Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “CK2”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 919 records · Page 51Linked to original sources
PubMed2003

Genomic organization of the rDNA cistron of the teleost fish Cyprinus carpio.

The seasonal adaptation of the teleost Cyprinus carpio to the cyclical changes of its habitat demands physiological compensatory responses. The process involves profound nucleolar adjustments and remarkable changes in rRNA synthesis, which affects ribosomal biosynthesis. In this context, we have demonstrated that the synthesis of several proteins involved in ribosomal biogenesis as protein kinase CK2, ribosomal protein L41 and nucleolin, as well as U3 snoRNP, are differentially regulated in summer-acclimatized carp compared to the cold-season adapted fish. To understand the mechanisms involved in the seasonal regulation of rRNA gene transcription, we have been studying the carp rDNA cistron structure. Because the cis-elements that regulate the expression of the tandem organized ribosomal genes are located in the non-transcribed intergenic spacer (IGS), we analyzed the primary structure of the carp rDNA gene IGS. The gene organization is similar to that described from other vertebrate species, including numerous repetitive sequences, the transcription start site, and some potential cis-elements such as ribosomal enhancers, proximal terminator and transcriptional terminators. Ribosomal DNA is a remarkable case of gene duplication and has been used as a model to test the concerted evolution theory. We performed sequence comparison analyses of 18S rRNA coding sequences from carp with different species, data with which an unrooted phylogram was constructed.

Animals↗
PubMed2003

Divalent cation hinder the solubilization of a tubulin kinase activity from Trypanosoma cruzi epimastigotes.

Trypanosoma cruzi epimastigotes were extracted under various conditions in order to examine the role of divalent cations in the solubilization of microtubule proteins. When epimastigotes were homogenized in the presence of 5 mM Mg+2 and 5 mM Ca+2, a protein kinase responsible for phosphorylating tubulin, as well as the tubulin that became phosphorylated, remained tightly associated with the parasite particulate and detergent-resistant fractions. On the contrary, tubulin kinase and its substrate were predominantly released into the parasite cytosolic and detergent-soluble fractions, when epimastigotes were extracted in the presence of 5 mM EDTA and 5 mM EGTA. These evidences demonstrated a divalent cation-dependent solubilization of the enzyme responsible for the phosphorylation of tubulin in T. cruzi epimastigotes and suggested a tight association between tubulin and this kinase. Under all conditions tested, tubulin kinase activity in epimastigote extracts was lower than the addition of the corresponding value in the parasite cytosolic and membranous fractions, suggesting the presence of a kinase inhibitor or regulatory subunit which also seemed to be modulated by divalent cations. Additionally, inhibition experiments in the presence of heparin, 2,3-bisphosphoglycerate and GTP established that the parasite tubulin kinase corresponded to a protein kinase CK2.

Animals↗
PubMed1999

Hepatic carcinoma with spleen metastasis in a California sea lion from the Gulf of California.

A primary hepatic carcinoma with a neuroendocrine pattern was detected in an adult female California sea lion (Zalophus californianus) found dead on Granito Island in the Gulf of California (Mexico) in January 1996. At necropsy, several light yellow nodules of different sizes were observed on the entire surface of the liver and spleen. Microscopic examination of these nodules using routine haematoxylin-eosin stain, revealed cubic, polyhedral and pleomorphic cells with three to four bizarre mitotic figures per field (40X). An immunohistochemistry test revealed a positive reaction of indirect immunoperoxide to cytokeratin (CK2). This is the first known case of a primary hepatic carcinoma in free-ranging California sea lions from Mexican waters.

Animals↗
PubMed1999

Interactions of protein kinase CK2beta subunit within the holoenzyme and with other proteins.

Protein kinase CK2 is a ubiquitous, highly conserved protein kinase with a tetrameric alpha2beta2 structure. For the formation of this tetrameric complex a beta-alpha dimer seems to be a prerequisite. Using the two-hybrid system and a series of CK2beta deletion mutants, we mapped domains involved in alpha-beta and beta-beta interactions. We also detected an intramolecular beta interaction within the amino acid stretch 132-165. Using CK2beta as a bait in a two-hybrid library screening several new putative cellular partners have been identified, among them the S6 kinase p90rsk, the putative tumor suppressor protein Doc-1, the Fas-associated protein FAF1, the mitochondrial translational initiation factor 2 and propionyl CoA carboxylase beta subunit.

Casein Kinase II↗
PubMed1999

[The clinical importance of keratin 18 in breast cancer].

OBJECTIVE: This study was performed to determine the prognostic significance and the biological function of the structure protein keratin 18 (K18) in a group of patients with breast cancer. MATERIAL AND METHODS: Paraffin sections from the primary tumors in 80 patients with breast cancer were examined for the expression of K18 by immunohistochemical staining with the monoclonal antibody CK2. The intensity of the expression measured by an immune reactive score (IRS) was compared with clinicopathological variables and follow-up data up to 10 years. Additionally K18 expression in different human breast cancer cell lines with well defined metastatic behavior were investigated to confirm the clinical data. RESULTS: A marked positive staining was observed in 13 (16.2%) women. Mortality rate in this group was 7.7% and 46.3% in the group with a low K18 expression. The recurrence rate was with 15.4% significantly lower in the positive group than in the negative group with 56.7%. Irrespective of the morphological tumor stage, almost all patients with strong K18 expression were still free of disease after 10 years. This clinical finding is supported by observations in cell cultures. CONCLUSIONS: In our collective K18 expression was found to be an independent and significant predictor for disease-free and overall survival.

Adult↗
PubMed2000

[Differences in phorbol-dependent phosphorylation of regulatory proteins and contraction of phasic and tonic smooth muscle].

Smooth muscles are divided into slowly contracting tonic and relatively fast phasic muscles. In both cases Ca2+ is a key mediator of the contractile response. However, the appearance of a tonic component during sphincter or arterial muscle contraction and its absence in contracting visceral smooth muscle is characteristic of their difference. We have found that in chicken tissues phorbol 12,13-dibutyrate (PDBu) induces a sustained contraction in carotid arterial muscle, but provokes no contraction in phasic gizzard smooth muscle. Next we were aimed to find differences in PDBu-induced phosphorylation of the key proteins involved in regulation of smooth muscle contraction, i.e. caldesmon, myosin light chain kinase (MLCK), and the myosin light chain kinase-related protein (KRP, also known as telokin). Two correlative differences were observed. 1. PDBu stimulated phosphorylation of MLCK in tonic smooth muscle and had no effect on the level of MLCK phosphorylation in phasic muscle. Phosphopeptide mapping suggests the involvement of mitogen-activated protein (MAP) kinases in phosphorylation of MLCK in situ. 2. PDBu induced phosphorylation of MAP-kinase sites in caldesmon in both types of smooth muscle, but this phosphorylation had no significant effect on caldesmon functional activity in vitro. For the first time we have shown that in gizzard PDBu also stimulates a yet unknown transitory caldesmon-kinase different from protein kinase, C, Ca2+/calmodulin-dependent kinase II and casein kinase CK2. 3. No significant difference was found in the kinetics of PDBu-dependent phosphorylation of KRP in tonic and phasic smooth muscles. KRP was also demonstrated to be a major phosphoprotein in smooth muscle phosphorylated in vivo at several sites located within its N-terminal sequence. Protein kinases able to phosphorylate these sites were identified in vitro. Among them, MAP-kinase was suggested to phosphorylate a serine residue homologous to that phosphorylated in MLCK. 4. p42erk2 and p38 MAP-kinases were found in phasic and tonic smooth muscles. Both were responsive to PDBu in cultured chicken aortic smooth muscle cells, and their role in phosphorylation of MLCK and low molecular weight isoform of caldesmon was evaluated.

Amino Acid Sequence↗
PubMedDate not supplied

Identification of avian infectious bronchitis virus by direct automated cycle sequencing of the S-1 gene.

Direct automated cycle sequencing (DACS) of a reverse transcription-polymerase chain reaction (RT-PCR) product of the S-1 subunit of the spike peplomer gene was used to identify infectious bronchitis virus (IBV) serotypes. Degenerate primers CK4 and CK2, utilized previously in our laboratory, were selected for DACS because they successfully amplify a wide range of serotypes represented by various reference strains and field isolates and the resulting polymerase chain reaction (PCR) product contains diagnostically relevant S-1 sequences that can be used to identify the serotype of IBV. The S-1 nucleotide sequences generated by DACS were aligned and analyzed with commercial software to determine their relationship to the S-1 nucleotide sequences of IBV strains on deposit in the GenBank and EMBL databases. Reference strains Massachusetts (Mass) 41, Connecticut (Conn), Arkansas (Ark) DPI, JMK, and DE/072/92 were initially tested by DACS to establish the feasibility of the procedure. The DACS procedure was further evaluated with a panel of "unknowns" comprised of IBV reference strains, field isolates, and variant serotypes collected by our laboratory. The DACS procedure provided high-quality and reproducible S-1 sequence for all IBV serotypes tested, including variant serotypes that had not been sequenced previously. The S-1 nucleotide sequences for the amplified PCR products of reference strains Mass 41, Conn, Ark DPI, JMK, and DE/072/92 generated by DACS were highly homologous (>99% nucleotide identity) with their respective GenBank database sequences. In the unknown panel, the nucleotide identities of the DACS S-1 sequences of field isolates of serotypes previously identified by virus neutralization were also found to be very high (> or = 95.5%) after alignment with database sequences. In contrast, the nucleotide identities of S-1 sequences of variant serotypes 37, 3330, and PA/1220/98 and reference strain Clark 333, for which database sequences were not available, ranged from 27.7% to 73.8%, well below the identity values for a homologous serotype. With alignment software, the identities of strains in mixtures of RNAs of two different serotypes were not resolvable. DACS of IBV S-1 RT-PCR products will enable researchers to rapidly identify field strains, including new, previously unrecognized variant virus serotypes.

Amino Acid Sequence↗
PubMed2000

Synergistic activation of stress-activated protein kinase 1/c-Jun N-terminal kinase (SAPK1/JNK) isoforms by mitogen-activated protein kinase kinase 4 (MKK4) and MKK7.

Stress-activated protein kinase 1 (SAPK1), also called c-Jun N-terminal kinase (JNK), becomes activated in vivo in response to pro-inflammatory cytokines or cellular stresses. Its full activation requires the phosphorylation of a threonine and a tyrosine residue in a Thr-Pro-Tyr motif, which can be catalysed by the protein kinases mitogen-activated protein kinase kinase (MKK)4 and MKK7. Here we report that MKK4 shows a striking preference for the tyrosine residue (Tyr-185), and MKK7 a striking preference for the threonine residue (Thr-183) in three SAPK1/JNK1 isoforms tested (JNK1 alpha 1, JNK2 alpha 2 and JNK3 alpha 1). For this reason, MKK4 and MKK7 together produce a synergistic increase in the activity of each SAPK1/JNK isoform in vitro. The MKK7 beta variant, which is several hundred-fold more efficient in activating all three SAPK1/JNK isoforms than is MKK7 alpha', is equally specific for Thr-183. MKK7 also phosphorylates JNK2 alpha 2 at Thr-404 and Ser-407 in vitro, Ser-407 being phosphorylated much more rapidly than Thr-183 in vitro. Thr-404/Ser-407 are phosphorylated in unstimulated human KB cells and HEK-293 cells, and phosphorylation is increased in response to an osmotic stress (0.5 M sorbitol). However, in contrast with Thr-183 and Tyr-185, the phosphorylation of Thr-404 and Ser-407 is not increased in response to other agonists that activate MKK7 and SAPK1/JNK, suggesting that phosphorylation of these residues is catalysed by another protein kinase, such as CK2, which also phosphorylates Thr-404 and Ser-407 in vitro. MKK3, MKK4 and MKK6 all show a strong preference for phosphorylation of the tyrosine residue of the Thr-Gly-Tyr motifs in their known substrates SAPK2a/p38, SAPK3/p38 gamma and SAPK4/p38 delta. MKK7 also phosphorylates SAPK2a/p38 at a low rate (but not SAPK3/p38 gamma or SAPK4/p38 delta), and phosphorylation occurs exclusively at the tyrosine residue, demonstrating that MKK7 is intrinsically a 'dual-specific' protein kinase.

Animals↗
PubMed2000

Molecular cloning and functional characterization of inhibitor-sensitive (mENT1) and inhibitor-resistant (mENT2) equilibrative nucleoside transporters from mouse brain.

Mammalian cells express at least two subtypes of equilibrative nucleoside transporters, i.e. ENT1 and ENT2, which can be distinguished functionally by their sensitivity and resistance respectively to inhibition by nitrobenzylthioinosine. The ENT1 transporters exhibit distinctive species differences in their sensitivities to inhibition by dipyridamole, dilazep and draflazine (human>mouse>rat). A comparison of the ENT1 structures in the three species would facilitate the identification of the regions involved in the actions of these cardioprotective agents. We now report the molecular cloning and functional expression of the murine (m)ENT1 and mENT2 transporters. mENT1 and mENT2 encode proteins containing 458 and 456 residues respectively, with a predicted 11-transmembrane-domain topology. mENT1 has 88% and 78% amino acid identity with rat ENT1 and human ENT1 respectively; mENT2 is more highly conserved, with 94% and 88% identity with rat ENT2 and human ENT2 respectively. We have also isolated two additional distinct cDNAs that encode proteins similar to mENT1; these probably represent distinct mENT1 isoforms or alternative splicing products. One cDNA encodes a protein with two additional amino acids (designated mENT1b) that adds a potential protein kinase CK2 phosphorylation site in the central intracellular loop of the transporter, and is similar, in this regard, to the human and rat ENT1 orthologues. The other cDNA has a 5'-untranslated region sequence that is distinct from that of full-length mENT1. Microinjection of mENT1, mENT1b or mENT2 cRNA into Xenopus oocytes resulted in enhanced uptake of [(3)H]uridine by the oocytes relative to that seen in water-injected controls. mENT1-mediated, but not mENT2-mediated, [(3)H]uridine uptake was inhibited by nitrobenzylthioinosine and dilazep. Dipyridamole inhibited both mENT1 and mENT2, but was significantly more effective against mENT1. Adenosine inhibited both systems with a similar potency, as did a range of other purine and pyrimidine nucleosides. These results are compatible with the known characteristics of the native mENT1 and mENT2 transporters.

5' Untranslated Regions↗
PubMed2000

Diazenes as modificators of drug-resistance in tumor cells.

To overcome the drug resistance, which is the major obstacle in the successful treatment of cancer patients, various compounds have been tested. Glutathione is one of the most promising targets for modulation. In the present study, we examined the influence of five new synthesized compounds--diazenes on the reduction of the intracellular level of GSH. Further, we investigated their ability to increase the cytotoxicity of cisplatin, vincristine and doxorubicin. In experiments human parental cervical (HeLa) and laryngeal (HEp2) carcinoma cells and their drug-resistant cell sublines (HeLaCA and CK2, respectively) were used. Intracellular GSH content was examined spectrophotometrically by the procedure developed by Tietze. The cell sensitivity to drugs was determined using a modified colorimetric MTT assay. Results showed that the rate of reduction of GSH concentration was dependent on the cell type and the type of diazenes. We did not find a correlation between the reduction in GSH level and increased cytotoxicity to selected anticancer drugs. Nevertheless, we found that: a) diazenes LV-35 and VZ-19 increased the cytotoxicity of cisplatin in HEp2 cells, b) diazene MG-19 potentiated the cytotoxicity of vincristine in HEp2 cells, and c) diazene VZ-19 in HeLaCA cells. These data suggest that specific combination of diazene and anticancer drug may be useful in the treatment of certain tumor types.

Antineoplastic Agents↗
PubMed2001

The genomic structure of two protein kinase CK2alpha genes of Xenopus laevis and features of the putative promoter region.

Protein kinase CK2 is an enzyme that is ubiquitous in eukaryotes. This enzyme, composed of catalytic (alpha and alpha') and regulatory (beta) subunits, is responsible for the phosphorylation of a large number of proteins and is implicated in cell division. Genomic clones coding for the CK2alpha subunit of Xenopus laevis have been isolated. Initial restriction enzyme profiles and subsequent PCR analysis and DNA sequencing indicated that these genomic clones correspond to two different genes. The two genes are highly homologous in the regions of the coding sequence (only 3 amino acid differences) but differ considerable in their intron sequences and lengths. Gene 1 corresponds to the cDNA of XlCK2alpha which had been previously isolated and described. The genomic clone for this gene was truncated. Gene 2 contains the entire coding region for CK2alpha subunit as well as a fragment of 6.4 kb of the 5' upstream region. The exon/intron boundaries of both genes obey the GT/AG rule with the exception of intron V where the less common GC/AG is seen. Comparison of the size of ten coding exons and sites where these are interrupted by introns shows strong conservation with respect to the human CK2alpha gene. RT-PCR analysis of mRNAs from X. laevis ovary, oocytes and early embryos using a specific primer for gene 2 demonstrated that this gene is expressed in these tissues and cells. Analysis of transcription start sites using 5'RACE and RNA from stage VI oocytes demonstrated that there are multiple start sites in the XlCK2alpha mRNA. It was also seen that a noncoding exon 1 is present 4 kb upstream of the translation start site and that alternate splicing occurs in gene 2 to give exon 1 of different lengths. Sequencing of the entire upstream genomic region of gene 2 revealed that there are regions of homology to the sequence of exon 1 of the human CK2alpha gene. Other sequences with consensus to transcription factor binding sites that are seen in the promoter region of human CK2alpha are also found in the X. laevis CK2alpha gene 2. These sites include Ets1, E2F, CCAAT and GC rich regions. No canonical TATA motif is observed.

Amino Acid Motifs↗
PubMed2002

[Molecular evolution of tandem heterochromatic repeats in connection with their function in the genome of Drosophila melanogaster].

Molecular evolution and divergence of paralogous tandem heterochromatic repeats Stellate and Su(Ste) located on the X and Y chromosomes, respectively, are discussed. These repeats appear to emerge as a result of amplification of a unique autosomal euchromatic gene encoding the regulatory beta-subunit of the CK2 protein kinase. The autosomal gene and the clusters of heterochromatic repeats are transcribed in testes. A high level of the Stellate expression leads to partial male sterility and disturbed meiosis. The Stellate expression and its adverse effects are suppressed by homologous Su(Ste) repeats. In genome evolution, the open reading frames (ORF) of Stellate and Su(Ste) putative ancestor were maintained by translational selection. Then the coding Su(Ste) function had been damaged and switched to a new one related to antisense Su(Ste) transcription and suppression of the Stellate genes. Symmetrical (sense and antisense) Su(Ste) transcription causes the formation of a double-strand RNA, which by interference (selective switching off the homologous gene expression) suppresses the Stellate genes. The biological significance and the driving forces of evolution of the species-specific balanced interaction of Stellate and Su(Ste) repeats remain mysterious.

Amino Acid Sequence↗
PubMed2003

[Effect of emodin and apigenin on invasion of human ovarian carcinoma HO-8910PM cells in vitro].

BACKGROUND & OBJECTIVE: Emodin inhibited the activity of TPK and CK2 and the degradation of I-kappaB. Apigenin inhibited the activity of MAPK and PI(3)K. In this study the authors observed the effect of emodin and apigenin on the invasion of HO-8910PM cells in vitro. METHODS: Trypan blue dye exclusion assay was used to examine the cytotoxity of emodin and apigenin. Reconstituted basement membrane invasion assay was utilized to evaluate the invasive activity. Type IV collagenase production was analyzed by PAGE substrate zymography. RESULTS: Emodin had weaker cytotoxity on HO-8910PM cells than apigenin, their IC(50) after treatment with the chemicals for 48 hours were (35.30+/-3.50) micromol/L, and (28.92+/-2.60)micromol/L, while emodin significantly inhibited membrane invasion and adhesion and migration of HO-8910PM cells. Their inhibition rates after treated with the chemical of 40 micromol/L were (45.31+/-3.10)%,(25.42+/-1.70)%, and (41.59+/-1.90)%. Emodin inhibited the production but not activity of MMP-9. Apigenin inhibited migration and adhesion of HO-8910PM cells, their inhibition rates after treated with the chemical of 40 micromol/L were (29.04+/-1.70)% and (30.80+/-3.00)%, while weakly inhibited membrane invasion (the inhibition rate only was 12.1%) and inhibited neither production nor activity of MMP-9. CONCLUSION: Both emodin and apigenin had cytotoxicity on HO-8910PM cells. Emodin was a potential agent inhibiting tumor invasion and metastasis.

Antineoplastic Agents↗
PubMed2005

[Effects of organic manures on CO2 and CH4 fluxes of farmland].

This paper studied the effects of chicken manure, swine waste and cattle manure on the CO2 and CH4 fluxes of a farmland planted with summer maize. The results showed that the CO2 flux had the same trend under different organic manure application, which was influenced by soil temperature and soil water content. The flux was significantly related with air temperature, soil surface temperature and soil temperature (P < 0.05). When soil temperature was not a limiting factor, soil water content was significantly related with soil CO2 flux. At most maize growth stages, soil was a sink of CH4. The variation of CH4 source-sink was influenced by environmental factors, but the correlation was not significant. The mean seasonal flux of CO2 was from 0.5124 to 0.8518 g x m(-2) x h(-1), and that of CH4 was from - 0.0068 to - 0.0484 mg x m(-2) x h(-1). Compared with CK2, maize planting and organic manure application enhanced CO2 emission. The application of organic manures inhibited the CH4 uptake by soil, and higher application rate had a higher inhibitory effect.

Animals↗
PubMed1991

Tax responsiveness of the GM-CSF promoter is mediated by mitogen-inducible sequences other than kappa B.

The mechanism by which the human T-cell leukemia viruses type I and II (HTLV-I and -II) transform T cells is unknown, but the nonstructural Tax protein that these viruses produce is known to be essential for viral replication and to have the capacity to trans-activate cellular gene expression. The HTLV-I and -II Tax proteins have been shown to activate the promoter of both the human and mouse granulocyte-macrophage colony-stimulating factor (GM-CSF) genes in mature T-cell lines. T-cell-specific Tax-responsive sequences were previously localized to the 90-bp region extending from base pairs -53 to +37 in the human GM-CSF promoter. In this study, a series of site-directed and deletion mutations were created in the human GM-CSF promoter, which was linked to the chloramphenicol acetyltransferase (CAT) gene, and the constructs were assayed for their response to Tax by using a Tax-expressing plasmid in transient cotransfection assays. The results demonstrated that both copies of the repeated sequence CATTA (A/T), located between base pairs -48 and -36, are required for Tax responsiveness in T cells and that these sequences bind nuclear factors present in T cells. The Tax-responsiveness of other sequences located 5' of base pair -53 was also examined, including an NF-kappa B consensus sequence and the CK1, CK2, and GC-rich regions identified in both the mouse and human GM-CSF promoters. These sequences did not have Tax-responsive regulatory activity when they were examined in the context of the intact human GM-CSF promoter in T cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Frequent down-regulation of major histocompatibility class I antigen expression on individual micrometastatic carcinoma cells.

An astoundingly high frequency of micrometastatic cells have been found in bone marrow aspirates of patients with colon carcinomas (G. Schlimok et al., J. Clin. Oncol., 8:831-837, 1990), although these tumors very rarely metastasize to the skeleton. This observation has raised questions about the malignant potential of such cells. In a first attempt to characterize this potential, we have assessed the expression of major histocompatibility complex (MHC) class I antigens on bone marrow micrometastases, inasmuch as down-regulation of these molecules is a potential mechanism to escape from MHC class I-restricted lysis by cytotoxic T-cells. The two groups of cancer patients compared were those with tumors known to rarely (stomach and colon cancer) or frequently (breast cancer) manifest skeleton metastases. Bone marrow aspirates taken from these patients were probed for individual disseminated tumor cells using the immunoalkaline phosphatase technique with monoclonal antibody CK2 to the epithelial differentiation antigen cytokeratin 18 (CK-18), as described previously (G. Schlimok et al., Proc. Natl. Acad. Sci. USA, 84:8672-8676, 1987). Specimens containing CK18-positive cells were colabeled with monoclonal antibody W6/32 directed to a framework (or nonpolymorphic) antigenic determinant of MHC class I heavy chains associated with beta 2-microglobulin. W6/32-positive CK-18-positive cells could be detected in 25 of 54 patients (46.3%) with significantly higher incidences in 26 breast cancer patients (61.9%) as compared to 28 patients with carcinomas of the stomach and colon (27.3 and 29.4%). Independent from the origin of the primary carcinoma, the incidence of W6/32-negative CK18-positive cells was positively correlated to both the differentiation grade of the primary tumor (P less than 0.05) and appeared to be linked to the occurrence of regional lymph node metastases (statistically not significant) determined by conventional histological examination. The present results demonstrate for the first time that down-regulation of MHC expression on individual micrometastatic cells correlates to the differential pattern of metastasis obtained by comparing breast and gastrointestinal carcinomas. This finding together with the suggestive link to clinical risk factors supports the significance of reduced MHC class I expression for the survival of residual metastatic cells which is a major determinant of prognosis for patients with solid tumors.

Adenocarcinoma↗
PubMed1986

Differential diagnosis of gastrointestinal carcinomas by using monoclonal antibodies specific for individual keratin polypeptides.

Monoclonal antibodies which recognize particular keratin polypeptides have been used to analyze normal human tissues including pancreas, stomach, colon, gall bladder, and liver as well as tumors of the gastrointestinal tract by immunohistological techniques. Broad specificity (lu5), ker 8 (Troma 1) and ker 18 (CK2) antibodies were positive while a ker 14 specific antibody (CKB1) was negative on all specimens tested. Differential staining patterns were seen with a ker 7 (CK7) and a ker 19 (KA4) antibody. Both antibodies stained gall bladder epithelium, pancreatic ducts but not acinar cells, as well as pancreatic ductal adenocarcinomas. KA4 but not the CK7 antibody stained adenocarcinomas of the stomach and large bowel. Both antibodies stained bile ducts and cholangiocellular carcinoma of the liver but did not stain hepatocytes or hepatocellular carcinomas. The results with keratin monoclonal antibodies compare well with those obtained by others using two dimensional gel electrophoresis and they further support the idea that monoclonal antibodies specific for particular keratin polypeptides will find applications in routine pathological diagnosis.

Antibodies, Monoclonal↗
PubMed1989

[Bone marrow micrometastases in colorectal cancers].

To date, the detection of individual micrometastases or disseminated tumor cells has not been possible with conventional diagnostic procedures. With the aid of new immunocytochemical investigation, however, histogenetically different cells can now be detected in the bone marrow. The monoclonal antibody, cytokeratin component 18, is most suitable for the detection of micrometastases from colorectal carcinoma. In 22 out of 82 patients with colorectal carcinoma, we were able to detect CK2-positive cells. The incidence of these "micrometastases" is represented as a function of primary tumor size, lymph node involvement, distant metastasis, and degree of malignancy of the tumor, age and sex of the patient, and tumor localization.

Adult↗