Expression and clinical significance of Flap endonuclease 1 in acute myeloid leukemia / 肿瘤研究与临床

Objective:To investigate the expression level of flap endonuclease 1 (FEN1) in bone marrow mononuclear cells of patients with acute myeloid leukemia (AML) and its relationship with clinicopathologic features and therapeutic effect, so as to provide a new direction for disease monitoring and targeted therapy in AML patients.Methods:The data of 57 newly treated AML patients and 26 healthy individuals (the healthy control) from the First Clinical College of Guangdong Medical University and Fujian Medical University Union Hospital from November 2018 to December 2020 were retrospectively analyzed. Bone marrow samples of all subjects were collected. Quantitative real-time fluorescence polymerase chain reaction (qRT-PCR) was used to detect FEN1 mRNA expression in bone marrow mononuclear cells of all subjects. Bone marrow samples from 9 newly-diagnosed AML patients and 4 healthy controls were collected, and FEN1 protein expression level was detected by using Western blotting. Differences in FEN1 mRNA expression in AML patients achieving different therapeutic effects were compared among AML patients whose data with evaluable efficacy. AML patients were divided into high FEN1 expression group (≥ critical value) and low FEN1 expression group (< critical value), taking the median relative expression level of FEN1 mRNA as the critical value. The correlation of FEN1 expression level with clinicopathologic features, laboratory indicators, cellular and molecular genetic changes in AML patients at initial diagnosis was analyzed.Results:The median relative expression of FEN1 mRNA in newly treated AML patients was higher than that in healthy controls [0.696 (0.025-3.661) vs. 0.246 (0.013-1.237), Z = 1.75, P = 0.041]. Western blotting showed that the expression level of FEN1 protein in AML patients was higher than that in healthy controls. The relative expression of FEN1 mRNA in 15 recurrent AML patients was higher than that in 19 patients patients achieving complete remission (CR) [1.153 (0.047-4.172) vs. 0.259 (0.023-1.148), Z = 2.71, P = 0.009]. The proportion of patients with French-American-British(FAB) type M 5, fever at initial diagnosis and lymph node enlargement in FEN1 high expression group (32 cases) was higher than that in FEN1 low expression group (25 cases) (all P < 0.05). There were no significant differences in the proportion of gender, age, fatigue, pale skin mucosa and large liver and spleen of patients between the two groups (all P > 0.05). At initial diagnosis, the white blood cell count, lactate dehydrogenase, C-reactive protein and bone marrow primitive cell proportion in FEN1 high expression group were higher than those in FEN1 low expression group (all P < 0.05), and the hemoglobin and platelet count in FEN1 high expression group were lower than those in FEN1 low expression group (all P < 0.05). There were no significant differences in procalcitonin level, the proportion of chromosome karyotype, cytogenetic prognosis grade and patients with or without gene mutation between the two groups (all P > 0.05). Conclusions:FEN1 expression is up-regulated in AML patients and further increased in relapsed patients. FEN1 expression in AML patients is associated with adverse clinicopathological features and poor detection results of laboratory indicators, which may become indicators for disease monitoring in AML patients.

Research progress of diagnosis platforms based on CRISPR/Cas system / 中华检验医学杂志

At present, nucleic acid testing technology has been widely used in clinical laboratory diagnosis. Conventional detection technique such as real-time PCR is complicated, time consuming, and dependent on specific instruments. Clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR associated protein (Cas) system is an adaptive immune defense system against viruses in bacteria and archaea, which has been developed into a powerful technology for genome editing. Recently, the leading groups engaged in CRISPR have set up new tools for nucleic acid detection based on Cas13a, Cas12a and newly discovered protein-Cas14, which plays an important role in rapid diagnosis of infectious diseases, detection of gene mutations in cancer and genotyping. Since they are ultrasensitive, specific, rapid and cost-effective, it is expected to bring great potential for molecular diagnosis. In this review, the mechanism of CRISPR/Cas system and the principle, the applications of the newly-developed diagnostic platforms are introduced. What′s more, the advantages, limitations and prospects of the technologies are summarized.

Genomic comparisons of Rhizobium species using in silico AFLP-PCR, endonuclease restriction, and AMPylating enzymes

Background: The whole-genome sequences of nine Rhizobium species were evaluated using different in silico molecular techniques such as AFLP-PCR, restriction digest, and AMPylating enzymes. The entire genome sequences were aligned with progressiveMauve and visualized by reconstructing phylogenetic tree using NTSYS pc 2.11X. The "insilico.ehu.es" was used to carry out in silico AFLP-PCR and in silico restriction digest of the selected genomes. Post-translational modification (PTM) and AMPylating enzyme diversity between the proteome of Rhizobium species were determined by novPTMenzy. Results: Slight variations were observed in the phylogeny based on AFLP-PCR and PFGE and the tree based on whole genome. Results clearly demonstrated the presence of PTMs, i.e., AMPylation with the GS-ATasE (GlnE), Hydroxylation, Sulfation with their domain, and Deamidation with their specific domains (AMPylating enzymes) GS-ATasE (GlnE), Fic, and Doc (Phosphorylation); Asparagine_hydroxylase and Collagen_prolyl_lysyl_hydroxylase; Sulfotransferase; and CNF (Cytotoxic Necrotizing Factors), respectively. The results pertaining to PTMs are discussed with regard to functional diversities reported in these species. Conclusions: The phylogenetic tree based on AFLP-PCR was slightly different from restriction endonuclease- and PFGE-based trees. Different PTMs were observed in the Rhizobium species, and the most prevailing type of PTM was AMPylation with the domain GS-ATasE (GlnE). Another type of PTM was also observed, i.e., Hydroxylation and Sulfation, with the domains Asparagine_hydroxylase and Collagen_prolyl_lysyl_hydroxylase and Sulfotransferase, respectively. The deamidation type of PTM was present only in Rhizobium sp. NGR234. How to cite: Qureshi MA, Pervez MT, Babar ME, et al. Genomic comparisons of Rhizobium species using in silico AFLP-PCR, endonuclease restrictions and ampylating enzymes.

Detection of stress-induced 5′tRNA halves by poly(A) tailed-RNase H digestion-RT-PCR / 军事医学

Objective To develop a simple and quick method for detection of stress-induced 5′transfer RNA( tRNA) halves.Methods Total RNA purified from stress induced cells was polyadenylated by poly( A) polymerase, and then degen-erate DNA probes were used to hybridize with 3′tRNA-halves of intact tRNAs,while RNase H specifically degraded the 3′tRNA-halves strand in tRNA-DNA probes hybrids.Using the RNase H digestion total RNA as templates, complementary DNA( cDNA) was synthesized by oligo ( dT) n-anchored primers.The primer of 5′tRNA halves and anchored-primer were used to amplify 5′tRNA halves by PCR.Results The results showed that the method of poly ( A )-tailed-RNase H digestion-RT-PCR could be successfully used to detect stress-induced 5′tRNA halves.Conclusion A simple and quick method for detection of 5′tRNA halves has been established,which is a user-friendly tool for 5′tRNA halves detection and function research.

Primary structure of nuclease-like proteins from Eisenia foetida / 中国组织工程研究

BACKGROUND:A group of nuclease-like proteins were previously purified from Eisenia foetida tissues, exploring primary structures of these proteins wil help to uncover basic structure characteristics of them and provide foundations for the study addressing the relationship of their structures and functions. OBJECTIVE:To explore primary structures of nuclease-like proteins EWD1 and EWD2. METHODS:Edman degradation method was used to sequence the N-terminal amino acids of EWD1 and EWD2, acid hydrolisis method was used to analyze amino acid compositions of EWD1 and EWD2, LC-MS/MS was used to analyze some peptide sequences within the proteins, and MALDI-TOF-MS was used to calculate the number of the disulfide bonds and the contents of polysaccharides. RESULTS AND CONCLUSION:Among the amino acid compositions in EWD1 and EWD2, the sum contents of aspartate and asparagines were the highest (al nearly 10%), the contents of hydrophobic amino acids were also high, and the contents of cysteine was low. The EWD1 and EWD2 had similar amino acid compositions with other nucleases. Edman degradation results showed that, the N-terminal sequences of the large subunit of EWD1 were in turn as fol ows:D, E, W, V, Y, P;the N-terminal sequences of EWD2 were as fol ows:L, L, G, P, Y, K, P, K, C. The results of LC-MS/MS indicated the two proteins were novel proteins;MALDI-TOF-MS results showed that 8 cysteine residues formed 4 disulfide bonds in EWD1, 6 cysteine residues formed 3 disulfide bonds in EWD2. EWD1 and EWD2 were al glycoproteins, the content of polysaccharides was 17.3%in EWD1 and 15.6%in EWD2.

Polymorphisms of ERCC1 gene and outcomes in epithelial ovarian cancer patients with platinum-based chemotherapy / 中华妇产科杂志

Objective To explore the relationship among single nucleotide polymorphism (SNP) of excision repair cross-complementing 1 (ERCC1) gene,chemotherapy sensitivity and clinical outcomes of epithelial ovarian cancer (EOC) patients treated with platinum.Methods Six tag single nucleotide polymorphisms (tagSNP;rs11615,rs3212986,rs735482,rs3212955,rs12610134 and rs3212958) were chose from ERCC1 gene.The genotypes of 6 tagSNP were determined by Snapshot method in 220 EOC patients.Primary clinical outcomes parameter contained EOC patients'responses to platinum-based chemotherapy,progression-free survival (PFS) and overall survival (OS) were analysed.Results The rs11615 C/T SNP of ERCC1,CC,CT and TT genotype frequencies were 53.1％,45.6％,1.4％ in responders to platinum-based chemotherapy,while 52.0％,35.6％,12.3％ in non-responders,respectively,in which there was significant difference between the two groups(P =0.002).Compared with the patients with CC genotype,the patients carrying TT genotype had a significantly poor response to platinum-based chemotherapy (OR =6.22,95％ CI:1.12-34.42).Similarly,the genotypes frequencies distribution of rs11615 C/T SNP of ERCC1 was different between the recurrence and non-recurrence group,death and survival group (all P ＜ 0.05).Kaplan-Meier survival analysis showed that the genotypes frequencies distribution of rs11615 C/T SNP of ERCC1 was associated with PFS and OS(P ＜ 0.01) of EOC patients.Cox's multivariate analysis suggested that patients with TT genotype had a shorter PFS (HR =2.19,95 ％ CI:1.14-4.22,P =0.009) and OS (HR =2.22,95 ％ CI:1.06-4.64,P =0.021) compared with those carrying CC genotype [adjusting for age,International Federation of Gynecology and Obstetrics (FIGO) stage,pathological type,grade and tumor residual size].The genotypes frequencies distribution of rs3212986,rs735482,rs3212955,rs12610134 and rs3212958 SNP of ERCC1 did not show the significant difference between the responders to platinum-based chemotherapy and non-responders.The other 5 tagSNP may not be associated with the PFS and OS of EOC patients (all P ＞ 0.05).Conclusion The rs 11615 SNP of ERCC1 may become a valuable prognostic biomarker for EOC patients treated with platinum-based chemotherapy.

Characterization of immobilized biomass by amplified rDNA restriction analysis (ARDRA) in an anaerobic sequencing-batch biofilm reactor (ASBBR) for the treatment of industrial wastewater

The performance of an anaerobic sequencing-batch biofilm reactor (ASBBR- laboratory scale- 14L )containing biomass immobilized on coal was evaluated for the removal of elevated concentrations of sulfate (between 200 and 3,000 mg SO4-2·L-1) from industrial wastewater effluents. The ASBBR was shown to be efficient for removal of organic material (between 90% and 45%) and sulfate (between 95% and 85%). The microbiota adhering to the support medium was analyzed by amplified ribosomal DNA restriction analysis (ARDRA). The ARDRA profiles for the Bacteria and Archaea domains proved to be sensitive for the determination of microbial diversity and were consistent with the physical-chemical monitoring analysis of the reactor. At 3,000 mg SO4-2·L-1, there was a reduction in the microbial diversity of both domains and also in the removal efficiencies of organic material and sulfate.

Effect of XPG down-regulation gene expression towards the proliferation of epithelial ovarian cancer cells and its chemosensitivity to platinum / 中华妇产科杂志

ObjectiveTo investigate the effect of XPG down-regulation gene expression towards the proliferation of epithelial ovarian cancer cells and its chemosensitivity to platinum.Methods The small interference RNA ( siRNA ) -XPG fragments were designed and tranfected into SKOV3/DDP cell lines by lipofectamine transiently for choosing the best siRNA-XPG fragment to silence XPG gene expression.The pGPU6/GFP/Neo vector was used to construct the siRNA-XPG vectors,which was transfected into SKOV3/DDP cell line with expression of XPG gene.Real-time PCR and western blot were employed to confirm the silencing efficacy of siRNA-XPG.The growth curve of cells,cell cycle,the drug-resistance index of cells and intracellular drug concentration were measured by 4-methyl-thiazolyl-tetrazolium (MTT),flow cytometer (FCM) and high performance liguid chromatograph respectively.Results( 1 ) Real-time PCR results showed that XPG mRNA expression copy number in SKOV3/DDP tranfected with siRNA-XPG-733 fragment was 1.050 ± 0.023,which was significantly lower than that in SKOV3/DDP tranfected with other siRNA-XPG fragments(P ＜ 0.05,respectively),and was chosed to construct the siRNA-XPG vectors.The XPG mRNA expression was down-regulated in short hairpin RNA (shRNA)-XPG-733-SKOV3/DDP cell lines that confirmed by western blot.( 2 ) The growth curve showed that growth velocity of shRNA-XPG-733-SKOV3/DDP cell lines was lower than that of shRNA-GAPDH and shRNA-NC cell lines( P ＜ 0.05,respectively).The results of FCM also showed that 34.0％ of cells in shRNA-XPG-733-SKOV3/DDP cell lines were in S + G2/M phase,while only 58.7％ and 51.3％ in shRNA-GAPDH and shRNA-NC cell lines respectively ( P ＜ 0.05,respectively).( 3 ) The drug-resistance index of shRNA-XPG-733-SKOV3/DDP cell lines [ 50％ inhibiting concertration( IC50 ):( 13.79 ± 0.06) μg/ml ] was lower than that in shRNA-GAPDH and shRNANC cell lines [ IC50:( 27.84 ± 0.34 ) μg/ml and ( 28.32 ± 0.42 ) μg/ml,respectively ] statistically significant (P ＜ 0.05,respectively) ; but there was not statistically significant difference in intracellular drug concentration between shRNA-XPG-733-SKOV3/DDP cell lines [ (0.026 ± 0.005 ) μg/ml ] and shRNAGAPDH [ (0.024 ± 0.003 ) μg/ml ] and shRNA-NC cell lines [ ( 0.025 ± 0.007 ) μg/ml ] after treated by cisplatin in vitro ( P ＞ 0.05,respectively ).Conclusion The down-regulating of XPG gene resulted in slowing growth velocity and descending the drug-resistance index of shRNA-XPG-733-SKOV3/DDP cell lines,which may be related with descending in capability of DNA excision repair in cells.

Predicting clinical chemo-sensitivity of primary ovarian cancer using adenosine triphosphate-tumor chemosensitivity assay combined with detection of drug resistance genes / 中华妇产科杂志

Objective To predict clinical chemotherapy sensitivity of primary ovarian cancer by jointing adenosine triphosphate(ATP) - tumor chemo-sensitivity assay(TCA) method in vitro and detection of drug resistance genes, provide reference for clinical treatment. Methods Forty-seven primary epithelial ovarian tumor samples were collected from the patients who received cytoreductive surgery. Viable ovarian cancer cells obtained from malignant tissue were tested for their sensitivity to carboplatin (CBP), cisplatin (DDP), paclitaxel(PTX) and CBP + PTX using ATP-TCA method in vitro; at same time, real-time quantitative PCR was used to analysis BRCA1 and ERCC1 mRNA relative expression in forty-six specimens (1 frozen tumor samples mRNA were not detected due to serious degradation). The relationship between ATP-TCA test results, clinical indicators, and the effectiveness of the joint prediction on clinical chemosensitivity by combining these two methods were statistically analyzed using chi-square test. Results (1)The results showns that three programs of DDP,CBP and PTX + CBP were significantly related with clinical results(P<0.05) in vitro, in which the compliance rate in PTX + CBP program was the highest 83%(39/47) ,and the predictive sensitivity, predictive specificity, positive predictive value, negative predictive value and predictive accurate rate were 90%,71%,84% and 80% ,respectively.PTX + CBP combined in vitro test results was also related with residual tumor size and neoadjuvant chemotherapy, which was more prone to drug resistance with residual tumor larger than 2 cm (P = 0. 023) and with neoadjuvant chemotherapy (P = 0.011). (2) BRCA1 mRNA expression levels in the clinical-resistant group and the clinical-sensitive group was 0.673 ± 2.143 and - 1.436 ± 2.594 (P=0.008), ERCC1 mRNA expression levels in the clinical-resistant group and the clinical-sensitive group was -0.529 ± 1.982 and - 3.188 ±2.601 (P =0.001). There were also significant correlation among the expression levels of BRCA1 ,ERCC1 mRNA and clinical efficacy (P<0.01). (3)ATP-TCA and detection of drug resistance genes combined to predict the clinical application of PTX + CBP resistance may occur in 8/9 cases. Conclusions ATP-TCA may be an ideal method of in vitro drug sensitivity testing method, which could effectively predict clinical chemotherapy sensitivity. Combination of the drug-resistant associated genes detection method and the ATP-TCA method can increase the predictive effectiveness of ovarian cancer chemosensitivity and guide individual chemotherapy of ovarian cancer.

Inhibitorv effect of emodin on heterotransplanted human bladder cancer in nude mice and its mechanism / 中国医师杂志

Objective To investigate the inhibitory effect of emodin on hetertransplanted human bladder cancer in nude mice and explore its mechanism.Methods Heterotransplanted models of human bladder cancer cell line BIU87 cells in nude mice were established.The mice were randomly divided into 4 groups during the experiment:blank control group,Z-VAD-FMK group,emodin group and emodin combined with Z-VAD-FMK group.The growth of tumors was observed and the growth curve was mapped.The nude mice were sacrificed 4 weeks later,the tumors were isolated and weighed.The pathological changes of tumor were observed after HE staining,the cells apoptosis were detected with flow cytometry,and the expression of AIF and Endo G were examined by reverse transcription PCR (RT-PCR) and Western blot.Results The tumor growth rate in emodin group was lower than that in the other three groups.The tumor quality in emodin group [(0.41 ± 0.05 ) g] and emodin combined with Z-VAD-FMK group [( 0.69 ±0.07)g]were lighter than that in the other two groups[(1.08 ±0.13,1.04 ±0.09)g,],and the differences were statistically significant( F =90.56,27.49,P ＜0.01 ).The quality difference in emodin group and emodin combined with Z-VAD-FMK group was statistically significant ( t =10.01,P ＜ 0.01 ).The apoptosis rate in emodin group [(42.71 ±2.69)％]was significantly higher than that in emodin combined with Z-VAD-FMK group[(34.38 ± 1.73)％] ( t =6.38,P ＜0.01 ).The expression of AIF and Endo G in emodin combined with Z-VAD-FMK group was significantly increased than other groups [( 1.65 ±0.12)vs(1.24±0.08),(0.51 ±0.07),(0.48 ±0.04);(2.12 ±0.16)vs(1.75 ±0.13),(0.57 ±0.06),(0.59±0.07);(2.42±0.13)vs(1.73 ±0.11),(0.78 ±0.07),(0.75 ±0.08);(3.13 ±0.25)vs(2.15± 0.18 ),(0.85 ± 0.09 ),(0.81 ± 0.14 )],and the differences were significant ( F =303.22,319.32,409.38,258.53,P ＜ 0.01 ).Conclusions Emodin could significantly inhibit the growth of hetertransplanted human bladder cancer in nude mice.The mechanism might be partly due to the expression increase of AIF and Endo G in bladder cancer cells,which might induce apoptosis through Caspase-independent pathway.

Variabilidade genética na região its do rDNA de isolados de trichoderma spp. (Biocontrolador) e Fusarium oxysporum f. sp. Chrysanthemi / Genetic variability in rDNA ITS region of Trichoderma spp. (biocontrole agent) and Fusarium oxysporum f. sp. chrysanthemi isolates

A análise de características morfológicas e culturais podem não ser suficientes para uma caracterização precisa das espécies de Trichoderma e Fusarium. Objetivou-se, neste trabalho, caracterizar a região do Espaço Interno Transcrito (ITS) do rDNA dos isolados UFSMT15.1, UFSMT16 e UFSMT17 de Trichoderma spp. utilizados no biocontrole de Fusarium oxysporum f. sp. chrysanthemi (isolado) UFSMF6. A extração de DNA de cada isolado foi realizada a partir de micélio produzido em meio líquido Batata-Dextrose. As amostras de DNA genômico foram submetidas à Reação em Cadeia da Polimerase (PCR) com os oligonucleotídeos iniciadores universais ITS1 e ITS4 e o produto gerado foi sequenciado. Os fragmentos gerados pela amplificação da PCR foram tratados com as enzimas de restrição HaeIII, HinfI e MboI. As regiões ITS1, ITS2 e 5.8S do rDNA desses isolados fúngicos foram amplificadas com sucesso. A região ITS dos isolados UFSMT15.1, UFSMT16 e UFSMT17 de Trichoderma e o isolado UFSMF6 de Fusarium apresentaram uma banda simples com um fragmento de aproximadamente 600 pares de base (pb). As enzimas de restrição HaeIII, HinfI e MboI geraram polimorfismo de bandas entre os isolados. Com base nas análises da sequência de DNA, os isolados UFSMT15.1, UFSMT16, UFSMT17 e UFSMF6 apresentaram maior similaridade com as espécies Trichoderma koningiopsis, Hypocrea virens, Hypocrea lixii e Fusarium oxysporum, respectivamente.

The analysis of morphological and cultural characteristics may not enough for the characterization of the species of Trichoderma and Fusarium. The aim of this work was to characterize the Internal Transcribed Spacer (ITS) region of the rDNA of UFSMT15.1, UFSMT16 and UFSMT17 isolates of Trichoderma spp. used in the biocontrol of Fusarium oxysporum f. sp. chrysanthemi UFSMF6. DNA extraction of each isolate was accomplished starting from hyphae produced in liquid medium Potato-Dextrose-Agar. The samples of genomic DNA were submitted to the Polymerase Chain Reaction (PCR) with the primers ITS1 and ITS4, and the product was sequenced. The fragments generated from PCR amplification were digested with the restriction enzymes HaeIII, HinfI and MboI. The ITS region of the Trichoderma's isolates UFSMT15.1, UFSMT16 and UFSMT17 and the Fusarium UFSMF6 isolate showed a simple band with a fragment with 600 base pairs (bp) approximately. The restriction enzymes HaeIII, HinfI and MboI generated band polymorphism among the isolates. The isolates UFSMT15.1, UFSMT16, UFSMT17 and UFSMF6 showed high similarity whit Trichoderma koningiopsis, Hypocrea virens, Hypocrea lixii and Fusarium oxysporum species, respectively.

Karyotypic characterization of Iheringichthys labrosus (Pisces, Pimelodidae): C-, G- and restriction endonuclease banding

Various chromosomal banding techniques were utilized on the catfish, Iheringichthys labrosus, taken from the Capivara Reservoir. C-banding regions were evidenced in telomeric regions of most of the chromosomes. The B microchromosome appeared totally heterochromatic. The restriction endonuclease AluI produced a banding pattern similar to C-banding in some chromosomes; the B microchromosome, when present, was not digested by this enzyme and remained stained. G-banding was conspicuous in almost all the chromosomes, with the centromeres showing negative G-banding. When the restriction endonuclease BamHI was used, most of the telomeres remained intact, while some centromeres were weakly digested. The B chromosome was also not digested by this enzyme. The first pair of chromosomes showed a pattern of longitudinal bands, both with G-banding and BamHI; this was more evident with G-banding. This banding pattern can be considered a chromosomal marker for this population of I. labrosus.