Benzo[a]pyrene diol epoxide suppresses retinoic acid receptor-β2 expression by recruiting DNA (cytosine-5-)-methyltransferase 3A

Tobacco smoke is an important risk factor for various human cancers, including esophageal cancer. How benzo [a]pyrene diol epoxide (BPDE), a carcinogen present in tobacco smoke as well as in environmental pollution, induces esophageal carcinogenesis has yet to be defined. In this study, we investigated the molecular mechanism responsible for BPDE-suppressed expression of retinoic acid receptor-beta2 (RAR-β2) in esophageal cancer cells. We treated esophageal cancer cells with BPDE before performing methylation-specific polymerase chain reaction (MSP) to find that BPDE induced methylation of the RAR-β2 gene promoter. We then performed chromatin immunoprecipitation (ChIP) assays to find that BPDE recruited genes of the methylation machinery into the RAR-β2 gene promoter. We found that BPDE recruited DNA (cytosine-5-)-methyltransferase 3 alpha (DNMT3A), but not beta (DNMT3B), in a time-dependent manner to methylate the RAR-β2 gene promoter, which we confirmed by reverse transcription-polymerase chain reaction (RT-PCR) analysis of the reduced RAR-β2 expression in these BPDE-treated esophageal cancer cell lines. However, BPDE did not significantly change DNMT3A expression, but it slightly reduced DNMT3B expression. DNA methylase inhibitor 5-aza-2'-deoxycytidine (5-Aza) and DNMT3A small hairpin RNA (shRNA) vector antagonized the effects of BPDE on RAR-β2 expressions. Transient transfection of the DNMT3A shRNA vector also antagonized BPDE's effects on expression of RAR-β2, c-Jun, phosphorylated extracellular signal-regulated protein kinases 1/2 (ERK1/2), and cyclooxygenase-2 (COX-2), suggesting a possible therapeutic effect. The results of this study form the link between the esophageal cancer risk factor BPDE and the reduced RAR-β2 expression

Visible-light promoted atom transfer radical addition-elimination (ATRE) reaction for the synthesis of fluoroalkylated alkenes using DMA as electron-donor

Here, we describe a mild, catalyst-free and operationally-simple strategy for the direct fluoroalkylation of olefins driven by the photochemical activity of an electron donor-acceptor (EDA) complex between DMA and fluoroalkyl iodides. The significant advantages of this photochemical transformation are high efficiency, excellent functional group tolerance, and synthetic simplicity, thus providing a facile route for further application in pharmaceuticals and life sciences

Fine Splitting in Charmonium Spectrum with Channel Coupling Effect

We study the fine splitting in charmonium spectrum in quark model with the channel coupling effect, including $DD$, $DD^*$, $D^*D^*$ and $D_sD_s$, $D_sD_s^*$, $D_s^*D_s^*$ channels. The interaction for channel coupling is constructed from the current-current Lagrangian related to the color confinement and the one-gluon exchange potentials. By adopting the massive gluon propagator from the lattice calculation in the nonperturbative region, the coupling interaction is further simplified to the four-fermion interaction. The numerical calculation still prefers the assignment $1^{++}$ of X(3872).Comment: Submitted to Chinese Physics

Alveolar Type II Cells Escape Stress Failure Caused by Tonic Stretch through Transient Focal Adhesion Disassembly

Mechanical ventilation-induced excessive stretch of alveoli is reported to induce cellular stress failure and subsequent lung injury, and is therefore an injurious factor to the lung. Avoiding cellular stress failure is crucial to ventilator-induced lung injury (VILI) treatment. In the present study, primary rat alveolar type II (ATII) cells were isolated to evaluate their viability and the mechanism of their survival under tonic stretch. By the annexin V/ PI staining and flow cytometry assay, we demonstrated that tonic stretch-induced cell death is an immediate injury of mechanical stress. In addition, immunofluorescence and immunoblots assay showed that the cells experienced an expansion-contraction-reexpansion process, accompanied by partial focal adhesion (FA) disassembly during contraction. Manipulation of integrin adherent affinity by altering bivalent cation levels in the culture medium and applying an integrin neutralizing antibody showed that facilitated adhesion affinity promoted cell death under tonic stretch, while lower level of adhesion protected the cells from stretch-induced stress failure. Finally, a simplified numerical model was established to reveal that adequate disassembly of FAs reduced the forces transmitting throughout the cell. Taken together, these results indicate that ATII cells escape stress failure caused by tonic stretch via active cell morphological remodeling, during which cells transiently disassemble FAs to unload mechanical forces

Follicular thyroid carcinoma but not adenoma recruits tumor-associated macrophages by releasing CCL15

Immunostain of CD68 in entire tissue of FTC/FA samples. (A) An example of immunohistochemistry analysis of CD68 in whole tissue samples of FTC (left panel) and FA (right panel). Stars indicated blank areas were taked out for tissue microarrays constructing. CD68+ cells in ten 200 μm *300 μm areas (green-red marked) of every sample were counted. Bar = 1 mm. (B) Enlarged picture of one count area (one green-red area in A). Arrows indicate the CD68+ macrophages in FTC (left panel) or FA (right panel). Bar = 20 μm. Figure S2. Densities of CD206+ cells in FTC are significantly higher than those in FA. Immunohistochemistry analysis of CD206 in 55 cases of tissue samples from FTC and FA patients. Arrows indicate the CD206+ macrophages. Bar = 20 μm. (PDF 509 kb

Corneal stromal acupuncture combined with amniotic membrane transplantation for treating bullous keratopathy

AIM: To investigate the clinical effect for treating bullous keratopathy(BK)by anterior corneal stromal acupuncture combined with amniotic membrane transplantation.<p>METHODS: Totally 35 patients(35 eyes)with bullous keratopathy were treated by corneal stromal acupuncture combined with amniotic membrane transplantation. All patients preoperative and postoperative underwent anterior segment OCT, corneal topography, corneal sensitivity and confocal microscopy. To observe postoperative ocular symptoms in patients with BK, recurrence of bulla, changes in corneal thickness, corneal sensitivity and changes in the organizational structure of the layers of the cornea.<p>RESULTS: Thirty-five were followed up for 6-18mo. The symptom of pain disappeared in 32 cases(91%)in the first day after operation and did not recur during follow-up. The symptom of pain relieved in 3 cases(9%)in the first day after operation and disappeared in 3 days. Corneal epithelium of 9 cases(26%)were all healed within 1wk, 21 cases(60%)were all healed within 2wk, and 5 cases(14%)were all healed within 3wk. Following up for 6-18mo, there was no recurrence of symptoms or bulla. A small amount of tiny bubbles in the surrounding area appeared in 2 cases after 3 and 4wk. All patients had no neovascularization, and had smooth corneal surface. The amnions of 30 cases(86%)were thinning after 2mo, partially dissolved and absorped, not seen with the naked eye after 3mo. Thirty-four cases(97%)had no changes in vision, one case(3%)was from the light to front of the manual. After 2mo, corneal sensation decreased in 30 cases(86%), corneal thickness increased from preoperative 788±35μm to 940±43μm. After 12mo, corneal thickness increased to 1060±27μm. Results of confocal microscopy: after 3mo, the number density of the trigeminal nerve fibers under corneal basement membrane reduced, shallow stromal cells became into fibrotic stroma, deep stroma was more loose, and cells swelled significantly. The number of endothelial cells reduced and form swelled more obviously compared with preoperatively.<p>CONCLUSION: Corneal acupuncture combined with amniotic membrane transplantation can effectively control the symptoms of BK, prevent the recurrence of BK, and especially it is a simple, safe and practical way for patients with poor visual function