451
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Gong Y, Owens DW, Weaver JH. Etching of double-height-stepped Si(100)-2 x 1: Steps and their interactions. Phys Rev B Condens Matter 1996; 53:R16144-R16147. [PMID: 9983518 DOI: 10.1103/physrevb.53.r16144] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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452
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Li XM, Salido EC, Gong Y, Kitada K, Serikawa T, Yen PH, Shapiro LJ. Cloning of the rat steroid sulfatase gene (Sts), a non-pseudoautosomal X-linked gene that undergoes X inactivation. Mamm Genome 1996; 7:420-4. [PMID: 8662223 DOI: 10.1007/s003359900125] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Although the human steroid sulfatase (STS) gene has been cloned and characterized in detail, several attempts to clone its mouse homologue, with either anti-human STS antibodies or human STS cDNA probes, have failed, suggesting a substantial divergence between these genes. However, partial amino-terminal sequence from purified rat liver STS is very similar to its human counterpart, and sequence comparisons have revealed several domains that are conserved among all the sulfatases characterized to date. Thus, we used a degenerate-primer RT-PCR approach to amplify a 321-bp fragment from rat liver cDNA, which was used as a probe to clone and characterize the complete cDNA. Comparison of the protein coding region between the rat and human genes showed 66% homology both at the DNA and the protein levels. STS activity was conferred to STS(-) A9 cells upon transfection with a rat Sts expression construct, indicating the authenticity of the cloned cDNA. While Sts has been shown to be located in the mouse pseudoautosomal region, both physical and genetic mapping demonstrate that Sts is not pseudoautosomal in the rat. The overall genomic organization of rat Sts and human STS is very similar, except that the insertion site for intron 1 in the rat is 26 bp upstream from that in the human. Rat Sts is only 8.2 kb long, while the human STS spans over 146 kb.
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Affiliation(s)
- X M Li
- UCSF School of Medicine, Department of Pediatrics 94143, USA
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453
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Abstract
The gene responsible for transcribing glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is commonly used as a reporter gene to estimate the amount of RNA present in Northern analyses. However, recent data suggest that GAPDH gene expression may vary with the extent of cell proliferation and differentiation. 28S-ribosomal RNA (28S-rRNA) has also been employed to normalize Northern blots prepared with total RNA. In the present study, we compared the expression of GAPDH messenger RNA (mRNA) with 28S-rRNA by Northern blot analyses in human hepatocellular carcinoma tissues (HCC) and adjacent non-HCC tissues from eight patients with chronic viral hepatitis-induced cirrhosis and normal liver tissue from eight healthy control subjects. The results of the study revealed that GAPDH mRNA levels in HCC were significantly higher (14X-16x) than those in adjacent non-HCC and normal liver tissues. Conversely, 28S-rRNA levels did not vary among HCC, adjacent non-HCC, and normal liver tissues. We also demonstrated that the 28S-RNA signal was proportional to the amount of RNA loaded. These findings indicate that 28S-rRNA, rather than GAPDH mRNA, should be used as RNA loading controls for Northern blot analyses involving HCC and nontumor tissues. The findings also raise the possibility that GAPDH mRNA gene expression might serve as a diagnostic indicator for human HCC.
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Affiliation(s)
- Y Gong
- Liver Diseases Unit, Department of Medicine, University of Manitoba, Winnipeg, Canada
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454
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Li XM, Alperin ES, Salido E, Gong Y, Yen P, Shapiro LJ. Characterization of the promoter region of human steroid sulfatase: a gene which escapes X inactivation. Somat Cell Mol Genet 1996; 22:105-17. [PMID: 8782490 DOI: 10.1007/bf02369901] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The human X-linked steroid sulfatase gene (STS) was among the first genes shown to escape X inactivation. At least fourteen genes regulated in this fashion have now been recognized. They are dispersed into several regions of the X chromosome and may be controlled in a locus specific manner. Studies of the promoters of these genes could provide insights into the mechanism of X inactivation, however little information of this nature is currently available. For this reason we examined 5' flanking sequences of the human STS gene for promoter function. Four transcription start sites scattered over a 50bp region were identified. Functional domains of this TATA-less and GC poor promoter were identified by study of a series of terminal and internal deletions. A putative promoter sequence was identified which by itself exhibits little or no basal activity. However when combined with upstream regulatory elements, this segment showed weak but reproducible activity in a CAT (chloramphenicol acetyltransferase) reporter assay. Several regulatory domains acting as enhancers and repressors were subsequently identified. The relationship of this 5' sequence to the ability of the STS gene to escape X-inactivation is discussed.
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Affiliation(s)
- X M Li
- Department of Pediatrics, University of California San Francisco 94143, USA
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455
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Liu J, Prakash O, Cai M, Gong Y, Huang Y, Wen L, Wen JJ, Huang JK, Krishnamoorthi R. Solution structure and backbone dynamics of recombinant Cucurbita maxima trypsin inhibitor-V determined by NMR spectroscopy. Biochemistry 1996; 35:1516-24. [PMID: 8634282 DOI: 10.1021/bi952466d] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The solution structure of recombinant Cucurbita maxima trypsin inhibitor-V (rCMTI-V), whose N-terminal is unacetylated and carries an extra glycine residue, was determined by means of two-dimensional (2D) homo and 3D hetero NMR experiments in combination with a distance geometry and simulated annealing algorithm. A total of 927 interproton distances and 123 torsion angle constraints were utilized to generate 18 structures. The root mean squared deviation (RMSD) of the mean structure is 0.53 A for main-chain atoms and 0.95 A for all the non-hydrogen atoms of residues 3-40 and 49-67. The average structure of rCMTI-V is found to be almost the same as that of the native protein [Cai, M., Gong, Y., Kao, J.-L., & Krishnamoorthi, R. (1995) Biochemistry 34, 5201-5211]. The backbone dynamics of uniformly 15N-labeled rCMTI-V were characterized by 2D 1H-15N NMR methods. 15N spin-lattice and spin-spin relaxation rate constants (R1 and R2, respectively) and [1H]-15N steady-state heteronuclear Overhauser effect enhancements were measured for the peptide NH units and, using the model-free formalism [Lipari, G., & Szabo, A. (1982) J. Am. Chem. Soc. 104, 4546-4559, 4559-4570], the following parameters were determined: overall tumbling correlation time for the protein molecule (tau m), generalized order parameters for the individual N-H vectors (S2), effective correlation times for their internal motions (tau e), and terms to account for motions on a slower time scale (second) due to chemical exchange and/or conformational averaging (R(ex)). Most of the backbone NH groups of rCMTI-V are found to be highly constrained ((S2) = 0.83) with the exception of those in the binding loop (residues 41-48, (S2) = 0.71) and the N-terminal region ((S2) = 0.73). Main-chain atoms in these regions show large RMSD values in the average NMR structure. Residues involved in turns also appear to have more mobility ((S2) = 0.80). Dynamical properties of rCMTI-V were compared with those of two other inhibitors of the potato I family--eglin c [Peng, J. W., & Wagner, G. (1992) Biochemistry 31, 8571-8586] and barley chymotrypsin inhibitor 2 [CI-2; Shaw, G. L., Davis, B., Keeler, J., & Fersht, A. R. (1995) Biochemistry 34, 2225-2233]. The Cys3-Cys48 linkage found only in rCMTI-V appears to somewhat reduce the N-terminal flexibility; likewise, the C-terminal of rCMTI-V, being part of a beta-sheet, appears to be more rigid.
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Affiliation(s)
- J Liu
- Department of Biochemistry, Kansas State University, Manhattan 66506, USA
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456
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Xue Q, Gong Y, Drake DL, Qian J, Coleman RV. Impurity-induced modulations in PdxNbSe3 coupled to charge-density-wave formation. Phys Rev B Condens Matter 1996; 53:1068-1071. [PMID: 9983557 DOI: 10.1103/physrevb.53.1068] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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457
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Guo R, Zhang L, Gong Y, Zhang B. The treatment of pain in bone metastasis of cancer with the analgesic decoction of cancer and the acupoint therapeutic apparatus. J TRADIT CHIN MED 1995; 15:262-4. [PMID: 8709605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The pain in 286 cases of bone metastasis of cancer was treated with an analgesic decoction of herbal drugs in combination with the Acupoint Therapeutic Apparatus that generated low frequency electric impulses into the acupoints. This series of patients comprised 104 cases of medium pain and 182 cases of severe pain, which was practically or completely relieved in 17 or 29 minutes respectively after the treatment; the total effective rate was 74.2% for 212 cases, and the duration of analgesic effect lasted 2.7 hours to 5.2 hours, averaging 3.6 hours. The cases that needed considerable dosages of analgesic tablets or sedatives markedly reduced their requests of such drugs. Determination of bone marrow stem cells indicated that the herbal treatment produced effects of promoting and protecting the stem cells. The rate of lymphocyte transformation was 45-76% before the treatment and rose to 57-96% after the treatment, demonstrating an increase of 15.2%, which was statistically significant (P < 0.001). The analgesic effect of the decoction was not correlated to the age and sex of the patients or the variety of cancer, except that it was not effective for uterine carcinoma. The main side effects included nausea, vomiting, somnolence, and numbness of the tongue.
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Affiliation(s)
- R Guo
- 28 PLA Hospital, Baoji, Shaanxi Province
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458
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Brewton RG, Wood BM, Ren ZX, Gong Y, Tiller GE, Warman ML, Lee B, Horton WA, Olsen BR, Baker JR. Molecular cloning of the alpha 3 chain of human type IX collagen: linkage of the gene COL9A3 to chromosome 20q13.3. Genomics 1995; 30:329-36. [PMID: 8586434 DOI: 10.1006/geno.1995.9870] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Type IX collagen is composed of three polypeptides derived from the human genes COL9A1, COL9A2, and COL9A3 that assemble to form a mature collagen molecule with the structure alpha 1(IX)alpha 2(IX)alpha 3(IX). We have identified overlapping cDNA and genomic clones that encode for the entire alpha 3 chain of human type IX collagen. Tryptic peptides from the human alpha 3(IX) collagen chain were subjected to N-terminal amino acid sequencing, and a stretch of 124 contiguous amino acids that included the NC1, COL1, and NC2 domains was obtained. Degenerate oligonucleotide primers were designed based on the amino acid sequences of the human tryptic peptides as well as bovine peptides and sequences from chicken cDNA clones. These primers were used to amplify three overlapping PCR products that covered the majority of the human alpha 3(IX) collagen. PCR products were then used to identify overlapping cDNA clones from a human chondrocyte library. A lambda genomic clone was identified that contained the 5'-most exon that encodes the signal peptide to complete the entire structure of the human alpha 3(IX) collagen chain. Genomic amplification identified a single-strand conformational polymorphism in COL1 that was used to map COL9A3 to chromosome 20q13.3 by linkage analysis. The present study completes the structure of human type IX collagen, and linkage for COL9A3 completes the genomic mapping of cartilage collagen genes. These data will greatly assist the genetic screening of families with degenerative cartilage and eye diseases by allowing investigators to screen for a complete set of candidate collagen gene markers.
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Affiliation(s)
- R G Brewton
- Department of Cell Biology, University of Alabama at Birmingham 35294, USA
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459
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Cai M, Gong Y, Prakash O, Krishnamoorthi R. Reactive-site hydrolyzed Cucurbita maxima trypsin inhibitor-V: function, thermodynamic stability, and NMR solution structure. Biochemistry 1995; 34:12087-94. [PMID: 7547948 DOI: 10.1021/bi00038a001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Reactive-site (Lys44-Asp45 peptide bond) hydrolyzed Cucurbita maxima trypsin inhibitor-V (CMTI-V*) was prepared and characterized: In comparison to the intact form, CMTI-V* exhibited markedly reduced inhibitory properties and binding affinities toward trypsin and human blood coagulation factor XIIa. The equilibrium constant of trypsin-catalyzed hydrolysis, Khyd, defined as [CMTI-V*]/[CMTI-V], was measured to be approximately 9.4 at 25 degrees C (delta G degrees = -1.3 kcal.mol-1). From the temperature dependence of delta G degrees, the following thermodynamic parameters were estimated: delta H degrees = 1.6 kcal.mol-1 and delta S degrees = 9.8 eu. In order to understand the functional and thermodynamic differences between the two forms, the three-dimensional solution structure of CMTI-V* was determined by a combined approach of NMR, distance geometry, and simulated annealing methods. Thus, following sequence-specific and stereospecific resonance assignments, including those of beta-, gamma-, delta-, and epsilon-hydrogens and valine methyl hydrogens, 809 interhydrogen distances and 123 dihedral angle constraints were determined, resulting in the computation and energy-minimization of 20 structures for CMTI-V*. The average root mean squared deviation in position for equivalent atoms between the 20 individual structures and the mean structure obtained by averaging their coordinates is 0.67 +/- 0.15 A for the main chain atoms and 1.19 +/- 0.23 A for all the non-hydrogen atoms of residues 5-40 and residues 48-67.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- M Cai
- Department of Biochemistry, Kansas State University, Manhattan 66506, USA
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460
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Abstract
We present a structural analysis of a peptide, the sequence of which includes amino acids that show preferences for specific positions near the N- and C-termini in protein helices. This peptide has the sequence ac-YMSEDELKAAEAAFKRHGVP-amide, which includes a strong version of an N-terminal Harper-Rose capping box structure as well as a Gly located close to the C-terminus designed to elucidate its role in C-terminal capping. The sequence of five residues at the middle is inserted to separate effects at the two ends via a helix-stabilizing linker. Application of a simulated annealing procedure using interproton distance constraints derived from 1H NOESY experiments in water reveals the presence of a C-terminal structure in this model. The C-terminus forms a folded back structure in a significant fraction of structures generated by the annealing, in most of which Gly assumes an alpha L conformation. This structure occurs within a highly flexible region of the molecule and hence is occupied only a fraction of the time.
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Affiliation(s)
- Y Gong
- Department of Chemistry, New York University, New York 10003, USA
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461
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Gong Y. Radiotherapy of midline malignant reticulosis. Chin Med J (Engl) 1995; 108:542-3. [PMID: 7555275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
The results of radiotherapy made on 23 patients with midline malignant reticulosis showed that the 1-, 3-, 5- and 8-year survival rates were 91.3%, 63.2%, 50.0% and 40.0%, respectively. The optimum radiation dose was 50-60 Gy / 5-6 weeks. Chemotherapy with CCNU following the radiotherapy facilitated the healing of lesion, reduced local recurrence and distant metastasis, improved the therapeutic effect and raised the survival rate.
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Affiliation(s)
- Y Gong
- Department of Radiotherapy, People's Hospital of Uygur Autonomous Region, Xinjiang
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462
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Gong Y, Guo R, Zhang L. Application of jiang ya paste onto yongquan acupoint for treatment of primary hypertension. J TRADIT CHIN MED 1995; 15:112-3. [PMID: 7650957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Y Gong
- Veterans Sanatorium Shaanxi Military Region, Baoji City
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463
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Song W, Cai Y, Deng X, Gong Y, Dong G. [Structural changes of extra pulmonary artery and pulmonary arterioles of rats during chronic hypoxia and their significance]. Zhongguo Yi Xue Ke Xue Yuan Xue Bao 1995; 17:197-203. [PMID: 8706155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The structural changes of extra pulmonary artery (PA) and pulmonary arterioles and their effects on the pulmonary arterial pressure (PAP) under chronically hypobaric hypoxia (5000 m) were studied. The results showed that (1) The endothelial edema of extra PA and pulmonary arterioles gradually reduced and the endothelial proliferation took place along with the prolongation of hypoxic exposure followed by the recovery of endothelium-dependent relaxation evoked by Ach from depression. This result suggested that the release of E-DRFs from endothelium increased with the structural changes of endothelium in the course of hypoxic exposure, which may be a reason why PAP did not increase any more after 21 to 40 of days exposure. However, the strengthened contraction of PA, the proliferation of cells on the vascular wall, and the muscularity of pulmonary arterioles being related to the hypoxic endothelium may produce a negative effect on decrease of PAP, resulting in persistently higher PAP. (2) The structural changes of pulmonary arteriole endothelium were more severe than those of extra PA endothelium, indicating that pulmonary arterioles might be more sensitive to the stimulation of hypoxia.
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Affiliation(s)
- W Song
- Institute of Basic Medical Sciences, CAMS, Beijing
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464
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Gong Y, Xue Q, Drake DL, Qian J, Coleman RV. Impurity-induced modulations in NbSe3 detected by atomic-force microscopy. Phys Rev B Condens Matter 1995; 51:12975-12988. [PMID: 9978092 DOI: 10.1103/physrevb.51.12975] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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465
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Abstract
Elevation of intracellular calcium levels in the presence of normal androgen levels has been implicated in apoptotic prostate cell death. Since the androgen receptor (AR) plays a critical role in the regulation of growth and differentiation of the prostate, it was of interest to determine whether Ca2+ would affect the expression of androgen receptor messenger RNA (mRNA) and protein, thus affecting the ability of androgens to control prostate function. AR-positive human prostate cancer cells, LNCaP, were incubated with either the calcium ionophore A23187 or the intracellular endoplasmic reticulum Ca(2+)-ATPase inhibitor thapsigargin. Subsequently, AR mRNA and protein levels were assessed by Northern and Western blot analysis. Both A23187 and thapsigargin were found to down-regulate steady state AR mRNA levels in a time- and dose-dependent manner. AR mRNA began to decrease after 6-8 h of incubation with 10(-6) M A23187 or 10(-7) M thapsigargin, reaching a nadir at 16 and 10 h of incubation, respectively. In contrast, control mRNA (glyceraldehyde 3-phosphate dehydrogenase) did not change significantly during the treatments with either A23187 or thapsigargin. AR protein levels were found to be decreased after 12 h of incubation with either 10(-6) M A23187 or 10(-7) M thapsigargin. The decrease in AR mRNA and protein seemed to precede apoptosis, since neither A23187 (24 h) nor thapsigargin (30 h) was found to alter cell morphology within the treatment time. Cycloheximide and actinomycin D were unable to change the calcium-mediated decrease in AR mRNA, ruling out the necessity for de novo protein synthesis or a change in mRNA stability. Moreover, the decrease in AR mRNA induced by calcium does not seem to involve protein kinase C- or calmodulin-dependent pathways, since inhibitors of these cellular components had no effect. Nuclear run-on assays demonstrated little or no effects of either A23187 or thapsigargin treatment on AR gene transcription (8 h and 10 h). In conclusion, these studies show that intracellular calcium seems to be a potent regulator of AR gene expression in LNCaP cells.
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Affiliation(s)
- Y Gong
- Department of Urology, Mayo Foundation, Rochester, Minnesota 55905, USA
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466
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Cai M, Liu J, Gong Y, Krishnamoorthi R. A practical method for stereospecific assignments of gamma- and delta-methylene hydrogens via estimation of vicinal 1H-1H coupling constants. J Magn Reson B 1995; 107:172-8. [PMID: 7599951 DOI: 10.1006/jmrb.1995.1074] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Stereospecific assignments are made for gamma- and delta-methylene hydrogens in a protein by means of estimation of vicinal 1H-1H spin-spin coupling constants from a short-mixing-time TOCSY experiment. 3J alpha beta coupling constants, as measured from a P.E. COSY map, are shown to be well correlated with alpha-beta cross-peak intensities of a short-mixing-time (10 ms) TOCSY map. The procedure is illustrated by application to a trypsin-inhibitor protein (M(r) approximately 7 Kd). Thus, gamma-methylene hydrogens of isoleucine residues have been stereospecifically assigned on the basis of 3J beta gamma 1H-1H coupling patterns and intraresidue cross-peak intensities in a NOESY map; gamma-hydrogens of other residues, such as lysine and arginine, have been stereospecifically assigned solely on the basis of cross-peak intensity patterns resulting from coupling of two beta-hydrogens to two gamma-hydrogens, and in conjunction with stereospecific assignments of beta-methylene hydrogens. However, intraresidue NOE intensities are needed if one or two pairs of coupling constants cannot be estimated because of cross peaks either overlapping or occurring proximal to the diagonal. The delta-methylene hydrogens have been stereospecifically assigned on the basis of coupling between two gamma-hydrogens and two delta-hydrogens, in combination with stereospecific assignments of gamma-hydrogens. Stereospecific assignments of side chains should contribute to the overall precision and accuracy of NMR-determined three-dimensional solution structures of proteins.
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Affiliation(s)
- M Cai
- Department of Biochemistry, Kansas State University, Manhattan 66506, USA
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467
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Cai M, Gong Y, Kao JL, Krishnamoorthi R. Three-dimensional solution structure of Cucurbita maxima trypsin inhibitor-V determined by NMR spectroscopy. Biochemistry 1995; 34:5201-11. [PMID: 7711040 DOI: 10.1021/bi00015a034] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The solution structure of Cucurbita maxima trypsin inhibitor-V (CMTI-V), which is also a specific inhibitor of the blood coagulation protein, factor XIIa, was determined by 1H NMR spectroscopy in combination with a distance-geometry and simulated annealing algorithm. Sequence-specific resonance assignments were made for all the main-chain and most of the side-chain hydrogens. Stereospecific assignments were also made for some of the beta-, gamma-, delta-, and epsilon-hydrogens and valine methyl hydrogens. The ring conformations of all six prolines in the inhibitor were determined on the basis of 1H-1H vicinal coupling constant patterns; most of the proline ring hydrogens were stereospecifically assigned on the basis of vicinal coupling constant and intraresidue nuclear Overhauser effect (NOE) patterns. Distance constraints were determined on the basis of NOEs between pairs of hydrogens. Dihedral angle constraints were determined from estimates of scalar coupling constants and intraresidue NOEs. On the basis of 727 interproton distance and 111 torsion angle constraints, which included backbone phi angles and side-chain chi 1, chi 2, chi 3, and chi 4 angles, 22 structures were calculated by a distance geometry algorithm and refined by energy minimization and simulated annealing methods. Both main-chain and side-chain atoms are well-defined, except for a loop region, two terminal residues, and some side-chain atoms located on the molecular surface. The average root mean squared deviation in the position for equivalent atoms between the 22 individual structures and the mean structure obtained by averaging their coordinates is 0.58 +/- 0.06 A for the main-chain atoms and 1.01 +/- 0.07 A for all the non-hydrogen atoms of residues 3-40 and 49-67. These structures were compared to the X-ray crystallographic structure of another protein of the same inhibitor family-chymotrypsin inhibitor-2 from barley seeds [CI-2; McPhalen, C. A., & James, M. N. G. (1987) Biochemistry 26, 261-269]. The main-chain folding patterns are highly similar for the two proteins, which possess 62% sequence differences. However, major differences are noted in the N- and C-terminal segments, which may be due to the presence of a disulfide bridge in CMTI-V, but not in CI-2.
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Affiliation(s)
- M Cai
- Department of Biochemistry, Kansas State University, Manhattan 66506, USA
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468
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Abstract
HIV-1 RNA extraction methodology, stability and cellular location in plasma were studied by quantitative analysis using reverse transcriptase (RT) and polymerase chain reaction (PCR). HIV-1 RNA as intact virus was stable in plasma at room temperature for at least for 24 h, or stable in RNAzol (Tel-Test, Inc. Texas) at -70 degrees C for at least 6 months. The HIV-1 RNA PCR signal did not decline significantly after freezing and thawing of the virus in plasma or in RNAzol. To assess the effect of plasma constituents from different individuals upon quantitative PCR, identical copy members of HIV LAI were spiked into plasma from 9 different, normal individuals. PCR detection of HIV-1 RNA did not show any significant variation in quantitative signals. Additionally, platelet-rich plasma from three seropositive subjects was fractionated into a platelet-free plasma fraction and a platelet pellet fraction. The quantitative analysis of HIV-1 RNA in these fractions, and in the corresponding peripheral blood lymphocytes (PBLs) from each patient, demonstrated that the majority of the HIV-1 RNA was distributed in the plasma, and the HIV-1 RNA in the plasma of these patients seemed not to be strongly platelet associated.
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Affiliation(s)
- Y S Zhu
- HRI, Research Inc., Concord, CA 94520, USA
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469
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Cai M, Gong Y, Krishnamoorthi R. Identification of hydrogen-bonded lysine and arginine residues in a protein by means of chi 4-torsional-angle determination. J Magn Reson B 1995; 106:297-9. [PMID: 7719629 DOI: 10.1006/jmrb.1995.1048] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- M Cai
- Department of Biochemistry, Kansas State University, Manhattan 66506
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470
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Gong Y, Deng C, Li S, Li L, Guan J. [Radiolabelling and assay of Chinese agkistrodon acutus venom with carrier-free Na 125I]. Hua Xi Yi Ke Da Xue Xue Bao 1995; 26:116-9. [PMID: 7657328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Chinese agkistroden acutus venom (CAAV) was radiolabelled with carrier-free Na 125I by the method of Iodogen. The specific activity and radiochemical purity for radiolabelled products were 4236.5 x 10(10) Bq/mmol and 98%, respectively. Each CAAV molecule carried 0.52 125I atom. Physical and chemical characterization of radiolabelled CAAV was similar to unradiolabelled CAAV. Binding analysis showed that 125I-CAAV was bound to platelet in a saturable manner. Binding sites per platelet were 13,255 +/- 6292/platelet. The dissociation constant (Kd) was 3.2 +/- 0.69 x 10(-10) mol/L. These results are similar to binding sites of other snake venom on platelet. The investigation showed that radiolabelled CAAV made by our laboratory was useful for radioligand binding assay.
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Affiliation(s)
- Y Gong
- Department of Internal Medicine, Guangzhou Medical College
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471
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Wen L, Lee I, Chen G, Huang JK, Gong Y, Krishnamoorthi R. Changing the inhibitory specificity and function of Cucurbita maxima trypsin inhibitor-V by site-directed mutagenesis. Biochem Biophys Res Commun 1995; 207:897-902. [PMID: 7864895 DOI: 10.1006/bbrc.1995.1270] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Cucurbita maxima trypsin inhibitor-V (CMTI-V) is also a specific inhibitor of human blood coagulation factor beta-factor XIIa. A recombinant version of CMTI-V has allowed probing of roles of individual amino acid residues including the reactive site residue, lysine (P1), by site-directed mutagenesis. The K44R showed at least a 5-fold increase in inhibitory activity toward human beta-factor XIIa, while there was no change toward bovine trypsin. This result demonstrates that beta-factor-XIIa prefers an arginine residue over lysine residue, while trypsin is non-specific to lysine or arginine in its binding pocket. On the other hand, the specificity of CMTI-V could be changed from trypsin to chymotrypsin inhibition by mutation of the P1 residue to either leucine or methionine (K44L or K44M).
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Affiliation(s)
- L Wen
- Department of Chemistry, Western Illinois University, Macomb 61455
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472
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Abstract
PURPOSE The mouse embryo assay (MEA) is used to test media used for in vitro fertilization (IVF). Negative controls usually consist of previously tested media known to support growth of embryos to the blastocyst stage by 72 h. Often, no concurrent positive (toxic) controls are reported. Thus, any unusually hardy cohort of embryos may go undetected. Endotoxin was tested for its suitability as a positive control in the MEA. RESULTS Female mice were stimulated with gonadotropins mated with males, and embryos flushed from their oviducts 36 h after HCG injection. Two-cell embryos were pooled and randomly distributed to culture dishes containing media without protein supplement. Endotoxin inhibited blastocyst growth beginning at 50 micrograms/ml, with complete suppression of development at 5000 micrograms/ml. With 500 micrograms/ml endotoxin, an average of 34.8% of the embryos developed to the blastocyst stage for eight separate assays. The interassay coefficient of variation (CV) was 76%, while the intraassay CV was 9.4%. At 48 h the zona pellucida was absent from all of the embryos exposed to the endotoxin. A large difference was found between two lots of endotoxin with the same claimed potency. CONCLUSIONS These studies demonstrate the importance for inclusion of a well-defined positive control when performing the mouse embryo assay.
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Affiliation(s)
- N H Dubin
- Department of Obstetrics and Gynecology, Union Memorial Hospital, Baltimore, Maryland 21218, USA
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473
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Gong Y, Herberman RR, Reynolds CW. The kinetics of cytoplasmic granule secretion in natural killer cytotoxicity. Chin Med Sci J 1994; 9:147-51. [PMID: 7865833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Antiserum against purified cytoplasmic granules from rat LGL tumor cells, and protein A-gold immunoelectron microscopy were used to study the secretory events in lysis of YAC-1 tumor cells by rat LGL tumor cells or by isolated LGL from normal rats. After 30 min incubation of effector and target cells together, gold-labeled cytoplasmic granules were often seen concentrated in the area of the LGL adjacent to the bound YAC-1 target. Within 60 min, the granules were observed to move to the cell border near the conjugated site. At this point, the granules were fused with the cell membrane, and subsequently released the gold-labeled contents into the junction between the LGL and the target cell. Gold particles could be seen at the E-T interface, on the LGL surface, or sometimes on the target cell surface. These data provide direct evidence for the hypothesis that under conditions of active cytotoxicity, natural killer cells secrete their cytoplasmic granule contents leading to the deposition of granule material on the target cell surface and the eventual lysis of the cell.
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Affiliation(s)
- Y Gong
- Department or Pathology, CAMS & PUMC, Beijing
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474
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Wang Q, Gong Y, Niu K. The Yantai model of community care for rural psychiatric patients. Br J Psychiatry Suppl 1994:107-13. [PMID: 7946222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The main characteristics of the Yantai model are (a) a three-tier (county, township, village) management structure; (b) the vertical integration of community mental health workers, including a professional advisory group of psychiatrists from the central psychiatric hospital, groups of community psychiatrists at small county psychiatric hospitals, non-psychiatric physicians who run psychiatric out-patient clinics at township general hospitals, and village paramedics ('village doctors') who supervise patients in the community; (c) ongoing training of all community mental health workers; (d) registration and yearly follow-up of all patients with mental illnesses in the community; (e) provision of home-care services to a proportion of acutely ill patients; and (f) most of the cost of the service is borne by the state. The network of services provided by this model makes it convenient for patients to obtain treatment and, if necessary, go into hospital; it reduces the economic burden on the family and the community; it combines treatment, prevention, rehabilitation, and supervision under one administrative network; and it decreases the overall level of psychopathology and psychosocial dysfunction in the community.
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Affiliation(s)
- Q Wang
- Yantai City Lai Yang Psychiatric Hospital, Shandong, PRC
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475
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Gong Y, Murphy LC, Murphy LJ. Hormonal regulation of proliferation and transforming growth factors gene expression in human endometrial adenocarcinoma xenografts. J Steroid Biochem Mol Biol 1994; 50:13-9. [PMID: 8049128 DOI: 10.1016/0960-0760(94)90167-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
We have previously shown that estrogen and progestins regulate both cellular proliferation and transforming growth factor (TGF) expression in human endometrial adenocarcinoma cells in vitro. In the current study we examined the regulation of TGF-alpha and -beta 1 expression in endometrial adenocarcinoma xenografts. Four human endometrial adenocarcinoma cell lines were inoculated into female BALB/c nude mice. Administration of 17 beta-estradiol (E2) increased tumor size in intact mice inoculated with Ishikawa, HEC-50 and HEC-1B cells but inhibited growth of HEC-1A xenografts. 4-Hydroxy tamoxifen (OH-Tam) had similar effects to E2 in animals carrying Ishikawa and HEC-1A cell xenografts but had no significant effect on growth of HEC-50 or HEC-1B xenografts. In intact mice inoculated with OH-Tam pellets and Ishikawa cells, the tumors were larger and had lower levels of TGF-alpha mRNA than in untreated or E2 treated mice. In mice carrying Ishikawa, HEC-50 and HEC-1B cell xenografts none of the hormones or agents tested altered TGF-beta 1 mRNA levels. In contrast, both E2 and OH-Tam significantly increased xenografts TGF-beta 1 mRNA levels in HEC-1A xenografts as well as significantly reduced tumor size. Medroxyprogesterone acetate (MPA) had no effect on tumor size of Ishikawa, HEC-1A and HEC-1B cell cell xenografts but significantly increased the size of HEC-50 xenografts. MPA significantly reduced TGF-alpha expression in Ishikawa cell xenografts but had no effect in the other cell xenografts. MPA had no effect on TGF-beta 1 expression in any of the xenografts. These observations demonstrate a discordance between the hormonal effects on TGF expression and cellular proliferation and argue against a major role for the TGFs in regulation of human endometrial adenocarcinoma cell proliferation in vivo.
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Affiliation(s)
- Y Gong
- Department of Physiology, Faculty of Medicine, University of Manitoba, Winnipeg, Canada
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476
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Abstract
Pre-exposure of HeLa or NIH:OVCAR-3 cells to selenite resulted in a dose-dependent decrease in the ability of the cells to invade a layer of Matrigel, a reconstituted basement membrane preparation. In contrast, selenate, selenomethionine and sulfite had no significant effect on cell invasiveness. Exposure of HeLa cells to selenite also resulted in a decrease in two of the necessary steps of the invasion process, attachment and mobility; in contrast, exposure of OVCAR cells decreased attachment but not mobility. There was an apparent correlation between the processes that are affected by selenite and those that involve the cellular fibronectin receptor (alpha 5 beta 1 integrin).
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Affiliation(s)
- Y Gong
- Department of Biological Sciences, Rutgers University, Newark, NJ 07102
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477
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Abstract
We performed a genetic analysis of 280 families with congenital indirect inguinal hernia ascertained in Shandong province. The multifactorial threshold model and segregation analysis were applied to these families to investigate the mode of inheritance of congenital indirect inguinal hernia. Our results indicate that congenital indirect inguinal hernia is not compatible with a multifactorial threshold model, and the frequent vertical transmission and high segregation ratio suggest autosomal dominant inheritance with incomplete penetrance and sex influence. Through further pedigree analysis of the multiple case families with at least two closely related affected members, we noted preferential paternal transmission of the disease gene, which might suggest the role of genomic imprinting in the aetiology of this condition.
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Affiliation(s)
- Y Gong
- Department of Medical Genetics, Shandong Medical University, Jinan, P R, China
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478
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Cheng H, Gong Y, Jusko WJ. A computer program for calculating distribution parameters for drugs behaving nonlinearly that is based on disposition decomposition analysis. J Pharm Sci 1994; 83:110-2. [PMID: 8138898 DOI: 10.1002/jps.2600830126] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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479
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Dai Z, Xue Q, Gong Y, Slough CG, Coleman RV. Scanning-probe-microscopy studies of superlattice structures and density-wave structures in 2H-NbSe2, 2H-TaSe2, and 2H-TaS2 induced by Fe doping. Phys Rev B Condens Matter 1993; 48:14543-14555. [PMID: 10007877 DOI: 10.1103/physrevb.48.14543] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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480
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Gong Y, Xue Q, Dai Z, Slough CG, Coleman RV, Falicov LM. Modulation of the crystal structure in quasi-one-dimensional solids induced by impurities: An atomic-force microscope study. Phys Rev Lett 1993; 71:3303-3306. [PMID: 10054939 DOI: 10.1103/physrevlett.71.3303] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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481
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Ghahary A, Shen YJ, Scott PG, Gong Y, Tredget EE. Enhanced expression of mRNA for transforming growth factor-beta, type I and type III procollagen in human post-burn hypertrophic scar tissues. J Lab Clin Med 1993; 122:465-73. [PMID: 8228562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
To explore the possible role of locally synthesized transforming growth factor beta-1 (TGF-beta 1) and procollagen gene expression in postburn hypertrophic scars, we have compared mRNA levels for type I and type III procollagen and TGF-beta 1 in human hypertrophic scar tissue with normal dermis obtained from the same patients as a control. Northern blot analysis of total RNA extracted from hypertrophic scar tissue and normal skin demonstrated two transcripts for the pro-alpha 1(I) chain (5.8 kb and 4.8 kb) and for the pro-alpha 1(III) chain (5.4 kb and 4.8 kb) and one transcript (4.9 kb) for TGF-beta 1. Quantitative analysis of dot blot autoradiograms of mRNA from three samples of hypertrophic scar tissue and normal skin showed average increases of 102% (p < 0.05) for pro-alpha 1(I), 91% (p < 0.06) for pro-alpha 1(III), and 61% (p < 0.05) for TGF-beta 1. Three additional hypertrophic scar samples were quantitatively analyzed on Northern blots and showed increases of 246%, 102%, and 250% of the specific messages for pro-alpha 1(I), pro-alpha 1(III), and TGF-beta 1 relative to a normal skin control. Two transcripts (4.9 kb and 2.5 kb) for TGF-beta 1 were identified in cultured fibroblasts. In contrast to the results from tissue, the level of these transcripts in fibroblasts cultured from hypertrophic scar tissue and normal skin were not significantly different, suggesting that the synthesis of this growth factor is stimulated in tissue by a presently unknown mechanism.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- A Ghahary
- Departments of Surgery and Oral Biology, University of Alberta, Edmonton, Canada
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482
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Xue Q, Dai Z, Gong Y, Slough CG, Coleman RV. Charge-density-wave structure and a metal-insulator transition in CrxNbSe3 detected by atomic force microscopy and transport measurements. Phys Rev B Condens Matter 1993; 48:1986-1988. [PMID: 10008580 DOI: 10.1103/physrevb.48.1986] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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483
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484
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Gong Y, Ballejo G, Alkhalaf B, Molnar P, Murphy LC, Murphy LJ. Phorbol esters differentially regulate the expression of insulin-like growth factor-binding proteins in endometrial carcinoma cells. Endocrinology 1992; 131:2747-54. [PMID: 1280205 DOI: 10.1210/endo.131.6.1280205] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
We have examined the effects of protein kinase-C (PKC) activation on expression of the six known insulin-like growth factor-binding proteins (IGFBPs) by human endometrial carcinoma cells. Each of six known IGFBPs was expressed in one or more of the three cell lines examined. The addition of 10(-7) M 4 beta-phorbol 12-myristate 13-acetate (PMA) to HEC-50 and HEC-1B cells resulted in changes in cell morphology, growth inhibition, activation of PKC, and an increase in expression of IGFBP-1. PMA had no effect on these parameters in the Ishikawa cell line, which did not express IGFBP-1. In HEC-50 cells, the effect of PMA was blocked by the concomitant addition of the PKC inhibitor staurosporin and the simultaneous addition of cycloheximide. PMA also resulted in an increase in IGFBP-3 in HEC-50 cells and an increase in IGFBP-6 expression in HEC-1B cells. In contrast, IGFBP-3 expression was down-regulated by PMA in HEC-1B and Ishikawa cells. The abundance of IGFBP-2 and IGFBP-5 mRNAs was also reduced in HEC-1B and Ishikawa cells, respectively. IGFBP-4 was expressed only in HEC-50 cells and was not affected by PMA treatment. These data establish a role for the PKC pathway in regulation of expression of IGFBP-1, -2, -3, and -5 in endometrial adenocarcinoma cells and illustrate the complexity of cell type-specific expression of the IGFBPs.
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Affiliation(s)
- Y Gong
- Department of Internal Medicine, Faculty of Medicine, University of Manitoba, Winnipeg, Canada
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485
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Gong Y, Alkhalaf B, Murphy LJ, Murphy LC. Differential effects of phorbol esters on proliferation and calcyclin expression in human endometrial carcinoma cells. Cell Growth Differ 1992; 3:847-53. [PMID: 1467312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Calcyclin is a member of the S-100 family of calcium-binding proteins, whose expression is enhanced when quiescent cells are exposed to mitogenic signals. The function of calcyclin is unknown, but it is thought to be involved in modulating the intracellular calcium concentration following mitogenic stimuli. Since activation of protein kinase C (PKC) also occurs following stimulation of quiescent cells by a variety of mitogens, we have investigated the relationship between calcyclin expression and PKC activation in three human endometrial adenocarcinoma cell lines. The addition of 10(-7) M 4 beta-phorbol 12-myristate 13-acetate (PMA) to HEC-50 and HEC-1B cell cultures resulted in a change in cell morphology, an inhibition of proliferation, an increase in calcyclin transcription rate, and an increase in calcyclin mRNA and calcyclin protein levels. In contrast, PMA had no effect on cell morphology or cell proliferation in the Ishikawa adenocarcinoma cell line but enhanced calcyclin expression. Another bioactive phorbol ester had the same effect, whereas the calcium ionophore A23187 and the non-phorbol-ester-type tumor promoter thapsigargin had no effect on calcyclin expression. The effect of PMA on calcyclin expression was blocked by the simultaneous addition of the PKC inhibitor staurosporine and by protein synthesis inhibition with cycloheximide. RNase protection assays and primer extension analysis demonstrated that PMA enhanced transcription from all three of the previously identified transcription start sites in the calcyclin gene. These data clearly demonstrate a dissociation between calcyclin expression and cellular proliferation and suggest that the enhanced calcyclin expression which is seen in quiescent cells following mitogenic stimuli may result from activation of the PKC system.
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Affiliation(s)
- Y Gong
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Manitoba, Winnipeg, Canada
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486
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Murphy LC, Dotzlaw H, Alkhalaf M, Coutts A, Miller T, Wong MS, Gong Y, Murphy LJ. Mechanisms of growth inhibition by antiestrogens and progestins in human breast and endometrial cancer cells. J Steroid Biochem Mol Biol 1992; 43:117-21. [PMID: 1525052 DOI: 10.1016/0960-0760(92)90195-o] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Marked changes in both growth factor and proto-oncogene expression occur due to treatment of hormonally-responsive human cancers with progestins and antiestrogens. In human endometrial cancer cell lines the antiproliferative effects of progestins and antiestrogens in a particular cell line appear to be associated with similar effects on growth factor and/or proto-oncogene expression. This suggests that although these compounds initially interact with different steroid hormone receptors, the molecular mechanisms of their growth inhibition may be essentially similar. In the case of human breast cancer cell lines, however, the effects of progestins and antiestrogens on gene regulation are often different, suggesting that the molecular mechanisms of progestin and antiestrogen growth inhibition may be essentially dissimilar.
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Affiliation(s)
- L C Murphy
- Department of Biochemistry and Molecular Biology, University of Manitoba, Winnipeg, Canada
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487
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Anzai Y, Gong Y, Holinka CF, Murphy LJ, Murphy LC, Kuramoto H, Gurpide E. Effects of transforming growth factors and regulation of their mRNA levels in two human endometrial adenocarcinoma cell lines. J Steroid Biochem Mol Biol 1992; 42:449-55. [PMID: 1616874 DOI: 10.1016/0960-0760(92)90256-i] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The effects of the transforming growth factor-beta 1 (TGF-beta 1) and epidermal growth factor (EGF) on the growth of cells from 2 endometrial cancer lines, Ishikawa and HEC-50 were evaluated by measuring rates of DNA synthesis and changes in cell numbers during culture. EGF at 17 and 1.7 nM concentrations consistently enhanced HEC-50 cell proliferation. TGF-beta 1 inhibited Ishikawa cell proliferation but, unexpectedly for epithelium-derived cells, stimulated HEC-50 cell growth. This effect is of interest as it indicates that endometrial cells can acquire an altered responsiveness to a growth inhibitor during the process of malignant transformation. Northern blot analyses showed expression of TGF-alpha, TGF-beta 1 and EGF receptors mRNA in both cell lines. Neither estradiol (E2) nor 4-hydroxytamoxifen (OHTam) affected mRNA levels for either TGF-alpha or TGF-beta in HEC-50 cells, a line unresponsive to E2 for proliferation. In Ishikawa cells, previously shown to respond to both E2 and OHTam by increasing proliferation rates, E2 increased TGF-alpha mRNA and reduced TGF-beta mRNA levels. OHTam lowered the levels of both mRNA species, although the effect was greater on TGF-beta than TGF-alpha mRNA. These data are consistent with, but do not prove, the existence of a possible autocrine regulation by TGF-alpha and TGF-beta of human cancer cell proliferation, which might be under E2 influence in Ishikawa cells.
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Affiliation(s)
- Y Anzai
- Department of Obstetrics, Gynecology and Reproductive Science, Mount Sinai School of Medicine, New York, NY 10029
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488
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Gong Y, Ballejo G, Murphy LC, Murphy LJ. Differential effects of estrogen and antiestrogen on transforming growth factor gene expression in endometrial adenocarcinoma cells. Cancer Res 1992; 52:1704-9. [PMID: 1551100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
While antiestrogens are useful agents in the treatment of breast cancer, the usefulness of these agents in the treatment of endometrial cancer remains controversial. There is some concern that the currently available antiestrogens may have partial agonist activity in uterine tissue. To better understand the mechanisms by which estrogens and antiestrogens modulate growth of endometrial adenocarcinoma cells, we have compared the effects of 17-beta estradiol and three antiestrogens, 4-hydroxytamoxifen (OH-TAM), ICI 164384, and LY 117018 on proliferation and transforming growth factor (TGF) mRNA accumulation in two human endometrial adenocarcinoma cell lines. In HEC-50 cells, neither estradiol nor anti-estrogens had any effect on cell proliferation or TGF mRNA abundance under estrogen-depleted culture conditions [basal medium containing 1% twice charcoal-treated fetal bovine serum (ctFBS)] or in the presence of estrogen (basal medium containing 5% fetal bovine serum). At very high concentrations, both estradiol and OH-TAM caused a small decrease in HEC-50 cell proliferation in medium containing 5% serum. In contrast, the antiestrogens had different effects on Ishikawa cells, depending upon the culture conditions. In medium containing 5% fetal bovine serum, the antiestrogens inhibited cell proliferation and significantly decreased TGF-alpha mRNA abundance and TGF-alpha secretion. OH-TAM was more potent than the other antiestrogens. Under these culture conditions, estradiol had no effect on cell proliferation or TGF-alpha mRNA levels but increased TGF-alpha secretion. In medium supplemented with 1% ctFBS, estradiol increased cell proliferation and TGF-alpha mRNA (2.72-fold, P less than 0.005) and TGF-alpha secretion (700 +/- 156 versus 250 +/- 23 pg/10(6) cells/24 h, P less than 0.05), whereas OH-TAM, which also stimulated cell proliferation, reduced TGF-alpha mRNA abundance (P less than 0.05) but had no significant effect on TGF-alpha secretion. Under these conditions, ICI 164384 and LY 117018 had no effect on either cell proliferation or TGF-alpha expression. Estradiol treatment decreased, whereas OH-TAM increased, epidermal growth factor receptors in Ishikawa cells. Both estradiol and the antiestrogens decreased TGF-beta 1 mRNA abundance when cells were grown in media containing 1% ctFBS. In summary, the response of human endometrial adenocarcinoma cells to estrogen and antiestrogens varied between cell lines and was dependent upon the culture conditions used. In addition, OH-TAM, unlike the other two antiestrogens tested, had growth-stimulating effects on Ishikawa cells.
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Affiliation(s)
- Y Gong
- Department of Physiology, Faculty of Medicine, University of Manitoba, Winnipeg, Canada
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489
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Abstract
We have examined the effects of medroxyprogesterone acetate (MPA) and 4-hydroxytamoxifen (OH-TAM) on the cell proliferation and the expression of TGF-alpha and TGF-beta genes in Ishikawa cells and HEC-50 human endometrial adenocarcinoma cells. The effects of exogenous TGF-alpha, TGF-beta and anti-EGF receptor monoclonal antibody on cell proliferation were also determined. Antisense oligonucleotides were used to determine the effects of endogenous expression of TGF-alpha and TGF-beta. In both cell lines, MPA resulted in a time and dose-dependent inhibition of cell proliferation whereas OH-TAM had no effect on HEC-50 cell proliferation. The relative abundance of TGF-alpha mRNA was significantly reduced by MPA in Ishikawa cells but not in HEC-50 cells. In Ishikawa cells, a reduction in TGF-alpha mRNA abundance was observed with OH-TAM under conditions where both inhibition and stimulation of cell proliferation were demonstrated. Anti-EGF receptor monoclonal antibody inhibited Ishikawa cell growth but had little effect on HEC-50 cell proliferation. Exogenous TGF-alpha stimulated proliferation of both cell lines whereas exogenous TGF-beta inhibited proliferation of Ishikawa cells but stimulated proliferation of HEC-50 cells. Antisense oligonucleotides to TGF-beta inhibited proliferation of HEC-50 cells. From these data we conclude that the antiproliferative effects of progestins and OH-TAM on endometrial cancer cells appear to be mediated by different mechanisms.
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Affiliation(s)
- L J Murphy
- Department of Internal Medicine, Faculty of Medicine, University of Manitoba, Winnipeg, Canada
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490
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Gong Y, Moses E. [Overexpression of an extracellular Bacteroides nodosus protease in E. coli and isolation and characterization of its promoter]. Wei Sheng Wu Xue Bao 1991; 31:433-7. [PMID: 1814046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Bacteroides nodosus is the essential causative agent of ovine footrot. It produces extracellular proteases which involved in pathogenesis of footrot. In this paper, we report the subcloning of Bacteroides nodosus protease, its overexpression in E. coli and its N-terminal polypeptide sequence. The subclone library was constructed in E. coli using SphI digested original clone (15 kb) and plasmid PTZ18R and screened using immunological assay. The expression was observed using SDS-PAGE. The subcloned DNA fragment was then cut with Sau3AI, cloned into pKK232-8 vector to perform promoter isolation and analysis. The promoter strength was determined using spectrophotometric assay.
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Affiliation(s)
- Y Gong
- National Animal Quarantine Institute, Qingdao
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491
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Gong Y, Anzai Y, Murphy LC, Ballejo G, Holinka CF, Gurpide E, Murphy LJ. Transforming growth factor gene expression in human endometrial adenocarcinoma cells: regulation by progestins. Cancer Res 1991; 51:5476-81. [PMID: 1833051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
In an attempt to understand the antiproliferative effects of progestins in endometrial cancer, we have examined the effects of the potent progestin, medroxyprogesterone acetate (MPA), on the cell proliferation and the expression of transforming growth factor (TGF) alpha and beta genes in human endometrial adenocarcinoma cell lines. The two cell lines used were Ishikawa, var 1, and HEC-50. In addition, the effects of exogenous TGF-alpha and anti-epidermal growth factor (EGF) receptor monoclonal antibody on cell proliferation were determined. Incubation of both cell lines with MPA resulted in a time- and dose-dependent inhibition of cell proliferation. Half-maximal growth inhibition was observed at 0.6 nM. In Ishikawa cells, the relative abundance of TGF-alpha was significantly reduced by MPA. A significant decrease in TGF-alpha mRNA was apparent 6 h after exposure to MPA and a further decrease was seen 12-24 h after addition of the progestin. The concentration of TGF-alpha immunoreactivity in conditioned medium of MPA-treated cells was also significantly reduced compared to control cultures. MPA had no effect on TGF-alpha expression by HEC-50 cells. EGF mRNA was not detected by Northern blot analysis in either cell type. MPA had no significant effect on EGF receptor mRNA abundance but resulted in a small increase in EGF receptor number in Ishikawa cells. Anti-EGF receptor monoclonal antibody (0.6-6 nM) inhibited Ishikawa cell growth but had no effect on HEC-50 cell proliferation. Exogenous TGF-alpha stimulated proliferation of both cell lines, but Ishikawa cells were significantly more sensitive to exogenous TGF-alpha than HEC-50 cells. Furthermore, TGF-alpha could reverse the growth inhibitory effects of MPA on Ishikawa cells. A decrease in TGF-beta mRNA abundance was also observed in MPA-treated Ishikawa and HEC-50 cells. This effect was of small magnitude, variable, and only observed after prolonged exposure to MPA. These observations are consistent with the hypothesis that the antiproliferative effects of progestins on Ishikawa cells are mediated by decreased expression and autocrine action of TGF-alpha. Since similar growth inhibition is also seen in the HEC-50 cells in which progestins have no effect on TGF-alpha expression, additional mechanisms are likely to be involved in the antiproliferative effects of progestins in human endometrial cancer.
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Affiliation(s)
- Y Gong
- Department of Physiology, Faculty of Medicine, University of Manitoba, Winnipeg, Canada
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492
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Affiliation(s)
- L J Murphy
- Department of Internal Medicine, University of Manitoba, Winnipeg, Canada
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493
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Gong Y, Lu X. [Trace elements in the aqueous extract of twenty Chinese drugs before and after charring]. Zhongguo Zhong Yao Za Zhi 1991; 16:85-7, 126-7. [PMID: 1872969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Our study on the variation of trace element contents in the aqueous extract of 20 Chinese drugs before and after charring has shown that after charring Ca ions increase noticeably in the extract of 6 drugs, increase slightly in another 6 and decrease in varying degrees in the remaining 8. In all the charred drugs no rise has been observed in the contents of trace elements, but instead, in most of them the contents tend to drop.
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494
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Murphy LC, Dotzlaw H, Wong MS, Miller T, Mrockowski B, Gong Y, Murphy LJ. Epidermal growth factor: receptor and ligand expression in human breast cancer. Semin Cancer Biol 1990; 1:305-15. [PMID: 2103505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The epidermal growth factor (EGF) gene is expressed by most human breast cancer cell lines as well as 83% of human breast cancers in vivo. Furthermore, EGF mRNA is detectable in normal human breast tissue. These data suggest that EGF may have a functional role in both normal and neoplastic human breast tissue. Expression of EGF was generally highest in steroid receptor positive human breast tumor biopsies and cell lines. EGF expression was increased by progestins in T-47D and ZR 75 human breast cancer cells. Furthermore, progestins specifically increased the level of TGF-alpha and EGF-receptor mRNA in T-47D cells. Under these same conditions progestins inhibit growth of the cells. Regulation of expression of EGF, TGF-alpha and the EGF-receptor is unlikely to be directly related to the mechanism of progestin induced growth inhibition in T47-D cells. T-47D-5 cells are more sensitive than T-47D cells to progestin and antiestrogen induced growth inhibition. T-47D-5 cells do not express EGF and contain very low levels of TGF-alpha mRNA. The higher level of EGF and TGF-alpha expression in T-47D cells may be one mechanism by which these cells decrease their sensitivity to growth inhibition by progestins and antiestrogens.
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Affiliation(s)
- L C Murphy
- Department of Biochemistry and Molecular Biology, University of Manitoba, Winnipeg, Canada
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495
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Sun B, Gong Y. [An identification method for mineral drugs]. Zhongguo Zhong Yao Za Zhi 1990; 15:266-9, 317. [PMID: 2275776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
This paper is a report on a method for chemical identification of 58 mineral drugs. Combined with the Chinese traditional identification, the method can differentiate the sham and genuine drugs in a few minutes.
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Affiliation(s)
- B Sun
- Workers Hospital, Second Construction Company of Metallurgical Industry, Nei Mongolia
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496
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Gong Y. A study on the urbanization of population in modern China. Chin J Popul Sci 1990; 2:125-37. [PMID: 12284835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/19/2023]
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497
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Abstract
The effect of copy number, integration site, and enhancers on the expression of stably integrated exogenous DNA was examined in Chinese hamster cells. Three similar plasmids were constructed with the mouse beta maj-globin promoter fused to the galK gene either with no enhancer or with the SV40 or Harvey sarcoma virus (HaSV) enhancer. Eighteen stable cell lines were obtained and characterized with respect to plasmid copy number and galactokinase activity. At copy numbers of four or less, the enhancers showed detectable activity and a DNase I hypersensitive site was present. Above four copies, gene activity decreased as the copy number increased, the enhancer sequences were apparently inactive, and the DNase I hypersensitive site disappeared. These data suggest that, at least in this model system, when exogenous DNA is integrated as multiple head-to-tail copies, the entire multigene unit expresses poorly and inappropriately. When the same exogenous DNA integrates as a single (or low number) copy, expression appears to be relatively normal as judged by enhancer stimulation and DNase I hypersensitivity.
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498
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Gong Y. [Human ovarian cancer antigen assayed by an active rosette formation test for immunodiagnosis]. Zhonghua Fu Chan Ke Za Zhi 1983; 18:164-6. [PMID: 6653198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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499
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Gong Y. [Antigenicity of ovarian cancer tissues (author's transl)]. Zhonghua Yi Xue Za Zhi 1982; 62:156-8. [PMID: 6179584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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