Hematologic parameters and genotype analysis in 166 children with HbH disease in the North Guangxi region / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the characteristics of genotype spectrum and hematologic parameters in children with HbH disease in the North Guangxi region.</p><p><b>METHODS</b>HbH disease was identified by clinical manifestations, routine blood tests and hemoglobin electrophoresis in 166 children who came form the North Guangxi region. Genotypes were determined by Multi-PCR combined with PCR reverse dot blot. DNA sequencing was used when the genotype could not be identified by regular methods.</p><p><b>RESULTS</b>Of the 166 children with HbH disease, 8 genotypes were identified: --SEA/-α3.7 (82 cases), --SEA/-α4.2 (40 cases), --SEA/αCSα (38 cases), --SEA/αQSα (1 case), --SEA/αWSα (1 case), --SEA/αCD43/44 (-C) α (1 case), --SEA/-α3.7 plus CD17 (A→T) (1 case) and --SEA/-α4.2 plus CD41-42(-TTCT) (1 case). One case was confirmed as the heterozygote of --SEA and an unknown mutation. In the 134 cases with complete medical data, 2 had normal hemoglobin levels, 36 manifested mild anemia, 90 manifested moderate anemia, and 6 (genotype: --SEA/αCSα) showed severe anemia because of the coexistence of infection. Children with the genotype of --SEA/-α3.7 (69 cases), --SEA/-α4.2 (31 cases) and --SEA/αCSα (34 cases) had hemoglobin levels of 62-120, 69-127 and 34-110 g/L respectively. The hemoglobin level in the --SEA/αCSα group was significantly lower than in the deletional HbH disease group (genotypes: --SEA/-α3.7 and --SEA/-α4.2 ) (P<0.05). In contrast, MCV levels in the --SEA/αCSα group were significantly higher than in the deletional HbH disease group (P<0.05).</p><p><b>CONCLUSIONS</b>The genotype spectrum of HbH disease is diverse in the North Guangxi region. Deletional genotype is prevalent. The disease is heterogeneous. The children with --SEA/αCSα HbH disease have severer anemia and higher MCV levels than those with deletional HbH disease.</p>

Expression and significance of new candidate tumor suppressor gene N-Myc downstream-regulated gene 2 in colorectal cancer / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To determine the expression of new candidate tumor suppressor gene N-Myc downstream-regulated gene 2(Ndrg2) in colorectal cancer with different differentiation, and analyze its clinical significance.</p><p><b>METHODS</b>Specimens of 50 colorectal cancer patients with different differentiation were collected. Immunohistochemistry and Western blot were used to examine the expression of Ndrg2. Colorectal cancer tissue array in large scale was applied to analyze the expression of Ndrg2 and the statistics analysis was performed referring to the patients information of the array.</p><p><b>RESULTS</b>Among 50 cases, Ndrg2 expression level of colorectal cancer was significantly lower in 32 cases as compared to adjacent and normal tissue of the same individual, while Ndrg2 expression of adjacent tissue was significantly lower than that of normal tissue. Ndrg2 protein levels increased from poor-differentiated to well-differentiated carcinomas(P=0.005).</p><p><b>CONCLUSIONS</b>The expression of Ndrg2 in different differentiated colorectal cancer tissues show a significant distinction. Ndrg2 may be involved in the regulation of differentiation in colorectal cancer.</p>

Effect of tyrosine-kinase Inhibitor on p15 gene transfected K562 cells / 中国实验血液学杂志

The objective of study was to investigate the combined effect of tyrosine-kinase inhibitor (imatinib) and p15 gene on the proliferation, cell cycle and apoptosis of chronic myeloid leukemia cell line K562. p15 gene was amplified from peripheral blood mononuclear cells by RT-PCR, and confirmed by DNA sequencing, then the recombinant p15-pcDNA3.1 vector was constructed and transfected into K562 cell line by Lipofectine. After screening with G418, p15-pcDNA3.1-K562 cell clone stably expressing P15 was isolated. P15 protein was identified by Western blot. The cell survival rate was determined by MTT, cell cycle and apoptosis were detected by flow cytometry. The results showed that partial deletion of p15 gene in K562 cells was verified by DNA sequencing, leading to the function of P15 protein to be lost. The expression of P15 protein can be detected by Western blot in p15-pcDNa3.1-K562 cells. A strong inhibition of cell proliferation was observed in p15-pcDNA3.1-K562 cells as compared with that of the control K562 cell. The cells of G(0)/G(1) phase in p15-pcDNA3.1-K562 cells increased apparently, and S phase cells declined signifcantly. Cell cycle was arrested in G(0)/G(1) phase. The percentage of apoptotic cells greatly increased after transfection with p15-pcDNA3.1-K562 cells combined with imatinib, and cell survival rate notably declined. It is concluded that the imatinib in combination with the expression of p15 gene has a synergistic effect on the inhibition of K562 cell proliferation and promotion of its apoptosis.

Distribution characteristic of NDRG2 expression in human fetal tissues / 生理学报

NDRG2, one of the new N-Myc downstream-regulated gene (NDRG) gene families, is believed to be involved in cell growth event. However, the exact function is still unknown. Identification of the tissue or cell types expressing this gene in vivo will provide clues in clarifying its physiological roles. Using RT-PCR and Western blot, we analyzed the expression level of NDRG2 mRNA and protein in human fetal tissues from different gestational ages. The anti-NDRG2 monoclonal antibody, which has been proved to react specifically with NDRG2 protein, was further used to analyze the cellular location of NDRG2 protein in various human fetal tissues by immunohistochemistry. We found that NDRG2 expression was developmentally dynamic, being generally lower in the early stages of development and markedly increasing during the later stages. NDRG2 mRNA and protein distribution were generally consistent in heart and lung. One of the differences was that NDRG2 protein appeared later than mRNA in kidney. Another unmatched expression was found in liver. NDRG2 mRNA appeared later than protein in liver. In human fetal tissues at sixteen and twenty-eight weeks of gestation, NDRG2 protein immunoreactions could be seen in epithelium of small intestine, epithelium of large intestine, superficial layer of epidermis, whisker follicles, epithelium of small bronchus, hepatocytes, cardiac myocytes, thymus corpuscles and epithelium of renal tubule, and the immunoreactions in those tissues from twenty-eight weeks of gestation was stronger than that from sixteen weeks of gestation. In the present study, we demonstrate the expression pattern and cellular location of NDRG2 protein in a large set of human fetal tissues. This is the first demonstration of NDRG2 protein expression in human fetal tissues. Taken together, the results suggest that NDRG2 protein found in a variety of tissues is not a tissue-specific protein, and may play important roles in histogenesis and organogenesis.

Regular expression of discoidin domain receptor 2 in the improved adjuvant-induced animal model for rheumatoid arthritis / 中国医学科学杂志(英文版)

<p><b>OBJECTIVE</b>To investigate the expression of discoidin domain receptor 2 (DDR2) of fibroblast-like synovial cells in improved adjuvant-induced animal (AIA) model for rheumatoid arthritis (RA) and to provide evidence for DDR2's antagonist use clinically.</p><p><b>METHODS</b>AIA was modified by administrating 0.1 mL of complete Freund's adjuvant (CFA, mixed with 5 mg Bacillus Calmette-Guerin vaccine/mL) into rats' right hind paws and 0.125 mL tumor necrosis factor-alpha (2 U/mL) into right ankles and subpatellar fatty tissue. The expression of DDR2 in fibroblast-like synovial cells was assessed using immunohistochemistry, immunofluorescence histochemistry, and in situ hybridization methods. Levels of anti-collagen II antibody were measured using enzyme-linked immunosorbent assay.</p><p><b>RESULTS</b>Given the terms mentioned above, we found a more practical rat model, apparently decreasing immunization time (average 3-5 days). DDR2 can be detected upon the 15th day of immunization; expression gradually increased with time going on, and reaching a peak 35 days after immunization before gradually decreasing. Serum anti-collagen II antibody showed similar expression patterns as DDR2, but reached peak later than DDR2, about 40 days after immunization.</p><p><b>CONCLUSION</b>Regular expression of DDR2 in animal models infers its important role in the pathological process of RA.</p>

Construction and analysis of subtractive cDNA library associated with multidrug resistance of acute leukemia / 中国实验血液学杂志

The study was aimed to construct subtractive cDNA library associated with multidrug resistance (MDR) of acute leukemia for screening genes related to MDR in leukemia. The improved PCR-based subtractive hybridization was performed to clone differential genes between HL-60/VCR and HL-60 cell line. The mRNA of HL-60/VCR and HL-60 cell line were isolated. Then the mRNA of HL-60/VCR group was reversely transcribed into cDNA by Cap-Finder method, and the mRNA of HL-60 was reversely transcribed into cDNA by ordinary method to be marked by biotin for the hybridization next with HL-60/VCR cDNA. After hybridizing, filtrating through the sephacryl S-400 column, absorbing by the magnetic beads, and amplifying by PCR method, the fragments were cloned by T-A method and the cDNA library was constructed. Then the quality of cDNA library was identified by dot-blotting hybridization method. The results showed that after constriction, the library demonstrated its good quality. There was a high proportion of large fragments in this library. From small amount of samples a large amount of candidate fragments could be screened rapidly at once by dot-blotting hybridization. It is concluded that a differentially-expressed subtractive cDNA library in MDR of leukemia with high quality and larger fragments can be efficiently constructed by improving subtractive hybridization and selective PCR method.

Experimental research on tyrosine-kinase inhibitor STI571 and P21WAF gene clone to treat chronic myeloid leukemia / 中国实验血液学杂志

To explore the effect of a tyrosine-kinase inhibitor STI571 and P21(WAF) gene clone on the proliferation, cycle, apoptosis of leukemia cell line K562, P21(WAF) gene was obtained by RT-PCR, and its sequence was approved to be correct, then P21-pcDNA3.1 vector was constructed and transfected into K562 cell line. After selected with G418, P21-pcDNA3.1-K562 cell clone that stably expression P21(WAF) was isolated. P21(WAF) protein was identified by Western blot. The survival rate were tested by MTT. Cell cycle and apoptosis were tested by flow cytometry. The results showed that the expression of P21(WAF) protein could be detected by Western blot in P21-pcDNa3.1-K562 cells. A strong inhibition of cell proliferation was observed in P21-pcDNA3.1-K562 cells as compared with that of the control. The cells cycle were arrested in G(0)/G(1) phase. The percentage of apoptosis was declined slightly after P21-pcDNA3.1-K562 cells were combined with STI571, meanwhile its survival rate declined more slowly than that of K562 cell with STI571. In conclusion, P21(WAF) inhibits the proliferation of K562 cell, meanwhile slightly inhibits its apoptosis induced by STI571and decrease its sensitivity to STI571.

Construction and significance of directional expression cDNA library from myeloid leukemia cell line U937 / 中国实验血液学杂志

To construct the cDNA expression library from human U937 cell, total RNA and purified mRNA in myeloid leukemia cell line U937 were extracted. The first and second strand of cDNA were synthesized through reverse transcription. After blunting the cDNA termini, the cDNA fragments were connected with EcoR I adapters, and the end of EcoR I adapters was phosphorylated. Then the cDNAs were digested by Xho I, and the fragments smaller than 400 bp were removed by Sephacryl-S400 spin column, the fragments longer than 400 bp were ligated with lambdaZAP vector. The recombinants were packaged in vitro, and a small portion of packaged phage was used to infect E coli XL1-Blue-MRF' for titration. The recombinants were examined by color selection. In order to evaluate the size of cDNA inserts and the diversity of library, the pBK-CMV phagemid was excised from the ZAP expression vector by using ExAssist helper phage with XLOLR strain, and then the pBK-CMV phagemid was digested by Xho I and EcoR I. The results showed that the U937 cell line cDNA library consisting of 2.87 x 10(6) recombinant bacteriophages was constructed. The average size of exogenous insert in the recombinants was about 1.7 kb. It is concluded that the constructed cDNA library can be used to screen target clones.

Application of two bacteria colony-PCR methods in the screening of phage antibody library / 医学研究生学报

Objective:To value the application of two bacteria colony-PCR methods in the screening of phage antibody library. Methods:Five positive monoclonal bacterium were respectively suspended in either deionized water or 0.1% Triton X-100, and then boiled to be used as template in PCR. . The DNAs products of PCR were extracted and digested by two enzymes, and then determined by electrophoresis. Results:The inserted genes were detected in all the 5 clones after PCR and enzyme digestion .Conclusion:Bacteria colony-PCR can be used in screening positive recombinant colonies. The bacteria colony-PCR method with bacteria colonies suspended in deionized water is valuable in large scale positive recombinant bacterium screening.