[Pollution characteristics and risk assessment of carcinogenicity or non-carcinogenicityonheavy metalsin Particulate Matter 2.5 in Shenzhen]

Objective: To assess the pollution characteristics and risk assessment of carcinogenicity or non-carcinogenicity on heavy metals in PM(2.5) in Shenzhen. Methods: PM(2.5) samples were collected monthly from the year of 2014 to 2015, and analyzed by seasons. 12 heavy metal elements (Pb, Hg, Mn, Sb, Al, As, Be, Cd, Cr, Ni, Se, Tl) in PM(2.5) were detected by ICP-MS spectrometry. Health risk assessment was conducted using the recommended United States Environmental Protection Agency (USA EPA) model. Results: The median of PM(2.5) concentration was 45.10 μg/m(3) in Longgang district of Shenzhen. The non-carcinogenecity risks of the metals in PM(2.5) existed in spring, autumn and winter (HQ>1). Three metal elements including As, Mn and Cd have higher HQ levels. The carcinogenecity risk levels in four seasons were winter, autumn, spring and summer, respectively. The carcinogenecity risks in four seasons were between 10(-6) to 10(-4). As, Cr and Cd have higher carcinogenicityrisks. Conclusion: The heavy metals in PM(2.5) have both carcinogenecity risk and non-carcinogenecity risk to residents in Longgang district of Shenzhen, the occupational health management must be continuously strengthened, the further research and the measures for prevention and control should be considered.

[Construction of 3β-HSD gene silencing cell line and its effects on apoptosis induced by DEHP]

Objective: To construct 3β-HSD gene shRNA lentivirus interference vecto, then transfect into human MCF-7 cells, and construct cell line with 3β-HSD gene silencing, finally to study the effects of 3β-HSD on apoptosis induced by di- (2-ethylhexyl) phthalate (DEHP) . Methods: According to the mRNA sequence of 3β-HSD gene provided by GenBank, three interference sequences were designed and connected to PLVX-shRNA2-puro after annealing. The recombinant lentivirus vector was transfected into 293FT cells, the virus supernatants were collected and infected with MCF-7 cells. After puromycin screening, MCF-7 cells with 3β-HSD gene silencing were constructed. The cells with 3β-HSD gene silencing were identified by real-time quantitative PCR and western blot. Then the 3β-HSD gene silencing cells and MCF-7 cells were treated at various doses of DEHP for 24 hours to detect the gene expression and protein expression of apoptosis genes including Bax, Caspase-3 and Caspase-8. Results: The interference sequence of 3β-HSD gene inserted into lentivirus vector PLVX-shRNA2-puro is consistent with the designed sequence. 3β-HSD gene expression level in MCF-7 cells with 3β-HSD gene silencing was 77% lower than than that of control MCF-7 cells. 3β-HSD protein level in MCF-7 cells with 3β-HSD gene silencing was 74% lower than that of control MCF-7 cells. After DEHP treatment in MCF-7 cells with 3β-HSD gene silencing and control MCF-7 cells, qRT-PCR results showed that Bax gene expression levels increased by 28%-54%, Caspase-3 gene increased by 13%-49%, Caspase-8 gene increased by 21%-70% in MCF-7 cells when compared with the control group. Additionally, in the 3β-HSD gene silencing cells, Bax gene expression level decreased by 11%-28%, Caspase-3 gene expression decreased by 12%-23%, Caspase-8 gene expression decreased by 11%-34%, compared with the same treatment group of MCF-7 cells. Western blot results showed that Bax protein expression level increased by 28%-61%, Caspase-3 protein expression level increased by 40%-48%, Caspase-8 protein increased by 31%-84% in MCF-7 cells when compared with the control group. In 3β-HSD gene silencing cells, Bax protein expression level increased by 11%-27%, Caspase-3 protein increased by 21%-40%, Caspase-8 protein increased by 12%-25%, compared with the same treatment group of MCF-7 cells. Conclusion: The stable 3β-HSD gene silencing cell line are successfully constructed in this study. DEHP can induce increased expression of apoptotic gene and protein. Silencing of 3β-HSD gene can inhibit the activation of apoptotic gene by DEHP in a certain degree.

[Performance of Knosp grade for cavernous sinus invasion of Cushing's disease]

Objective: To review the outcomes in patients with Cushing's disease (CD) after transsphenoidal surgery (TSS) and to assess the performance of Knosp grade for cavernous sinus invasion (CSI). Methods: Medical records were reviewed for patients with CD undergoing TSS from 1978 to 2017 at Peking Union Medical College Hospital. Based on whether CSI was observed during surgery, the sensitivity and specificity of Knosp grade for CSI were evaluated. Results: There were 1 061 records of CD reviewed, 83 (7.82%) of which were invasive tumors evaluated by surgery, and 44 (53.0%) of these remained in endocrinological remission at the last follow-up. The sensitivity of Knosp grade for CSI was 47.0%, and the specificity was 91.1%; besides, the positive predictive value was 31.0%, and the negative predictive value was 95.3%. Conclusions: Initial TSS for CD with invasive adenomas is of relatively low remission rate. Knosp grade 0-2 for non-invasive tumors is reliable, while it is doubtful whether or not Knosp grade 3-4 indicates invasive tumor.

Cognitive Frailty and Its Association with Nutrition and Depression in Community-Dwelling Older People

BACKGROUND

Cognitive frailty is a condition where physical frailty and mild cognitive impairment (MCI) co-exist. It is associated with increased risk of dementia and dependency. Previous studies reported that malnutrition and depression are associated with physical frailty and MCI; however, their relationships with cognitive frailty remained to be explored. The aims of this study were to examine the association of nutrition and depression with cognitive frailty, in comparison to having physical frailty or MCI alone.

METHODS

This study employed a cross-sectional design. Data collection was conducted in the community settings on the older people without dementia. Dependent variables were cognitive frailty, physical frailty, and MCI. The independent variables were depression and nutrition. Multi-nominal regression was employed to examine the relationships between the dependent and independent variables. The associations were adjusted by four known co-variates, including age, gender, education and APOE ε4 carrier status.

RESULTS

A total of 185 participants were recruited from four community centres and one elderly hostel and completed the data collection. Approximately 44.9% of the older people with physical frailty and 82.5% of elderly with MCI belonged to cognitive frailty. Multi-nominal regression models showed that depression is positively associated with cognitive frailty and with physical frailty, but not associated with solely MCI. Nutrition is negatively associated with cognitive frailty, but not associated with physical frailty or MCI alone.

CONCLUSION

Cognitive frailty is associated with malnutrition and depression. Therapeutic interventions managing depression and malnutrition may focus the older people with cognitive frailty to improve efficacy and cost-effectiveness.

[Factors influencing survival of patients with pancreatic adenocarcinoma after surgical resection]

Objective: To investigate the clinical outcomes and prognostic factors in patients with pancreatic cancer after surgical resection with curative intent and analyze factors affecting 2-year and 5-year survival of patients. Methods: A total of 469 patients with pancreatic adenocarcinoma undergoing curative resection were included in the study, and the clinical data of these patients were analyzed retrospectively. Univariate and multivariate analyses were performed to examine factors affecting prognosis of these patients. The clinicopathological characteristics of patients who survived for ≤2 years and >2 years as well as ≤5 years and >5 years were compared, respectively. Results: The multivariate analysis showed that lymphovascular invasion (P=0.024), lymph node metastasis (P<0.001), vascular resection (P=0.002), maximum tumor diameter >2 cm (P=0.009), poor differentiation (P<0.001) were negative prognosis factors, but postoperative chemotherapy (P<0.001) was an independent positive prognostic factor. Comparison of the patients who survived for ≤2 years and >2 years showed that lymphovascular invasion (P=0.012), lymph node metastasis (P<0.001), vascular resection (P=0.014), maximum tumor diameter>2 cm (P=0.004), poor differentiation (P<0.001), peri-pancreatic fat invasion (P=0.005), absence of postoperative chemotherapy (P<0.001), advanced tumour, node and metastasis (TNM stage) (P<0.001) were associated with 2-year survival. With regard to 5-year survival, lymph node metastasis (P=0.005), poor differentiation (P=0.014) and TNM stage(P=0.025) were associated with it. Conclusions: Our results suggest that lymphovascular invasion, lymph node metastasis, vascular resection, maximum tumor diameter >2 cm, poor differentiation and absence of postoperative chemotherapy were independent negative prognostic factors. Lymph vascular invasion, lymph node metastasis, vascular resection, maximum tumor diameter >2 cm, poor differentiation, peri-pancreatic fat invasion, absence of postoperative chemotherapy, advanced TNM stage were associated with 2-year survival, and lymph node metastasis, degree of differentiation and TNM stage are important prognosis factors affecting long-term survival of patients.

A modified method for plasmid extraction from Lactobacillus plantarum contained lysozyme removal step

Plasmids of Lactobacillus plantarum PC518 cannot be effectively extracted by existing methods. It was studied that the effect of lysozyme treatment and removal on plasmid extraction by 7 protocols. The modified method was compared with a commercial kit using L. plantarum PC518, 410, 9L15, and JS193 and Weissella cibaria M2 as the tested strains. The results suggested that the step of lysozyme removal is the key to improve the efficiency of plasmid extraction. The concentrations of plasmid DNA isolated from the 5 tested strains were increased by 10.6, 9.5, 6, 5.6 and 1.5 times respectively compared with the commercial kit.

Correction to: Characterization of bactericidal efficiency, cell selectivity, and mechanism of short interspecific hybrid peptides

Facing rising global antibiotics resistance, physical membrane-damaging antimicrobial peptides (AMPs) represent promising antimicrobial agents. Various strategies to design effective hybrid peptides offer many advantages in overcoming the adverse effects of natural AMPs.

Computational study of aortic hemodynamics for patients with an abnormal aortic valve: The importance of secondary flow at the ascending aorta inlet

Blood flow in the aorta is helical, but most computational studies ignore the presence of secondary flow components at the ascending aorta (AAo) inlet. The aim of this study is to ascertain the importance of inlet boundary conditions (BCs) in computational analysis of flow patterns in the thoracic aorta based on patient-specific images, with a particular focus on patients with an abnormal aortic valve. Two cases were studied: one presenting a severe aortic valve stenosis and the other with a mechanical valve. For both aorta models, three inlet BCs were compared; these included the flat profile and 1D through-plane velocity and 3D phase-contrast magnetic resonance imaging derived velocity profiles, with the latter being used for benchmarking. Our results showed that peak and mean velocities at the proximal end of the ascending aorta were underestimated by up to 41% when the secondary flow components were neglected. The results for helical flow descriptors highlighted the strong influence of secondary velocities on the helical flow structure in the AAo. Differences in all wall shear stress (WSS)-derived indices were much more pronounced in the AAo and aortic arch (AA) than in the descending aorta (DAo). Overall, this study demonstrates that using 3D velocity profiles as inlet BC is essential for patient-specific analysis of hemodynamics and WSS in the AAo and AA in the presence of an abnormal aortic valve. However, predicted flow in the DAo is less sensitive to the secondary velocities imposed at the inlet; hence, the 1D through-plane profile could be a sufficient inlet BC for studies focusing on distal regions of the thoracic aorta.

Effects of Leukaemia Inhibitory Factor Receptor on the Early Stage of Osteogenic Differentiation of Human Bone Marrow Mesenchymal Cells

Leukaemia inhibitory factor (LIF) has a wide variety of biological activities. While recent studies have focused on the role of LIF in osteoblast differentiation, the exact role of LIFR during the early stage of osteogenic differentiation remains unclear. We observed that LIFR expression gradually decreased during the early stage of osteogenic differentiation of hMSCs. To evaluate how LIFR regulates osteogenic differentiation in greater depth, we transfected hMSCs with LIFR overexpression and siRNA lentiviral plasmids. Cells were divided into four groups: a negative overexpression control group, a LIFR overexpression group, a negative siRNA control group, and a LIFR siRNA group. On different days (0, 3, and 6) of the osteogenic differentiation of hMSCs, alkaline phosphatase (ALP) activity was assayed with an ALP staining and activity assay kit. Cells were harvested to assess the mRNA and protein expression of LIF, LIFR, and osteogenesis-related factors (ALP; RUNX2; osteonectin) by qRT-PCR and western blot analyses, respectively. In addition, culture supernatants were tested for the LIF content by ELISA. Our results showed that overexpression of LIFR significantly suppressed the osteoblast differentiation of hMSCs. In contrast, LIFR siRNA markedly improved this osteoblast differentiation as determined by ALP staining and activity measurements. Moreover, RUNX2, ALP, and ONN expression was also significantly changed by altering LIFR expression. We further analysed the expression of LIF and LIFR, revealing consistent LIF and LIFR trends during the osteogenic differentiation of hMSCs. Together, these results suggested that LIFR may be a novel negative regulator during the early stage of hMSC osteogenic differentiation.

Characterization of bactericidal efficiency, cell selectivity, and mechanism of short interspecific hybrid peptides

Facing rising global antibiotics resistance, physical membrane-damaging antimicrobial peptides (AMPs) represent promising antimicrobial agents. Various strategies to design effective hybrid peptides offer many advantages in overcoming the adverse effects of natural AMPs. In this study, hybrid peptides from different species were investigated, and three hybrid antimicrobial peptides, LI, LN, and LC, were designed by combining the typical fragment of human cathelicidin-derived LL37 with either indolicidin, pig nematode cecropin P1 (CP-1) or rat neutrophil peptide-1 (NP-1). In an aqueous solution, all hybrid peptides had an unordered conformation. In simulated membrane conditions, the hybrid peptide LI displayed more β-turn and β-hairpin structures, whereas LN and LC folded into α-helix structures. The three interspecific hybrid peptides LI, LN, and LC exhibited different levels of antimicrobial activity against Gram-positive and Gram-negative bacteria. LI demonstrated the highest antimicrobial activity and cell selectivity. The results of the swimming motility indicated that LI repressed bacterial motility in a concentration-dependent method. Endotoxin binding assay demonstrated that hybrid peptide LI conserved the binding ability to LPS (polyanionic lipopolysaccharides) of its parental peptides. Fluorescence assays, flow cytometry, and SEM further revealed that hybrid peptide LI acted through different bacteriostatic mechanisms than LL37 and indolicidin and that LI killed bacterial cells via membrane damage. In summary, this study demonstrated that hybrid peptide LI produced by interspecific hybrid synthesis possessed strong cell selectivity and is a promising therapeutic candidate for drug-resistant bacteria infection.

[Silencing of vacuolar ATPase c subunit ATP6V0C inhibits invasion of prostate cancer cells]

OBJECTIVE

Vacuolar ATPase (V-ATPase) was found within the membranes and internal organelles of a vast array of eukaryotic cells, and was related to various kinds of highly metastatic tumors. LASS2/TMSG1 gene was a novel tumor metastasis suppressor gene cloned from human prostate cancer cell line PC-3M in 1999 by our laboratory. It was found out that protein encoded by LASS2/TMSG1 could interact with the c subunit of V-ATPase (ATP6V0C). In this study, To use RNA interference to suppress the expression of ATP6V0C and try to further investigate the molecular mechanism of ATP6V0C in tumor metastasis and its relationship with LASS2/TMSG1 gene.

METHODS AND RESULTS

The expression level of ATP6V0C mRNA and protein in high metastatic potential prostate cancer cell lines (PC-3M-1E8 and PC-3M) was significantly higher than that in low metastatic potential prostate cancer cell lines (PC-3M-2B4 and PC-3), the expression level in PC-3M-1E8 being the highest. Follow-up tests selected PC-3M-1E8 cells for gene silencing. The expression and secretion of MMP-2 and the expression of MMP-9 in ATP6V0C siRNA transfected PC-3M-1E8 cells displayed no obvious change, but the activity of secreted MMP-9 was abated noticeably compared with the controls (P<0.05). Extracellular hydrogen ion concentration and V-ATPase activity in interference group were both reduced significantly compared with the controls (P<0.05). The migration and invasion capacity of ATP6V0C siRNA interfered cells in vitro were diminished significantly compared with the controls (P<0.05). Furthermore, a dramatic reduction of LASS2/TMSG1 mRNA and protein level after transfection of siRNA in PC-3M-1E8 cells was discovered (P<0.05). Confocal immunofluorescence showed a vast co-localization of ATP6V0C protein and LASS2/TMSG1 protein in plasma and membrane. The co-localization signals of control group were much stronger than those of interference group.

CONCLUSION

Specific siRNA silencing of ATP6V0C gene inhi-bits the invasion of human prostate cancer cells in vitro by mechanism of inhibiting V-ATPase activity and then reducing the extracellular hydrogen ion concentration, inhibiting MMP-9 activation and affecting ECM degradation and reconstruction. Meanwhile, ATP6V0C and LASS2/TMSG1 have interaction and it is likely that ATP6V0C functions as a feedback regulator of LASS2/TMSG1.

[Serum CXCL-10 level in chronic hepatitis C patients with cryoglobulinemia and its influence on antiviral therapy]

Objective: To investigate the serum CXCL-10 level in chronic hepatitis C (CHC) patients with cryoglobulinemia and its influence on the effect of antiviral therapy. Methods: A total of 50 CHC patients were enrolled in the study. Cryoprecipitation was used to determine the nature of cryoglobulins in serum before treatment, and ELISA was used to measure the serum CXCL-10 level. The hepatitis C virus (HCV) genotype was detected, and serum HCV RNA level was measured at baseline, 4, 12, and 24 weeks of treatment, the end of treatment, and 24 weeks after treatment.. Results: Compared with the cryoglobulin-negative patients, the cryoglobulin-positive patients had significantly higher baseline levels of HCV RNA [(6.28±0.79) log10 copies/ml vs (5.48±1.20) log10 copies/ml, P = 0.009] and CXCL-10 (541.67±224.07 pg/ml vs 394.39±179.71 pg/ml, P = 0.015). After the treatment with pegylated interferon-α-2a and ribavirin, the cryoglobulin-positive patients had a significantly lower proportion of individuals who achieved rapid virological response compared with the cryoglobulin-negative patients (33.3% vs 82.6%, P < 0.001). The cryoglobulin-positive patients had a significantly lower rate of sustained virologic response than the cryoglobulin-negative patients (33.3% vs 78.3%, P = 0.001). Conclusion: The patients with cryoglobulinemia have higher serum levels of HCV RNA and CXCL-10 and poor outcomes compared with those without cryoglobulinemia.

[Feasibility and value of index of microcirculatory resistance in patients with acute myocardial infarction after primary percutaneous coronary intervention]

Objective: To evaluate the feasibility of detecting index of microcirculatory resistance (IMR) and the relationship between IMR and left ventricular (LV) systolic function after acute myocardial infarction (AMI) undergoing primary percutaneous coronary intervention (PCI). Methods: The patients with first AMI received primary PCI in Peking University Third Hospital were enrolled from January 2014 to March 2016. IMR were measured immediately after PCI by using pressure/temperature wire. The relationship between IMR and left ventricular ejection fraction (LVEF) assessed by echocardiography at first day and 6 months after admission was evaluated. Results: Twenty-eight patients with anterior wall AMI were enrolled, with an average age (56±13) years. The success rate of IMR detection was 100%. The mean IMR was (33±18 )mmHg·s. There was no complication related to intravenous adenosine triphosphate (ATP) (140 μg· kg(-1)· min(-1)). The IMR was negatively correlated with TIMI blood flow grade after primary PCI (r=-0.386, P=0.043), and positively correlated with female gender, CK peak value and TnT peak value (r=0.430, P=0.022; r=0.431, P=0.025; r=0.434, P=0.024). After 6 months of follow-up, no adverse cardiovascular events (including cardiac death, nonfatal myocardial infarction, malignant arrhythmia, unplanned revascularization, hospitalization for unstable angina pectoris and severe heart failure requiring hospitalization) occurred. LVEF increased significantly compared with the first day after PCI (0.54±0.08 vs 0.47±0.06, P=0.001), and IMR was negatively correlated with LVEF after 6 months (r=-0.477, P=0.014). Multivariable linear regression analysis showed that CK peak and IMR were predictors of LVEF after six months ( β=-0.595, t=-3.814, P=0.01; β=-0.352, t=-2.26, P=0.036). Conclusions: Immediate detection of IMR in patients with anterior wall AMI after PCI is safe and feasible. The immediate IMR after PCI reflects the extent of myocardial necrosis and myocardial perfusion, and is a predictor of LVEF at 6 months after PCI.

[High expression of hnRNPAB/Kap1 together promote poor prognosis in HCC]

Objective: To further understand the interaction protein spectrum of heterogeneous ribonucleoprotein AB (hnRNP AB), and to investigate their clinical significance in hepatocellular carcinoma (HCC). Methods: We carried out mass spectrometry to reveal the specific peptides of KRAB-associated protein 1 (Kap1) and hnRNPAB, and verified their interaction by immunocoprecipitation and western blotting. Expression of hnRNPAB/Kap1 proteins were detected by immunohistochemical staining in the tissue microarrays. Categorical data were analyzed by the chi square test or Fisher exact test; enumeration data between groups were compared using Student t-test or Wilcocon signed rank test; the cumulative recurrence and survival rates were evaluated using the Kaplan-Meier method and the differences were assessed using the log-rank test. Results: We identified Kap1 as a molecular partner for hnRNPAB in HCCLM3 cells and HepG2 cells as well. We found that the 5-year survival rate of the Kap1high patients was significantly lower than the survival rate of those of the Kap1low group (36% vs 59% , HR = 1.67, P < 0.001). Similarly, Kap1high HCC patients had the poorest prognosis at 5-years, with higher cumulative recurrence rate than Kap1low patients (72% vs 54%, HR = 1.66, P = 0.001). Univariate and Multivariate analyses revealed that hnRNPAB /Kap1 alone (HR = 1.35 /1.28, P = 0.001) or in combination with Kap1 (HR =1.24 /1.27, P < 0.05) were independent prognostic indicators for overall survival and time to recurrence. Conclusion: In HCC cells, hnRNPAB and Kap1 form protein complexes. The expression levels of hnRNPAB alone or in combination with Kap1 in HCC patients are important because they provide not only a predictor for HCC prognosis but also a therapeutic target for future studies.

On the choice of outlet boundary conditions for patient-specific analysis of aortic flow using computational fluid dynamics

Boundary conditions (BCs) are an essential part in computational fluid dynamics (CFD) simulations of blood flow in large arteries. Although several studies have investigated the influence of BCs on predicted flow patterns and hemodynamic wall parameters in various arterial models, there is a lack of comprehensive assessment of outlet BCs for patient-specific analysis of aortic flow. In this study, five different sets of outlet BCs were tested and compared using a subject-specific model of a normal aorta. Phase-contrast magnetic resonance imaging (PC-MRI) was performed on the same subject and velocity profiles extracted from the in vivo measurements were used as the inlet boundary condition. Computational results obtained with different outlet BCs were assessed in terms of their agreement with the PC-MRI velocity data and key hemodynamic parameters, such as pressure and flow waveforms and wall shear stress related indices. Our results showed that the best overall performance was achieved by using a well-tuned three-element Windkessel model at all model outlets, which not only gave a good agreement with in vivo flow data, but also produced physiological pressure waveforms and values. On the other hand, opening outlet BCs with zero pressure at multiple outlets failed to reproduce any physiologically relevant flow and pressure features.

Identification of genes related to floral organ development in pak choi by expression profiling

Pak choi is a highly nutritious vegetable that is widely grown in China, Southeast Asia, and other parts of the world. Because it reproduces by seed, it is very important to understand the mechanism of floral organ development. Therefore, using the Chinese cabbage genome as a reference, this study analyzed the expression profiles of shoot apex genes at flower bud differentiation stages 1 and 5, in order to identify genes related to floral organ development. The results showed that the proportion of mapped genes was high, with 84.25 and 83.80% of clean reads from the two sample saligned to the reference genome, respectively. A total of 525 differentially expressed genes (DEGs) were identified, 224 of which were upregulated and 301 were downregulated. The expression levels of genes homologous to Chinese cabbage flowering genes were also analyzed at stages 1 and 5; the expression levels of Bra012997 (ap1), Bra000393 (SOC1), and Bra004928 (SOC1) were significantly upregulated at stage 5, suggesting that these three genes positively regulate floral development in pak choi. DEGs involved in floral organ development were analyzed with homologous genes from Arabidopsis thaliana; the homologous genes Bra029281 (AGL42), Bra026577 (ARPN), Bra022954 (SPL3), Bra029293 (ARF2), Bra007978 (AtRLP12), Bra033221 (SPL8), Bra008037 (LOX4), Bra001598 (IAA19), Bra003892 (PATL1), Bra038778 (AT4G21323), Bra025315 (KLCR2), and Bra013906 (DTX35) are directly related to floral organ development in Arabidopsis, suggesting that these genes have corresponding functions during flower organ development in pak choi, and could be candidates for further genetic research. These results provide a foundation for research on the molecular mechanism of flower organ development in pak choi and other Brassica rapa vegetables.

[Effects of chrysin on sphere formation and CK2α expression of ovarian cancer stem-like cells derived from SKOV3 cell line]

OBJECTIVE

To investigate whether inhibitory effect of chrysin on sphere formation of ovarian cancer stem-like cells(spheroids derived from human ovarian cancer SKOV3 cell line ) is involved in the down-regulating of the protein expression of casein kinase CK2α.

METHODS

SKOV3-derived ovarian cancer stem-like cells obtained by suspension culture in stem cell-condition medium using ultra-low adhesion plate were treated with various concentrations (5.0, 10.0 and 20.0 μmol/L) of chrysin. Sphere formation assay was used to determine the sphere forming rate of SKOV3-derived ovarian cancer stem-like cells. Western blot was used to analyze the protein expressions of CK2α and cancer stem cell markers CD133 and CD44. Silence of CK2α by siRNA and ectopic expression of CK2α by transfection with pcDNA3.1-CK2α plasmid were used to explore the mechanism underlying the effect of chrysin on sphere formation of SKOV3-derived ovarian cancer stem-like cells.

RESULTS

Chrysin (5.0, 10.0 and 20.0 μmol/L) significantly reduced the sphere forming rate of SKOV3-derived ovarian cancer stem-like cells, in a concentration-dependent manner (22.3%±2.5% vs 14.7%±2.1%, 8.6%± 1.7% and 3.8% ± 1.1% respectively; P<0.05). In addition, chrysin (5.0, 10.0 and 20.0 μmol/L) obviously down-regulated the protein expressions of CK2α, CD133 and CD44 in SKOV3-derived ovarian cancer stem-like cells. In combination with CK2α siRNA transfection and chrysin synergistically decreased sphere formation (P<0.05) and the protein expressions of CK2α, CD133 and CD44 in SKOV3-derived ovarian cancer stem-like cells. However, transfection with pcDNA3.1-CK2α plasmid attenuated inhibitory effects of chrysin on sphere formation capability and the expressions of CK2α, CD133 and CD44 of SKOV3-derived ovarian cancer stem-like cells.

CONCLUSION

Down-regulation of CK2α protein expression is involved in the inhibition effect of chrysin on the sphere formation capability of SKOV3-derived ovarian cancer stem-like cells.

[Large-cell lung carcinoma by the 2015 WHO classification: a clinicopathologic analysis of 93 cases]

OBJECTIVE

To analyze the clinicopathologic characteristics of large-cell lung carcinoma (LCC) subtypes according to the 2015 WHO classification.

METHODS

A total of 93 cases of LCC were identified among 1 634 cases of morphologically undifferentiated non-small cell lung carcinoma. Clinicopathologic and immunohistochemical characteristics were retrospectively reviewed.

RESULTS

Among 93 cases of LCC, 50 cases were solid adenocarcinoma (53.8%), 21 cases were non-keratinzing squamous cell carcinoma (22.6%), 3 cases were adenosquamous carcinoma (3.2%), 8 cases were large cell carcinoma with unclear immunohistochemical features (8.6%), and 11 cases were large cell carcinoma with null immunohistochemical features (11.8%). No significant differences in clinical features were found among various immunophenotypes. The overall survival of 1, 3 and 5 years of all cases was 51.0%, 5.4% and 1.1%, respectively and the mean survival was (15.2±1.2)months. Notably the null type had the lowest survival rate of 18% in one year, significantly worse than those of solid adenocarcinoma and non-keratinzing squamous cell carcinoma.

CONCLUSIONS

The 2015 WHO classification based on immunohistochemical phenotype replaces the morphological approach in separating poorly differentiated non-small cell lung carcinoma from the former large cell lung carcinoma. The null immunohistochemical subtype may represent a distinct subtype of undifferentiated carcinoma with the worst prognosis.

Studies of Blood Flow in Arterial Bifurcations Using Computational Fluid Dynamics

The local blood flow in arteries, especially at bends and bifurcations, is correlated with the distribution of atherosclerotic lesions. The flow is three-dimensional, unsteady and difficult to measure in vivo. In this paper a numerical treatment of blood flow in general three-dimensional arterial bifurcations is presented. The flow is assumed to be laminar and incompressible, the blood non-Newtonian and the vessel wall rigid. The three-dimensional time-dependent Navier-Stokes equations are employed to describe the flow, and a newly developed computational fluid dynamics (CFD) code AST EC based on finite volume methods is used to solve the equations. A comprehensive range of code validations has been carried out. Good agreement between numerical predictions and in vitro model data is demonstrated, but the correlation with in vivo measurements is less satisfactory. Effects of the non-Newtonian viscosity have also been investigated. It is demonstrated that differences between Newtonian and non-Newtonian flows occur mainly in regions of flow separation. With the non-Newtonian fluid, the duration of flow separation is shorter and the reverse flow is weaker. Nevertheless, it does not have significant effects on the basic features of the flow field. As for the magnitude of wall shear stress, the effect of non-Newtonian viscosity might not be negligible.

Increased Expression of Lamin A/C Correlate with Regions of High Wall Stress in Abdominal Aortic Aneurysms

BACKGROUND

Since aortic diameter is the most -significant risk factor for rupture, we sought to identify stress-dependent changes in gene expression to illuminate novel molecular processes in aneurysm rupture.

MATERIALS AND METHODS

We constructed finite element maps of abdominal computerized tomography scans (CTs) of seven abdominal aortic aneurysm (AAA) patients to map wall stress. Paired biopsies from high- and low-stress areas were collected at surgery using vascular landmarks as coordinates. Differential gene expression was evaluated by Illumina Array analysis, using the whole genome DNA-mediated, annealing, selection, extension, and ligation (DASL) gene chip (n = 3 paired samples).

RESULTS

The sole significant candidate from this analysis, Lamin A/C, was validated at the protein level, using western blotting. Lamin A/C expression in the inferior mesenteric vein (IMV) of AAA patients was compared to a control group and in aortic smooth muscle cells in culture in response to physiological pulsatile stretch. -Areas of high wall stress (n = 7) correlate to those -regions which have the thinnest walls [778 µm (585-1120 µm)] in comparison to areas of lowest wall stress [1620 µm (962-2919 µm)]. Induced expression of Lamin A/C -correlated with areas of high wall stress from AAAs but was not significantly induced in the IMV from AAA patients compared to controls (n = 16). Stress-induced expression of Lamin A/C was mimicked by exposing aortic smooth muscle cells to prolonged pulsatile stretch.

CONCLUSION

Lamin A/C protein is specifically increased in areas of high wall stress in AAA from patients, but is not increased on other vascular beds of aneurysm patients, suggesting that its elevation may be a compensatory response to the pathobiology leading to aneurysms.

Linker length affects expression and bioactivity of the onconase fusion protein in Pichia pastoris

The aim of this study was to analyze the effect of linker length on the expression and biological activity of recombinant protein onconase (ONC) in fusion with human serum albumin (HSA) in Pichia pastoris. Four flexible linkers with different lengths namely Linker L0, L1: (GGGGS)1, L2: (GGGGS)2, and L3:(GGGGS)3 were inserted into the fusion gene and referred to as HSA-n-ONC, where N = 0, 5, 10, or 15. The sequence of the fusion gene HSA-ONC was designed based on the GC content and codon bias in P. pastoris; the signal peptide of albumin was used as the secretion signal. Gene sequences coding for the fusion protein with different linkers were inserted into pPICZα-A to form recombinant plasmids pPICZα-A/HSA-n-ONC, which were then transformed into P. pastoris X-33 for protein expression. Ideal conditions for expression of the fusion proteins were optimized at a small scale, using shake flasks before proceeding to mass production in 10-L fermenters. The recombinant fusion proteins were purified by aqueous two-phase extraction coupled with DEAE anion exchange chromatography, and their cytotoxic effect on the tumor cell was evaluated by the sulforhodamine B assay. The results showed that the expressed amount of fusion proteins had no significant relationship with the length of different linkers and rHSA-0-ONC had no cytotoxic effect on the tumor cells. While rHSA-5-ONC and rHSA-10-ONC had a weak cytotoxic effect, rHSA-15-ONC could kill various tumor cells in vitro. In summary, the biological activity of the fusion protein gradually improved with increasing length of the linker.

Decreased expression of tumor suppressive miR-874 and its clinical significance in human osteosarcoma

Dysregulation of microRNAs (miRs) is associated with cancer development and progression and aberrant expression of miR-874 have been found in some types of cancer. However, the expression and function of miR-874 in osteosarcoma remain unclear. The aim of this study was to explore the effects of miR-874 in osteosarcoma tumorigenesis and development. The expression level of miR-874 was quantified by real-time reverse transcription-polymerase chain reaction (RT-PCR) in human osteosarcoma cell lines and tissues. Using a miR-874 mimic, cell proliferation and migration assays were performed in an osteosarcoma cell line and tumorigenicity was observed in vivo in order to determine the effects of miR-874 in osteosarcoma cell lines and tissues. MiR-874 was significantly downregulated in osteosarcoma cell lines and clinical specimens. Decreased miR-874 expression was significantly associated with large tumor size, distant metastasis, and advanced clinical stage, and was an independent predictor of poor survival. Overexpression of miR-874 inhibited cell proliferation, invasion and migration in vitro, promoted cell apoptosis in vitro, and suppressed tumorigenicity in vivo. These findings indicate that miR-874 may act as a tumor suppressor in osteosarcoma and could serve as a novel therapeutic agent for miR-based therapy.

Clinical significance of microRNA-34a in esophageal squamous cell carcinoma

MicroRNA-34a (miR-34a) has been found to be downregulated in esophageal squamous cell carcinoma (ESCC) tissues compared with that in normal tissues (P < 0.05), and miR-34a overexpression increased apoptosis and decreased clonogenic formation. However, the clinical significance and prognostic value of miR-34a in ESCC has not yet been investigated. In total, 111 patients with ESCC diagnosed and treated at the Department of Thoracic Surgery of Fujian Provincial Hospital between March 2008 and February 2014 were included in this retrospective study. Quantitative real-time PCR was performed to detect expression levels of miR-34a. The associations between miR-34a expression and clinicopathological features were analyzed using χ(2) tests. For analysis of survival data, Kaplan-Meier curves were constructed, and the log-rank test was performed. The expression levels of miR-34a in ESCC tissues were significantly decreased (P < 0.01), compared with those in adjacent normal esophageal tissues. Low miR-34a expression in ESCC tissues was significantly associated with tumor differentiation (P = 0.013), lymph node status (P = 0.038), and advanced clinical stage (P < 0.001). The Kaplan-Meier analysis and log-rank test revealed that low miR-34a levels had a significant impact on overall survival of patients with ESCC (P = 0.006). Multivariate analyses showed that the expression of miR-34a was an independent prognostic factor for ESCC (P = 0.018). Our findings indicate that there is reduced expression of miR-34a in human ESCC tissues and suggest a crucial role for miR-34a downregulation in ESCC progression and prognosis.