Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0242379 (lung cancer)
 71,905 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In an earlier publication (Harvey, et al. (1982) J. Biol. Chem., 257, 5645-5651) the discovery of a family of unusually large molecules with plasminogen activator activity in the conditioned medium of a human lung cancer cell line was reported. These molecules are related to urokinase (uPA) by functional and immunological criteria. We have now purified two representatives of this glycoprotein family of Mr 900,000 (PA900) and Mr 660,000 (PA660). While these could be fractionated into subspecies exhibiting size and charge differences, reduction yielded in all cases two predominant chains of 70 and 40 kDa, respectively. Since the amino acid composition of the subfractions was identical, we conclude that the heterogeneity is due to demonstrated differences in glycosylation. The amino acid composition of the unreduced species and of the major reduced chains differed from that of 55 kDa uPA. These enzymes are active toward the substrate, plasminogen, as well as toward the uPA-specific synthetic substrate, Spectrozyme UK, and these activities are inhibitable by diisopropylphosphorofluoridate (DFP). Treatment of PA660 with [3H]DFP resulted in the incorporation of 1.4 mol of DFP into 1 mol of enzyme, suggesting the presence of a single active site. The label was quantitatively recovered in a 21 kDa fragment in a reduction experiment. This fragment also demonstrated immunological reactivity with antiurokinase. It is postulated that PA660 is composed of five or six pairs of the 70 and 40 kDa chains, and of a single uPA-like entity. All of these chains are linked by disfulfide bonds. Whether larger portions of uPA are also present in this molecule, is not yet clear. By electron microscopy, PA900 shows a filamentous structure, while PA660 is predominantly globular. The occurrence of large uPA-like activators in extracts of human colon carcinomas that crossreact with monospecific antibody against uPA, is discussed.
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PMID:Characterization of a family of high-molecular-weight plasminogen activators secreted by a lung tumor cell line. 185 26

Human non-small lung cancer cell lines HS-24 (established from a primary squamous cell carcinoma) and SB-3 (established from a metastasis of a primary adenocarcinoma of the lung into the adrenal gland) were analysed for the proteinases tissue-type plasminogen activator (tPA), urokinase-type plasminogen activator inhibitor (PAI-1). The proteinases were characterized by activity measurements, inhibition studies, enzyme-linked immunosorbent assay (ELISA), and Western blot analysis. Cell-associated proteinases were determined in cell lysates, secreted proteinases in cell conditioned culture media. Both cell lines were found to secrete uPA and PAI-1, whereas tPA could be detected only in HS-24 conditioned media. No cathepsin B activity could be detected in media of both cell lines. However, activation experiments and western blot analysis showed, that at least HS-24 secrete an inactive precursor. Cell lysates of HS-24 and SB-3 show PA activity, but on a low level. Cathepsin B activity was also found to be low in HS-24 lysates. However, SB-3 lysates show high cathepsin B activity. Further characterization of the proteinases by their sensitivity against several inhibitors suggests that they are similar to the corresponding proteinases of normal, nonmalignant cells.
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PMID:Detection of cathepsin B, plasminogen activators and plasminogen activator inhibitor in human non-small lung cancer cell lines. 222 60

A 64-year-old woman experienced high grade fever, chest pain, and hemosputum. She was admitted to a hospital for evaluation of the infiltrate on an chest X-ray. She was diagnosed as having lung cancer by sputum cytology and transferred to our hospital for operation. The tumor was obscure on palpation during thoractomy, but malignancy could not be ruled out based on analysis of frozen sections. Therefore, a right lower lobectomy and mediastinal lymph node dissection were performed. Pulmonary infarct was not suspected until thrombi were observed in the dissected pulmonary artery. Urokinase and heparin were intravenously administered soon after the operation, but the patient died of pulmonary thromboembolism of the sixth postoperative day. Examination of the operative specimen revealed pulmonary thromboembolism with infarction and no evidence of malignancy. Atypical cells observed in sputum cytology seemed to be derived from basal cell hyperplasia in the area of infarction. Type II alveolar epithelial cell hyperplasia was observed in the periphery of the infarction. These findings seemed to make accurate analysis of frozen sections difficult. An increasing number of cases of pulmonary thromboembolism is being reported in Japan. Therefore, pulmonary infarct with false positive cytology may be encountered more frequently in the future.
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PMID:[Pulmonary infarct hardly differentiated from lung cancer--a case report]. 759 62

We investigated the importance of the urokinase (uPA)-plasmin system in fostering invasion of human lung cancer cells through artificial basement membranes composed of Matrigel. Eight cell lines (including 1 small cell and 7 non-small cell lines) were examined. One cell line did not express any components of the urokinase system. Four cell lines had substantial levels of endogenous uPA detectable on their surfaces. Three of these cell lines co-expressed the plasminogen activator inhibitor PAI-1 in addition to uPA. Assays for invasiveness revealed 4 cell lines capable of traversing a Matrigel barrier, including the 3 which co-expressed uPA, PAI-1 and uPA receptor. Surprisingly, the cell line expressing only uPA and uPA receptor displayed no invasive capacity despite levels of secreted uPA more than 20-fold higher than the other cell lines studied. Based on these observations, we hypothesized that both uPA and PAI-1 might be important for invasion by lung tumor cells, at least in vitro. We therefore tested polyclonal antibodies which inhibit uPA and PAI-1 activity for their effects on the highly invasive H292 cell line. After 3 days, invasive capacity was inhibited by antibodies to both uPA and PAI-1 in a dose-dependent manner. The plasmin inhibitor aprotinin reduced H292 cell invasion by 70%. Taken together, our data demonstrate that in cultured human lung cancer cells the uPA-plasmin system is important in promoting invasion into basement membranes and suggest that a critical balance between uPA and PAI-1 is necessary for optimal invasiveness. Our data are consistent with results from recent clinical studies showing that PAI-1 expression in tumor tissue is an adverse prognostic feature.
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PMID:Co-expression of urokinase, urokinase receptor and PAI-1 is necessary for optimum invasiveness of cultured lung cancer cells. 782 64

Recent advance in cell-molecular biological studies have revealed various prognostic factors in lung cancer. The aim of this paper is to critically review the current status of molecular biological prognostic markers in non-small cell lung cancer. DNA ploidy, AgNORs and PCNA as marker of tumor cellular proliferative activity are reported to be a prognostic marker but still remain controversial. The proteases such as uPA, MMPs and CB catalyze degradation of the extracellular matrix and basement membranes. Although the prognostic implications of the uPA and MMPs still remain unclear, cathepsin B appears to be one of the most useful prognostic markers so far reported for non-small cell lung cancer. In a number of studies, genetic abnormalitis has been reported to be a prognostic marker in cancer patients. In non-small cell lung cancer, the prognostic implication of the altered p53 expression or ras p21 expression still remain unclear, especially p53 is conflicting. The most useful clinical prognostic marker may be obtained by the combined analysis of some prognostic information.
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PMID:[Molecular biological prognostic markers in lung cancer]. 904 11

Human tissue factor pathway inhibitor-2 (TFPI-2) is a Kunitz-type serine protease inhibitor that inhibits plasmin, trypsin, chymotrypsin, cathepsin G and plasma kallikrein but not urokinase (uPA) or tissue-type plasminogen activator and thrombin. Earlier studies from our and other laboratories have shown that the production of TFPI-2 is downregulated during the progression of various cancers. To investigate the role of TFPI-2 in the invasion and metastasis of lung tumors, the human lung cancer cell line A549, which produces high levels of TFPI-2, was stably transfected with a vector capable of expressing an antisense transcript complementary to the full-length TFPI-2 mRNA. Northern blot analysis was used to quantify the TFPI-2 mRNA transcript, and western blot analysis was used to measure TFPI-2 protein levels in parental cells and stably transfected (vector and antisense) clones. The levels of TFPI-2 mRNA and protein were significantly less in antisense clones than in the parental and vector controls. The invasive potential of the parental cells and stably transfected vector clones in vitro, as measured by the Matrigel invasion assay, was also markedly less than that of antisense clones. Further characterization of these clones showed that more cells migrated from antisense clones than from parental and vector clones. These data suggest that TFPI-2 is critical for the invasion and metastasis of lung cancer and that the downregulation of TFPI-2 production may be a feasible approach to increase invasiveness and metastasis.
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PMID:In vitro modulation of human lung cancer cell line invasiveness by antisense cDNA of tissue factor pathway inhibitor-2. 1131 97

It has been suggested that uPA in cancer cells is up regulated by the p 185 kD form of the HER-2/neu oncogene. We elected to see if the extra cellular domain of HER-2/neu, the p 105 fraction, which is found in the circulation, has any regulatory influence on uPA or uPAR in those patients with NSCLC Levels of uPA, uPAR and p 105 HER-2/neu were determined in blood from age-matched controls and patients with advanced NSCLC. In the patients with NSCLC, samples were obtained before and following treatment. A large increase in both uPA and uPAR compared to controls was seen in the patients prior to treatment. The uPAR level post-treatment decreased from pre-treatment values, which is favorable. There was a significant increase in uPA and a decrease in HER-2/neu in the post-treatment time frame. Additionally, correlation analysis of circulating uPAR, uPA and HER-2/neu against each other in both the controls and treatment groups indicated no relationship. It appears that circulating uPA and uPAR are elevated in NSCLC patients. The up-regulation of uPA by HER-2/neu seen in lung cancer cells in vitro is apparently lost in the blood in vivo as is evidenced by the lack of correlation between them which is also true for the receptor as well.
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PMID:The circulating urokinase plasminogen activator (uPA) and its soluble receptor (suPAR) are not up-regulated by the circulating P105 fraction of the HER-2/neu proto-oncogene: in vivo evidence from patients with advanced non-small cell lung cancer (NSCLC). 1217 85

The low density lipoprotein (LDL) receptor-related protein 1B (LRP1B) is a newly identified member of the LDL receptor family and is closely related to LRP. It was discovered as a putative tumor suppressor and is frequently inactivated in lung cancer cells. In the present study, we used an LRP1B minireceptor (mLRP1B4), which mimics the function and trafficking of LRP1B, to explore the roles of LRP1B on the plasminogen activation system. We found that mLRP1B4 and urokinase plasminogen activator receptor (uPAR) form immunoprecipitable complexes on the cell surface in the presence of complexes of uPA and its inhibitor, plasminogen activator inhibitor type-1 (PAI-1). However, compared with cells expressing the analogous LRP minireceptor (mLRP4), cells expressing mLRP1B4 display a substantially slower rate of uPA.PAI-1 complex internalization. Expression of mLRP1B4, or an mLRP4 mutant deficient in endocytosis, leads to an accumulation of uPAR at the cell surface and increased cell-associated uPA and PAI-1 when compared with cells expressing mLRP4. In addition, we found that expression of mLRP1B or the mLRP4 endocytosis mutant impairs the regeneration of unoccupied uPAR on the cell surface and that this correlates with a diminished rate of cell migration. Taken together, these results demonstrate that LRP1B can function as a negative regulator of uPAR regeneration and cell migration.
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PMID:Low density lipoprotein (LDL) receptor-related protein 1B impairs urokinase receptor regeneration on the cell surface and inhibits cell migration. 1219 87

We compared the prognostic value of routine pathology, cytokeratin-positive (CK+) cells in the bone marrow (BM) and serum tumour markers (TM) in patients with non-small cell lung cancer (NSCLC) at the time of diagnosis with regard to overall survival (OS) and time to progression (TTP). Eighty patients with NSCLC, staged as T2-4, N0-3, M0 (n=52), M1 (n=27), (Mx = 1) were evaluated. Treatment included chemo-radiotherapy with cisplatin/etoposide and subsequent radical surgical resection. There were 23 complete responders, 50 non-responders and 7 patients who died of non-lung cancer causes. The median follow-up was 12 months (range 1-44 months). Besides routine pathology for tissue and BM, CK+ BM cells were detected by immunocytochemistry (IC) and 4 different tumour markers as well as the shedded domain of the oncoprotein Her-2/neu and urokinase plasminogen activator uPA were determined by radio- or enzyme-immunoassay. Patients classified as stage IV and patients with metastases had a significantly lower TTP and OS. No significant correlation was demonstrated for grading, tumour size or number of involved lymph nodes. The tumour marker tissue polypeptide antigen (TPA) and Cyfra 21-1 were the only marker which significantly correlated with OS. Interestingly, routine pathology could not detect minimal residual BM involvement as IC was able to (p=0.0004) and the presence of even a few CK+ cells significantly correlated with reduced OS. Thus, we conclude that the detection of CK+ cells should be added to routine pathology and for tumour marker determination, studies should focus on Cyfra 21-1 and TPA.
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PMID:Evaluation of different markers in non-small cell lung cancer: prognostic value of clinical staging, tumour cell detection and tumour marker analysis for tumour progression and overall survival. 1257 92

To express the fusion protein ATF-PAI2CD (urokinase-type plasminogen activator amino terminal fragment-plasminogen activator inhibitor type 2 with the region inter C and D helices deleted ) gene in E.coli and determine the biological characterization of fusion protein ATF-PAI2CD, the cDNA fragment encoding ATF-PAI2CD was cloned into the expression vector pLY-4 and transformed into E.coli JF1125. After temperature induction, the expression amount of ATF-PAI2CD account for 15% of total bacterial protein. The result was confirmed by Western blot. ATF-PAI2CD protein was isolated and purified by washing and solubilization of inclusion body, renaturation and ion exchange chromatography. The final product displayed a single band with a corresponding molecular weight 62 kD in SDS-PAGE. The purity was over 90%, the protein yield was 50% and the specific activity was 12 000 IU/mg. The PAI activity was measured by chromogenic assay. The purified fusion protein inhibited urokinase-type plasminogen activator as measured by milk-agarose plate assay, and bound to human lung cancer cells via uPA receptor (uPAR), which was confirmed by radio competition experiments. The results indicate that the biological characteristics of ATF-PAI2CD were very similar to those of the wide type PAI-2 (or mutants PAI-2, PAI-2CD) and to pro-uPA in binding to uPAR-bearing cells.
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PMID:[Biological function of fusion protein ATF-PAI2CD]. 1288 32


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