Through virtual saturation mutagenesis and rational design for superior substrate conversion in engineered d-amino acid oxidase.

The d-amino acid oxidase (DAAO) is pivotal in obtaining optically pure l-glufosinate (l-PPT) by converting d-glufosinate (d-PPT) to its deamination product. We screened and designed a Rasamsonia emersonii DAAO (ReDAAO), making it more suitable for oxidizing d-PPT. Using Caver 3.0, we delineated three substrate binding pockets and, via alanine scanning, identified nearby key residues. Pinpointing key residues influencing activity, we applied virtual saturation mutagenesis (VSM), and experimentally validated mutants which reduced substrate binding energy. Analysis of positive mutants revealed elongated side-chain prevalence in substrate binding pocket periphery. Although computer-aided approaches can rapidly identify advantageous mutants and guide further design, the mutations obtained in the first round may not be suitable for combination with other advantageous mutations. Therefore, each round of combination requires reasonable iteration. Employing VSM-assisted screening multiple times and after four rounds of combining mutations, we ultimately obtained a mutant, N53V/F57Q/V94R/V242R, resulting in a mutant with a 5097% increase in enzyme activity compared to the wild type. It provides valuable insights into the structural determinants of enzyme activity and introduces a novel rational design procedure.

Efficient Production of 3-Amino-2-Hydroxy Acetophenone by Multi-Enzyme Biosynthesis.

We developed a synthetic route for producing 3-amino-2-hydroxy acetophenone (3AHAP) from m-nitroacetophenone (3NAP) using an in vitro approach. Various reaction systems were evaluated, and a direct reaction method with crude enzyme and supersaturated substrates for optimal catalytic efficiency was chosen. The reaction system included three enzymes and was enhanced by adjusting enzyme molar ratios and optimizing ribosomal binding sites. We performed substrate docking and alanine scanning to identify key sites in the enzymes nitrobenzene nitroreductase (nbzA) and hydroxylaminobenzene mutase (habA). The optimal mutant was obtained through site-directed mutagenesis, and incorporated into the reaction system, resulting in increased product yield. After optimization, the yield of 3AHAP increased from 75 mg/L to 580 mg/L within 5 hours, the highest reported yield using biosynthesis. This work provides a promising strategy for the efficient and sustainable production of 3AHAP, which has critical applications in the chemical and pharmaceutical industries.

[Effect of chromosomal polymorphisms on reproductive outcomes of in vitro fertilization-embryo transfer].

OBJECTIVE: To explore the effect of chromosomal polymorphic variations on the outcome of in vitro fertilization/intracytoplasmic sperm injection-embryo transfer (IVF/ICSI-ET) treatment for infertile couples. Methods： In this retrospective study, 418 infertile couples, who received their first IVF/ICSI-ET treatment cycles in Reproductive Medicine Center of Xi'an People's Hospital (Xi'an Fourth Hospital) from Jan. 2021to Jan. 2023, were included and divided into two groups: group A (the infertile couples with normal chromosome) and group B(with chromosomal polymorphic variations); The group B divided into 2 groups, group C(male carrier, n= 44), group D (female carrier, n= 37). The No. of oocyte, 2PN fertilization rate, fertilization rate,multi-PN fertilization rate, quality embryo rate, cleavage rate, normal cleavage rate, blastocyst formation rate,clinical pregnancy rate after IVF/ICSI-ET treatment were compared and analyzed. Logistic regression analysis was performed to study the relationship between clinical pregnancy rate and chromosome variation. Results： A total of 418 infertile couples received IVF/ICSI-ET treatment were enrolled, with 81 in the chromosomal polymorphic group (group A), and 337 in the normal chromosomal group (group B). The quality embryo rate were signifcantly higher in the group A（59.21% vs 52.42%,P<0.05）,the other outcomes have no significant differences between the two groups ( P>0.05). The No. of oocyte, 2PN fertilization rate, fertilization rate,multi-PN fertilization rate, quality embryo rate, cleavage rate, normal cleavage rate, blastocyst formation rate showed no signifcantdiferences among group A, group C and group D (P>0.05). The clinical pregnancy rate in group A is higer than group C and group D (56.7% vs 52.3% vs 40.5%), But there were no signifcantly diferent among the three groups (P>0.05). Logistic regression analysis indicated that the Chromosomal polymorphisms were not associated with clinical pregnancy rate (P>0.05).Conclusion： Chromosomal polymorphisms appear to have no significant effect on the outcome of IVF/ICSI-ET treatment for infertile couples.

[Doxorubicin Hydrochloride Liposome-Based CHOP Regimen in the Initial Treatment of Elderly Patients with Diffuse Large B-Cell Lymphoma: A Retrospective Study].

OBJECTIVE: To evaluate the efficacy and safety of CHOP regimen based on doxorubicin hydrochloride liposome in the initial treatment of elderly patients with diffuse large B-cell lymphoma (DLBCL). METHODS: Thirty-one patients with DLBCL treated from January 1, 2012 to December 31, 2019 were analyzed retrospectively, their median age was 83 (71-95) years old, and all of them were in Ⅲ-Ⅳ stage, including 17 cases who had international prognostic index (IPI) ≥ 3. The patients were treated with R-CHOP and CHOP regimens based on doxorubicin hydrochloride liposome. The efficacy and safety were evaluated during and after treatment. RESULTS: A total of 219 chemotherapy cycles and 7 median cycles were performed in 31 patients. The overall response (OR) rate and complete remission (CR) rate was 80.7% (25/31) and 61.3% (19/31), respectively, as well as 2 cases (6.5%) stable, 4 cases (12.9%) progressive. The main toxicities were as follows: the incidence of grade Ⅲ -Ⅳ neutropenia was 29% (9/31); two patients (6.5%) developed degree Ⅰ-Ⅱ cardiac events, which were characterized by new degree Ⅰ atrioventricular block; there were no cardiac events requiring emergency treatment and discontinuation of chemotherapy. The 1-year, 2-year and 3-year overall survival rate was 83.9%, 77.4% and 61.3%, respectively. The 1-year, 2-year and 3-year progression-free survival rate was 77.4%, 64.5% and 61.3%, respectively. CONCLUSION: The chemotherapy regimen based on doxorubicin hydrochloride liposome has better efficacy and higher cardiac safety for elderly patients with DLBCL.

Bioactive terpenoids from Croton laui.

Two new highly-oxygenated neo-clerodane diterpenoids, 3S-acetoxyl-mollotucin D dilactone ester (1) and 6S-crotoeurin C (2), and a new lupane-type triterpene, 16ß-hydroxyl-3ß-O-trans-coumaroyl-betulin (6), as well as three known analogues (3-5) were obtained from the leaves of Croton laui. The structures of the new compounds were determined by extensive spectroscopic methods, and their absolute configurations were determined by combination of single-crystal X-ray diffraction analysis, electronic circular dichroism (ECD) spectra, and literature data. Compounds 2 and 3 exhibited inhibitory activities of lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW 264.7 macrophages with IC50 values of 1.2 and 1.6 µM, respectively. Additionally, compound 6 exhibited activity against Col205 and HepG2 cell lines with IC50 values of 12.9 and 17.7 µM, respectively.

Downregulation of lncRNA ZFAS1 and upregulation of microRNA-129 repress endocrine disturbance, increase proliferation and inhibit apoptosis of ovarian granulosa cells in polycystic ovarian syndrome by downregulating HMGB1.

OBJECTIVE: The objective was to find the role of long-non-coding RNA zinc finger antisense 1 (lncRNA ZFAS1)/microRNA (miR)-129/high-mobility group box protein 1 (HMGB1) axis in polycystic ovary syndrome (PCOS). METHODS: Ovarian granulosa cells from non-PCOS patients and PCOS patients were collected, and HMGB1, miR-129 and lncRNA ZFAS1 expression were detected. Ovarian granulosa cells were transfected with si-ZFAS1 or miR-129 mimics to verify their roles in P4 and E2 secretion, and the biological functions of ovarian granulosa cells. RESULTS: LncRNA ZFAS1 and HMGB1 were elevated, while miR-129 was down-regulated in ovarian granulosa cells of PCOS patients. Down-regulated lncRNA ZFAS1 or overexpressed miR-129 could decrease HMGB1 expression, increase P4 and E2 secretion, promote proliferation activity while inhibit apoptosis of ovarian granulosa cells in PCOS. CONCLUSION: LncRNA ZFAS1 could bind to miR-129 to promote HMGB1 expression, thereby affecting the endocrine disturbance, proliferation and apoptosis of ovarian granulosa cells in PCOS.

[Triptolide induces autophagy of ovarian granulosa cells via PI3K/AKT/m TOR pathway].

The aim of this paper was to observe the concentration,time and mechanism of autophagy induced by triptolide( TP) in ovarian granulosa cells( OGCs). CCK-8 method was used to compare the inhibitory effects of TP at different concentrations on primary cultured rat OGCs and IC50 was calculated. The effects of TP at different concentrations and time points on the expression of OGCs autophagy factor protein and the cascade of PI3 K/AKT/m TOR pathway were detected by Western blot. The effects of TP,autophagy inducer( brefeldin A) and PI3 K/m TOR inhibitor( NVP-BEZ235) on the expression of PI3 K/AKT/m TOR cascade and autophagy related factor protein were detected by Western blot. The results show that the IC50 of different concentrations of TP on OGCs of rat ovary was14. 65 µmol·L-1,and the minimum inhibitory concentration of TP was 0. 1 µmol·L-1( 100 nmol·L-1). Compared with the control group,the expression levels of beclin1 and LC3Ⅱ in each group were significantly higher than those in the control group( P<0. 05 or P<0. 01). After 12 hours of treatment with TP,brefeldin A and NVP-BEZ235,respectively,compared with the control group,TP could significantly promote the expression level of downstream autophagy effect or molecule beclin1,LC3Ⅱ and inhibit the expression level of LC3Ⅰ,p62 protein( P<0. 05 or P< 0. 01). Moreover,the expression of beclin1 and LC3Ⅱ/LC3Ⅰ in TP group was higher than that in brefeldin A group( P<0. 05 or P<0. 01),and the expression of p62 in TP group was lower than that in brefeldin A group( P<0. 05 or P<0. 01). At the same time,TP could significantly inhibit the expression of p-PI3 K,p-AKT,p-mTOR protein,and the inhibitory effect of TP was better than that of NVP-BEZ235 group. This study suggests that 100 nmol·L-1 TP could induce OGCs autophagy successfully in cultured rat ovary for 12 h; TP may induce OGCs autophagy by inhibiting PI3 k/Akt/m TOR signaling pathway.

Bu Shen Yang Xue Prescription Has Treating Effect on Endometrial Cancer through FSH/PI3K/AKT/Gankyrin/HIF-α/cyclinD 1 Pathway in Ishikawa Cells.

Background. The formulation of Bu Shen Yang Xue (BSYX) has been clinically used in treating gynecologic disease in China, especially for the development of the endometrium. Endometrial carcinoma is the most common malignant tumor of the female genital tract in developed countries. And few studies have been reported on the antitumor activity of BSYX. Therefore, this study aimed to investigate the effect of BSYX on endometrial cancer and make an initial discussion of the underlining mechanisms in Ishikawa cells. Methods and Results. Firstly, 60 SPF female nude mice were randomly divided into control group, model group, BSYX group, and positive group. The models of subcutaneous tumor xenograft of nude mice were established by injection of human endometrial carcinoma cell line Ishikawa tumor cell suspension. Compared with model group, BSYX reduced effectively tumor volume and changed pathological feature in mice tumor issue. Meanwhile, proteins from tumor issues were detected by western blot analysis. The protein levels of follicle-stimulating hormone receptor (FSHR), p-Akt/Akt, Gankyrin, and cyclinD1 in the model group were higher than those in control group but the expression in BSYX group was lower than that in the model group. The hypoxia inducible factor alpha (HIF-α) protein level in the model group was lower than those in control group and upregulated in BSYX group. In addition, Ishikawa cells were cultured and then exposed to follicle-stimulating hormone (FSH), LY294002, a highly selective PI3K inhibitor and serum containing BSYX, respectively. LY294002 and BSYX markedly decreased the cancer cell viability and migration ability and increased the apoptosis rate. FSH promoted the cancer cell ability and migration ability. LY294002 and BSYX evidently downregulated the proteins levels of FSHR, p-Akt/Akt, Gankyrin, and cyclinD1 and upregulated the expression of HIF-α protein, and FSH was on the opposite. Conclusions. Taken together, our results showed that the formulation of BSYX had antitumor effect on endometrial cancer in vivo and in vitro and was related with FSH/PI3K/AKT/Gankyrin/HIF-α/cyclinD1 transduction pathway.

Chinese guidelines for treatment of adult primary immune thrombocytopenia.

Primary immune thrombocytopenia (ITP) is a bleeding disorder commonly encountered in clinical practice. The International Working Group (IWG) on ITP has published several landmark papers on terminology, definitions, outcome criteria, bleeding assessment, diagnosis, and management of ITP. The Chinese consensus reports for diagnosis and management of adult ITP have been updated to the 4th edition. Based on current consensus positions and new emerging clinical evidence, the thrombosis and hemostasis group of the Chinese Society of Hematology issued Chinese guidelines for management of adult ITP, which aim to provide evidence-based recommendations for clinical decision making.

[Clinical Analysis of 153 Cases of Refractory/Relapsed Diffuse Large B-cell Lymphoma].

OBJECTIVE: To analyze the clinical features and treatment methods of refractory/relapsed diffuse large B cell lymphoma (DLBCL) patients, and to explore the curative effect and the main factors affecting prognosis. METHODS: Clinical data of 1043 cases of DLBCL in our hospital from January 2008 to April 2016 were retrospectively analyzed, then the clinical data of 153 patients with refractory/relapsed lymphoma were selected and analyzed for determing the relationship of the related factors with therapeutic effect and prognosis. Treatment methods include chemotherapy alone and chemotherapy combined with radio-therapy, the first line regimen was CHOP or R-CHOP program, the salvage regimens are ICE, Hyper CVAD or EPOCH, etc. The median age of these 153 patients was 50 years old, the ratio of male and female was 1.59:1. RESULTS: 4 cases were not treated in 153 patients, 6 cases (4.03%) of 149 patients have been treated and achieved complete remission(CR), 18 cases (12.08%) achieved partial remission(PR), and the total response rate was 16.1%. Single factor analysis showed that the patients' serum LDH values, IPI score, bulky, extra-node involvement, bone marrow infiltration and the salvage regimen all could influence the survival rate, with statistically significantce (P<0.05). CONCLUSION: Refractory/relapsed DLBCL mainly occurs in the middle-aged and male, the serum LDH value, IPI score, bulky and scope of lesions are mainly factors influencing the prognosis of refractory/relapsed DLBCL patients.

[Prognostic and Therapeutic Significance of Molecular Subtyping on Aged Patient with Advanced Diffuse Large B Cell Lymphoma---A Case Report].

OBJECTIVE: To analyze the clinical course of a very elderly patient with advanced diffuse large B cell lymphoma (DLBCL), so as to explore the incidence, prognosis and treatment of DLBCL and to analyse the prognostic and therapeutic significance of molecular subtype. METHODS: The clinical history, auxiliary examinations, clinical diagnostic standards, therapeutic methods, biopsy and autopsy of this patient were retrospectively analyzed; the incidence, current treatment status, molecular biological features, and prognostic and therapeutic significance of molecular subtype were studied. RESULTS: After admission, this patient was diagnosed as non-GCB DLBCL, NOS, stage IV B and in the high risk group (IPI = 5, ECOG = 2). She achieved a decent partial response after many times of imunochemotherapy, but his disease status soon progressed. The liver occupying biopsy revealed non-GCB, while the spleen tumor pathology revealed GCB; pathological typing of these two methods was completely opposite. Autopsy pathological diagnosis showed that the death causes included extensive tumor metastasis, dyscrasia and respiratory circle failure. CONCLUSION: Incidence of aged patients with DLBCL is high, and the disease is aggressive; the treatment is low responsive and difficult, and new therapeutic methods are needed. Gene expression profile (GEP) can provide molecular subtype and potential pathogenic mechanism, which can promote the development of new targeted therapy and individualized treatment.

The effect of amifostine on differentiation of the human megakaryoblastic Dami cell line.

Amifostine is a cytoprotective drug that was initially used to control and treat nuclear radiation injury and is currently used to provide organ protection in cancer patients receiving chemotherapy. Clinical studies have also found that amifostine has some efficacy in the treatment of cytopenia caused by conditions such as myelodysplastic syndrome and immune thrombocytopenia, both of which involve megakaryocyte maturation defects. We hypothesized that amifostine induced the differentiation of megakaryocytes and investigated this by exposing the human Dami megakaryocyte leukemia cell line to amifostine (1 mmol/L). After 12 days of amifostine exposure, optical microscopy showed that the proportion of Dami cells with diameters >20 µm had increased to 24.63%. Transmission electron microscopy identified the development of a platelet demarcation membrane system, while flow cytometry detected increased CD41a expression and decreased CD33 expression on the Dami cell surface. Ploidy analysis found that the number of polyploid cells with >4N DNA content increased to 27.96%. We did not detect any elevation in the mRNA or protein levels of megakaryocytic differentiation-associated transcription factors GATA-binding factor 1 (GATA-1) and nuclear factor, erythroid 2 (NF-E2), but nuclear import assay revealed an increased nuclear translocation of these proteins. These findings indicate that amifostine induced the differentiation of Dami cells into mature megakaryocytes via a mechanism involving increased nuclear translocation of the transcription factors, NF-E2 and GATA-1.

[Cytogenetic Abnormalities and Outcomes of 117 Patients with Multiple Myeloma Detected by FISH].

OBJECTIVE: To analyze the cytogenetic abnormalities and prognostic outcomes of patients with multiple myeloma (MM) detected by fluorescence in situ hybridization (FISH). METHODS: The clinical record of 117 newly-diagnosed patients with MM treated in department of hematology and geriatric hematology of our hospital for 7 years were collected, and their molecular cytogenetic abnormalities detected by FISH and the clinical outcome were analyzed retrospectively. RESULTS: The detected rate of cytogenetic abnormality was 76.9%(90/117), the most common abnormality deteted by FISH was 1q21+ (71.1%), followed by 13q- (56.6%). The cross comparison method showed that 13q- and 17p13-, t(11;14) and t(4;14) were related respectively. All the patients with cytogenetic abnormalities showed no significant difference in the overall survival from cytogenetic normal patients. CONCLUSION: The positive rate of molecular cytogenetic abnormalities detected by FISH in MM patients is high, but data from larger and longer studies are needed to evaluate the prognostic outcomes.

[Prognostic significance of cytogenetics in aged patients with acute myeloid leukemia].

Aged patients with acute myeloid leukemia accounted for more than half of the adult AML patients, which has characteristics of low complete remission rate, short overall survival and poor prognosis. Recently, the importance of cytogenetics in AML was gradually realized. The diagnosis and typing, prognosis stratification and guide for treatment are performed on the basis of cytogenetics, but the research on influence of cytogenetics on adged patients with AML are relatively few. This review briefly summarizes the prognostic significance of cytogenetics in aged patients with AML.

[Elderly chronic lymphocytic leukemia combined with invasive aspergillosis infection in one case].

OBJECTIVE: This study was aimed to investigate the morphological, immunophenotype, cytogenetic characteristics, clinical and therapy features in one elderly patient with chronic lymphocytic leukemia (CLL) combined with invasive aspergillose infection(IAI). METHODS: The morphological features of bone marrow cells from patient were observed by light microscope, the immunophenotype were detected by flow cytometry, the cytogenetic characteristics were assayed by conventional chromosomal analysis and fluorescence in situ hybridization (FISH). RESULTS: at onset of disease, the patient was diagnosed as B-CLL, Rai stage is II. He was treated with a course of RF(fludarabine 50 mg×5, rituximab 600 mg×5) chemotherapy, and achived complete remission (CR) lasting for five years, then the patient was treated with multiple courses of chemotherapy and maintained at a steady state of disease. After the last chemotherapy, this patient developed a fever, his temperature fluctuated at 37.2-38.7°C, the lung CT showed the presence of massive shadow, repeated 1-3-ß-D-glucan test was positive,and he was considered as invasive aspergillosis infection, voriconazole was intravenously injected him for 2 months, his lung CT showed better efficacy. However, the leukemia continued progress, his hemogram was extremely low, invasive aspergillosis infection relapsed,voriconazole treatment was poor effect,ultimately this patient died of the rapid progress of leukemia and multiple organ invasive aspergillosis. Autopsy showed chronic lymphocytic leukemia with multiple metastases and multiple organ invasive aspergillosis. CONCLUSION: invasive aspergillosis is a serious complication for CLL patients,once occurs, the prognosis is poor,so early diagnosis and prophylactic antifungal therapy may reduce fungal infection complication.

[Association of XRCC1 genetic polymorphism with susceptibility to non-Hodgkin's lymphoma].

The purpose of this study was to explore the association between X-ray repair cross-complementing group 1 (XRCC1)gene polymorphism and non-Hodgkin's lymphoma risk. A total of 282 non-Hodgkin's lymphoma (NHL) patients and 231 normal controls were used to investigate the effect of three XRCC1 gene polymorphisms (rs25487, rs25489, rs1799782) on susceptibility to non-Hodgkin's lymphoma. Genotyping was performed by using SNaPshot method. All statistical analyses were done with R software. Genotype and allele frequencies of XRCC1 were compared between the patients and controls by using the chi-square test. Crude and adjusted odd ratios and 95% confidence intervals were calculated by using logistic regression on the basis of genetic different models. For four kinds of NHL, subgroup analyses were also conducted. Combined genotype analyses of the three XRCC1 polymorphisms were also done by using logistic regression. The results showed that the variant genotype frequency was not significantly different between the controls and NHL or NHL subtype cases. Combined genotype analyses of XRCC1 399-280-194 results showed that the combined genotype was not associated with risk of NHL overall, but the VT-WT-WT combined genotype was associated with the decreased risk of T-NHL (OR: 0.21; 95%CI (0.06-0.8); P = 0.022), and the WT-VT-WT combined genotype was associated with the increased risk of FL(OR:15.23; 95%CI (1.69-137.39); P = 0.015). It is concluded that any studied polymorphism (rs25487, rs25489, rs1799782) alone was not shown to be rela-ted with the risk of NHL or each histologic subtype of NHL. The combined genotype with mutation of three SNP of XRCC1 was not related to the risk of NHL. However, further large-scale studies would be needed to confirm the association of decreased or increased risk for T-NHL and FL with the risk 3 combined SNP mutants of XRCC1 polymorphism.

Light management in flexible glass by wood cellulose coating.

Ultra-thin flexible glass with high transparency is attractive for a broad range of display applications; however, substrates with low optical haze are not ideal for thin film solar cells, since most of the light will go through the semiconductor layer without scattering, and the length of light travelling path in the active layer is small. By simply depositing a layer of TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl radical)-oxidized wood fibers (TOWFs), we are able to tailor the optical properties of flexible glass dramatically from exhibiting low haze (<1%) to high haze (~56%) without compromising the total forward transmittance (~90%). The influence of the TOWFs morphology on the optical properties of TOWFs-coated flexible glass is investigated. As the average fiber length decreases, the transmission haze of TOWF-coated flexible glass illustrates a decreasing trend. Earth-abundant natural materials for transparent, hazy, and flexible glass have tremendous applicability in the fabrication of flexible optoelectronics with tunable light scattering effects by enabling inexpensive and large-scale processes.

[Clinical significance of ID4 methylation detection by quantitative methylation-specific PCR in acute leukemia].

The advances of treatment improved the prognosis of the patients with acute leukemia (AL) in the last decade, but the lack of general biomarker for predicting relapse in AL, which is one of the most important factors influencing the survival and prognosis. DNA methylation of ID4 gene promoter occurred frequently in patients with AL and was found to be highly related to the tumor progression. Based on the previous work of the setup of methylation-specific quantitative PCR system for ID4 gene, this study was designed to investigate the relation between the quantitative indicator of methylation density, percentage of methylation reference(PMR) value, and different disease status of AL. PMR of ID4 was detected by MS-PCR in bone marrow (BM) samples of 17 healthy persons and 54 AL patients in the status of newly diagnosis, complete remission and disease relapse. The results showed that at different disease status, PMR value in newly diagnosed group was significantly lower than that in complete remission group (P = 0.031). Among serial samples, PMR value remained very low at the status of patients with continuous complete remission (<1.5‰), and increased along with the accumulation of tumor cells at relapse. In 1 relapse case, the abnormal rise of PMR value occurred prior to morphological relapse. PMR value seemed to be related to body tumor cell load. It is concluded that the quantitative indicator of methylation density and PMR value may reflect the change of tumor cell load in acute leukemia patients. Dynamic monitoring of PMR maybe predict leukemia relapse.

[Establishment of methylation-specific quantitative PCR system for ID4 gene in acute leukemia cells and its specificity and sensitivity].

DNA methylation of ID4 gene promoter occurred frequently in patients with acute leukemia and was found to be highly related to the tumor progression. Due to lack of the appropriate methylation detection methods, the relation between the quantification of ID4 methylation and the states of acute leukemia is still unclear. This study purposed to set up a methylation-specific quantitative PCR system for ID4 and investigate the specificity and sensitivity of this methylation detection. The plasmids combined with target gene as well as with internal reference were constructed, and the standard curves were set up by using above mentioned plasmids. The specificity of this detection system in cell lines was verified through techniques of MSP and quantitative MSP. The sensitivity of this detection system was verified by mixing methylation-positive and negative cell lines in varying proportions and through amplification of qualitative MSP. The results showed that the standard curves were establish successfully. The results of quantitative MS-PCR in cell lines were consistent with those of MS-PCR, and as low as 1: 10(-5) of ID4 methylation positive cells could be detected by the new methylation detection assay. In newly diagnosed acute leukemia patients, the positive rate of quantitative MSP was higher. It is concluded that a complete quantitative MSP system for ID4 methylation detection has been established and this quantitative MSP method has good specificity and high sensitivity.