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)

Photodynamic therapy is a promising treatment for human brain tumors because of the selective retention of certain compounds by tumor cells. Certain lipophilic cationic compounds, such as tetraphenylphosphonium (TPP), are selectively taken up by a variety of carcinomas. Although preferential retention of TPP has been demonstrated for the breast carcinoma cell line MCF-7, this compound had not been tested previously on cells derived from nervous system tumors. In the present study, tritiated-TPP (3H-TPP) uptake and retention for eight different cell cultures of three histologically different types of nervous system tumors was measured and the data were compared to a positive control (MCF-7) and negative controls (normal African Green monkey kidney epithelium (CV-1) and the normal human fibroblast (WI-38) cell lines). Uptake and retention characteristics could be grouped by specific pathological tumor types, but individual tumor variability was notable. Malignant astrocytoma (grade III/III glioblastoma) and malignant neurofibrosarcoma cells showed preferential uptake and retention of 3H-TPP relative to meningioma cells and normal controls. A clonogenic assay utilizing the cytotoxic lipophilic cationic compound dequalinium showed strong retainers of 3H-TPP to be more susceptible to the effects of dequalinium than weak retainers. These data demonstrate that certain human and experimental animal nervous system tumor cell lines retain lipophilic compounds possessing a delocalized positive charge. Lipophilic cationic compounds may be useful in the intraoperative delineation of tumor margins and in the photodynamic therapy of certain nervous system tumors.
 ...
PMID:Enhanced in vitro uptake and retention of 3H-tetraphenylphosphonium by nervous system tumor cells. 198 90

To determine whether glial growth factor (GGF)-like activity is associated with human Schwann cell tumors, we tested extracts from these tumors for their ability to stimulate the proliferation of rat Schwann cells in culture. Extracts from 3 of 3 bilateral acoustic neuromas and from 5 of 7 unilateral acoustic neuromas demonstrated dose-dependent stimulation similar to that of partially purified bovine pituitary GGF. One neurofibroma also contained high levels of GGF-like activity, one demonstrated an intermediate level, and three showed low or no activity. Minimal activity was found in one neurofibrosarcoma and in one trigeminal schwannoma. Non-Schwann cell tumors studied included 3 meningiomas, 2 pituitary adenomas, 1 cerebellar astrocytoma, 1 glioblastoma, 1 hemangioblastoma, and 2 metastatic brain tumors. The cerebellar hemangioblastoma demonstrated high GGF-like activity; the others showed little or no activity. Normal tissues used as control specimens included brain, peripheral nerve, muscle, and fat. Some activity was noted in one nerve biopsy; all others showed minimal or no GGF-like activity. High-performance liquid chromatography demonstrated that the GGF-like activity from two acoustic neuromas eluted in a single peak close to that of bovine pituitary GGF. We conclude that acoustic neuromas contain a factor that is closely related to bovine pituitary GGF and that this factor may have a role in the abnormal proliferation of Schwann cells in these tumors.
 ...
PMID:Glial growth factor-like activity in Schwann cell tumors. 376 16