TP53 mitigates cisplatin resistance in non-small cell lung cancer by mediating the effects of resistant cell-derived exosome mir-424-5p.

Background: Cisplatin (DDP) is the principal agent used for chemotherapy in patients with non-small cell lung cancer (NSCLC). Nevertheless, DDP resistance is an essential cause for a worse prognosis of patient. Therefore, this study proposes to discover features of miR-424-5p in DDP resistance of NSCLC. Method: After exogenous modulation of miR-424-5p expression, A549 cell activity was measured using CCK-8 and flow cytometry. A549/DDP and A549/DDP-associated subcutaneous tumor model were constructed to investigate the effect of miR-424-5p on DDP resistance in NSCLC in vivo. TargetScan and JASPAR databases predicted the potential molecular mechanism of miR-424-5p. A549-and A549/DDP-derived exosomes were isolated and characterized using a transmission electron microscope and nanoparticle tracking analysis. Result: Overexpression of miR-424-5p facilitated proliferation and DDP resistance in A549 cells, and knockdown of miR-424-5p did the opposite. Knockdown of miR-424-5p enhanced DDP restriction on tumor weight and volume. Moreover, SOCS5 and SOCS56 (SOCS5/6) were downstream targets of miR-424-5p. miR-424-5p down-regulated SOCS5/6 expression to activate JAK2/STAT3 and PI3K/AKT pathways. Notably, tumor protein p53 (TP53) is a transcription factor for the miR-424-5p host gene, as confirmed by the dual-luciferase reporter gene. Cellular and animal experiments indicated that TP53 limited the regulatory function of miR-424-5p on NSCLC growth, DDP resistance, and related molecules. Interestingly, miR-424-5p was markedly enriched in A549/DDP cell-derived exosomes than in A549 cell-derived exosomes, and TP53 down-regulated miR-424-5p expression in A549/DDP cell-derived exosomes. Conclusion: DDP-resistant cell-derived exosome miR-424-5p contributes to NSCLC growth and DDP resistance by targeting SOCS5 and SOCS6 to activate JAK2/STAT3 and PI3K/AKT pathways, which are blocked by TP53.

Identification of the interchromophore interaction in the electronic absorption and circular dichroism spectra of bis-phenanthrenes.

We characterize the low-lying excited electronic states of a series of bis-phenanthrenes using our newly developed diabatic scheme called the fragment particle-hole density (FPHD) method and calculate both the electronic absorption and circular dichroism (ECD) spectra using the time-dependent density functional theory (TDDFT) and the FPHD-based exciton model which couples intrachromophore local excitations (LEs) and the interchromophore charge-transfer excitations (CTEs). TDDFT treats each bis-phenanthrene as a single molecule while the mixed LE-CTE exciton model partitions the molecule into two phenanthrene-based aromatic moieties, and then applies the electronic coupling between the various quasi-diabatic states to cover the interactions. It is found that TDDFT and the mixed LE-CTE model reproduce all experimentally observed trends in the spectral profiles, and the hybridization between LE and CTE states is displayed differently in absorption and ECD spectral intensities, as it usually decreases the absorption maxima and affects the positive/negative extrema of the ECD irregularly. By comparing the results yielded by the LE-CTE model with and without the LE-CTE coupling, we identify the contribution of CTE on the main dipole-allowed transitions.

Palladium-Catalyzed Direct Arylation of 2-Pyridylmethyl Silanes with Aryl Bromides.

The first palladium-catalyzed direct arylation of 2-pyridylmethyl silanes with aryl bromides to generate a diverse array of aryl(2-pyridyl)-methyl silane derivatives has been developed. This protocol facilitates access to various kinds of heterocycle-containing silanes in good to excellent yields (40 examples, 66-97% yield) with good functional group tolerance. The scalability of this transformation is demonstrated.

[The relationship between the aquaporin-4 and brain edema, pathologic change, ultrastructure in peri-hematoma tissue in patients with intracerebral hemorrhage].

OBJECTIVE: To observe the expression of aquaporin-4 (AQP-4) mRNA and study the relationship between AQP-4, brain edema, pathological changes and ultrastructure of peri-hematoma tissue in intracerebral hemorrhage (ICH) patients. METHODS: Intracranial operation was performed via nonfunctional area with a funnel-like approach on 30 ICH patients. The brain tissue which must be removed 1 cm away the hematoma was removed within 12 hours for observation as normal brain tissue and taken as the control group (7 patients), and which of the brain tissue within 1 cm around hematoma was taken as the study specimens. The experimental group was subdivided into five groups according to the time interval after ICH: <6 hours (6 cases), 6-12 hours (7 cases), 12-24 hours (5 cases), 24-72 hours (6 cases), and >72 hours ( 6 cases ). Expression of the AQP-4 mRNA, brain edema, pathological and ultrastructural changes were observed with reverse transcription-polymerase chain reaction (RT-PCR), light microscope and electron microscope. RESULTS: The expression of the AQP-4 mRNA was not remarkable, the morphology and construction were basically normal in control group. The expression of AQP-4 mRNA was mild (1.17+/-0.41)and there was edema of neuroglia in the <6 hours group. After 6 hours, besides neuroglial edema, the expression of the AQP-4 mRNA was gradually obvious, capillary endothelial cells began to swell too, and tight junctions gradually began to loosen. In the 12-72 hours group the expression of the AQP-4 mRNA reached its peak (3.50+/-0.55, 3.60+/-0.55, both P<0.01), and brain edema was most prominent, and electron microscopy showed that neurons, neuroglia, and capillary endothelial cells were markedly deformed. After 72 hours, the expression of AQP-4 mRNA gradually recovered, and brain cells showed less damage. On the 5th day the damage began to repair, and on the 8th day, the damage was basically repaired. The correlation analysis showed that there was a remarkable positive correlation between the expression of the AQP-4 mRNA and the degree of brain edema and the size of hematoma (r(1)=0.67, P<0.01; r(2)=0.44, P<0.05) . CONCLUSION: Secondary edema and brain damage may correlate with the expression of the AQP-4 mRNA in the peri-hematoma brain edema area. Removal of hematoma will help decrease the AQP-4 mRNA expression and brain edema damage in the early stage.

[Pathologic changes caused by highly pathogenic H5N1 avian influenza virus: postmortem study of a case].

OBJECTIVE: To report the postmortem findings of a case of highly pathogenic H5N1 avian influenza virus occurring in human beings. METHODS: Postmortem examination was carried out in a deceased caused by highly pathogenic H5N1 avian influenza virus. Detailed light microscopy of major organs, including heart, lungs, liver, spleen, kidneys and brain, was performed. The lung tissue was further investigated by histochemistry, immunohistochemistry and electron microscopy. RESULTS: Major histopathologic changes in lungs secondary to highly pathogenic H5N1 avian influenza virus included diffuse alveolar damage, hyaline membrane formation and focal hemorrhage. Some of the alveolar spaces contained lightly eosinophilic liquid, lymphocytes, macrophages, plasma cells and small number of neutrophils. Congested capillaries were commonly seen in the alveolar septa which were focally rimmed by hyaline membrane. Immunohistochemical study showed that the lymphocytes were mainly of T lineage and macrophages were also demonstrated. CONCLUSIONS: Highly pathogenic H5N1 avian influenza virus causes pathologic changes mostly in lungs, including diffuse alveolar damage and acute exudative changes (involving mainly T lymphocytes and macrophages). The resulting parenchymal destruction, consolidation, pulmonary edema and hemorrhage eventually lead to respiratory distress and death.

[Study of relationship between inflammatory response and apoptosis in perihematoma region in patients with intracerebral hemorrhage].

OBJECTIVE: To investigate the relationship between inflammatory response and cell apoptosis in the perihematoma region in patients with intracerebral hemorrhage (ICH). METHODS: Surgical specimens were obtained from the area 1 cm adjacent to the hematoma. Thirty patients with ICH were divided into five groups: 6, 7, 5, 6, 6 patients in surgery<6 hours, 6-12 hours, 12-24 hours, 24-72 hours and >72 hours groups after the onset, respectively. The control group specimens were obtained from the brain tissues distant to the hematoma in the process of craniotomy in the patients of two former groups. Sections were stained with hematoxylin and eosin (HE) for the examination of pathological changes. Immunohistochemistry, terminal deoxynucleotidyl transferase mediated dUTP biotin nick end labeling (TUNEL) and reverse transcription-polymerase chain reaction (RT-PCR) were applied to determine apoptosis cells, Bax and Bcl-x protein and mRNA. RESULTS: The tissues from perihematoma region were almost normal in control group and <6 hours group. They were slightly damaged in 6-12 hours group, became worse in 12-24 hours group and most severe in 24-48 hours group, and they became better latter and were similar to the control group on 8th day. Infiltration of neutrophils, macrophages and lymphocyte appeared gradually at 6-12 hours, and became much more prominent at 12-24 hours (all P<0.01). The reactive gliosis began to appear at 24-72 hours, and enhanced after 72 hours (all P<0.01). The expression of the apoptosis and Bax protein increased gradually after 6 hours, reaching the peak at 12-24 hours (P<0.05 or P<0.01), and decreased gradually later. The changes in the levels of Bax mRNA were similar to that of the result of immunohistochemistry. Although the expression of Bcl-x protein and mRNA seemed to be increased at 12-72 hours, there was no significant difference between groups (P>0.05). The correlation analysis showed that the infiltration of neutrophils, macrophages and lymphocyte was positively correlated to the TUNEL positive cells and expression of Bax protein and mRNA (P<0.05 or P<0.01), and showed no correlation to Bcl-x protein and mRNA (all >0.05). CONCLUSION: There is a close relationship between inflammatory response and apoptosis and tissue damage in the perihematoma area in ICH.