Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0001418 (adenocarcinoma)
 68,496 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The unique combination of immunocytochemistry with embedment-free electron microscopy was applied for precise and specific localisation of BAX in the human colon adenocarcinoma COLO 205 cell line stimulated to undergo apoptosis by camptothecin (DNA topoisomerase I inhibitor). Camptothecin-induced apoptosis was associated with redistribution of BAX from cytosol to organelle membranes: mitochondria, Golgi apparatus, endoplasmic reticulum and via nuclear envelope pores to the nucleus, occurring within 60-180 min of cell exposure to the drug. An increase in BAX immunoreactivity on fine filaments and the lamina-pore complex of the nuclear matrix was also observed. The increase in BAX expression in the nuclear area of camptothecin-treated COLO 205 cells was confirmed by quantitative analysis using laser scanning cytometry. The subcellular translocations of BAX preceded the appearance of any morphological symptoms of apoptosis.
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PMID:Expression of BAX in cell nucleus after experimentally induced apoptosis revealed by immunogold and embedment-free electron microscopy. 1148 96

BAX is the 192-amino acid, 21-kDa protein which is ubiquitously distributed in normal tissues and is regarded as a tumor suppressor sensitizing malignant cells to anticancer drugs. In spite of many studies, the molecular mechanism of BAX action is still obscure. In the present study subcellular BAX translocations in human colon adenocarcinoma COLO 205 cells exposed to various anticancer drugs [camptothecin (CPT), etoposide (ETO), staurosporine (STP), 2-chloro-2'-deoxyadenosine (2CdA) and nimesulide (NIM)] was examined. Cells were grown on coverslips under optimal conditions (10% FCS/DMEM) or were stimulated to apoptosis with the drugs examined. Laser scanning cytometry was applied for the quantitative analysis of BAX expression, and distribution in the cytoplasmic (BAX Cf) and nuclear (BAX Nf) area. BAX maximal pixel (BAX MP), the parameter corresponding to aggregation of BAX in the cell, was also measured. All examined drugs increased the number of cells with high BAX MP, reaching the peak at 60 min after drug administration. The most pronounced effect was in the case of 2CdA, CPT and STP. The increase in BAX MP was observed only when antibody recognizing the 43-61 amino acid sequence was used. When antibody binding the N-terminal epitope (11-30 amino acid sequence) was applied, the number of cells expressing high BAX MP significantly decreased. These results indicate that apoptotic stimuli delivered by anticancer drugs led to aggregation of BAX in cancer cells, which is dependent on BAX activation by its cleavage at the N-terminal epitope and exposure of the BH3 domain. It was shown that BAX Nf increased in cells treated with CPT, STP, ETO, 2CdA and NIM, whereas BAX Cf rose after STP and NIM. The increase in BAX Nf and, occurring in most treatments, the increase in the BAX Nf:Cf ratio indicates a BAX shift from the cytoplasm to the nucleus. Furthermore, staining with different antibodies showed that only the activated form of BAX was translocated to the nucleus. Immunoelectron microscopy revealed that CPT-induced apoptosis was associated with translocation of BAX from the cytosol to organellar membranes (mitochondrial, Golgi apparatus and endoplasmic reticulum) and via nuclear envelope pores to the nucleus, occurring within 60-180 min of cell exposure to the drug. The subcellular translocations of BAX preceded in time the appearance of morphological symptoms of apoptosis. In conclusion, (i) in spite of different molecular mechanisms of apoptosis induction by the anticancer drugs examined, BAX remains a common link in the chain of reactions leading to cell death, and (ii) BAX activation and subcellular translocations from the cytosol to organellar membranes and nucleus are key cellular responses to drugs bearing proapoptotic properties.
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PMID:Subcellular redistribution of BAX during apoptosis induced by anticancer drugs. 1148 18

Hypericin, a natural polycyclic quinone extracted from Hypericum perforatum, has been recently shown to be a powerful sensitiser for photodynamic therapy (PDT). However, its intracellular localisation remains unclear and contradictory. In the present work we compared the intracellular localisation of hypericin in three cultured cell lines (adenocarcinoma cells WiDr, carcinoma cells NHIK 3025 and glioblastoma cells D54Mg) with the distribution of fluorescent probes specific to lysosomes (LysoTracker Blue DND-22), mitochondria (MitoTracker Green FM) and endoplasmic reticulum (ERTracker Blue-White DPX). It was shown that the hypericin staining pattern was different compared to the intracellular distribution of mitochondria or lysosomes. Hypericin was concentrated in the perinucleolar cytoplasmic area mainly on one side of the nucleus--the region rich in endoplasmic reticulum and Golgi. Sometimes nuclear envelope was also stained. Plasma membrane was not stained but the dye was often accumulated in the intercellular space between the tightly contacting WiDr cells in colonies. Hypericin concentrations of 10 microM or less were not toxic for WiDr cells in the dark. Orange light (lambda max approximately 600 nm; 6 mW/cm2) killed the cells stained with 1 microM hypericin with LD50 approximately 1 J/cm2.
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PMID:Intracellular localisation of hypericin in human glioblastoma and carcinoma cell lines. 1170 33

Sialyl-Tn (STn), a mucin-associated disaccharide antigen carried by apomucins such as MUC2, plays an important role in tumor biology. However, little is known about the subcellular localization and compartments involved in STn synthesis. In this study we used immunoelectron microscopy to localize STn and MUC2 apomucin in human colorectal tissues. MUC2 apomucin was localized predominantly in the rough endoplasmic reticulum (RER) in normal colorectal mucosa (n=6), colorectal adenoma (n=8), and colorectal adenocarcinoma (n=10). STn, recognized by monoclonal antibody TKH2, was not readily detectable in normal colorectal mucosa but becomes manifest in both trans-Golgi apparatus and mucin droplets in colorectal adenoma. In colorectal adenocarcinoma, STn was localized not only in late but also in early Golgi compartments, and particularly in some RER lumens. Furthermore, electron microscopic in situ hybridization revealed that gold particles representing MUC2 mRNA are primarily localized over the RER. Our findings indicate that in colorectal adenoma STn sialylation takes place in the trans-Golgi apparatus, whereas in colorectal cancer STn sialylation occurs in all the Golgi compartments and in the RER.
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PMID:Altered GalNAc-alpha-2,6-sialylation compartments for mucin-associated sialyl-Tn antigen in colorectal adenoma and adenocarcinoma. 1172 6

The feasibility of using tobacco for production of a recombinant antibody (T84.66/GS8 diabody) directed against the carcinoembryonic antigen (CEA) and used for tumor imaging was investigated. Two constructs were generated for targeting the protein either to the apoplast or to the endoplasmic reticulum. Expression of the diabody in tobacco leaves after vacuum-assisted infiltration of engineered Agrobacteria (agro-infiltration) and in regenerated transgenic tobacco plants was analyzed and compared. Results in terms of protein expression and accumulation between both systems showed a good correlation. His6-tagged T84.66 diabody was readily purified from agro-infiltrated tobacco leaves and from transgenic plants by immobilized metal ion affinity chromatography. The purified protein was analyzed by polyacrylamide gel electrophoresis, Western blot, gel filtration, electrospray mass spectrometry, direct and competition ELISA, electrophoretic mobility shift assay, and staining of CEA-positive colon adenocarcinoma cell line LS174T. Our results demonstrate that tobacco is a competent production system for this clinically relevant diabody.
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PMID:A carcinoembryonic antigen-specific diabody produced in tobacco. 1179 Jul 22

We studied apolipoprotein B100 (apoB) metabolism in a series of non-hepatic cell lines (HT29 colon adenocarcinoma, HeLa cervical epithelioid carcinoma, and 1321N1J astrocytoma human cell lines) and in the human hepatoma cell line HepG2. ApoB mRNA was detected by reverse transcription polymerase chain reaction in each non-hepatic cell line. ApoB was detected in HepG2 cells by immunoprecipitation, Western blotting, and immunocytochemistry using a polyclonal anti-human low-density lipoprotein (LDL) antibody, an anti-human apoB peptide antibody, and several monoclonal anti-apoB antibodies. ApoB was identified in the three non-hepatic cell lines by each method using the anti-apoB peptide and monoclonal antibodies, but not with the anti-LDL antibody. Immunocytochemistry indicated that epitopes of apoB were evident throughout the endoplasmic reticulum, and gel mobility of newly labeled apoB and immunoblot with anti-ubiquitin showed that apoB was highly ubiquinated in non-hepatic cells. The observations that apoB is synthesized in non-hepatic cell lines but never recognized by the anti-LDL antibody suggests that apoB is not processed into a nascent lipoprotein in these cells. Immunocytochemical localization of apoB epitopes at many locations throughout non-hepatic cells raises the exciting possibility that apoB can be used for other purposes in these cells.
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PMID:Apolipoprotein B is synthesized in selected human non-hepatic cell lines but not processed into mature lipoprotein. 1196 74

Invariant chain (Ii) has been shown to play a significant part in the assembly of MHC class II molecules. Ii also binds to MHC class I, although it is not known when this first occurs or whether it can affect class I assembly. Our examination of lysates of L(d)-transfected T2 cells showed that Ii bound intracellularly to folded, but not to open, forms of MHC class I. Furthermore, addition of peptides to the lysates dissociated Ii from the Ii-folded MHC class I complex. Thus, unlike other known chaperones, Ii associates only with folded, peptide-free class I molecules. To determine whether Ii can affect MHC class I transport and surface expression, we used both wild-type Ii and a mutant Ii that lacked the endosomal targeting sequence. Neither Ii nor Ii(Delta 20) increased the rate of MHC class I migration; however, Ii and (to a greater extent) Ii(Delta 20) increased cell surface expression of MHC class I. In HeLa cells, this effect was allele-specific, affecting HLA-A28 more than -B75. Ii also increased the surface expression of K(b) more than D(b) on Panc02 pancreatic adenocarcinoma cells. Neither form of Ii was detectable at the cell surface with MHC class I, indicating that Ii had exercised its effect on class I intracellularly. In total, these data suggest that Ii can bind peptide-free folded class I/beta(2)m heterodimers, but not open MHC class I heavy chains, in the endoplasmic reticulum, and that Ii can facilitate the surface expression of the MHC class I molecule.
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PMID:Expression of invariant chain can cause an allele-dependent increase in the surface expression of MHC class I molecules. 1203 99

We report the cytology findings of a rare case of myxoid leiomyosarcoma of the uterus with intraabdominal dissemination. The cytology showed uniformly dispersed spindly to polygonal "epithelioid" tumor cells focally linked by background matrix. Spindly tumor cells attaching to and radiating from branching capillary structures were also present. Occasionally, scattered "signet-ring" cells were found, mimicking metastatic poorly differentiated adenocarcinoma. The background mucoid substance was more conspicuous in the cell block sections. Gross and histologic examination of the surgical specimen revealed a large uterine leiomyosarcoma with prominent myxoid change. Ultrastructural study showed that the "signet-ring" appearance was mainly due to degenerative cytoplasmic change with ballooning of mitochondria, dilatation of endoplasmic reticulum, and elevation of outer nuclear membrane. In contrast to other spindle cell malignancies such as sarcomatoid mesothelioma, sarcomatoid carcinoma, or malignant melanoma, true sarcoma cells in general carry a distinctive cytologic appearance in washing/effusion fluid. In a correct clinical setting, the peculiar association with mucoid matrix and absence of classic lipoblasts should also raise the suspicion of metastatic myxoid leiomyosarcoma.
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PMID:Peritoneal washing cytology findings of disseminated myxoid leiomyosarcoma of uterus: report of a case with emphasis on possible differential diagnosis. 1267

Rab proteins are small-molecular-weight guanosine triphosphatases (GTPases) that control vesicular traffic in eukaryotic cells. The small GTPase Rab2 is a resident of pre-Golgi intermediates and is required for protein transport from the endoplasmic reticulum to the Golgi complex. We identified a novel human Rab (Rab2B) gene that was 2312 bp in length and encoded a protein of 216 amino acid residues. The protein shared high homology with mouse Rab2 (identity 83%, similarity 91%). The expression pattern of the human Rab2B gene showed that there is a transcript in kidney, prostate, lung, liver, thymus, colon, pancreas, and skeletal muscle, and low levels in placenta, whereas specific bands of the transcript could not be detected in heart, brain, spleen, testis, ovary, small intestine, and leukocyte. Overexpression has been observed in colon adenocarcinoma CX-1. The Rab2B gene consists of nine exons and eight introns and is mapped to chromosome 14q11.1-14q11.2 by bioinformatics analysis.
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PMID:Molecular cloning and characterization of a novel human Rab ( Rab2B) gene. 1237 46

Intracellular photosensitiser localisation significantly influences the mechanism of response to photodynamic therapy (PDT), since the primary sites of damage are closely related to the specific sensitiser distribution. Foscan subcellular localisation in the MCF-7 human adenocarcinoma cell line has been studied by means of confocal microscopy and microspectrofluorometry. The fluorescence topographic profiles recorded after cells costained with Foscan and organelle-specific fluorescent probes revealed that Foscan presents low localisation in lysosomes and a weak accumulation in mitochondria. Alternatively, the Foscan fluorescence topographic profile turned out to colocalise perfectly with that obtained for the endoplasmic reticulum (ER) and the Golgi apparatus. The patterns of fluorescence derived from confocal microscopy studies were consistent with predominant localisation of Foscan in these organelles. Furthermore, evaluation of enzymatic activity of selected organelles immediately after laser light irradiation (650 nm) indicated the Golgi apparatus and ER as the primary damaged sites resulting from Foscan-mediated PDT in the MCF-7 cell line. To our knowledge, this is the first study to demonstrate unambiguously that the ER and the Golgi apparatus are preferential sites of Foscan accumulation.
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PMID:Endoplasmic reticulum and Golgi apparatus are the preferential sites of Foscan localisation in cultured tumour cells. 1255 74


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