only 408 patients were to be enrolled, but the company increased the size of the trial to conduct an appropriately powered subgroup analysis in patients with brain metastases from breast and NSCLC. The study was designed to demonstrate a 35% increase in median survival in the subgroup of patients compared with standard WBRT alone. The primary endpoint was survival. Allos began screening US patients for a phase III trial in NSCLC in early 2003. However, in May 2003, the company announced that as part of its revised operating plan it had suspended the screening of patients for this trial. The trial, which was known as ELITE (Enhanced Lung cancer treatment with Induction chemotherapy and Thoracic radiation and Efaproxiral), was comparing induction chemotherapy followed by thoracic radiation therapy with supplemental oxygen, with or without efaproxiral. The trial was enrolling patients with locally advanced, unresectable NSCLC. ELITE was planned to enrol up to 600 patients across North America and Western and Eastern Europe. Phase II trials in patients with inoperable NSCLC have been conducted in the US and Canada. Patient enrolment in one of these studies was completed in August 2000, with a total of 52 patients enrolled. This was an open-label, multicentre study of induction therapy with paclitaxel plus carboplatin followed by chest irradiation and efaproxiral in patients with locally advanced NSCLC. Positive results from this study were reported at the annual meeting of the European Society for Therapeutics Radiology and Oncology in September 2002. Efaproxiral has completed phase I trials as a treatment of surgical hypoxia in elective surgery patients receiving general anaesthesia. However, no recent development has been reported for these indications. In 1994, Allos signed an agreement with CIT for the exclusive worldwide rights to 17 US patents, a European patent covering the UK, France, Italy and Germany plus two pending patents in these territories, two issued patents in Japan, and a pending patent in Canada. These patents cover methods of allosterically modifying haemoglobin with efaproxiral and other compounds, the binding site of efaproxiral and therapy in certain indications including cancer, ischaemia and hypoxia. In addition to the licensed patents from CIT, Allos exclusively owns two patent families with pending applications directed to a formulation of efaproxiral and to methods of its use in BLOD MRI (blood oxygenation level-dependent magnetic resonance imaging) applications. These patents are pending in the US, Canada and Europe, and include an international patent application. In a May 2002 interview with the Wall Street Transcript, the CEO of Allos estimated the overall market for radiation therapy to be approximately 750 000 patients/year. Of this, brain metastases, NSCLC and glioblastoma therapy accounts for about 170 000, 140 000 and 6000 patients, respectively. Allos intend to use a speciality sales force to market efaproxiral directly to radiation therapists in North America. To penetrate the non-oncology market in the US, the company will seek partnership with one or more pharmaceutical companies with direct sales forces and with established distribution systems. Allos is also hoping to secure an oncology marketing partner for non-North American territories. At the time, the company had been issued 21 patents in the US, Canada, Europe and Japan.
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PMID:Efaproxiral: GSJ 61, JP 4, KDD 86, RS 4, RSR 13. 1586 22

Inhibitor of apoptosis protein (IAP) suppresses apoptosis through binding and inhibiting active caspases-3, -7 and -9 via its baculoviral IAP repeat (BIR) domains. During apoptosis the caspase inhibition by IAPs can be negatively regulated by a mitochondrial protein second mitochondrial-derived activator of caspase (Smac). Smac physically interacts with multiple IAPs and relieves their inhibitory effect on caspases-3, -7 and -9. Recently, a small molecule Smac-mimic compound (Smac-mimic), which potentiates TNF-related apoptosis-inducing ligand (TRAIL) and tumor necrosis factor (TNF)-alpha mediated cell death in glioblastoma T98G cells and HeLa cells, was identified and characterized. To determine the efficacy of this compound in breast cancer cells, we first measured protein expression of three IAPs: XIAP, cIAP-1, and cIAP-2 in nine independent breast cancer cell lines. Three cell lines were chosen: a high IAPs expressing line MDA-MB-231, and two low IAPs expressing lines, T47D and MDA-MB-453. The cell lines were tested for their sensitivity to Smac-mimic alone or in combination with TRAIL or etoposide. Acting alone, Smac-mimic was quite potent with a cytotoxic IC50 of 3.8 nM in high IAPs expressing MDA-MB-231 cells, but was inactive at a much higher concentration in low IAPs expressing T47D and MDA-MB-453 cells. In fact, as low as 2.5 nM of Smac-mimic alone was sufficient to activate caspase-3 and induce apoptosis in MDA-MB-231 cells. In combinational treatments with TRAIL or etoposide, Smac-mimic significantly sensitized cells to growth suppression in MDA-MB-231 cells, but to a lesser extent in T47D and MDA-MB-453 cells. Furthermore, it significantly synergized MDA-MB-231, but not T47D cells to apoptosis induced by either TRAIL or etoposide. Thus, in these cell lines, Smac-mimic acts in an apparent IAPs dependent manner to induce apoptosis alone as well as sensitizes breast cancer cells to TRAIL or etoposide induced apoptosis via caspase-3 activation.
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PMID:A small molecule Smac-mimic compound induces apoptosis and sensitizes TRAIL- and etoposide-induced apoptosis in breast cancer cells. 1604 55

Erucylphosphocholine (ErPC) exerts strong anticancer activity in vivo and in vitroand induces apoptosis even in chemoresistant glioma cell lines. We investigated the contribution of Apaf-1 and caspase-3 to the apoptotic response to ErPC using RNA interference (RNAi) in human glioblastoma cells. We could demonstrate that human glioma cell lines are susceptible to RNAi. Apaf-1 and caspase-3 are amenable to specific small interfering RNA (siRNA)-induced degradation resulting in a reduction of protein levels to 8-33% (Apaf-1) and to 30-50% (caspase-3). Transfection of siRNA directed to Apaf-1 and caspase-3 specifically reduced caspase-3 processing induced by ErPC treatment and yielded a reduction in cells that undergo ErPC-induced apoptosis to 17-33% (Apaf-1) and to 38-50% (caspase-3). The caspase-3 siRNA experiments were corroborated in caspase-3-deficient and -reconstituted MCF-7 breast cancer cells. Survival assays and morphological observations revealed that caspase-3 reconstitution significantly sensitized MCF-7 cells to ErPC. Exploring the caspase cascade responsible for ErPC-induced apoptosis MCF-7 cells provided evidence that caspase-3 is required for the activation of caspases-2, -6 and -8 and also participates in a feedback amplification loop. Our results provide evidence that Apaf-1 and caspase-3 are major determinants of ErPC-induced apoptosis and the possible use of ErPC in a clinical setting is discussed.
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PMID:Downregulation of Apaf-1 and caspase-3 by RNA interference in human glioma cells: consequences for erucylphosphocholine-induced apoptosis. 1615 49

It has previously been implicated that nerve growth factor (NGF) with its high-affinity receptor tyrosine kinase A (TrkA) could play an important role in the growth modulation of human tumor cells, such as glioblastoma multiform cell lines and human breast cancer cell lines. However, the direct mitogenic effects of NGF and TrkA in these tumor cells still remain to be elucidated. Herein we show, by immunofluorescence staining, that NGF was colocalized with gamma-tubulin at the centrosomes or the spindle poles throughout the cell cycle and phosphorylated TrkA was colocalized with alpha-tubulin at mitotic spindle in the glioma cell line U251. The results suggest that NGF concentrated to centrosome can recruit its receptor TrkA there and cause phosphorylation of the latter. The phosphorylated TrkA with the tyrosine kinase activity may phosphorylate the tubulin and promote the mitotic spindle assembly. By these mechanisms, NGF can modulate the mitosis of human glioma cells.
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PMID:Localization of NGF and TrkA at mitotic apparatus in human glioma cell line U251. 1618 9

The association between breast cancer and glioblastoma multiforme has not been amply analyzed in the literature. We describe 11 female patients with a diagnosis of glioblastoma multiforme who were treated when younger for breast cancer. We believe that this association is not due to chance but rather to genetic changes in hormone status and in particular to sex hormones. Another important point of view is represented by the chemotherapy treatment of breast cancer, which could have a carcinogenic effect and explain the growth of glioblastoma. This consideration, in our opinion, is important, because more effort should be made to understand the pathogenesis of glioblastoma multiforme and to improve the therapeutic approaches.
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PMID:Glioblastoma multiforme and breast cancer: report on 11 cases and clinico-pathological remarks. 1620 51

A novel radiation targeted therapy is investigated for HER-2 positive breast cancers. The proposed concept combines two known approaches, but never used together for the treatment of advanced, relapsed or metastasized HER-2 positive breast cancers. The proposed radiation binary targeted concept is based on the anti HER-2 monoclonal antibodies (MABs) that would be used as vehicles to transport the nontoxic agent to cancer cells. The anti HER-2 MABs have been successful in targeting HER-2 positive breast cancers with high affinity. The proposed concept would utilize a neutral nontoxic boron-10 predicting that anti HER-2 MABs would assure its selective delivery to cancer cells. MABs against HER-2 have been a widely researched strategy in the clinical setting. The most promising antibody is Trastuzumab (Herceptin). Targeting HER-2 with the MAB Trastuzumab has been proven to be a successful strategy in inducing tumour regression and improving patient survival. Unfortunately, these tumours become resistant and afflicted women succumb to breast cancer. In the proposed concept, when the tumour region is loaded with boron-10 it is irradiated with neutrons (treatment used for head and neck cancers, melanoma and glioblastoma for over 40 years in Japan and Europe). The irradiation process takes less than an hour producing minimal side effects. This paper summarizes our recent theoretical assessments of radiation binary targeted therapy for HER-2 positive breast cancers on: the effective drug delivery mechanism, the numerical model to evaluate the targeted radiation delivery and the survey study to find the neutron facility in the world that might be capable of producing the radiation effect as needed. A novel method of drug delivery utilizing Trastuzumab is described, followed by the description of a computational Monte Carlo based breast model used to determine radiation dose distributions. The total flux and neutron energy spectra of five currently available neutron irradiation treatment facilities are examined for this application. The tumour boron concentrations and tumour to healthy tissue concentration ratios required to deliver 50 Gy-Eq to the tumour without exceeding 18 Gy-Eq in the skin are determined, as well as the associated therapeutic ratios. Discussion is provided to address the future research direction for assessing the feasibility of the proposed concept.
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PMID:Radiation binary targeted therapy for HER-2 positive breast cancers: assumptions, theoretical assessment and future directions. 1651 Sep 50

The phosphatidylinositol 3' kinase (PI3K)-signaling pathway plays a critical role in a variety of cellular responses such as modulation of cell survival, glucose homeostasis, cell division, and cell growth. PI3K generates important lipid second messengers-phosphatidylinositides that are phosphorylated at the 3' position of their inositol ring head-group. These membrane restricted lipids act by binding with high affinity to specific protein domains such as the pleckstrin homology (PH) domain. Effectors of PI3K include molecules that harbor such domains such as phosphoinositide-dependent kinase (PDK1) and protein kinase B (PKB), also termed Akt. The mammalian genome encodes three different PKB genes (alpha, beta, and gamma; Akt1, 2, and 3, respectively) and each is an attractive target for therapeutic intervention in diseases such as glioblastoma and breast cancer. A second family of three protein kinases, termed serum and glucocorticoid-regulated protein kinases (SGKs), is structurally related to the PKB family including regulation by PI3K but lack a PH domain. However, in addition to PH domains, a second class of 3' phosphorylated inositol phospholipid-binding domains exists that is termed Phox homology (PX) domain: this domain is found in one of the SGKs (SGK3). Here, we summarize knowledge of the three SGK isoforms and compare and contrast them to PKB with respect to their possible importance in cellular regulation and potential as therapeutic targets.
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PMID:Serum and glucocorticoid-regulated protein kinases: variations on a theme. 1661 68

In a family with a high incidence of postmenopausal breast cancer and a case of glioblastoma, the constitutional translocation t(11;22)(q23;q11.2) was shown to segregate with the malignancies. The breakpoints in this family coincided with the common breakpoints in t(11;22) as shown by a translocation-specific PCR assay. Loss of heterozygosity analysis of breast tumor tissue revealed deletion of the normal chromosome 22, but retention of der(22) in the tumor cells, suggesting a predisposing effect of the der(22) for breast and brain tumor development in this family.
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PMID:High incidence of familial breast cancer segregates with constitutional t(11;22)(q23;q11). 1684 57


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