Objective:By detecting the level changes of CXC chemokine ligand 8(CXCL8)in acute myelogenous leukemia(AML)patients at different disease stages,to analyze its correlation with the clinical condition and prognosis of AML patients,and to explore the effect of CXCL8 in the bone marrow microenvironment on the occurrence and development of AML and the regulatory mech-anism of malignant biological behavior of AML cell lines,to provide novel reference for the basic research and clinical diagnosis and treatment of AML.Methods:Bone marrow specimens from AML patients at different disease stages were collected,and ELISA was used to detect the content of CXCL8;quantitative real-time PCR(qRT-PCR)was used to detect the expression of CXCL8-specific receptor CXCR1/2 in different AML cell lines.U937 cells were selected as the AML disease model,and different concentrations of exogenous rCXCL8 were intervened in U937 cells,and the morphological changes of the cells were observed under the microscope.BM-MSCs from newly diagnosed AML patients were co-cultured with U937 cells,and ELISA was used to detect the difference in the content of CXCL8 in the co-culture system;Annexin V/PI double staining flow cytometry was used to detect the effects of rCXCL8 and anti-CXCL8 on the apoptosis of U937 cells respectively,and Western blot was used to reveal the accompanying molecular protein mechanism.Results:The level of CXCL8 in newly diagnosed and relapsed AML patients was significantly higher than that in healthy people(P<0.05),the level of CXCL8 in relapsed stage of AML was significantly higher than that in other disease stages of AML(P<0.01),and the level of CXCL8 in AML patients with CR stage and no infection was significantly higher than that in healthy people(P>0.05).The content of CXCL8 in the co-culture system of BM-MSC and U937 cells and the level of CXCL8 mRNA in U937 cells in the co-culture system were significantly higher than those in the monoculture group without BM-MSC(P<0.05).Intervention of rCXCL8 in U937 cells could promote cell proliferation by up-regulating Bcl-2 expression and down-regulating Bax expression,and up-regulate the expression of CXCL8-specific receptors CXCR1/2.After antagonizing CXCL8(anti-CXCL8),it will induce U937 cell apoptosis by up-regulating of Bax expression and down-regulating of Bcl-2 expression while inhibiting the activation level of ERK1/2 signaling pathway.Conclusion:CXCL8 is closely related to the disease and prognosis of AML,and is an effective monitoring indicator for disease pro-gression and prognosis evaluation of AML patients.CXCL8 in the bone marrow microenvironment is an important chemokine for malig-nant proliferation and immune escape of leukemia cells.By antagonizing CXCL8,U937 cells can be induced to undergo apoptosis,whose mechanism may be related to the expression changes of Bcl-2 family proteins and the inhibition of ERK1/2 signaling pathway activation.

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.

Cytochrome P450 enzyme 1A1 (CYP 1A1) is one of the main members of CYP1A subfamily, which participates in metabolizing and activating a variety of indirect carcinogens. CYP1A1 can induce carcinogenesis by participating in activating exogenous compounds to produce intermediates or active metabolites that bind to specific biomolecules. CYP1A1 plays a critical role in the metabolic activation of benzo(a)pyrene e ［B(a)P］, and plays a key role in activating the toxic and carcinogenic effects of B(a)P. CYP1A1 involves in the metabolic activation of 7,12-dimethyl benzanthracene and 2-amino-1-methyl-6-phenylimidazo［4,5-b］pyridine (PhIP), and plays an important role in PhIP-induced genotoxicity. CYP1A1 is the main enzyme to metabolize and activate 7H-dibenzo［c,g］carbazole (DBC), a key factor in the carcinogenic effect of DBC. CYP1A1 is also associated with metabolic activation of indirect carcinogens such as aflatoxin B1, 3-nitrobenzene, and naphthalene. Inhibition of the catalytic activity of CYP1A1 can decrease the CYP1A1-mediated activity of carcinogens, thus playing a role in the prevention and treatment of malignant tumors.

Objective:To investigate and analyze the status quo of death cognition and hospice care attitude of clinical medical graduate students, to compare the differences between the two groups, and to explore the correlation between death cognition and hospice care attitude, so as to provide the reference for the reform and construction of death cognition and hospice care education in medical colleges and universities in China.Methods:A survey was carried out on 496 doctoral and postgraduate students majoring in clinical medicine by using the "Questionnaire of General Sociology Survey", the Chinese version of the "Death Attitude Profile Revised Scale", and the Chinese version of the "Frommelt Attitudes Toward Care of the Dying Scale Form B (FATCOD-B)" to investigate the death cognition and hospice care attitude of 496 doctoral and postgraduate students majoring in clinical medicine, and classified and compared the survey results of the two groups. The results of this study were statistically analyzed by t-test, Pearson correlation analysis and other statistical methods. Results:A total of 469 valid questionnaires were recovered after excluding 27 unqualified questionnaires. Statistical analysis showed that the scores of each dimension in the death attitude description scale of doctoral students were ranked as follows: approach acceptance (4.28±0.53), neutral acceptance (3.99±0.41), death avoidance (2.74±0.63), fear of death (2.65±0.57) and escape acceptance (2.47±0.69) the scores of postgraduates were ranked as neutral acceptance (3.96±0.52), approach acceptance (2.84±0.61), fear of death (2.78±0.65), death escape (2.62±0.73), escape acceptance (2.39±0.77). At the same time, the scores of hospice care attitude in the doctoral group were higher than those in the master group [(110.63±8.96) vs. (106.78±6.52)], and the difference was statistically significant ( P<0.001). In addition, the scores of "fear of death" and the scores of hospice care attitudes were negatively correlated with the scores of doctoral and master students ( r=-0.25, r=-0.21), while the scores of hospice care attitudes were positively correlated with the scores of "neutral acceptance" in death cognition ( r=0.50, r=0.32). However, the hospice care attitude scores of doctoral students were negatively correlated with the "death avoidance" scores in death cognition ( r=-0.27). Conclusion:Doctoral and postgraduate students have a certain awareness of hospice care, while their death cognition and hospice care attitude still need to be improved and strengthened from sociology, psychology, ethics and other perspectives. The above will promote the harmony between doctors and patients while meeting the needs of an aging society in China.

Objective:To investigate the expression level of small nucleolar RNA SNORD15A in bone marrow of patients with acute leukemia (AL) and its relationship with clinical characteristics and prognosis of patients.Methods:Bone marrow blood samples of 53 newly treated AL patients and 29 healthy subjects without clinical diagnosis of hematologic diseases or other malignant diseases (control group) at the Affiliated Hospital of Guangdong Medical University from March 2018 to December 2021 were collected. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the relative expression of SNORD15A in bone marrow blood mononuclear cells of the two groups. The median relative expression of SNORD15A (0.148) was used as the boundary, and AL patients were divided into low expression group (<0.148) and high expression group (≥0.148). The relationship between the expression level of SNORD15A and the clinical characteristics, clinical indicators and overall survival (OS) of AL patients was analyzed. Kaplan-Meier method was used for survival analysis and log-rank test was performed; Cox proportional hazards model was used for univariate and multivariate analyses of OS of patients.Results:The relative expression of SNORD15A was 0.148 (0.012-1.376) in newly treated AL patients and 0.921 (0.513-2.288) in the control group, and the difference was statistically significant ( Z = -6.85, P < 0.01). The differences in SNORD15A relative expression between patients with different prognostic stratification, efficacy and with or without fever and bleeding were statistically significant (all P < 0.05). The differences in platelet count, plateletcrit and albumin levels between SNORD15A low expression group and high expression group were statistically significant (all P < 0.05), and the differences in molecular biology and cytogenetic characteristics were not statistically significant (all P > 0.05). The patients in SNORD15A high expression group had better OS than the low expression group ( P < 0.05). The results of univariate Cox regression analysis showed that SNORD15A was an influencing factor for patients' OS ( HR = 0.063, 95% CI 0.005-0.766, P < 0.05); the results of multivariate Cox regression analysis showed that fatigue ( HR = 4.754, 95% CI 1.014-22.290), fever ( HR = 0.147, 95% CI 0.029-0.746) and hemoglobin ( HR = 0.970, 95% CI 0.944 -0.998) were independent influencing factors for OS (all P < 0.05). Conclusions:SNORD15A is lowly expressed in AL and may be an indicator for disease monitoring and prognostic assessment in AL patients.

Using novel virtual reality (VR) technology to carry out the construction of clinical medical examination question bank, while deepening the reform of clinical medical course examination, it continues to innovate the medical professional evaluation system and improve the flexibility, diversity and scientificity of clinical medicine in teaching and assessment. It is of great and far-reaching significance to improve the teaching level and the quality of medical education in medical colleges and universities. This paper analyzes and discusses the necessity and feasibility of building a clinical medical examination question bank, and the advantages and prospects of integrating VR technology to carry out the construction of clinical medical examination question bank. At the same time, the exploration and practice of the examination question bank construction based on VR technology disscussed in detail would provide innovative thinking and reference for the clinical medical teaching and evaluation, medical personnel training and other aspects in China.

Objective To investigate the prevalence and influencing factors of sub-health status of the migrant workers in Dongguan City,in order to provide scientific preferences for preventing sub-health status.Methods Using the stratified random sampling method,740 migrant workers from ten towns(disetricts) in Dongguan city from August 2015 to August 2016 were recruited in this study.The sub-health measurement scale version 1.0 (SHMS V1.0) was applied to evaluate the sub-health status of migrant workers.The SHMS V1.0 scores were compared among migrant workers with different demographic characteristics,and the multivariate linear regression analysis was utilized to explore the influencing factors.Results A total of 718 valid questionnaires were collected,and the effective recovery rate was 97.03％.The sub-health status was detected in 483 migrant workers,and the prevalence rate of sub-health status was 81.6％.The migrant workers' subscale scores of physical sub-health (PS),mental subhealth (MS),social sub-health (SS) and total scale (TS) were (70.25-4-12.25),(64.21± 13.83),(62.21-4-13.87) and (66.114-11.15),respectively.The PS scale scores among migrant workers with different monthly household incomes per capita,and different inhabit situations;the MS scale scores among migrant workers with different ages,educations,marital status,monthly household incomes per capita,and inhabit situations;the SS scale scores among migrant workers with different genders,educations,and inhabit situations;and TS scores mong migrant workers with different educations,monthly household incomes per capita,and inhabit situations were statistically significant different (P＜0.05).The multivariate linear regression analysis showed that educations and inhabit situations were the influencing factors for TS score (P＜0.05).Conclusion The sub-health status of migrant workers in Dongguan City is serious,and the influencing factors are educations and inhabit situations.

OBJECTIVE: To explore the effect of silencing of poly( ADP-ribose) polymerase-1( PARP-1) on cell apoptosis induced by hydroquinone( HQ) in rat bone marrow-derived mesenchymal stem cells( BMMSCs). METHODS: i) The RNA expression vectors for PARP-1 gene were transfected into BMMSCs. Neomycin was used to select the transfected cells that stably expressed PARP-1-shRNA. Western blotting was used to examine the gene silencing efficiency. ii) BMMSCs with PARP-1 silencing were sorted as the treated group,while BMMSCs with empty vector were considered as the control group.HQ dissolved in phosphate buffer solution at the concentrations of 0. 0,2. 5,5. 0,10. 0,20. 0,40. 0,80. 0,160. 0 and320. 0 μmol / L were given to both groups for 24 hours. The cell viability was detected by methyl thiazolyl tetrazolium assay,and the concentration of HQ was chosen for the following study based on cell viability. iii) Both groups were treated by HQ at concentrations of 0. 0-20. 0 μmol / L for 24 hours,then the apoptosis of BMMSCs was detected by flow cytometry. The PARP-1 mRNA expression was determined by real-time fluorescent quantitative polymerase chain reaction assay. RESULTS: i) PARP-1 silencing cells and empty vector control cells were successfully screened with a mass concentration of 400 mg / L neomycin,and confirmed by level of protein expression. The interference efficiency of PARP-1 gene and inhibition efficiency was 85. 00%. ii) Based on the result of cell viability,HQ at concentrations of 0. 0-20. 0 μmol / L was chosen for the following study. iii) Compared with the group treated by HQ at concentration of 0. 0 μmol / L,the rate of early apoptosis of control group increased significantly with HQ at concentration of 10. 0 μmol / L while that of treated group was increased significantly at concentration of 5. 0 μmol / L( P < 0. 05). In addition,at concentrations of 0. 0-10. 0 μmol / L,the rates of early apoptosis in both groups increased in a dose-dependent manner( P < 0. 01). Compared with the group treated by HQ at concentrations of 0. 0 μmol / L,the expression of PARP-1 mRNA of both groups increased significantly at the concentration of 5. 0 μmol / L( P < 0. 05). The expression of PARP-1 mRNA of treated group was less than that of control group with HQ at every concentration( P < 0. 05). At concentrations of 0. 0-20. 0 μmol / L,the expression of PARP-1 mRNA of both groups increased in a dose-dependent manner( P < 0. 01). CONCLUSION: Silencing PARP-1 in BMMSCs caused cell apoptosis. PARP-1 may participate in cell apoptosis induced by HQ.

OBJECTIVE: To investigate the mechanism of miR-7-5p in TK6 cell damage induced by hydroquinone( HQ) by constructing stable miR-7-5p over-expressing human lymphoblastoid TK6 cell line using lentivirus. METHODS: i) The miR-7-5p over-expression lentivirus vectors were constructed,and then infected to TK6 cells. The miR-7-5p overexpression stable TK6 cell line( TK6-miR-7-5p cells) and negative control cells( TK6-NC cells) were selected with puromycin. The infection efficiency was confirmed by real-time fluorescent quantitative polymerase chain reaction assay.ii) TK6,TK6-NC and TK6-miR-7-5p cells were treated with HQ at final concentrations of 0 and 40 μmol/L for 48 hours.Cell viability was determined by CCK-8 assay. The early apoptosis rate of cells was detected by flow cytometry. The relative expression of poly( ADP-ribose) polymerase-1( PARP-1) and breast cancer susceptibility gene 1( BRCA1) proteins in 3 kinds of cells treated with HQ at the final concentration of 40 μmol/L was detected by Western blotting. RESULTS: i) The TK6 cell line with stable expression of miR-7-5p were successfully screened. Compared with normal TK6 cells,the relative expression of miR-7-5p in TK6-miR-7-5p cells increased by about 17 times( P < 0. 01) with no significant changes in cell morphology. ii) After treatment with 40 μmol/L HQ,the survival rate of TK6-miR-7-5p cells decreased compared with normal TK6 cells and TK6-NC cells( P < 0. 01),early apoptosis rate increased( P < 0. 01),the relative expression of PARP-1 and BRCA1 protein was decreased( P < 0. 05). CONCLUSION: MiR-7-5p may lead to the increase of early apoptosis in TK6 cells induced by HQ through inhibiting the DNA damage repair capacity related to PARP-1 and BRCA1.

OBJECTIVETo investigate the role of sphingosine kinase 1 (SphK1) in regulating the proliferation of hypoxia-exposed glioma cells in vitro and explore the possible molecular mechanisms.

METHODSHuman glioblastoma U87MG cells was transfected with specific small interfering RNA (siRNA) constructs targeting SphK1, and the efficiency of SphK1 knockdown was validated by real-time PCR and Western blotting. The cells transfected with SphK1 siRNA and with a negative control siRNA were then exposed to 3% oxygen or 150 µmol/L CoCl2 to induce hypoxia. The cell proliferation and cell cycle changes following the exposure were evaluated with the Cell Counting Kit-8 and flow cytometry, respectively, and the intracellular Ca(2+) changes were monitored using Flou-4/AM under an inverted laser scanning confocal microscope.

RESULTSSphK1 knockdown significantly reduced hypoxia-induced calcium reflux and suppressed the cell proliferation. Application of OAG, an activator of calcium channels, however, obviously enhanced the cell proliferation under hypoxia.

CONCLUSIONSphK1 promotes the proliferation of glioma cells under hypoxia via regulating calcium signaling.

Calcium Signaling ; Cell Cycle ; Cell Hypoxia ; Cell Line, Tumor ; Cell Proliferation ; Glioblastoma ; Glioma ; pathology ; Humans ; Phosphotransferases (Alcohol Group Acceptor) ; metabolism ; RNA, Small Interfering