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OBJECTIVE：To investigate th e stabilities of antitumor candid ate Gedatolisib in plasma in vitro and simulated gastric/intestinal fluids ，and to analyze the possible catabolites in plasma. METHODS ：HPLC method was adopted. Using indometacin as internal standard ，the contents of Gedatolisib incubated in plasma of SD rats （male）for 0，0.5，1.0，1.5，2.0，3.0 h and blank simulated gastric fluid （pH 1.3，no enzyme ），blank simulated intestinal fluid （pH 6.8，no enzyme ），simulated gastric fluid（pH 1.3，containing pepsin ）and simulated intestinal fluid （pH 6.8，containing trypsin ）for 0，0.5，1.0，2.0，3.0，4.0，6.0 h were determined. The remaining percentage of Gedatolisib was calculated. UPLC-Q-TOF/MS was used to analyze the TIC of blank plasma and incubated samples. The differential peaks were compared， and catabolites were inferred by MS 1Z073）.gzwjkj2019-1- chromatograms. RESULTS ： The remaining percentage in plasma of rats for 2.0 h was about 63％，and there was nosignificant change after continued incubation. The remaining percentage of Gedatolisib incubated in blank simulated intestinal fluid for different time ranged （99.18 ± 2.15）％ -（103.20 ± 3.41）％ . The remaining percentage in simulated com intestinal fluids for 2.0 h ranged （88.76 ± 1.53）％ . The remaining percentage in blank simulated gastric fluids for 2.0 h was ranged （85.63±1.55）％，and there was no significant change after continued incubation. The remaining percentage in simulated gastric fluid was from （94.94±3.52）％（0 h）to（16.19±1.17）％ （6.0 h）. TIC of UPLC-Q-TOF/MS showed that the differential peaks of incubated samples and blank plasma was 6.42 min under positive mode scanning ，molecular ion peak of m/z 616.335 1，simulated 632.327 7，630.317 0，602.278 6 [M+H]+ could be found in scanning channel. It was speculated that Gedatolisib could generate 1-（4-（3-（4，6-dimorpholino-1，3，5-triazin-2-yl）phenyl）urea） benzoyl）-N，N-dimethylpiperidin-4-amine oxide ，1-（4-（4-（dimethylamino）piperidine-1-carbonyl）phenyl）-3-（4-（4-morpholino-6- （3-oxomorpholino）-1，3，5-triazin-2-yl）phenyl）urea and 1-（4-（3-（4-（4，6-dimorpholino-1，3，5-triazin-2-yl）phenyl）urea） benzoyl）-N-methylpiperidine. CONCLUSIONS ：Gedatolisib is not stable in rat plasma ，and it may undergo terminal N oxidation， morpholine ring oxidation and terminal N demethylation. Gedatolisib is stable in artificial intestinal fluid and blank artificial gastric/ intestinal fluid ，and degrades obviously in the presence of pepsin.
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Objective To study the relationship between glutamine metabolism and radiotherapy resistance in nasopharyngeal carcinoma (NPC).Methods The glutaminase 1 (GLS1) knockout CNE1,6-10B cell lines and the control cell lines were established by lentivirus transfection technology.The CNE2 cell lines with GLS1 overexpression and control cell lines were established by liposome transfection technology.BPTES,one of Glutamine enzyme inhibitors,was used to inhibit the activity of GLS1.Glutamine/Glutamate(Gln/Glu) and Glu kits were used to detect glutamine metabolism in NPC cells;in vitro radiation clone formation experiment and flow cytometre mediated apoptosis assay were adopted to detect the effects of glutamine metabolism modulation on NPC radiosensitivity.Western blot and autophagic puncta monitor assay were carried out to detect the effects of glutamine metabolism modulation on autophagy status in NPC cells.Results Inhibiting the glutamine metabolism led to decreased clone formation,increased apoptotic rates,and decreased autophagic level in NPC cells;while activating the glutamine metabolism led to increased clone formation,decreased apoptotic rates and increased autophagic level in NPC cells.Conclusions The reduction of glutamine metabolism inhibits autophagy and increases radio sensitivity of NPC.
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Mig1 and Snf1 are two key regulatory factors involved in glucose repression of Saccharomyces cerevisiae. To enhance simultaneous utilization of glucose and xylose by engineered S. cerevisiae, single and double deletion strains of MIG1 and SNF1 were constructed. Combining shake flask fermentations and transcriptome analysis by RNA-Seq, the mechanism of Mig1 and Snf1 hierarchically regulating differentially expressed genes that might affect simultaneous utilization of glucose and xylose were elucidated. MIG1 deletion did not show any significant effect on co-utilization of mixed sugars. SNF1 deletion facilitated xylose consumption in mixed sugars as well as co-utilization of glucose and xylose, which might be due to that the SNF1 deletion resulted in the de-repression of some genes under nitrogen catabolite repression, thereby favorable to the utilization of nitrogen nutrient. Further deletion of MIG1 gene in the SNF1 deletion strain resulted in the de-repression of more genes under nitrogen catabolite repression and up-regulation of genes involved in carbon central metabolism. Compared with wild type strain, the MIG1 and SNF1 double deletion strain could co-utilize glucose and xylose, and accelerate ethanol accumulation, although this strain consumed glucose faster and xylose slower. Taken together, the MIG1 and SNF1 deletions resulted in up-regulation of genes under nitrogen catabolite repression, which could be beneficial to simultaneous utilization of glucose and xylose. Mig1 and Snf1 might be involved in the hierarchical regulatory network of genes under nitrogen catabolite repression. Dissection of this regulatory network could provide further insights to new targets for improving co-utilization of glucose and xylose.
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Transport of cyclic AMP across Escherichia coli membrane was studied using membrane vesicles. Uptake of cyclic AMP was measured using normally oriented vesicles, whereas uptake in everted vesicles was taken as a measure of the efflux of cyclic AMP. Ultraviolet irradiation of the cells led to an inhibition of both uptake and efflux of cyclic AMP across the membrane. The presence of cyclic AMP in the growth medium prior to ultra-violet irradiation caused an enhancement of the uptake and efflux. The uptake and efflux of cyclic AMP were less in vesicles from glucose grown cells as compared to the uptake and efflux by the vesicles prepared from glycerol grown cells. Similarly both uptake and efflux of cyclic AMP were more in vesicles prepared from cells grown on glycerol or glucose in the presence of cyclic AMP than in vesicles from cells grown in absence of cyclic AMP. It is suggested that the number of cyclic AMP carrier molecules were reduced in cells under catabolite repression by glucose as well as by ultra-violet irradiation.