1.Cellular Responses to DNA Double Strand Breaks and Its Medical Significance
Progress in Biochemistry and Biophysics 2006;0(09):-
The DNA damage response is a cornerstone of genomic stability.The cell utilizes mutiple mechanisms including damage detection,cell cycle regulation,damage repair and apoptosis to keep cell homeostasis.The DNA damage response include several biochemical pathways:first,the recognition and repair of damaged DNA;second,the activation of DNA damage checkpoint,which arrests cell cycle progression so as to provides time for DNA repair and prevention of the transmission of genomic abnormalities to the daughter cells;third,apoptosis,which eliminates serious damaged cells.The double strand break(DSB) is believed to be one of the most severe types of DNA damage,and errors in DSB repair could result in genomic instability that might lead to malignancy.It has been reported recently that constitutive activation of the ATM-Chk2-p53 pathway and phosphorylation of histone H2AX acts as an inducible anti-cancer barrier in the early stages of human tumorigenesis.This ATM-regulated DNA damage response network maintains genomic integrity and delays or prevents cancer by eliciting growth arrest or cell death.In context with a recent report,the ATM-dependent DNA-damage cellular signaling has also been shown to be involved in the integration of human immunodeficiency virus type-1(HIV-1) into host genomes,and KU55933,a specific ATM inhibitor,attenuated the infection of HIV-1 into host cells.The regulation and mechanisms of the signaling pathways of DSB response,and its role in HIV-1 infection and malignancy genesis were reviewed.
2.Gene clone and activity assay of apoptin
GuoJing, SUN ; Xin, TONG ; ZhiXian, SUN
Bulletin of The Academy of Military Medical Sciences 2001;25(2):85-88
Objective:To obtain apoptin gene and to induce tumor cell (HeLa) apoptosis. Methods:Apoptin gene was amplified by PCR from CAV TK5803 genomic DNA,and was then cloned into pCDNA3.1/His/Topo vector. After confirming by DNA sequencing, apoptin gene was subcloned into pCIneo vector.Recombinant plasmid pCDNA3.1/His/Topo-apoptin and pCIneo-apoptin were transformed into HeLa cells by Lipofectamine reagent. Three days after transfection,the HeLa cell was stained by Honchest 33258 and apoptosis was analysed by fluorescence microscope. Results and Conclusions: The full-length apoptin gene was cloned by PCR and inserted into pCDNA3.1/His/Topo vector. Sequence analysis demonstrated that it was same as published apoptin gene sequence. Three days after transfection, HeLa cell turned into apoptosis.
3.Cloning of the Regulatory Sequence of Mouse Egr-1 Gene and Characteristics of Its Radiation-Inducible Property
Xing LU ; Ruiyun XING ; Zhixian SUN
Chinese Journal of Cancer Biotherapy 1994;0(01):-
Egr-1 is a radiation-inducible transcription factor. It was demonstrated that the regulatory sequence in 5' flanking region of Egr-1 gene could confer the radiation inducibility upon a tumoricidal gene to which it was linked, and was consequently used in experiments on the gene-radiotherapy to tumor. As a first step to test the possibility, we have isolated the 445 bp-long regulatory sequence of Egr-1 gene from BALB/c mouse gcnomic DNA with PCR method. Sequence analysis confirmed that nucleotide sequence of this cloned fragment was identical with one reported previously with only one base difference in A to G substitution at residue - 392, and had six CC( A + T)6GG domains which were essential to the radiation-inducible property of Egr-1 gene. This fragment then was inserted into the Mlu I-Bgl II site of pGL3, a reporter vector containing luciferase gene. The constructs were used to transfect mouse malignant melanoma cells (B16) to characterize the regulatory function of this CC ( A + T)_(6)GG-rich sequence after exposure to r-radiation by a ~(60) Co source. The results indicate that the activity of luciferase in transfectant increases by 138% as compared with control levels, demonstrating that r-radiation inducibility of gene expression can be conferred by the regulatory sequence.
4.Chromosome Location and Elongation of Radiation-induced Expressed Sequence Tag by the Aid of Bioinformatics
Ying LUO ; Jianli SUI ; Yi TIE ; Pingkun ZHOU ; Zhixian SUN
Progress in Biochemistry and Biophysics 2001;28(2):188-191
Regulation of gene expression is one of the most importa nt responses of cells to DNA damage induced by radiation. A novel expressed seq u ence tag (EST) fragment had been cloned from human embryo lung cells induced by 50cGy radiation and named RIG1. To clone the full-length cDNA of RIG1, a non-c loned cDNA library of human embryo lung cells induced by low dose irradiation ha d been established. This library was used as template in enchanced nest RACE PCR and biotin-labeled probe was used for further purification. The 3′ flanking s equence of this EST was cloned and sequenced with this set of technology. It was illuminated by homology analysis that this 3′ flanking sequence and the origin al EST are well aligned with a BAC clone of 20th chromosome and the predic ted exons sequence of this chromosome is well consisten ce with the real EST. Thus the RIG1 can be roughly located in 20th chromos ome. By use of the exons sequence predicted from chromosome sequence by GENSCA N, full-length of RIG1 gene has been cloned. Chromosome location of RIG1 gene i s further determined by this successful verification of Bioinformatics predictio n by experiment. By the same step, genome sequence of RIG1 has been determined. Therefore,by the combined use of Bioinformatics analysis,the full-length cDNA sequence and genome sequence of RIG1 gene are obtained and the predicted protei n sequence is determined.
5.CLONING AND EXPRESSION OF A GENE MEDIATINGγ-RADIATION-INDUCED APOPTOSIS IN HL-60 CELLS
Xiaoming LI ; Tianbao SONG ; Xin TONG ; Zhixian SUN
Journal of Pharmaceutical Analysis 2000;12(1):1-4,14
Objective To identify the member of the caspase family proteases involved in γ-radiation-induced apoptosis in HL-60 cells and to study the expression of the caspase gene in normal, apoptotic cells and in immortal tu mor cells. Methods By using degenerate oligonucleotide primers encoding the highly conserved peptides that were pre sent in all known caspases, we performed RT-PCR on poly(A)RNA from γ-radiation-induced apoptotic HL-60 cells. Caspase-3 mRNA in apoptotic HL-60 cells and in human tumor cell lines was analyzed by Northern blot. Results The amplified DNA fragment was identified with caspase-3 cDNA by cloning and sequencing. The Northern blot analysis of caspase-3 mRNA of different human tumor cell lines showed that the caspase-3 gene transcript was more highly ex pressed in leukemia cell lines and the SH-SY5Y cell line than in HeLa and MCF-7 cells. It was more highly expressed in the radiation-induced apoptotic HL-60 cells than in control HL-60 cells. Conclusion These results indicated that caspase-3 was involved in γ-radiation-induced apoptosis in HL-60 cells. The high level of expression of caspase-3 may aid efforts to understand the insensitivity of some tumor cells to radiation, their inherent ability to survive, and apop tosis.
6.Downregulation of Ro60 inhibits migration and invasion of human lung adenocarci-noma A549 cells
Wan YAO ; Jilai LIU ; Pengda SUN ; Baolei TIAN ; Bin LIU ; Yi SONG ; Zhixian SUN
Military Medical Sciences 2016;40(3):213-216
Objective To study the effect of Ro60 on migration and invasion of lung adenocarcinoma A 549 cells. Methods We knocked down Ro60 and analyzed the ability of migration and invasion of A 549 cells.Quantitative real time ( RT)-PCR and Western blotting were performed to detect mRNA and protein levels of selected molecules associated with migration and invasion of neoplasm .Results When Ro60 was downregulated , the migration and invasion of A 549 cells decreased markedly.Meanwhile,the mRNA expression of matrix metalloproteinase (MMP)9,c-Src etc was observably reduced.Furthermore, downregulation of Ro60 diminished the expression of Src protein and the activation of MMP-9 protein.Conclusion Downregulation of Ro60 inhibits migration and invasion of A549 cells by regulating Src protein and activating MMP-9 protein.
7.Clinical-electroencephalogram characteristics and its evolutionary process of Dravet syndrome
Jianmin QIU ; Xiaoyan LIU ; Yuehua ZHANG ; Huihui SUN ; Zhixian YANG ; Xiuwei MA
Chinese Journal of Neurology 2010;43(10):712-715
Objective To analyze the clinical and electroencephalogram (EEG) characteristics as well as its evolutionary process of Dravet syndrome (DS) in order to improve early diagnosis and appropriate treatment.Methods Fifty patients with DS were studied including onset age, trigger factors, seizure types on different age stages and relationship with EEG characteristics and its evolution process.Results The average age of seizure onset was ( 5.5 ± 1.9 ) months.The fever sensitivity continuously existed in the entire course of disease.In the early stage, generalized tonic-clonic seizures (GTCS) and focal or unilateral seizures were main types.Multi seizure types included myoclonic seizures (MS) and atypical absence occurred later.The onset ages of MS were average (M50) of 16 months.MS never occurred in 26% of the patients.During the first year of life, EEGs were normal in 76% of these patients.The epileptiform discharges only recorded in about 50% of the patients in spite of multi seizure types had presented.After three years ago, both EEG background abnormalities and discharges occurred in more 90% of the all patients.Photosensitivity response with MS occurred in the 28% of 18 patients.Conclusions The clinical and EEG are not parallel progressively process in early stage of DS.The children often express more severe clinical seizures than EEG abnormalities until 2 years of age.Various abnormal EEG manifestation obviously display gradually after 3 years age.Precise recognizing with the clinical and EEG characteristics of DS will help get correct early diagnosis and screen the candidate cases to test SCN1A gene.
8.MRI in differential diagnosis of primary central nervous system lymphoma and high grade glioma in deep brain
Lei GENG ; Yi SUN ; Zhixian SUN ; Xiuling WANG ; Kai XU
Chinese Journal of Interventional Imaging and Therapy 2018;15(2):95-99
Objective To explore the value of MRI in differential diagnosis of primary central nervous system lymphoma (PCNSL) and high grade glioma (HGG) in deep brain.Methods Features of routine MRI and DWI of 28 PCNSL (PCNSL group) and 30 HGG patients (HGG group) with single lesion in deep brain confirmed clinically and pathologically were analyzed,then apparent diffusion coefficient (ADC) and relative ADC (rADC) were measured.The optimal diagnostic threshold (OT) and diagnostic performance of ADC and rADC values were calculated according to the ROC curve.Results The incidence of capsule,necrosis,hemorrhage,enhancement heterogeneity and DWI signal strength were significantly different between the two groups (all P<0.05).ADC values were statistically different between lesions and the control side of the brain white matter in PCNSL and HGG patients (both P<0.001).ADC values and rADC values of PCNSL lesions were significantly lower than those of HGG lesions (all P<0.001).Taking ADC=0.86 × 10-3 mm2/s as a threshold,the sensitivity,specificity and accuracy in differential diagnosis of PCNSL and HGG was 92.9%,80.0% and 86.2%,respectively,and the area under curve was 0.946 (P< 0.001).Taking rADC =1.02 as a threshold,the sensitivity,specificity and accuracy in differential diagnosis of PCNSL and HGG was 92.9%,86.7% and 89.7%,respectively,and the area under curve was 0.957 (P<0.001).Conclusion MRI differential diagnosis can provide reliable information for clinical treatment of PCNSL and HGG in deep brain.
9.Influence of mind mapping combined with Wechat platform on the self-management ability of patients with PICC catheterization in the intermittent period of chemotherapy
Chinese Journal of Practical Nursing 2020;36(14):1057-1061
Objective:To explore the influence of mind mapping combined with Wechat platform on the self-management ability of patients with PICC catheterization in the intermittent period of chemotherapy.Methods:Ninety patients with PICC catheterization were selected as the study subjects. According to the order of treatment, 30 patients were divided into control group, 30 patients with simple mind mapping group and 30 patients with mind mapping combined with wechat platform group. The PICC self-management ability and health education satisfaction of the three groups of patients were compared.Results:The PICC self-management ability scores of the three groups were (137.23±8.42), (144.97±6.43) and (148.20±6.04) points, respectively. There was a statistically significant difference in self-management ability scores among the three groups ( F value was 19.216, P<0.05). Control group and observation group 1, control group and observation group 2, observation group 1 and observation group 2, there was a statistically significant difference in self-management ability scores between the two groups ( t values were -3.997, -5.796, -2.008, P<0.05). The health education satisfaction scores of the three groups were (76.50±12.47), (84.17±10.67) and (90.87±8.54) points, respectively. There was a statistically significant difference in the scores of health education satisfaction among the three groups ( F value was 13.590, P<0.05). Control group and observation group 1, control group and observation group 2, observation group 1 and observation group 2, the difference in health education satisfaction scores between the two groups was statistically significant ( t values were -2.559, -5.208, -2.685, P<0.05). Conclusion:Mind mapping combined with wechat platform can improve the self-management ability and health education satisfaction of patients with PICC catheterization during the intermittent period of chemotherapy, which is worthy of promotion in the clinic.
10.Comparison of dexmedetomidine and opioids as local anesthetic adjuvants in patient controlled epidural analgesia: a meta-analysis
Yafen GAO ; Zhixian CHEN ; Yu HUANG ; Shujun SUN ; Dong YANG
Korean Journal of Anesthesiology 2024;77(1):139-155
Background:
Data on the efficacy and incidence of adverse effects associated with dexmedetomidine (DEX) as a local anesthetic adjuvant for patient-controlled epidural analgesia (PCEA) are inconclusive. This meta-analysis assessed the efficacy and risks of DEX for PCEA using opioids as a reference.
Methods:
Two researchers independently searched PubMed, Embase, Cochrane Library, and China Biology Medicine for randomized controlled trials comparing DEX and opioids as local anesthetic adjuvants in PCEA.
Results:
In total, 636 patients from seven studies were included in this meta-analysis. Postoperative patients who received DEX had lower visual analog scale (VAS) scores than those who received opioids at 4–8 h (mean difference [MD]: 0.61, 95% CI [0.45, 0.76], P < 0.001, I2 = 0%), 12 h (MD: 0.85, 95% CI [0.61, 1.09], P < 0.001, I2 = 0%), 24 h (MD: 0.59, 95% CI [0.06, 1.12], P = 0.030, I2 = 82%), and 48 h (MD: 0.54, 95% CI [0.05, 1.02], P = 0.030, I2 = 91%). Additionally, patients who received DEX had a lower incidence of itching (odds ratio [OR]: 2.86, 95% CI [1.18, 6.95], P = 0.020, I2 = 0%) and nausea and vomiting (OR: 6.83, 95% CI [3.63, 12.84], P < 0.001, I2 = 24%). In labor analgesia, no significant differences in neonatal (pH and PaO2 of cord blood, fetal heart rate) or maternal outcomes (duration of labor stage, mode of delivery) were found between the DEX and opioid groups.
Conclusions
Compared with opioids, using DEX as a local anesthetic adjuvant in PCEA improved postoperative analgesia and reduced the incidence of itching and nausea and vomiting without increasing the incidence of adverse events.