The E3 ubiquitin ligase RNF135 modulates chemotherapy resistance to oxaliplatin for colorectal cancer by modulating autophagy.

BACKGROUND: RING finger protein 135 plays an important role in tumorigenesis and is associated with drug resistance. METHODS: Bioinformatics analysis showed that RNF135 was significantly differentially expressed in colorectal cancer. RT-qPCR and western blot were used to detect the expression of RNF135. Immunohistochemical analysis were used to measure the expression of RNF135 and Ki-67. RESULTS: The expression of RNF135 was up-regulated in human tissue samples and colorectal cancer and was positively correlated with Ki-67. Compared with oxaliplatin sensitive patients, RNF135 expression levels were higher in the tissue of resistant patients. The regulatory effect of RNF135 on colorectal cancer cells was further investigated in vitro. Therefore, inhibition of autophagy by down-regulating RNF135 can partially increase its susceptibility to oxaliplatin.

Resveratrol protects left ventricle by increasing adenylate kinase and isocitrate dehydrogenase activities in rats with myocardial infarction.

Our prior study had shown that resveratrol was a potent cardioprotective agent in rats with myocardial infarction (MI). In this study, we further evaluated the mechanism of cardioprotection of resveratrol by proteomic analysis. After permanent ligation of the left anterior descending artery under isoflurane anesthesia, surviving rats were randomly allocated to three groups and treated with resveratrol at 1 mg/kg/day (MI/R group), or vehicles (sham group and MI group) once daily for four weeks. In proteomic analysis, the MI group showed decreased expression of adenylate kinase 1 (AK1) and mitochondrial NADP⁺-dependent isocitrate dehydrogenase (IDPm) after MI compared with the sham group. These variations were reversed by resveratrol in the MI/R group. Validation with Western blot and immunohistochemical analyses showed similar trends in protein expression profiling. Our studies suggest that the beneficial effects of resveratrol on ventricular modeling may be due to increased expression of AK1 and IDPm, which have been known to increase myocardial energetic efficiency and reduce reactive oxygen species-mediated damage, respectively.

Determination of flavone C-glucosides in antioxidant of bamboo leaves (AOB) fortified foods by reversed-phase high-performance liquid chromatography with ultraviolet diode array detection.

Reversed-phase high-performance liquid chromatography (RP-HPLC) with ultraviolet diode array detection (UV-DAD) was used for the simultaneous determination of four flavone C-glucosides, i.e. orientin, homoorientin, vitexin and isovitexin in several food systems fortified by the antioxidant of bamboo leaves (AOB), such as high temperature sterilized milk, sunflower seed oil and extruded rice cake for the first time. The method included extraction of flavone C-glucosides from AOB-fortified foods by methanol aqueous solution, deproteinating with saturated lead acetate solution and potassium oxalate, defatting with n-hexane and clean-up by solid-phase extraction (SPE) with Phenomenex C18 cartridges. Analytes were separated with Luna C18 5 microm 250mm x 4.6mm column using acetonitrile and 1% (v/v) acetic acid (pH 3.0) as mobile phase. Good results were obtained with respect to repeatability (relative standard deviation (RSD)< 2.2%) and recovery (81.4-91.8%) which fulfilled the requirements defined by European Union (EU) legislation. The total amounts of four flavone C-glucosides were 12.56 microg/100 mL, 881.08 microg/100 mL and 1420.83 microg/100 g dry weight in AOB-fortified sterilized milk, sunflower seed oil and extruded rice cake, respectively. The method was successfully applied to the analysis of flavone C-glucosides in AOB-fortified samples. The optimized procedure could also be referenced for the separation of flavone C-glucosides in other fortified foodstuffs.