miR-216b Post-Transcriptionally Downregulates Oncogene KRAS and Inhibits Cell Proliferation and Invasion in Clear Cell Renal Cell Carcinoma

Background/Aims: Increasing evidence has shown that miR-216b plays an important role in human cancer progression. However, little is known about the function of miR-216b in renal cell carcinoma. Methods: The expression levels of miR-216b in renal cell carcinoma tissues and cell lines were examined by qRT-PCR. The biological role of miR-216b in renal cell carcinoma proliferation and/or metastasis was examined in vitro and in vivo. The target of miR-216b was identified by a dual-luciferase reporter assay. The expression level of KRAS protein was measured by western blotting. Results: The expression of miR-216b was downregulated in clear cell renal cell carcinoma (ccRCC) cell lines and specimens compared to the adjacent normal tissues. Furthermore, miR-216b can bind to the 3’untranslated region (UTR) of KRAS and inhibit the expression of KRAS through translational repression. The in vitro study revealed that miR-216b attenuated ccRCC cell proliferation and invasion. Furthermore, in vivo study also showed that miR-216b suppressed tumor growth. MiR-216b exerted its tumor suppressor function through inhibiting the KRAS-related MAPK/ERK and PI3K/AKT pathways. Conclusion: Our findings provide, for the first time, significant clues regarding the role of miR-216b as a tumor suppressor by targeting KRAS in ccRCC

Optimization of initial substrate and pH levels for germination of sporing hydrogen-producing anaerobes in cow dung compost

[[abstract]]Biohydrogen production by anaerobic microbes enriched from heat-shocked cow dung compost was studied by using an artificial medium containing sucrose. Initial pH and substrate levels were selected as target factors in this study. Our experimental results demonstrated that optimal substrate concentration and pH for the composts generating hydrogen gas were 4.0 ± 0.5 g sucrose/l and 5.4 ± 0.2, respectively. Supplementary experiments confirmed that chemical oxygen demand reduction efficiency (69%) obtained from the conditions of sucrose=4.0 g/l and pH=5.5 was significantly greater than that (37%) from sucrose=5.0 g/l and pH=5.0. Experimental results of metabolites analysis led us to the conclusion that Clostridium sp. predominated in the anaerobic composts, suggesting that inocula used to seed the batch experiment can be obtained from a common natural source

有机废弃物氢发酵制备生物氢气的研究

[[abstract]]Biological hydrogen production is a process of applying anaerobic biological fermentation method to produce hydrogen from organic wastes. Hydrogen production potential of different microbiological source and organic wastes, as well as the composition of fermentation product in liquid phase, were studied in the batch culture experiments. Magnifying experiment of biohydrogen production was carried out in 30 L improvement UASB reactor using anaerobic fermentation of artificial wastewater containing starch by activated sludge process. The experiment confirm that hydrogen and carbon dioxide percentage of biogas were 40%-51% and 49%-60% under the condition of hydrogen production process (pH was 4.5-5.5 sludge VSS was 10 g/L; starch-COD was 5000 mg/L), and no methane was observed. Hydrogen purity was more than 97% by an absorption of sodium hydrate solution, continuous hydrogen production was more than 120 days

Studies on biohydrogen production by biohydrogen fermentation of natural anaerobic microorganism

[[abstract]]以牛粪堆肥作为天然厌氧微生物菌种来源处理含蔗糖和淀粉的模拟有机废水,通过厌氧氢发酵产生生物氢气,同时使废水得到净化处理.在实验条件下,生物气中氢气浓度可达61%,产物中无甲烷气生成.以蔗糖为底物时,最佳初始pH值6.0,最大产氢能力为146mL/g;以淀粉为底物时,最佳初始pH值7.5,最大产氢能力为166mL/g,最佳底物浓度均为5g/L.模拟废水中COD去除率可达40%~60%