Genome-wide expression profiling of 8-chloroadenosine- and 8-chloro-cAMP-treated human neuroblastoma cells using radioactive human cDNA microarray

Previous reports raised question as to whether 8-chloro-cyclic adenosine 3,5-monophosphate (8-Cl-cAMP) is a prodrug for its metabolite, 8-Cl-adenosine which exerts growth inhibition in a broad spectrum of cancer cells. The present study was carried out to clarify overall cellular affects of 8-Cl-cAMP and 8-Cl-adenosine on SK-N-DZ human neuroblastoma cells by ystematically characterizing gene expression using radioactive human cDNA microarray. Microarray was prepared with PCR-amplified cDNA of 2,304 known genes spotted on nylon membranes, employing (1)P-labeled cDNAs of SK-N-DZ cells as a probe. the expression levels of approximately 100 cDNAs, representing about 8% of the total DNA elements on the array, were altered in 8-Cl-adenosine- or 8-Cl-cAMP-treated cells, respectively. The genome-wide expression of the two samples exhibited partial overlaps; different sets of up-regulated genes but the same set of down-regulated genes. 8-Cl-adenosine treatment up- egulated genes involved in differentiation and development (LIM protein, connexin 26, neogenin, neurofilament triplet L protein and p21( WAF1/CIP1)) and immune response such as natural killer cells protein 4, and down-regulated ones involved in proliferation and transformation (transforming growth factor-beta, DYRK2, urokinase-type plasminogen activator and proteins involved in transcription and translation) which were in close parallel with those by 8-Cl-cAMP. Our results indicated that the two drugs shared common genomic pathways for the down-regulation of certain genes, but used distinct pathways for the up-regulation of different gene clusters. Based on the findings, we suggest that the anti-cancer activity of 8-Cl-cAMP results at least in part through 8-Cl-adenosine. Thus, the systematic use of DNA arrays can provide insight into the dynamic cellular pathways involved in anticancer activities of chemotherapeutics.

Apoptosis of Surrounding Neurons by Brain tumor

BACKGROUND: As brain tumor cells are immunologically active, they release various factors like a cytokine, growth factor and express a death domain on their surfaces. Accordingly they support proliferation, vascularity, invasiveness and maintain immune privileged sites. However, the relationship between tumor cells and surrounding neuron cells have been rarely reported in tumor patients with epilepsy that inhibitory neuron cells have been lost around peritumoral sites. This study was designed to address that tumor cells directly damage neuron cells. METHODS: Using LDH assay and special stain, we investigated whether or not cultured supernatants of astrocytoma cells induce the damage of neuron cells. RESULTS: The neuron cells were killed by tumor cells supernatant and increased by pretreatment of neuron cells supernatant and lysates. Protein extracted tumor cells supernatant also damage neuron cells. It was proved by Annexin-PI stain and DNA fragmentation that neuronal death by tumor cells was apoptosis. The more malignant tumor cells, the more neuronal death was induced and the more their cytokines were expressed. In comparison with various cytokine expressions in tumor cells, it can be assumed that the released protein from tumor cells was associated with TNF (tumor necrosis factor)-alpha. CONCLUSIONS: Brain tumor cells are active processing cells that they recognize surrounding normal neuron cells, release death factors and induce apoptosis of neuron cells. Released death factors are related toTNF-alpha. (J Korean Neurol Assoc 19(3):266~277, 2001)

Cross-linking of CD4 induces cytoskeletal association of CD4 and p56lck

A membrane glycoprotein CD4 functions as a co-receptor of a T lymphocyte. The co-receptor function has been attributed to a protein tyrosine kinase, p56lck, which is activated upon CD4 binding to MHC molecule. In this study, we present evidences that one of the pathways through which CD4 transmits its signal is cytoskeleton association of p56lck tyrosine kinase as well as CD4 itself. Cytoskeletal association of both proteins is inhibited by a tyrosine kinase inhibitor, genistein, indicating that tyrosine protein kinase activation is important for cytoskeletal association of CD4 and p56lck. Cytoskeletal association of these proteins by CD4 cross-linking is not affected by inhibitors of protein kinase C nor PI3-kinase. Taken together, these results suggest that CD4 cross-linking activates a tyrosine kinase which then induces the simultaneous association of CD4 and p56lck with cytoskeleton.

Regulation of bcl-2 family in hydrogen peroxide-induced apoptosis in human leukemia HL-60 cells

Numerous types of cells have been shown to undergo apoptosis when exposed to oxidant agent such as hydrogen peroxide. In order to understand the functional relationship between the anti- and pro-apoptotic regulatory proteins in the cells under oxidant stress, we have studied the level of expression of apoptosis regulatory proteins, bcl-2 and bax, in human leukemia HL-60 cells. The exposure of HL-60 cells to different concentrations of H2O2 for 6 h resulted in a typical apoptosis of the cells as characterized by flow cytometry, cell cycle analysis, and DNA fragmantation. There was a block in G1 to S transition and apoptotic cells were mainly derived from S and G2 cells. Kinetic study demonstrated that the levels of both bcl-2-mRNA and -protein expression were decreased with the progression of cellular apoptosis whereas the level of bax-mRNA was unchanged but the expressed bax-protein was not detectable. Cycloheximide, a nonspecific translation inhibitor, did not prevent the hydrogen peroxide-mediated apoptosis in HL-60 cells. These results suggest that the regulation of bcl-2, but not of bax are important factor in the oxidative stress-induced apoptosis in HL-60 cells.

Effects of TGF-beta, GM-CSF, and PDGF on Proliferation and Expression of Cytokine and Metalloproteinase Genes in Rheumatoid Synovial Cells / 대한면역학회지

To investigate effects of cytokines on rheumatoid synovial cells, proliferation and expression of cytokine and metalloproteinase genes were studied with the primary culture of rheumatoid synovial cells which was treated with TNF-alpha, GM-CSF, TGF-alpha, PDGF and IL-B. By [3H] thymidine incorporation assay, TGF-beta and PDGF increased proliferation of synovial cells by 1.5 and 2.5 folds respectively. Cytokine gene expression was assessed by RT-PCR. Rheumatoid synovial cells expressed constitutively TGF-beta and IL-B at a high level and IL-1B, GM-CSF, and MIP-1a at a relatively low level. TGF-beta, GM-CSF and PDGF increased IL-B expression. Expression of pro-inflammatory cytokines and chemokines was increased by GM-CSF and PDGF. Both GM-CSF and PDGF increased the expression of IL-1B, GM-CSF MIP-la and IL-8. In addition, GM-CSF enhanced expression of TNF-alpha. Stromelysin and collagenase are the major proteinases responsible for destruction ot joints in rheumatoid arthritis (RA). These genes were expressed constitutivefy in rheumatoid synovial cells. In summary, PDGF and GM-CSF may piay an important role by inducing or increasing expression of IL-1B, TGF-beta and PDGF by increasing proliferation of rheumatoid synovial cells.

Heavy Chain V Regions of IgG Produced by Rheumatoid Synovial B Cells / 대한면역학회지

No abstract available.

Interleukin-4 Receptor Expression on Human Renal Cell Carcinoma Cell Lines by a Reverse Transcription-Polymerase Chain Reaction / 대한비뇨기과학회지

Recently interleukin-4 (IL-4) has been suggested to be a promising therapeutic agent for the malignant tumors of both murine and human origin. The effect of IL-4 is mediated by IL-4 receptor (IL-4R), which has been shown to be expressed in many normal and tumor cell lines. We herein tested two cell lines of human renal cell carcinoma (RCC), Caki-1 and CURC-II, for the expression of IL-1R gene. On the reverse transcription-polymerase chain reaction study, both cell lines expressed IL-4R mRNA. The present study suggests that it would be worthwhile to investigate the anti-tumor effect of IL-4 on Caki-l and CIJRC-II, which may help to develop new therapeutic strategies for RCC using IL-4.

Screening of the Cardiac Beta Myosin Heavy Chain Gene for the Linkage to Familial Hypertrophic Cardiomyopathy in a Korean Family

BACKGROUND: Through a genome-wide search using the genetic markers(RFLP genetic markers), the familial hypertrophic cardiomyopathy(FHCM) with an autosomal dominant mode of inheritance has been firstly detected to be genetically linked to chromosome 14q1. The subsequent studies have shown that the point mutations at the exons encoding for the head and head /rod junction of the cardiac beta myosin heavy chain(beta-MHC) are the most frequent type of mutation in the FHCM families genetically implicated with a linkage to beta-MHC, whereas the alpha/beta-MHC hybrid gene and a large deletion at the 3' region of beta-MHC gene were also rarely detected. With the other families genetically implicated with the chromosomes 1,11,15,16 and 18, FHCM also manifests locus heterogeneity, a phenomenon in which abnormalities at different genes are involved in different families. In addition, a korean FHCM family with 403Arg-->Gln mutation of beta-MHC gene has been previously found by an american research group. METHODS: For clinical diagnosis, echocardiography and electrocardiography were performed on the individual members of a korean FHCM family. The microsatellite markers(MYO-I,MYO-II) located in the beta-MHC gene region were amplified by PCR(polymerase chain reaction) and the polymorphism was analyzed for the possible linkage to the phenotypic expression of FHCM. Independently, the same PCR products of the exons 13 and 23 were digested with the specific restriction enzymes for the presence of the most frequently reported point mutations of beta-MHC gene (403 and 908 amino acid mutations). Single strand conformation polymorphism(SSCP) of the exon 13 and 23 of the beta-MHC gene was also analyzed of the mobility shift expected if any point mutation is present at these two exons. RESULTS: The inheritance pattern of HCM(hypertrophic cardiomyopathy) in the family is considered as autosomal dominant. In this family(KU 101), one of the microsatellite markers(MYO-II) indicated the possible cosegregation between the allele was also present in the 32-year-old brother of the proband, who reveals no clinical signs of the disease. The other microsatellite genetic marker(MYO-I) was uninformative, without giving the discriminating power to verify the linkage to beta-MHC gene. In the analysis for two common mutations of beta-MHC gene by PCR-RFLP and PCR-SSCP, no evidence was found for 403 and 908 amino acid mutations and any point mutation in the exons 13 and 23. CONCLUSIONS: Based on the linkage analysis using microsatellite genetic markers, there was a possibility that the disease could be linked to an abnormality in the beta-MHC gene of the chromosome 14q1.

Screening of the Cardiac Beta Myosin Heavy Chain Gene for the Linkage to Familial Hypertrophic Cardiomyopathy in a Korean Family

BACKGROUND: Through a genome-wide search using the genetic markers(RFLP genetic markers), the familial hypertrophic cardiomyopathy(FHCM) with an autosomal dominant mode of inheritance has been firstly detected to be genetically linked to chromosome 14q1. The subsequent studies have shown that the point mutations at the exons encoding for the head and head /rod junction of the cardiac beta myosin heavy chain(beta-MHC) are the most frequent type of mutation in the FHCM families genetically implicated with a linkage to beta-MHC, whereas the alpha/beta-MHC hybrid gene and a large deletion at the 3' region of beta-MHC gene were also rarely detected. With the other families genetically implicated with the chromosomes 1,11,15,16 and 18, FHCM also manifests locus heterogeneity, a phenomenon in which abnormalities at different genes are involved in different families. In addition, a korean FHCM family with 403Arg-->Gln mutation of beta-MHC gene has been previously found by an american research group. METHODS: For clinical diagnosis, echocardiography and electrocardiography were performed on the individual members of a korean FHCM family. The microsatellite markers(MYO-I,MYO-II) located in the beta-MHC gene region were amplified by PCR(polymerase chain reaction) and the polymorphism was analyzed for the possible linkage to the phenotypic expression of FHCM. Independently, the same PCR products of the exons 13 and 23 were digested with the specific restriction enzymes for the presence of the most frequently reported point mutations of beta-MHC gene (403 and 908 amino acid mutations). Single strand conformation polymorphism(SSCP) of the exon 13 and 23 of the beta-MHC gene was also analyzed of the mobility shift expected if any point mutation is present at these two exons. RESULTS: The inheritance pattern of HCM(hypertrophic cardiomyopathy) in the family is considered as autosomal dominant. In this family(KU 101), one of the microsatellite markers(MYO-II) indicated the possible cosegregation between the allele was also present in the 32-year-old brother of the proband, who reveals no clinical signs of the disease. The other microsatellite genetic marker(MYO-I) was uninformative, without giving the discriminating power to verify the linkage to beta-MHC gene. In the analysis for two common mutations of beta-MHC gene by PCR-RFLP and PCR-SSCP, no evidence was found for 403 and 908 amino acid mutations and any point mutation in the exons 13 and 23. CONCLUSIONS: Based on the linkage analysis using microsatellite genetic markers, there was a possibility that the disease could be linked to an abnormality in the beta-MHC gene of the chromosome 14q1.