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Query: UMLS:C0017638 (
glioma
)
30,880
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Common polymorphisms in DNA repair genes may alter protein function and an individual's capacity to repair damaged DNA; deficits in repair capacity may lead to genetic instability and carcinogenesis. To establish our overall understanding of possible in vivo relationships between DNA repair polymorphisms and the development of cancer, we performed a literature review of epidemiological studies that assessed associations between such polymorphisms and risk of cancer. Thirty studies of polymorphisms in OGG1, XRCC1, ERCC1, XPC, XPD, XPF, BRCA2, and XRCC3 were identified in the April 30, 2002 MEDLINE database (National Center for Biotechnology Information. PubMed Database: http://www.ncbi.nlm.nih.gov/entrez). These studies focused on adult
glioma
, bladder cancer,
breast cancer
, esophageal cancer, lung cancer, prostate cancer, skin cancer (melanoma and nonmelanoma), squamous cell carcinoma of the head and neck, and stomach cancer. We found that a small proportion of the published studies were large and population-based. Nonetheless, published data were consistent with associations between: (a) the OGG1 S326C variant and increased risk of various types of cancer; (b) the XRCC1 R194W variant and reduced risk of various types of cancer; and (c) the BRCA2 N372H variant and increased risk of
breast cancer
. Suggestive results were seen for polymorphisms in other genes; however, small sample sizes may have contributed to false-positive or false-negative findings. We conclude that large, well-designed studies of common polymorphisms in DNA repair genes are needed. Such studies may benefit from analysis of multiple genes or polymorphisms and from the consideration of relevant exposures that may influence the likelihood of cancer in the presence of reduced DNA repair capacity.
...
PMID:Polymorphisms in DNA repair genes and associations with cancer risk. 1249 39
SPARC (secreted protein acidic and rich in cysteine)/BM40/Osteonectin is a matricellular protein with multiple effects on cell behaviour. In vitro, its major known functions are anti-adhesive and anti-proliferative, and it is associated with tissue remodelling and cancer in vivo. SPARC is overexpressed in many cancers, including
breast cancer
, and the effects of SPARC seem to be cell type-specific. To study the effects of SPARC on
breast cancer
, we transfected SPARC into the MDA-MB-231 BAG, human
breast cancer
cell line using the Tet-On inducible system. By western analysis, we found low background levels in the MDA-MB-231 BAG and clone X parental cells, and prominent induction of SPARC protein expression after doxycycline treatment in SPARC transfected clones X5, X21, X24 and X75. Induction of SPARC expression did not affect cell morphology or adhesiveness to collagens type I and IV, but it slowed the rate of proliferation in adherent cultures. Cell cycle analysis showed that SPARC slowed the progression to S phase. Doxycycline induction of SPARC also slowed the rate of monolayer wound closure in the cultured wound healing assay. Thymidine inhibition of proliferation abrogated this effect, confirming that it was due to anti-proliferation rather than inhibition of migration. Consistent with this, we were unable to detect any differences in migration and Matrigel outgrowth analysis of doxycycline-stimulated cells. We conclude that SPARC is inhibitory to human
breast cancer
cell proliferation, and does not stimulate migration, in contrast to its stimulatory effects reported for melanoma (proliferation and migration) and
glioma
(migration) cells. Similar growth repression by SPARC has been reported for ovarian cancer cells, and this may be a common feature among carcinomas.
Breast Cancer
Res Treat 2002 Sep
PMID:Doxycycline-inducible expression of SPARC/Osteonectin/BM40 in MDA-MB-231 human breast cancer cells results in growth inhibition. 1250 Sep 36
Peroxisome proliferator-activated receptors (PPARs) belong to the superfamily of steroid-thyroid-retinoid nuclear receptors. PPARs are transcription factors activated by specific ligands and play an important role during cell signalling. Intensive study of PPARs during recent years has revealed their importance in both normal physiology and in the pathology of various tissues. They participate in the regulation of lipid metabolism, inflammation and the development of atherosclerosis or diabetes. They also play a role in the regulation of growth and differentiation of cancer. It has been suggested that PPAR ligands may have potent anticancer effects and therefore may serve as potential anticancer drugs. In this review we focus on a role of PPARs in
breast cancer
and in
glial tumors
of the brain.
...
PMID:Peroxisome proliferator-activated receptors (PPARs) in health and disease. 1257 88
We have reported that mice with an intracerebral (i.c.) malignant
glioma
or
breast cancer
treated with i.c. injection of allogeneic fibroblasts genetically engineered to secrete interleukin-2 (IL-2) survived longer than mice in various control groups. The goal of the present study was to determine the effectiveness of utilizing IL-2 secreting allogeneic fibroblasts as a protective treatment to prevent the development of an i.c.
glioma
or breast carcinoma. Using an intracranial microcannula system that we developed, the animals received weekly injections of the cellular vaccine prior to the introduction of tumor cells via the cannula. The results demonstrate a significant delay (P < 0.005) in the development of
glioma
in the animals pre-treated with either allogeneic non-secreting or IL-2-secreting fibroblasts prior to introduction of tumor cells. In addition, 50% of the animals pre-treated with IL-2 secreting allogeneic fibroblasts injected subsequently with G1261
glioma
cells did not develop a tumor, while all of the animals injected with
glioma
cells alone and 92% of those treated with non-secreting fibroblasts eventually died. The long-term survivors from the pre-treatment group were subsequently re-challenged with tumor and compared to naive controls. There was evidence that long-term immunity was established in the pre-treated animals, since there was a significant prolongation of survival (P < 0.01). In similar experiments using
breast cancer
cells, 62% of the animals pre-treated with non-secreting allogeneic fibroblasts and 75% of the animals pre-treated with allogeneic IL-2 secreting fibroblasts subsequently injected with SB-5b breast carcinoma cells did not develop tumors and had a significant prolongation of survival. These data suggest that i.c. injection of allogeneic IL-2 secreting fibroblasts are effective as a protective treatment in the prevention of the development of a brain tumor when the fibroblasts are introduced into the same site where the tumor is subsequently injected.
...
PMID:Treatment with allogeneic interleukin-2 secreting fibroblasts protects against the development of malignant brain tumors. 1295 94
Epidermal growth factor (EGF) receptor (EGFR) is commonly amplified and/or mutated in high-grade gliomas. Abnormal signaling from this receptor tyrosine kinase is believed to contribute to the malignant phenotypes seen in these tumors. Highly specific small molecule inhibitors of this receptor tyrosine kinase have been developed and may potentially improve the treatment of these highly aggressive brain tumors. A
glioma
cell line overexpressing EGFR was developed to mimic the situation of a malignant
glioma
with amplified EGFR, and this line was used to characterize the response to specific EGFR inhibitors. Treatment of our in vitro
glioma
model with the EGFR kinase inhibitors ZD1839 (Iressa) or PD153035, synthetic anilinoquinazolines with high specificity for EGFR, resulted in significant suppression of EGFR autophosphorylation even with very low levels of drug. However, significantly higher levels of drug were required to fully inhibit signaling through the phosphatidylinositol 3'-kinase/AKT and mitogen-activated protein kinase kinase/extracellular signal-regulated kinase (ERK) pathways. Interestingly, not all downstream signaling pathways displayed this resistance to inhibition. EGF-dependent activation of signal transducers and activators of transcription-3 occurred at low doses of EGFR inhibitors. The uncoupling of EGFR autophosphorylation and signaling through AKT and ERK was not dependent on EGFR overexpression. In addition, although this response was seen in other
glioma
and the SK-BR3
breast cancer
cell lines, it was not universally present. The SQ20B head and neck squamous carcinoma cell line demonstrated loss of EGF-dependent AKT and ERK activation even at low doses of inhibitor. Despite significant loss of EGF-dependent autophosphorylation, the inability of low levels of EGFR inhibitor to suppress some downstream signaling pathways in our model
glioma
cell line permitted continued EGF-responsive decreases in the expression of the cyclin-dependent kinase inhibitor p27KIP and EGF-dependent proliferation/cell cycle progression. Although the mechanism responsible for the differential sensitivity of the various signal transduction pathways to EGFR inhibitors remains unclear, signaling through erbB2 does not appear to be involved. The ability of certain tumor cells to maintain signaling through AKT and ERK under EGFR inhibition may represent a potential mechanism of resistance by which a tumor cell may escape the antiproliferative activity of this new class of drugs.
...
PMID:Resistance to small molecule inhibitors of epidermal growth factor receptor in malignant gliomas. 1461 44
A novel cyclopentenedione, asterredione (1), two new terrecyclic acid A derivatives, (+)-5(6)-dihydro-6-methoxyterrecyclic acid A (2) and (+)-5(6)-dihydro-6-hydroxyterrecyclic acid A (3), and five known compounds, (+)-terrecyclic acid A (4), (-)-quadrone (5), betulinan A (6), asterriquinone D (7), and asterriquinone C-1 (8), were isolated from Aspergillus terreus occurring in the rhizosphere of Opuntia versicolor, using bioassay-guided fractionation. Acid-catalyzed reaction of 2 under mild conditions afforded 4, whereas under harsh conditions 2 yielded 5 and (-)-isoquadrone (9). Catalytic hydrogenation and methylation of 4 afforded 5(6)-dihydro-terrecyclic acid A (10) and (+)-terrecyclic acid A methyl ester (11), respectively. The structures of 1-11 were elucidated by spectroscopic methods. All compounds were evaluated for cytotoxicity in a panel of three sentinel cancer cell lines, NCI-H460 (non-small cell lung cancer), MCF-7 (
breast cancer
), and SF-268 (CNS
glioma
), and were found to be moderately active. Cell cycle analysis of 2, 4, and 5 using the NCI-H460 cell line indicated that 4 is capable of disrupting the cell cycle through an apparent arrest to progression at the G(1) and G(2)/M phases in this p53 competent cell line. A pathway for the biosynthetic origin of asterredione (1) from asterriquinone D (7) is proposed.
...
PMID:Cytotoxic constituents of Aspergillus terreus from the rhizosphere of Opuntia versicolor of the Sonoran Desert. 1469 98
Motexafin gadolinium [gadolinium (III) texaphyrin, gadolinium texaphyrin, Gd-Tex, GdT2B2, PCI 0120] is a radiosensitising agent developed for use in cancer therapy. It is cytotoxic in haematological malignancies by selectively localising in cancer cells that have high rates of metabolism. Motexafin gadolinium inhibits cellular respiration resulting in the production of reactive oxygen species and inducing apoptosis. It is being developed by Pharmacyclics in the US. Bulk motexafin gadolinium is supplied to Pharmacyclics by the US company, Celanese, through a manufacturing and supply agreement between the two companies. In June 2003, at the 39th Annual Meeting of the American Society of Clinical Oncology (ASCO-2003), the importance of having an agent for the treatment of brain metastases from lung cancer was highlighted. Results of a phase III study were presented that showed that motexafin gadolinium treatment was associated with a delay in time to neurological and neurocognitive progression in lung cancer patients. This was an important finding, as 46.6% of lung cancer patients already have brain metastases at the time of initial diagnosis, compared with only 2.7% of
breast cancer
patients. Brain metastases are also often the only site of metastatic disease in patients with lung cancer. In December 2002, Pharmacyclics began a phase III trial of motexafin gadolinium in patients with brain metastases (brain cancer in phase table) from lung cancer in the US, Europe, Canada and Australia. The trial is known as the Study of neurologic progression with Motexafin gadolinium And Radiation Therapy (SMART) and will compare whole-brain irradiation with whole-brain irradiation plus motexafin gadolinium in 550 patients. The primary efficacy endpoint is time to neurological progression and the secondary endpoints are survival and neurocognitive function. In January 2003, the US FDA completed its Special Protocol Assessment (SPA) of the SMART trial with a positive result and by June 2003, enrollment had begun. In addition, phase I trials are underway in children with intrinsic pontine
glioma
and adults with head and neck, lung and pancreatic cancers. A phase II trial is also being conducted in the US in patients with glioblastoma multiforme. Enrollment in this trial has been completed and preliminary results have been reported. Pharmacyclics has completed enrollment and follow-up of adults in its pivotal phase III trial of motexafin gadolinium as a radiation sensitiser for the treatment of brain metastases. The trial was conducted at 35 centres in Europe, Canada and the US. Full results from this initial phase III trial were presented at the annual meeting of the American Society of Clinical Oncology (ASCO) in Orlando, Florida, USA, held in May 2002. Pharmacyclics also announced in October 2002, at the 44th Annual Meeting of the American Society for Therapeutic Radiology and Oncology (ASTRO), that motexafin gadolinium significantly prolonged time to neurological progression when added to whole brain radiation therapy and reduced the number of deaths in patients with brain tumour. Pharmacyclics announced in September 2000 that it has initiated two NCI-sponsored phase I trials conducted under a Cooperative Research and Development Agreement (CRADA) between Pharmacyclics and the NCI. The first trial, conducted in patients with stage IIIA non-small cell lung cancer, was designed to determine the safety of two different dosing regimens of motexafin gadolinium during preoperative radiotherapy after induction chemotherapy. The second study was designed to examine the use of motexafin gadolinium in combination with stereotactic Gamma Knife radiosurgery in patients with primary glioblastoma mutiforme. Two phase I clinical trials have also been conducted for the treatment of newly diagnosed glioblastoma multiforme at the UCLA Jonsson Comprehensive Cancer Center, USA. These phase I studies were sponsored by the NCI and were conducted under a CRADA with the NCI. Pharmacyclics has also completed multicentre US phase II clinical trials of motexafin gadolinium fin gadolinium in patients with metastatic tumours of the brain who require whole brain radiotherapy. Motexafin gadolinium is in a phase II trial in patients with lymphomas and multiple myeloma in the US.
...
PMID:Motexafin gadolinium: gadolinium (III) texaphyrin, gadolinium texaphyrin, Gd-Tex, GdT2B2, PCI 0120. 1472 95
The Na(+)/I(-) symporter (NIS) is the plasma membrane glycoprotein that mediates the active uptake of I(-) in the thyroid, ie, the crucial first step in thyroid hormone biosynthesis. NIS also mediates I(-) uptake in other tissues, such as salivary glands, gastric mucosa, and lactating (but not nonlactating) mammary gland. The ability of thyroid cancer cells to actively transport I(-) via NIS provides a unique and effective delivery system to detect and target these cells for destruction with therapeutic doses of radioiodide.
Breast cancer
is the only malignancy other than thyroid cancer to have been shown to functionally express NIS endogenously. The considerable potential diagnostic and therapeutic use of radioiodide in
breast cancer
is currently being assessed. On the other hand, exogenous NIS gene transfer has successfully been carried out into a variety of other cell lines and tumors, including A375 human melanoma tumors, and SiHa cervix cancer, human
glioma
, and hepatoma cell lines. Most notably, significant radioiodine therapy results have been obtained in the NIS-transfected human prostatic adenocarcinoma cell line LNCaP and in NIS-transfected myeloma cells, both of which exhibited prolonged retention of radio iodide even in the absence of I(-) organification. The therapeutic potential of alternative NIS-transported radioisotopes with different decay properties and a shorter, physical half-life than 131I(-), such as beta-emitter 188Rhenium (188ReO(4)-) and alpha-emitter 211Astatine (211At(-)), has been evaluated. In conclusion, it is clear that the remarkable progress made in the last few years in the molecular characterization of NIS has created new opportunities for the development of diagnostic and therapeutic applications for NIS in nuclear medicine.
...
PMID:The Na/I symporter (NIS): imaging and therapeutic applications. 1473 56
Gliomas
of astrocytic origin are the most common primary brain tumors, accounting for over 40 to 50% of all central nervous system tumors. The TP53 tumor suppressor gene is the most frequently mutated gene found in human malignancies. A mutation of this gene can lead to an increased half-life of the resulting protein and loss of biological function. High levels of p53 have been detected in the serum of colon cancer patients, although p53 protein has not been detected in the serum of brain tumor patients. Besides circulating p53, several studies have detected antibodies against p53 in patients with lung and
breast cancer
, as well as those with other types of cancer. We studied p53 protein and anti-p53 antibodies in the plasma of Brazilian brain tumor patients. Plasma samples were drawn from 24 untreated brain tumor patients and from 15 healthy donors without clinical signs of cancer. Western blotting techniques were used to detect p53 protein and anti-p53 antibodies. We found anti-p53 antibodies in 5/24 brain tumor patients. Age appears to affect the immune response, as four of six tumor patients under 16 years old had detectable anti-p53 antibodies, while these were found in only 1 of 18 adults (over 16 years old). We found no p53 protein in any of the serum samples from the brain tumors. Possibly the presence of this protein is affected by tumor type or by the organs that are sampled.
...
PMID:Anti-P53 antibodies in Brazilian brain tumor patients. 1496 83
The farnesyltransferase inhibitors (FTIs) were designed to inhibit the post-translational processing of Ras proteins, which are mutated in 30% of all human cancers. Recent studies suggest, however, that the target of FTIs may be a protein other than Ras, and that these agents may be more appropriately used to treat tumors with activated wild-type ras signaling. Preliminary results from several phase II and phase III studies have been reported. The FTIs fail to show significant single-agent activity in non-small cell lung cancer, small cell lung cancer, pancreatic cancer, refractory colorectal cancer, and bladder cancer. Activity has been shown in hematologic malignancies (acute myeloid leukemia, chronic myeloid leukemia, myelodysplastic syndrome),
breast cancer
, and
glioma
. Several combination studies of FTIs and standard cytotoxic agents are ongoing.
...
PMID:Farnesyltransferase inhibitors. 1498 78
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