OBJECTIVE:To establish the method for the determination of mildronate in human plasma and urine,and to study the pharmacokinetic characteristics in healthy volunteers. METHODS:After precipitating plasma and urine sample,LC-MS/MS method was adopted. Dikma Diamonsil C18 column was used with mobile phase consisted of methanol-water(containing 0.2% for-mic acid,0.3% ammonium acetate)(31∶69,V/V)at the flow rate of 0.6 ml/min. ESI was adopted in MRM mode,by using nega-tive ion. The ion for quantitative analysis were m/z 147.10→58.20 (mildronate) and m/z 152.00→110.10 (internal standard,acet-aminophen). The pharmacokinetic parameters of mildronate with single administration and multiple administration were calculated by using DAS 2.1 software and compared. RESULTS:The linear range of mildronate in plasma were 0.02-20 ng/ml(r=0.999 3) and in urine were 0.05-40 ng/ml(r=0.998 2). The lowest limits of quantitation were 0.02 and 0.05 ng/ml. Precision and recovery met the requirements of biological specimen determination,and endogenous impurities hadn’t effect on the determination. The main pharmacokinetics parameters of low-dose,medium-dose and low-dose(250,500,750 mg)of mildronate in plasma with single ad-ministration were as follows:t1/2 were(3.39±0.81),(5.52±0.57)and(5.32±0.96)h;tmax were(0.80±0.45),(1.38±0.43)and (1.10±0.36)h;cmax were(4.17±1.46),(8.08±1.04)and(15.04±1.86)ng/ml;AUC0-36 h were(24.55±5.81),(45.50±7.07)and (85.60 ± 13.09)ng·h/ml. In the dose range,cmax,AUC0-36 h h had a linear relationship with dose (R2 were 0.974 5 and 0.968 3). The main pharmacokinetic parameters of low-dose of mildronate with multiple administration after keeping stable were as follows:cmin was(0.28 ± 0.10)ng/ml;AUCs was(38.78 ± 4.18)ng·h/ml;cs was(1.62 ± 0.17)ng/ml;DF was(3.81 ± 1.14);t1/2 was(6.17 ± 1.46)h;tmax was(1.20 ± 0.33)h;cmax was(6.46 ± 1.96)ng/ml;AUC0-36 h was(40.33 ± 4.65)ng·h/ml;accumulation factor of cmax and AUC were(1.73±0.90)and(1.64±0.40). Compared with single administration,t1/2,cmax and AUC of mildronate with multiple admin-istration after keeping stable all changed,and tmax had no signifi-cant difference. After single administration,26 h accumulative excretion rate of those groups were (0.004 009 ± 0.001 1)%, (0.004 026±0.001 01)% and(0.003 858±0.000 68)% respec-tively. CONCLUSIONS:Established method is sensitive,accurate and specific,and suitable for the determination of mildronate concentration in human plasma and urine and pharmacokinetics study. Mildronate capsule shows certain accumulation effect in healthy volunteers,and linear pharmacokinetic characteristics.

Glioma,especially glioblastoma,is one of the most common malignancies in the central nervous system.Traditional surgery combined with radiotherapy and chemotherapy did not significantly change the survival time of gliomas.Invasive growth,high heterogeneity and existence of glioma stem cell are the main causes of tumor recurrence.In addition,various immune cells and cytokines secreted by them in tumor microenvironment,as well as their activation status,are the key factors affecting tumor progress and effecacy of various immunotherapy.Interleukin (IL)-33 is a member of IL-1 gene family,and in recent years,it has been confirmed that IL-33 is highly expressed in some brain tumors,and IL-33 is the main coordinator of microenvironment regulation in brain tumors.In this paper,we will introduce the immunosuppressive state of brain tumors and their microenvironment and the limitation of tumor growth and immunotherapy,and recent advance that cytokine regulate and intervene the microenvironment of glioma to adapt tumor-lytic virus-immunotherapy.

Objective To study the in vitro killing effect of novel small molecule inhibitors, ribosomal S6 kinase1 (RSK1) inhibitor (BI-D1870) and polo-like kinase 1 (PLK1) inhibitor (BI2536), combined with recombinant attenuated vesicular stomatitis virus VSVΔM51 on various glioma cells. Methods (1) In vitro cultured GL261, CT2A and HS68 cells were divided into control group, rapamycin group, BI-D1870 group, BI-2536 group, VSVΔM51 group, rapamycin +VSVΔM51 group, BI-D1870+VSVΔM51 group, and BI2536+VSVΔM51 group; pretreatments with 100 nmol/L rapamycin, 10 μmol/L BI-D1870, and 100 nmol/L BI-2536 for 2 h were given to the cells from the above groups, respectively, and then, they were infected with VSVΔM51 virus at 0.1 mutiplicity of infection (MOI); at 72 h after treatments, the cell survival rate was determined by Alarma Blue method; VSV△M51 virus was infected at 10 MOI one h after pretreatment with the above drugs, apoptosis of GL261 cells was detected by cleaved caspase-3 staining 24 h after that; the expression of apoptotic protein polyadp-ribosomal polymerase (PARP) was detected by Western blotting; Annexin V-FITC/propidium iodide double staining was used to detect the cell apoptosis. (2) GL261 and CT2A cells were divided into VSVΔM51 group, rapamycin+VSVΔM51 group, BI-D1870+VSVΔM51 group, and BI2536+ VSVΔM51 group; VSV△M51 virus was infected at 0.1 MOI one h after pretreatment with the above drugs,; 48 h after treatments, fluorescence microscope was used to detect the expression of green fluorescent protein (GFP); IVIS200 in vivo imaging system was used to detect the changes of cell virus luciferase in the 4 groups. (3) Fifteen CT2A intracranial implanted glioma model mice were divided into VSVΔM51 group, BID-1870+VSVΔM51 group and BI2536+VSVΔM51 group according to random number table method (n=5); mice in the latter two groups were intraperitoneally injected with BI-1870 (100 mg/kg) or intravenously injected with BI-2536 (20 mg/kg); 24 h after that, mice in the three groups were intravenously injected with virus VSVΔM51; virus luciferase was detected by IVIS200 in vivo imaging system 24 and 72 h after treatments; the grouping and treatments of GL261 intracranial glioma model mice were the same as above, the expression of virus GFP was observed under fluorescence microscope 48 h after treatments, and virus titers of these mice were detected by virus plaque assay. Results (1) As compared with the control group, rapamycin group, BI-D1870 group, BI-2536 group, and VSVΔM51 group, the rapamycin+VSVΔM51 group, BI-D1870+VSVΔM51 group, and BI2536+VSVΔM51 group had significantly lower cell survival rate (P<0. 05); cleaved Caspase-3 staining showed no cell apoptosis in the control group, a small amount of apoptotic corpuscles in the rapamycin group, BI-D1870 group, BI-2536 group, and VSVΔM51 group, but obvious increased amount of apoptotic corpuscles in the rapamycin+VSVΔM51 group, BI-D1870+VSVΔM51 group, and BI2536+ VSVΔM51 group; Western blotting indicated that GL261 and CT2A cells from the control group, rapamycin group, BI-D1870 group, BI-2536 group, and VSVΔM51 group had lower cleaved PARP expression level than those from the rapamycin+VSVΔM51 group, BI-D1870+VSVΔM51 group, and BI2536+VSVΔM51 group. The results of Annexin V-FITC/propidium iodide double staining were consistent with those of cleaved Caspase-3 staining. (2) As compared with VSVΔM51 group and rapamycin+VSVΔM51 group, BI-D1870+VSVΔM51 group and BI2536+VSVΔM51 group had significantly increased GFP expression and statistically higher intensity of virus luciferase (P<0.05). (3) CT2A cells in the VSVΔM51 group, BID-1870+VSVΔM51 group and BI2536+VSVΔM51 group had increased intensity of virus luciferase successively, with significant differences (P<0.05); GL261 cells in the VSVΔM51 group, BID-1870+VSVΔM51 group and BI2536+VSVΔM51 group had increased virus titers successively, with significant differences (P<0.05). Conclusion Both small molecule inhibitors promote the replication of VSVΔM51 virus and enhance the killing effect on glioma cells, and its synergistic effect is obviously better than rapamycin.