Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.24.3 (collagenase)
 18,340 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We describe, for the first time, the development of a technique for a long-term selective culture of endocrine (PE) cells from the lungs of normal animals. Epithelial cells were isolated from 1-day-old hamster lungs through mechanical and enzymatic dissociation with collagenase type II. Cells were then cultured in HITES medium which contained RPMI 1640, hydrocortisone, insulin, transferrin, estradiol, sodium selenite, and supplemented with 5% fetal bovine serum (FBS), or medium which contained HITES medium supplemented with bovine serum albumin, phosphoethanolamine, arginine vasopressin, bombesin, and 2% FBS (9N). HITES medium, originally developed for establishment and long-term culture of human small cell lung cancer (SCLC) cell lines, allowed propagation of normal hamster PE cells up to 12 months as a mixed floating-attached cell culture. No difference was noted in the results using HITES or 9N. By 3 months, 80% of the cultured cells contained characteristic dense-core (endocrine type) granules. The cultured PE cells also expressed creatine kinase brain isoenzyme, and general NE markers including neuron specific enolase, and amine handling enzyme activity within the range of SCLC cell lines. Moreover, cultured PE cells contained and secreted immunoreactive calcitonin (iCT) which had a molecular profile similar to that of intact hamster lung. This long-term culture technique should markedly assist in elucidating the role of PE cells in health and disease.
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PMID:Long-term selective culture of hamster pulmonary endocrine cells. 838 31

Within the mammalian lung, cells with a neuroendocrine phenotype are few in number and are sparsely distributed. In contrast, neuroendocrine neoplasms represent a major group of lung cancers. The aim of this study was to develop a model of mammalian PNECs and to compare glucocorticoid regulation of calcitonin secretion in normal and neoplastic cells with neuroendocrine differentiation. Cell cultures of PNECs were initiated after the disaggregation of neonatal hamster lungs with 0.1% collagenase and fractionation of the resultant cell suspension on a gradient of iodixanol (1.320 g/mL). Cell fractions enriched in PNECs were identified by positive staining for 5-hydroxytryptamine and the presence of calcitonin. Calcitonin secretion was investigated after exposure to hydrocortisone (0 to 1,000 nM). A dose-dependant inhibition of calcitonin secretion was seen after 7 days between 10 nM (55% of control), and 1,000 nM (29%) hydrocortisone. Cell cultures grown in the presence of hydrocortisone also contained significantly fewer PNECs between 10 nM (90% of control), and 1,000 nM (45%). Human bronchial carcinoid cells (NCIH727) cultured under identical conditions showed a similar inhibition of calcitonin secretion between 10 nM (53%) and 1,000 nM (52%), although at these concentrations, no reduction in cell number was seen. In contrast, 2 human small cell lung cancer cell lines (DMS-79 and COR-L24 cells) showed no dose-dependent inhibition of calcitonin secretion and no effect on cell proliferation in response to hydrocortisone. These results show that enriched cultures of mammalian PNECs can be used to investigate functional aspects of their biology, including peptide secretion in response to potential regulators. Furthermore, calcitonin secretion is inhibited in normal PNECs and bronchial carcinoid cells at physiological concentrations of glucocorticoids, but this feature appears not to be present in the 2 more invasive neuroendocrine neoplasms (small cell lung cancer cells) investigated in this study.
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PMID:Differential regulation of calcitonin secretion in normal and neoplastic pulmonary neuroendocrine cells in vitro. 1176 19

Marimastat [BB 2516, TA 2516] is a second-generation anticancer drug originally developed with British Biotech in Europe and North America. It is an orally active metalloprotease inhibitor of the same class as batimastat, and is the first compound in this class to have completed a pivotal clinical trial. Marimastat also has collagenase- and angiogenesis-inhibiting properties. British Biotech and Schering-Plough have signed an agreement enabling the latter to develop and market marimastat in North America and Europe. Under the terms of the agreement, British Biotech will receive an up-front license fee of 4 million US dollars and a 4 million US dollars equity investment in British Biotech by Schering-Plough. Schering-Plough holds rights to marimastat in all countries other than the Far East and Japan. The two companies are considering asking the FDA for accelerated approval in gastric cancer based on the secondary endpoint of progression-free survival. Marimastat is licensed to Tanabe Seiyaku in Japan, where phase II clinical trials are underway for the treatment of advanced gastric cancer and lung cancer. Further phase II trials in other tumour types are planned. The commencement of phase II trials in Japan resulted in a milestone payment of 5 million US dollars to British Biotech from Tanabe Seiyaku. Tanabe Seiyaku also holds rights to marimastat in the Far East. Marimastat has been in pivotal phase III trials in glioblastoma, breast, ovarian and small and non-small cell lung cancer, but these trials have all been discontinued because marimastat failed to show superior efficacy over either standard chemotherapy or placebo. Results from the marimastat 131 trial in patients with glioblastoma, for example, indicated that marimastat was no better than placebo at prolonging survival in these cancer patients. In June 2000, when the results of this study were released, shares in British Biotech fell 21.6% to just 19 pence per share. The phase III trial in small cell lung cancer was discontinued when the results of study 140 were released in February 2001 showing that marimastat was not significantly more effective than placebo in prolonging the survival of small cell lung cancer patients. The results of this study were consistent with those reported in study 117. British Biotech has also conducted a phase III placebo-controlled study of marimastat as monotherapy in patients with inoperable gastric cancer at 37 centres throughout Europe. Results from this trial indicated that it did not achieve its primary endpoint of a statistically significant survival benefit over placebo. However, data collected during the follow-up period have shown increases in survival benefit in the treatment group in addition to a significant improvement in disease-free progression, the secondary endpoint of the trial. Development of marimastat for this indication is ongoing. In May 2001, British Biotech reported data from an interim analysis of results from the remaining phase III study in pancreatic cancer (study 183) that showed no patient benefit for marimastat recipients compared with gemcitabine. However, these results did not meet stopping criteria and the study continues under the guidance of Schering-Plough. The multicentre trials are being conducted in the US, Canada and the European Union. The phase III trial of marimastat in combination with carboplatin that was being conducted in patients with ovarian cancer was discontinued because British Biotech realised that the design of the trial was insufficient for registration in the US or Europe. Altogether, seven phase III studies have failed to meet their primary end-points, but the company has stated that the effectiveness of marimastat is more likely to be seen in patients with less advanced disease. Phase II trials in prostate and head and neck cancer are still underway in the US.
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PMID:Marimastat: BB 2516, TA 2516. 1275 9

Tissue factor pathway inhibitor-2 (TFPI-2) is a potent inhibitor of plasmin, a protease which is involved in tumour progression by activating (MMPs). This therefore makes TFPI-2 a potential inhibitor of invasiveness and the development of metastases. In this study, low levels of TFPI-2 expression were found in 65% of patients with small cell lung cancer (SCLC), the most aggressive type of lung cancer. To study the impact of TFPI-2 in tumour progression, TFPI-2 was overexpressed in NCI-H209 SCLC cells which were orthotopically implanted in nude mice. Investigations showed that TFPI-2 inhibited lung tumour growth. Such inhibition could be explained in vitro by a decrease in tumour cell viability, blockade of G1/S phase cell cycle transition and an increase in apoptosis shown in NCI-H209 cells expressing TFPI-2. We also demonstrated that TFPI-2 upregulation in NCI-H209 cells decreased MMP expression, particularly by downregulating MMP-1 and MMP-3. Moreover, TFPI-2 inhibited phosphorylation of the MAPK signalling pathway proteins involved in the induction of MMP transcripts, among which MMP-1 was predominant in SCLC tissues and was inversely expressed with TFPI-2 in 35% of cases. These results suggest that downregulation of TFPI-2 expression could favour the development of SCLC.
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PMID:Beneficial role of overexpression of TFPI-2 on tumour progression in human small cell lung cancer. 2390 12