Inhibition of G9a attenuates cell proliferation via the mitochondrial apoptosis pathway in lung adenocarcinoma / 中华肿瘤杂志

Objective@#The aim of this study is to investigate the effect of G9a inhibitor BIX-01294 on attenuating cell proliferation in human lung adenocarcinoma A549 cell line and the underlying molecular mechanism.@*Methods@#Treated with BIX-01294, the growth and proliferation of A549 cells were detected by MTT assay and colony formation assay, and its impact on cell apoptosis was analyzed using flow cytometry. By Western blot, we explored the alterations in the expression of apoptosis-related proteins and the G9a catalysate, H3K9me and H3K9me2. In addition, in the pretreatment with caspase inhibitor Z-VAD-FMK, we detected the apoptotic dependence of BIX-01294 attenuating impact on A549 cell proliferation.@*Results@#Compared with the control group, the histone methyltransferase G9a inhibitor BIX-01294 attenuated cell proliferation in A549 cells in a dose- and time-dependent manner. There were 42.5±8.7 colonies after BIX-01294 (10 μmol/L) treatment for 7 days, while 172.7±23.0 colonies in the control group, with a statistical significance (P<0.05). After treatment with BIX-01294 (10 μmol/L) for 24 hours, the cell apoptotic rate was(47.6±8.4)%, with a significant difference in comparison with the control group [(7.2±3.6)%, P<0.05]. The expression of G9a catalysate, H3K9me and H3K9me2 was downregulated, the same with anti-apoptotic protein Bcl-2, while the proteins in mitochondrial apoptosis pathway, Bax, Bak and cleaved caspase-9, were upregulated, so was the expression of cleaved caspase-3 and cleaved PARP, and there was no alteration in the expression of cleaved caspase-8, which is a protein related with death receptor apoptosis pathway. Furthermore, after Z-VAD-FMK pretreatment, the cell apoptotic rate was decreased significantly, and the expression of apoptosis-related proteins were downregulated.@*Conclusions@#Our results indicate that BIX-01294 can attenuate cell proliferation in lung adenocarcinoma, and it can be considered as one of the underlying mechanisms, the apoptosis may be induced by activating mitochondrial pathway.

Changes in the Expression and Distribution of Claudins, Increased Epithelial Apoptosis, and a Mannan-Binding Lectin-Associated Immune Response Lead to Barrier Dysfunction in Dextran Sodium Sulfate-Induced Rat Colitis

BACKGROUND/AIMS: This animal study aimed to define the underlying cellular mechanisms of intestinal barrier dysfunction. METHODS: Rats were fed 4% with dextran sodium sulfate (DSS) to induce experimental colitis. We analyzed the sugars in 24-hour urine output by high pressure liquid chromatography. The expression of claudins, mannan-binding lectin (MBL), and MBL-associated serine proteases 2 (MASP-2) were detected in the colonic mucosa by immunohistochemistry; and apoptotic cells in the colonic epithelium were detected by the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling method assay. RESULTS: The lactulose and sucralose excretion levels in the urine of rats with DSS-induced colitis were significantly higher than those in the control rats. Mannitol excretion was lower and lactulose/mannitol ratios and sucralose/mannitol ratios were significantly increased compared with those in the control group (p<0.05). Compared with the controls, the expression of sealing claudins (claudin 3, claudin 5, and claudin 8) was significantly decreased, but that of claudin 1 was increased. The expression of pore-forming claudin 2 was upregulated and claudin 7 was downregulated in DSS-induced colitis. The epithelial apoptotic ratio was 2.8%+/-1.2% in controls and was significantly increased to 7.2%+/-1.2% in DSS-induced colitis. The expression of MBL and MASP-2 in the intestinal mucosa showed intense staining in controls, whereas there was weak staining in the rats with colitis. CONCLUSIONS: There was increased intestinal permeability in DSS-induced colitis. Changes in the expression and distribution of claudins, increased epithelial apoptosis, and the MASP-2-induced immune response impaired the intestinal epithelium and contributed to high intestinal permeability.

Ethics Issues and Strategy for New Endoscopy Techniques / 中国医学伦理学

Digestive endoscopic diagnosis and treatment technology in the development of ethical issues are :the expansion of endoscopic treatment indications , violation of patient choice;Health care costs increase , the pa-tient cannot enjoy medical equality;Staff is uneven , the patient can′t enjoy the fair medical treatment;Paternalistic doctor-patient relationship , ignore the patient′s autonomy and so on .Puts forward some Suggestions to solve these problems:people-oriented , fully respect patients option;Standard medical behavior , advocates the equal medical treatment;Standardized training for everyone to enjoy fair medical treatment;Build the good doctor -patient rela-tionship , respect the autonomy of patients .

Endoscopic measurement by virtual internal standard:Feasibility and accuracy / 医学研究生学报

Objective: Endoscopic measurement mainly depends on visual estimation or open biopsy forceps,which have been proved lacking in accuracy due to the image barrel distortion caused by wide-angle lens in endoscope.This study aimed to validate a new concept of "virtual internal standard" proposed by ourselves and develop a new method for endoscopic measurement based on the concept.Methods: We photographed planar grid graphs printed with standard calibrations with an electronic endoscope at different object distances,obtained the information on the virtual internal standard from each photo at the corresponding object distance,and analyzed the digital characteristics of the barrel distortion photos,including the size of the visual field,the image compression ratio,and the credible area for measurement with the virtual internal standard.Based on the analyses,the method of endoscopic measurement by the virtual internal standard was established and experiments both in vivo and in vitro were conducted.Results: The ratio of the object distance to the visual field was 1 ∶ 2 when the former was between 10 mm and 40 mm.Calculation of the compression ratio showed that the credible area of measurement in the central area was 10 mm at the object distance of 10-15 mm,20 mm at 20-30 mm,and 30 mm at 30-50 mm.The credible area of measurement on various planes accounted for 2/5 to 3/5 of the total image width.There was a tendency of double-curve change in the arrangement of pixel values of the central grids on different planes.The differences between the pixel values per centimeter became slight at the object distance of 35-50 mm.Conclusion: Endoscopic measurement by the virtual internal standard is a objective,accurate,simple and practical method.