Objective To investigate the roles of dCK Ser-74 in radiation-induced cell death in breast cancer cells.Methods Different phenotypes of dCK plasmids were transfected into MCF-7 cells by liposome transfection,including dCK-Vector,dCK-WT (wild type),dCK-S74A (non-phosphorylation) and dCK-S74E (hyper-phosphorylation).All these cells were irradiated by 0,2,4,6,8 Gy X-rays,respectively.The transcriptional and translational level of dCK were detected with real time-PCR and Western blot,respectively.Radiosensitivity was analyzed using cell counting kit (CCK-8) and colony formation assays.Monodansylcadaverine staining (MDC) and flow cytometry were used to detect autophagy and apoptosis,respectively.Results Four phenotypes of dCK cell models were established successfully.After irradiation,the cell viabilities of MCF-7 and dCK-Vector decreased significantly as compared with mock group (t =14.469 and 9.357,P ＜ 0.05),the cell viabilities of dCK-WT,dCK-S74A and dCK-S74E showed no changes (P ＞ 0.05).The total mortalities of dCK-WT and dCK-S74E decreased significantly as compared with dCK-Vector (x2 =3.857-3.971,P ＜ 0.05),but no changes in dCK-S74A cells (P ＞0.05).The apoptosis rates in dCK-S74A,dCK-Vector and control group were up-regulated after irradiation (t =-4.531,-3.688 and-7.076,P ＜ 0.05),and the irradiation-induced apoptosis was reversed in dCK-WT and dCK-S74E (66％ and 68％ of the increase level in dCK-Vector group).The autophagy in dCK-WT and dCK-S74E increased by 22％ and 26％ (t =-9.051 and-8.411,P ＜0.01),but no changes were observed in dCK-S74A,dCK-Vector and control groups (P ＞ 0.05).Conclusions The dCK-WT and dCK-S74E could reverse the irradiation-induced apoptosis,increase the autophagy occurence,and decrease the total mortality,indicating that the phosphorylation of dCK at Ser-74 sites is related to the radiosensitivity of MCF-7 cells.

Objective To evaluate the agreement of antinuclear antibody (ANA) titer reported in clinical laboratories and analyze possible problems in clinical laboratories.Methods Experiment survey.The panel consisting of 5 samples was distributed to 533 laboratories.Each panel contains one negative sample and 4 positive samples,which were from individuals of autoimmune disease.ANA titer system was divided into traditional titer system with two-fold dilution and titer system with 3.2 times dilution.Clinical laboratories were required to report the ANA titers and initial screening dilution according to the standard used in routine work.Results were expressed as median titers and range for acceptable performance.As to titer system with two-fold dilution,acceptable performance on proficiency testing was defined by a result equal to median titer ± two two-fold dilutions.While as to titer system with 3.2 times dilution,acceptable performance on proficiency testing was defined by a result equal to median titer ± 3.2 times dilutions.The laboratories percentages with acceptable performance were calculated to evaluate their agreements.Results 412 laboratories reported ANA titer results,of which 11.9％ (49/412)reported results with two-fold dilution titer system,88.1％ (363/412)reported results with 3.2 times dilution titer system.The median titers of sample 1211,1212,1213 and 1215 reported with two-fold titer system were 1 ∶ 640,1∶ 320,＞ 1 ∶ 1280 and1∶ 160,respectively.The agreement within the median ANA titer reported with two-fold dilution titer system ranged from 24.5％ (12/49) to 57.1％ (28/49) and the lowest percentage of the results within the acceptable limits was 87.8％ (43/49).The median titers of sample 1211,1212,1213 and 1215 reported with 3.2 times dilution titer system were 1 ∶ 1000,1∶ 1000,＞ 1 ∶ 3200 and 1 ∶ 320,respectively.The agreement within the median ANA titer reported with 3.2 times dilution titer system ranged from 63.3％ (31/49)to 83.7％ (41/49).The lowest percentage of the results within the acceptable limits was 98.0％ (48/49).Conclusions The results of ANA titer reported are unsatisfactory.Standardization for reagent,microscopy,procedure and result interpretation is necessary to improve the agreement of ANA titer report in different laboratories.