Synthesis and characterization of surface-modified Fe3O4 super-paramagnetic nanoparticles / 华中科技大学学报（医学）（英德文版）

Aqueous dispersion and stability of Fe3O4 nanoparticles remain an issue unresolved since aggregation of naked iron nanoparticles in water. In this study, we successfully synthesized different Fe3O4 super-paramagnetic nanoparticles which were modified by three kinds of materials [DSPE-MPEG2000, TiO2 and poly acrylic acid (PAA)] and further detected their characteristics. Transmission electron microscopy (TEM) clearly showed sizes and morphology of the four kinds of nanoparticles. X-ray diffraction (XRD) proved successfully coating of the three kinds of nanoparticles and their structures were maintained. Vibrating sample magnetometer (VSM) verified that their magnetic properties fitted for the super-paramagnetic function. More importantly, the particle size analysis indicated that Fe3O4@PAA had a better size distribution, biocompatibility, stability and dispersion than the other two kinds of nanoparticles. In addition, using CNE2 cells as a model, we found that all nanoparticles were nontoxic. Taken together, our data suggest that Fe3O4@PAA nanoaparticles are superior in the application of biomedical field among the four kinds of Fe3O4 nanoparticles in the future.

Synthesis and characterization of surface-modified Fe3O4 super-paramagnetic nanoparticles / 华中科技大学学报（医学）（英德文版）

Aqueous dispersion and stability of Fe3O4 nanoparticles remain an issue unresolved since aggregation of naked iron nanoparticles in water. In this study, we successfully synthesized different Fe3O4 super-paramagnetic nanoparticles which were modified by three kinds of materials [DSPE-MPEG2000, TiO2 and poly acrylic acid (PAA)] and further detected their characteristics. Transmission electron microscopy (TEM) clearly showed sizes and morphology of the four kinds of nanoparticles. X-ray diffraction (XRD) proved successfully coating of the three kinds of nanoparticles and their structures were maintained. Vibrating sample magnetometer (VSM) verified that their magnetic properties fitted for the super-paramagnetic function. More importantly, the particle size analysis indicated that Fe3O4@PAA had a better size distribution, biocompatibility, stability and dispersion than the other two kinds of nanoparticles. In addition, using CNE2 cells as a model, we found that all nanoparticles were nontoxic. Taken together, our data suggest that Fe3O4@PAA nanoaparticles are superior in the application of biomedical field among the four kinds of Fe3O4 nanoparticles in the future.

Correlation between increased circulating endothelial progenitor cells and stage of non-Hodgkin lymphoma / 华中科技大学学报（医学）（英德文版）

This study aims to examine the levels of circulating endothelial progenitor cells (cEPCs) in the peripheral blood of patients with non-Hodgkin lymphoma (NHL) and their correlation with the tumor stage. Forty-one patients with biopsy-proven NHL and 16 healthy individuals were recruited. Peripheral blood mononuclear cells (PBMCs) were isolated by density gradient centrifugation, and cEPCs were characterized by triple staining using antibodies against CD133, CD34 and vascular endothelial growth factor receptor-2 (VEGFR-2, CD309) and quantified by flow cytometry. In NHL patients, the number of cEPCs was significantly greater than in control group (P=0.000). The cEPCs counts in patients with NHL of stage III-IV were significantly greater than in stage I-II (P=0.010). FACS analysis revealed that the number of cEPCs in NHL patients had no correlation with the gender (P=0.401) or the pathological category (P=0.852). It was suggested that the over-expression of cEPCs in NHL patients may serve as a novel biomarker for disease progression in NHL.

Association between CHRNA3 rs1051730 genotype and lung cancer risk in Chinese Han population: A case-control study / 华中科技大学学报（医学）（英德文版）

Recent population-based genome wide association studies have revealed potential susceptibility loci of lung cancer at the region of chromosome 15q25.1 containing nicotinic acetylcholine receptor genes. The loci increasing lung cancer risk has been widely identified in Caucasians, but whether this association also exists in Asians and whether this association is a direct role or mediated via tobacco smoking indirectly has not been fully established. We conducted a case-control study comprising of 210 histologically confirmed lung cancer cases and 200 healthy controls to examine rs1051730 genotyping, a single nucleotide polymorphism receiving much attention recently, and its influence on lung cancer risk as well as nicotine dependence in a Chinese Han population. Our results showed that the heterozygous C/T genotype and minor allele T conferred a significant higher risk of lung cancer than the CC homozygotes and allele C (adjusted OR=2.25, 95% CI=1.04-4.89, P=0.040 and OR=2.18, 95% CI=1.02-4.67, P=0.045 respectively). However, no association between the smoking habit and the CHRNA3 rs1051730 polymorphism was observed in this study. The results suggested that the rs1051730 polymorphism may modify susceptibility to lung cancer via a smoking-independent manner among Chinese Han population. Additional studies in vitro and in vivo are warranted to further elucidate the impact of rs1051730 on lung cancer susceptibility.

Suppression of low-dose hyper-radiosensitivity in human lung cancer cell line A549 by radiation-induced autophagy / 华中科技大学学报（医学）（英德文版）

This study explored the role of radiation-induced autophagy in low-dose hyperradiosensitivity (HRS) in the human lung cancer cell line A549. A549 cells, either treated with an autophagic inhibitor 3-methyladenine (3-MA), or with a vehicle control, were irradiated at different low doses (≤0.5 Gy). The generation of autophagy was examined by laser scanning confocal microscopy. Western blotting was used to detect the expression of microtubule-associated protein l light chain 3B II (LC3B-II). Flow cytometry (FCM) and clonogenic assays were used to measure the fraction of surviving cells at the low irradiation doses. Our results showed that there was a greater inhibition of autophagic activity, but a higher degree of low-dose HRS in A549 cells treated with 3-MA than in control group. Our data demonstrated that radiation-induced autophagy is correlated with HRS in A549 cells, and is probably one of the mechanisms underlying HRS.

Correlation between increased circulating endothelial progenitor cells and stage of non-Hodgkin lymphoma / 华中科技大学学报（医学）（英德文版）

This study aims to examine the levels of circulating endothelial progenitor cells (cEPCs) in the peripheral blood of patients with non-Hodgkin lymphoma (NHL) and their correlation with the tumor stage. Forty-one patients with biopsy-proven NHL and 16 healthy individuals were recruited. Peripheral blood mononuclear cells (PBMCs) were isolated by density gradient centrifugation, and cEPCs were characterized by triple staining using antibodies against CD133, CD34 and vascular endothelial growth factor receptor-2 (VEGFR-2, CD309) and quantified by flow cytometry. In NHL patients, the number of cEPCs was significantly greater than in control group (P=0.000). The cEPCs counts in patients with NHL of stage III-IV were significantly greater than in stage I-II (P=0.010). FACS analysis revealed that the number of cEPCs in NHL patients had no correlation with the gender (P=0.401) or the pathological category (P=0.852). It was suggested that the over-expression of cEPCs in NHL patients may serve as a novel biomarker for disease progression in NHL.

Suppression of low-dose hyper-radiosensitivity in human lung cancer cell line A549 by radiation-induced autophagy / 华中科技大学学报（医学）（英德文版）

This study explored the role of radiation-induced autophagy in low-dose hyperradiosensitivity (HRS) in the human lung cancer cell line A549. A549 cells, either treated with an autophagic inhibitor 3-methyladenine (3-MA), or with a vehicle control, were irradiated at different low doses (≤0.5 Gy). The generation of autophagy was examined by laser scanning confocal microscopy. Western blotting was used to detect the expression of microtubule-associated protein l light chain 3B II (LC3B-II). Flow cytometry (FCM) and clonogenic assays were used to measure the fraction of surviving cells at the low irradiation doses. Our results showed that there was a greater inhibition of autophagic activity, but a higher degree of low-dose HRS in A549 cells treated with 3-MA than in control group. Our data demonstrated that radiation-induced autophagy is correlated with HRS in A549 cells, and is probably one of the mechanisms underlying HRS.

Association between CHRNA3 rs1051730 genotype and lung cancer risk in Chinese Han population: a case-control study / 华中科技大学学报（医学）（英德文版）

Recent population-based genome wide association studies have revealed potential susceptibility loci of lung cancer at the region of chromosome 15q25.1 containing nicotinic acetylcholine receptor genes. The loci increasing lung cancer risk has been widely identified in Caucasians, but whether this association also exists in Asians and whether this association is a direct role or mediated via tobacco smoking indirectly has not been fully established. We conducted a case-control study comprising of 210 histologically confirmed lung cancer cases and 200 healthy controls to examine rs1051730 genotyping, a single nucleotide polymorphism receiving much attention recently, and its influence on lung cancer risk as well as nicotine dependence in a Chinese Han population. Our results showed that the heterozygous C/T genotype and minor allele T conferred a significant higher risk of lung cancer than the CC homozygotes and allele C (adjusted OR=2.25, 95% CI=1.04-4.89, P=0.040 and OR=2.18, 95% CI=1.02-4.67, P=0.045 respectively). However, no association between the smoking habit and the CHRNA3 rs1051730 polymorphism was observed in this study. The results suggested that the rs1051730 polymorphism may modify susceptibility to lung cancer via a smoking-independent manner among Chinese Han population. Additional studies in vitro and in vivo are warranted to further elucidate the impact of rs1051730 on lung cancer susceptibility.

Effects of GM3 on proliferation, apoptosis and VEGF expression in human lung adenocarcinoma cell line A549 cells / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To determine the effect of exogenous GM3 on proliferation, apoptosis and VEGF expression in human lung adenocarcinoma cell line A549 cells.</p><p><b>METHODS</b>A549 cells were treated with GM3 at different concentrations for 48 hours. MTT assay was used to detect the cell proliferation and flow cytometry was applied to analyze cell apoptosis. RT-PCR was used to detect the expression level of VEGF mRNA and confocal laser scanning microscopy was applied to observe the localization and fluorescence intensity of VEGF.</p><p><b>RESULTS</b>Comparing with the control, being treated with higher than 10 µmol/L GM3 significantly inhibited A549 cell proliferation (P < 0.05), and the suppressive effect could be enhanced following increasing doses. The IC(50) was 412 µmol/L. Comparing with the control, being treated with higher than 40 µmol/L GM3 significantly promoted the apoptotic rate of A549 cells (P < 0.05). Comparing with the control, being treated with higher than 40 µmol/L GM3 significantly decreased the VEGF mRNA level of A549 cells (P < 0.05), and the fluorescence intensity of VEGF distinctly weakened.</p><p><b>CONCLUSIONS</b>Exogenous ganglioside GM3 can inhibit the proliferation, promote apoptosis, and down-regulate the VEGF expression level in A549 cells. This may be considered as two mechanisms of GM3 for its anti-tumor effect by modulating cell apoptosis and angiogenesis.</p>

Growth of breast cancer cells is inhibited in vitro by cyclin E-siRNA / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the changes of biological characteristics of breast cancer cell line by cyclin E expression.</p><p><b>METHODS</b>Human breast cancer cell line MCF-7 was transfected with cyclin E siRNA vector pEGFP/CCNE2. siRNA-induced silencing of cyclin E was determined by RT-PCR at RNA level and Western blot at protein level. The proliferation of MCF-7 cells and their sensitivity to chemotherapy was measured by CCK-8 assay. The cells were examined by FCM. The cell line was injected into nude mice and the tumor size was measured.</p><p><b>RESULTS</b>The expression of cyclin E was inhibited in the MCF-7 cells. The relative expression level of cyclin E mRNA was 0.23 +/- 0.05, and that of cyclin E protein was 0.24 +/- 0.05. The cell growth was inhibited by 68.56% +/- 0.08%, and their sensitivity to chemotherapy was increased. Most cells were blocked at G(1) (77.38%), their tumorigenic ability in nude mice was reduced, and the size of tumor formed in mice of the experimental group was decreased than that of controls.</p><p><b>CONCLUSION</b>Inhibition of cyclin E expression in breast cancer cells can block their cell cycle at G(1) phase, reduce their cell growth, differentiation and proliferation, and increase their sensitivity to chemotherapy.</p>

Establishment of an I-SceI system and its application to introduce DNA double-strand break into human hepatoma cell line HepG2 / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To construct a system of I-SceI and induce a site-specific DNA double-strand break (DSB) in the genome of HepG2 for using this system in future exploration of the potential mechanisms of HBV integration by DSB repair.</p><p><b>METHODS</b>The eukaryotic expression plasmid pEGFP2 was constructed and transfected into human hepatoma cell line HepG2. The positive neomycin-resistant transfected cell clones were generated by G418 selection. Then the positive cells containing an 18-bp I-SceI endonuclease site were transfected transiently with pCMV(3NLS) I-SceI, an I-SceI expression plasmid. At 24 h post-transfection with pCMV (3NLS) I-SceI, gamma-H2AX, as an early cellular marker of DSB, was detected using immunocytochemistry and Western blot analysis.</p><p><b>RESULTS</b>Restriction analysis and DNA sequencing verified that the plasmid pEGFP2 was successfully constructed. gamma-H2AX increased significantly in cells transfected with the I-SceI system.</p><p><b>CONCLUSIONS</b>Genomic DSB can be induced into HepG2 by introducing an I-SceI system. The cell model could provide us with a practical tool for further study to see if DSB is a potential target for HBV integration.</p>

The simultaneous knock-down of Ku70 and Ku80 by a tandem Ku-shRNA-encoding plasmid expression system / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To extend the use of vector-derived siRNA by generating multiple shRNAs in the same plasmid.</p><p><b>METHODS</b>Construct a vector that expresses shRNAs targeting on Ku70 and Ku80 in tandem. The gene silencing efficiency of each shRNA was verified previously. After identification by restriction digestion and DNA sequencing, the reconstructed plasmid, named psiRNAKus, was transfected into the human hepatoma cell line HepG2. The tandem-shRNA-induced silencing of targeted genes was determined by RT-PCR at RNA level and Western blot at protein level.</p><p><b>RESULTS</b>The shRNAs encoded by psiRNAKus down-regulated both the expression of Ku70 and Ku80.</p><p><b>CONCLUSION</b>The vector-derived siRNA delivery system that allows multiple shRNA species to be expressed from the same vector may be of value in experimental and therapeutic applications.</p>