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Query: UMLS:C0007097 (
carcinoma
)
152,788
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Neutrophil gelatinase-associated lipocalin (NGAL) is a novel member of the lipocalin family and may be a new human oncogene product, but function of NGAL is not clear in the cancer. It was recently found that NGAL was overexpressed in the progression of malignant transformation from human immortalized esophageal epithelial cell line SHEE to esophageal
carcinoma
cell line SHEEC. This indicated that cell line SHEEC was a good model for exploring functions of NGAL in the carcinogenesis. The effects of blocking transcription of NGAL gene on invasion, division and proliferation of SHEEC cells were studied by antisense blocking RNA technique and tumor formation in nude mice. The results showed that the antisense blocking of transcription of NGAL gene not only decreased effectively the activity of MMP-9 and MMP-2 secreted by SHEEC cells, but suppressed significantly also the invasion of these cells in nude mice. However, the telomere length, the content of the cellular
topoisomerase
II-alpha and cellular proliferation index (PI) of the SHEEC cells have not been changed markedly. These results indicate that NGAL is possibly involved in invasion of tumor cells by regulating activity of MMP-9 and MMP-2, but is not apparently related with division and proliferation of tumor cells in SHEEC.
...
PMID:[Functions of neutrophil gelatinase-associated lipocalin in the esophageal carcinoma cell line SHEEC]. 1262 49
There has been much recent investigation of the cyclooxygenase (Cox) enzymes in tumor biology, but, to our knowledge, no study has yet been published describing Cox activity in medullary carcinoma of the thyroid (MTC). Nine cases of MTC from the past 10 yr were retrieved from our hospital archives. Slides cut from formalin-fixed paraffin-embedded tumor tissue from these cases were assessed for the activities of Cox-1 and Cox-2 enzymes by immunohistochemistry as well as by a battery of immunohistochemical stains for intermediate filaments, peptide hormone, and proliferation and promoter antigens. The staining reactions were semiquantitatively assessed and scored for comparison with each other as well as with each patient s clinical presentation and course. Staining for Cox-1 and Cox-2 enzymes was present only in tumorous tissue, not in nontumorous thyroid tissue or C-cells. Cox-2 staining was not consistently increased over Cox-1 staining; however, Cox-2 staining bore statistically significant correlations with the expression of low molecular weight keratin, thyroid-transforming factor-1,
topoisomerase
, and MIB1. Hyperplastic C-cells from patients with diverse physiologic conditions and from three patients with C-cell hyperplasia accompanying medullary
carcinoma
or multiple endocrine neoplasia type IIa showed no reactivity for the Cox antibodies. It appears that Cox enzyme immunoreactivity is present only in the neoplastic C-cells of medullary
carcinoma
, but with variable expression. A practical application of the preceding finding might involve the use of Cox staining to distinguish invasive medullary
carcinoma
cells from hyperplastic C-cells.
...
PMID:An immunohistochemical survey of nine cases of medullary carcinoma of thyroid including reactivity for Cox-1 and Cox-2 enzymes. 1266 51
The role of HER2 in predicting response to doxorubicin (DXR) therapy in breast cancer was evaluated in vivo in a series of breast carcinomas from 220 patients with tumors larger than 2.5 cm and treated with 3 cycles of DXR (75 mg/m(2)) as neoadjuvant chemotherapy. Patients with HER2-positive tumors were more frequently responsive to DXR treatment compared with HER2-negative patients (p = 0.05; Mantel-Haenszel Chi(2) = 0.009). Progesterone receptor (PgR) negativity, but not mutated p53, was also associated with response to DXR (p = 0.05; Mantel-Haenszel Chi(2) = 0.004). Further analysis of those correlations using breast
carcinoma
cell lines characterized for different biologic parameters revealed a trend between HER2 positivity/PgR negativity and greater DXR sensitivity, but the strongest direct correlation was found between the proliferation rate and sensitivity to DXR (r = 0.82, p = 0.00009). Neither p53 nor the DXR target molecule
topoisomerase
-II-alpha was significantly associated with in vitro sensitivity to DXR. Thus, whereas data showed that the major biologic parameter associated with in vitro response to DXR in breast cancer cells appears to be the tumor proliferation rate, HER2 expression together with PgR negativity may serve as the counterpart of the proliferation marker in predicting the in vivo response to DXR.
...
PMID:Role of proliferation in HER2 status predicted response to doxorubicin. 1271 52
There is little information on the pharmacokinetics and pharmacodynamics of doxorubicin (DXR) administered during locoregional treatments of colon carcinoma under hyperthermic conditions. The aim of this study was to evaluate distribution and activity of DXR in healthy tissue and tumor tissues under hyperthermic conditions by using an experimental model of ex vivo isolated vascular perfusion of human colon segments bearing primary
carcinoma
. The influence of
topoisomerase
-II alpha (TPI2 alpha) expression on the anti-cancer activity of DXR combined with heat was evaluated as well. Twenty seven colon segments surgically resected for primary
carcinoma
were perfused ex vivo under physiological conditions (group A, n = 7), with DXR (group B, n = 6), under hyperthermic conditions (group C, n = 6), and with the combination DXR-hyperthermia (group D, n = 8). Samples of perfusate and tissues (normal and pathologic) were collected during 90 minutes of perfusion. Doxorubicin concentration in perfusate and tissues was assessed with high-performance liquid chromatography. Protein expression of TPI2 alpha, the main molecular target of DXR, was measured by image analysis in normal mucosa and tumor samples. Drug uptake was increased by heat equally in healthy and diseased tissue. Under hyperthermic conditions, DXR activity was significantly higher in pathologic mucosa than in normal mucosa. Furthermore, the activity of DXR combined with heat correlated with baseline TPI2 alpha levels in tumor tissue. From these findings, it appears that heat sensitizes tumor cells-but not normal mucosa-to DXR activity. Furthermore, protein levels of TPI2 alpha in pretreatment samples could predict tumor sensitivity to DXR.
...
PMID:Doxorubicin activity is enhanced by hyperthermia in a model of ex vivo vascular perfusion of human colon carcinoma. 1273 80
ICBP90 (Inverted CCAAT box Binding Protein of 90 kDa) is a recently identified nuclear protein that binds to one of the inverted CCAAT boxes of the
topoisomerase
IIalpha (TopoIIalpha) gene promoter. Here, we show that ICBP90 shares structural homology with several other proteins, including Np95, the human and mouse NIRF, suggesting the emergence of a new family of nuclear proteins. Towards elucidating the functions of this family, we analysed the expression of ICBP90 in various cancer or noncancer cell lines and in normal or breast
carcinoma
tissues. We found that cancer cell lines express higher levels of ICBP90 and TopoIIalpha than noncancer cell lines. By using cell-cycle phase-blocking drugs, we show that in primary cultured human lung fibroblasts, ICBP90 expression peaks at late G1 and during G2/M phases. In contrast, cancer cell lines such as HeLa, Jurkat and A549 show constant ICBP90 expression throughout the entire cell cycle. The effect of overexpression of E2F-1 is more efficient on ICBP90 and TopoIIalpha expression in noncancer cells (IMR90, WI38) than in cancer cells (U2OS, SaOs). Together, these results show that ICBP90 expression is altered in cancer cell lines and is upregulated by E2F-1 overexpression with an efficiency depending on the cancer status of the cell line.
...
PMID:ICBP90 belongs to a new family of proteins with an expression that is deregulated in cancer cells. 1283 12
We have previously synthesised a number of novel head-to-head bis-benzimidazole derivatives that are structurally related to the fluorochrome, Hoechst 33258, and which possess strong affinity for A:T sites in the minor groove of duplex DNA. Initial studies revealed these compounds to exhibit potent antiproliferative activity against a range of ovarian cell lines and to inhibit transcription in an in vitro setting. In this study, we have examined their cellular behaviour in detail and have shown that two of these compounds (ABA13 and ABA833) potently inhibit the proliferation of a range of human tumour cell lines, and show some specificity towards breast
carcinoma
cell lines. In most of the cell lines investigated, ABA833 was the more potent of the two compounds. Flow cytometric analysis revealed that ABA13 and ABA833 (50-500 nM) induced an S phase block and increased the pre-G1 population in MCF-7 and MDA 468 human breast cancer cells. An increase in the pre-G1 population of RKO colon carcinoma cells was seen only at 500 nM with ABA833, reflecting the reduced sensitivity of this cell line to the bis-benzimidazoles in comparison to the breast cancer cell lines. Mechanistic studies revealed that neither ABA13 or ABA833 act as topoisomerase I (topo I) or
topoisomerase
II (topo II) poisons in plasmid or kinetoplast DNA (kDNA) relaxation assays, but both compounds do inhibit the catalytic activity of these enzymes. Drug uptake studies showed that reduced sensitivity of MCF-7adr and RKO cells compared with MCF-7 to both ABA13 and ABA833 correlated with a markedly reduced intracellular drug accumulation.
...
PMID:Mechanistic and anti-proliferative studies of two novel, biologically active bis-benzimidazoles. 1460 41
We have recently shown that the
topoisomerase
II inhibitor, etoposide (VP16), could trigger caspase-2 pre-mRNA splicing in human leukemic cell lines. This leads to increased inclusion of exon 9, which is specifically inserted into the short caspase-2S isoform mRNA and absent from the long caspase-2L isoform mRNA. One of the consequences of this alternative splicing is a decrease in the total amount of the mature form of caspase-2L mRNA and protein. In this study, we analyzed the effects of several representative molecules of various classes of cytotoxic agents on caspase-2 pre-mRNA splicing in both U937 leukemic cells and in HeLa cervix
carcinoma
cells. Very strikingly, both topoisomerase I (camptothecin and homocamptothecin derivatives) and II (VP16, amsacrine, doxorubicin, mitoxantrone) inhibitors induced exon 9 inclusion. DNA intercalating glycosyl indolocarbazole derivatives as well as DNA alkylating agents, such as cisplatin and melphalan, antimetabolites like 5-fluorouracil, and mitotic spindle poisons like vinblastine had no effect. Therefore, both classes of DNA topoisomerases can control pre-mRNA splicing of the caspase-2 transcript. In addition, the splicing reaction brought about by camptothecin was hampered in human CEM/C2 and in murine P388-45R leukemic deficient in topoisomerase I activity. Conversely, VP16 did not trigger caspase-2 alternative splicing in human HL60/MX2 leukemic cells harboring a mutant
topoisomerase
II. Minigene transfection analysis revealed that
topoisomerase
inhibitors did not change the splicing profile when cis-acting elements in intron-9, reported to control exon 9 inclusion independently of drug treatment, were removed. Rather, our experiments suggest that exon 9 inclusion induced by
topoisomerase
inhibitors reflects the activity exerted by topoisomerase I or II on proteins that control splicing reactions, or their direct involvement in pre-mRNA splicing.
...
PMID:Topoisomerase I and II inhibitors control caspase-2 pre-messenger RNA splicing in human cells. 1475 46
New strategies for improving treatment of patients with breast
carcinoma
have focused on the HER2 oncoprotein with regard to response to traditional therapy regimes and the effect of a new drug specifically directed against the protein. Furthermore, the status of the
topoisomerase
IIalpha (TOP2A) gene has been suggested as a predictive marker of anthracycline treatment. In this study of 120 tumours, immunohistochemically detected HER2 overexpression with HercepTest has been compared to the HER2 gene amplification investigated with a new HER2 probe for fluorescence in situ hybridization (FISH). In addition, the HercepTest was evaluated as a screening tool for choosing cases for FISH investigation of TOP2A gene aberrations. The HercepTest score 3+ identified HER2 gene amplification in 27 of 30 amplified tumours (sensitivity of 0.90) with a false-negative rate of 0.10 and a false-positive rate of 0.06. TOP2A gene amplification or deletion was found in 20 cases. Sixteen (80%) of these carcinomas were in the HercepTest 3+ group, but four tumours had alterations in the TOP2A gene with normal HER2 status. Traditionally, in the FISH technique the result has been based on counting 60 cells. However, we found that a much less time-consuming method of counting 60 signals gave equally good results.
...
PMID:Amplification of HER2 and TOP2A and deletion of TOP2A genes in breast cancer investigated by new FISH probes. 1506 18
Resistance of tumors due to restricted drug accumulation and reversal of DNA lesions in tumor cells as well as normal tissue toxicity limit the efficacy of
topoisomerase
inhibition based anticancer drugs. It has been proposed that selective inhibition of energy dependent repair processes and enhanced retention of drug in cancer cells can significantly improve the therapeutic efficacy. The purpose of these studies was to verify this proposition by investigating the effects of 2-deoxy-D-glucose (2-DG) an inhibitor of the glycolytic ATP production on the cytotoxicity of certain
topoisomerase
inhibitors in human tumor cell lines. Human glioma (BMG-1 and U-87) and squamous
carcinoma
(4197 and 4451) cell lines were investigated with topo-poisons like etoposide (topo II inhibitor), camptothecin (topo I inhibitor) and hoechst-33342 (topo I and II inhibitor). DNA damage induction (halo assay), cell survival (macro colony assay), cytogenetic damage (micronuclei) and apoptosis (morphological analysis) were investigated. Presence of 2-DG for 2 h following exposure to the
topoisomerase
inhibitors enhanced the cell death (macro colony assay) in a concentration dependent manner and a 2-3-fold increase was observed at 5 mM (equimolar with glucose). Halo assay revealed that 2-DG inhibited the reversal of cleavable complex leading to the accumulation of DNA strand breaks. Under these conditions 2-DG enhanced the drug-induced micronuclei formation by nearly 2 folds with etoposide and hoechst-33342 and a 4-fold increase in delayed apoptosis was observed in case of etoposide. These results clearly demonstrate that presence of 2-DG for a few hours following exposure to topo-inhibitors enhances the cytotoxicity, primarily by increasing the cytogenetic damage.
...
PMID:2-deoxy-D-glucose enhances the cytotoxicity of topoisomerase inhibitors in human tumor cell lines. 1525 10
We reported recently that exposure of hamster V79 fibroblasts to 6 drugs that varied in their ability to produce DNA double-strand breaks stimulated formation of phosphorylated histone H2AX (serine 139 phosphorylated histone H2AX; gammaH2AX). Using flow cytometry to analyze gammaH2AX antibody-stained cells 1 h after a 30-min drug treatment, the fraction of cells that showed the control levels of gammaH2AX correlated well with the fraction of cells that survived to form colonies. This observation is now extended to V79 and SiHa human cervical
carcinoma
cells grown as multicell spheroids and SiHa xenografts and SCCVII tumors in mice. Animals were injected with etoposide, a
topoisomerase
-II inhibitor that targets proliferating cells or 3-amino-1,2,4-benzotriazine-1,3-dioxide (tirapazamine), a bioreductive cytotoxin that targets hypoxic cells. For spheroids, gammaH2AX intensity predicted clonogenic cell survival for cells recovered 90 min after drug injection, regardless of position of the cells within the spheroid. Similar results were obtained for etoposide in tumors; however, the gammaH2AX signal for tirapazamine was smaller than expected for the observed amount of cell killing. Frozen sections of tumors confirmed the greater intensity of gammaH2AX staining in cells close to blood vessels of tumors soon after treatment with etoposide and the opposite pattern for tumors exposed to tirapazamine. Analysis of cells or frozen sections from mouse spleen and kidney suggests that information can also be obtained on initial damage in normal tissues. These results support the possibility of using gammaH2AX antibody staining as a method to aid in prediction of tumor and normal tissue response to treatment.
...
PMID:Phosphorylated histone H2AX in spheroids, tumors, and tissues of mice exposed to etoposide and 3-amino-1,2,4-benzotriazine-1,3-dioxide. 1528 43
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