Objective To investigate the effect of different subtypes of fractionated doses on multidrug resistance in ovarian cancer cells.Methods The human ovarian cancer cell lines SKOV3 and its drug-resistant subtype SKVCR were divided into four groups i.e., sham-irradiated, single dose (10 Gy),fractionated dose (2 Gy × 5 ) and multi-fractionated dose (1 Gy × 2 × 5).Cell sensitivity to vincristine(VCR),etoposide ( VP-16),pirarubicin (THP) and cisplatin (DDP) was measured by MTT assay.Western blot was applied to detect the expression of P-gp after irradiation.Results The doubling time of SKVCR was about 1.8-fold of that of SKOV3 cells.P-gp was expressed in SKVCR but not in SKOV3.IC50 values of SKVCR were higher than those of SKOV3.To SKOV3 cells,single dose irradiation decreased cell sensitivity to THP and DDP and fractionated irradiation decreased cell sensitivity to VCR,THP and VP-16.Multi-fractionated irradiation decreased cell sensitivity to VP-16.In SKVCR cells,all these irradiation treatments increased cell sensitivity to VCR and VP-16 but not to DDP.In addition,single and fractionated irradiation decreased P-gp expression in SKVCR cells.Conclusions Single,fractionated and multi-fractionated radiation induced chemotherapy resistance in SKOV3 cells,while reversed drug resistance to VCR and VP-16 in SKVCR cells.

Abstract: Objective To understand the morphological characteristics and ultrastructure of the dominant species of Rhipicephalus sanguineus in Hainan at different developmental stages, and provide theoretical basis for the identification of the lineage and control of Rhipicephalus sanguineus. Methods The external morphology of different developmental stages of the dominant species of Rhipicephalus sanguineus, including larva, nymph and adult tick in Hainan were observed by scanning electron microscope. Results The division between each segment of larva pedipalps was not obvious, and setae was serrated; dental formula type 2 | 2; 3 pairs of podomere; a pair of setae on the anal valve; none of anal groove, spiracular plate, porous area and genital aperture. There was a clear boundary at the beginning of each segment of nymph pedipalps; dental formula type 2 | 2; 4 pairs of podomere; 3 pairs of setae on the anal valve; anal groove; none of porous area and genital aperture. The male adult tick's trichotheca are covered by the pedipalps, and the whole bristles are conical; dental formula type 3 | 3; 4 pairs of podomere; anal groove and paraprocts; 7 setae on the anal valve; genital aperture was oval. The female of adult tick can be distinguished by dental formula 3 | 3; pairs of podomere; porous areas with 3 short setae; anal groove; 4 pairs of setae and 2 pores on the anal valve; genital pore was broadly U-shaped. In addition, the male adult's scutum occupies almost the entire dorsal surface, the basis capituli of larva, nymph and adult tick all were hexagonal, and the existence of Haller's organ was found on the first pair of legs. Conclusions Scanning electron microscopy observation of the different developmental stages of R.sanguineus revealed clear morphological features, preliminarily suggesting that R.sanguineus in Hainan Province may belong to the tropical lineage, which provide a certain experimental basis for the identification of the tick and the comprehensive prevention and control of local tick-borne diseases.

Objective To investigate the expression of DRAM in breast cancer cell line MCF-7 in radiation-induced autophagy. Methods GFP-LC3 transfection method was used to observe autophagy bubble.Real time-PCR was used to detect DRAM and MAPLC3 from transcriptional and translational level,respectively. The silencing vector from gene engineering was introduced by calcium phosphate transfection.Results Compared with the control group,GFP-LC3 increased significantly after 8 Gy irradiation by immunofluorescent assay,and the level of MAP-LC3 expression was higher than control group after 8 Gy irradiation by Western blot ( F =5.38,8.72,10.63,15.23,20.78 and 55.23,P ＜ 0.05 ).DRAM protein expression increased significantly at 2 h in the 8 Gy time-dose study,up to maximum at the 32 h( F =116.34,P ＜ 0.05 ).In DRAM model,the expression of LC3 and DRAM decreased significantly (F =20.36 and 40.35,P ＜ 0.05 ) and DRAM expression increased 8 Gy post-irradiation,but still lower than that in 8 Gy irradiation wild-type group.The LC3 expression also decreasaed 8 Gy post-irradiation(F =50.34,P ＜ 0.05 ).Conclusions DRAM plays an important role in irradiation-induced autophagy in breast cancer cell.DRAM might participate in the process and serve as a theoretical target for clinical treatment of breast cancer.

Objective To explore the effect of CD40 small interfering RNA(siRNA)on the expressions of pe-ripheral blood interleukin(IL)-21 and IL -35 in rats with experimental autoimmune myocarditis (EAM)and its sig-nificance.Methods Twenty 6 -8 week male Lewis rats were divided into normal group,EAMgroup,CD40 siRNA group and siRNA group by using random number table,with 5 rats in each group.The normal rats were induced with phos-phate buffer saline in double foot pads on day 0 and day 7,while the rest 3 groups were induced with cardiac myosin protein to establish EAMmodels.The rats in CD40 siRNA group and siRNA group were respectively injected with CD40 siRNA and siRNA slow virus expression vector through the tail vein of rats on day 7.The rats were executed on 21 day after echocardiogram examination was made.The histopathologic changes were observed by using light microscope and the myocardial histopathology scores were calculated.Enzyme -linked immunosorbent assay was used to determine the levels of IL -21 and IL -35 in peripheral blood.Results (1)Except the normal group,the total incidence rate of rats of each group was 100%,and there was no rat death.(2)Compared with EAM group,the heart mass/body ratio and myocardial histopathology scores were lower in CD40 siRNA group,and the differences were significant (3.13 ±0.21 vs 3.80 ±0.29,2.22 ±0.43 vs 3.32 ±0.51,F =0.332,0.456,all P <0.05).(3)The echocardiogram showed that there was only 1 rat in EAM group with massive pericardial effusion,and there was no pericardial effusion in CD40 siRNA group.EAMgroup,CD40 siRNA group and siRNA group displayed hypertrophy of the ventricular septum and left ventricular wall,narrow heart cavity and weakening of ventricular wall motion.The left ventricular shortening rate in CD40 siRNA group was significantly higher than that in the EAMgroup[(63.34 ±11.06)% vs (38.56 ±6.98)%,F =16.080,P <0.05].(4)The peripheral blood level of IL -21 in CD40 siRNA group was lower than that in EAM group [(141.19 ±17.46)ng/L vs (157.81 ±17.58)ng/L,F =57.008,P <0.05],while its level of IL -35 was signifi-cantly higher than that in the EAMgroup [(195.96 ±18.26)ng/L vs (174.78 ±13.91 )ng/L,F =31.727,P <0.05].(5)The level of IL -21 in peripheral blood was positively correlated with myocardial histopathology scores in EAM group (r = 0.69,P < 0.05 ),but IL -35 was negatively correlated with myocardial histopathology scores (r =-0.64,P <0.05).Conclusions CD40 siRNA might relieve the myocardial inflammation and reduce the myocar-dial injury of EAMrats.The levels of IL -21 and IL -35 can partly reflect the degree of myocardial injury.The mecha-nism may be related to down -regulating the expression IL -21 and up -regulating the expression of IL -35.

This study was aimed to design the first dual-target small-molecule inhibitor co-targeting poly (ADP-ribose) polymerase-1 (PARP1) and bromodomain containing protein 4 (BRD4), which had important cross relation in the global network of breast cancer, reflecting the synthetic lethal effect. A series of new BRD4 and PARP1 dual-target inhibitors were discovered and synthesized by fragment-based combinatorial screening and activity assays that together led to the chemical optimization. Among these compounds, 19d was selected and exhibited micromole enzymatic potencies against BRD4 and PARP1, respectively. Compound 19d was further shown to efficiently modulate the expression of BRD4 and PARP1. Subsequently, compound 19d was found to induce breast cancer cell apoptosis and stimulate cell cycle arrest at G1 phase. Following pharmacokinetic studies, compound 19d showed its antitumor activity in breast cancer susceptibility gene 1/2 (BRCA1/2) wild-type MDA-MB-468 and MCF-7 xenograft models without apparent toxicity and loss of body weight. These results together demonstrated that a highly potent dual-targeted inhibitor was successfully synthesized and indicated that co-targeting of BRD4 and PARP1 based on the concept of synthetic lethality would be a promising therapeutic strategy for breast cancer.