[Mediation effect of smoking and healthy diet score on the association between educational level and the risk of lung cancer incidence]

Objective: To evaluate the possible mediation effect of smoking and healthy diet score on the association between educational level and the risk of lung cancer incidence. Methods: After excluding individuals with missing educational levels and cancer information at baseline, 446 772 participants in the UK Biobank (UKB) prospective cohort study were included. Cox regression models were used to investigate the associations of educational level and smoking and healthy diet score with the incidence of lung cancer. Mediating effect analysis was conducted to analyze the mediating effect of smoking and healthy diet score on the correlation between educational level and lung cancer. Results: During a median follow-up of 7.13 years, 1 994 new- onset lung cancer cases were observed. Per 1 standard deviation (5 years) increase in educational level was associated with a 12% lower risk of lung cancer (HR=0.88, 95%CI: 0.84-0.92). The corresponding level 1-5 in the International Standard Classification for Education (ISCED) were mapped to UKB self-report highest qualification to estimate the educational level. A higher rank means a higher educational level. Compared with level ISCED-1, the HR(95%CI) of level ISCED-2, ISCED-3, ISCED-4 and ISCED-5 were respectively 0.83 (0.72-0.94), 0.67 (0.53-0.85), 0.76 (0.65-0.89) and 0.72 (0.64-0.80) for lung cancer. Education years were negatively correlated with smoking, with β coefficients (95%CI) being -0.079 (-0.081- -0.077), but positively correlated with healthy diet score (β=0.042, 95%CI: 0.039-0.045). Analysis of mediating effect indicated that the association of educational level with lung cancer risk was mediated by smoking and healthy diet score, the proportions of mediating effect were 38.952% (95%CI: 31.802%-51.659%) and 1.784% (95%CI: 0.405%-3.713%), respectively. Conclusion: Smoking and healthy diet score might mediate the effect of educational level on the incidence of lung cancer, indicating that improving the level of education can reduce the risk of lung cancer by changing lifestyles such as smoking and diet.

Mass oscillations and matter wave's phase and amplitude modulations of relativistic quantum particles induced by Heisenberg's uncertainty principle

We present a flip-flop dual-component model to treat quantum dynamics of relativistic particles with a rest mass and investigate the matter waves’ phase and amplitude modulations due to Heisenberg’s uncertainty principle. Their matter waves behave like a traveling Gaussian-shaped wave packet accompanied by a guiding pilot wave, and the phase modulations result in mass oscillations. These effects are more prominent for light-weighted elementary particles, such as neutrinos and electrons. This mechanism is solely due to the uncertainty principle and has nothing to do with the flavor-mixing of neutrinos. Simulations using neutrinos and electrons are presented, which indicate an oscillation period on the order of ps. This study primarily focuses on the predicted mass oscillations induced by the uncertainty principle. A slit-type interference experiment using neutrinos and electrons from reactors is proposed to test the predicted behaviors.

[Association between polygenic risk score and age at onset of gastric cancer]

Objective: To explore the association between polygenic risk score (PRS) and age at onset and early-onset risk of gastric cancer (GC). Methods: Gastric cancer cases from existing genome-wide association study were included, and 112 single nucleotide polymorphisms associated with GC risk were used to derive individual PRS. Analysis of variance and Pearson correlation test was used to depict the relationship between PRS and GC onset age. Cases diagnosed before 50 years old were defined as early-onset gastric cancer. Cox proportional hazard model was used to test the association between PRS and early-onset GC risk with early-onset age as the timescale and low genetic risk (PRS ≤20%) as the reference group. Results: A total of 8 629 cases, including 6 284 males (72.82%) and 2 345 females (27.18%), were included, and the mean age was (60.61±10.80) years old. The PRS was negatively correlated with age of GC onset (r=-0.05, P<0.001). The mean age of gastric cancer cases with low, intermediate, and high genetic risk were (61.68±10.33), (60.53±10.79), (59.80±11.20), respectively. PRS was significantly associated with the risk of early-onset GC in a dose-response manner (intermediate genetic risk: HR=1.19, 95%CI: 1.03-1.39, P=0.022; high genetic risk: HR=1.44, 95%CI: 1.20-1.71, P<0.001). Conclusions: PRS may contribute to the risk of both GC and early-onset GC. PRS can be used as a measurable indicator for risk prediction for occurrence and early-onset of GC.

[Baseline characteristics of the participants of China National Birth Cohort]

Objective: To explore the effects of environmental, genetic factors as well as the interactions in early life on the short-term and long-term health of offspring and to systematically evaluate the pregnancy outcomes and health of offspring after birth between families with assisted reproductive technology (ART) conception and families with spontaneous conception. Methods: The China National Birth Cohort (CNBC), a multicenter prospective birth cohort study, includes both families with ART conception and families with spontaneous conception. Since 2016, CNBC has recruited families from 24 hospitals located in 12 provinces, municipalities and autonomous regions throughout China. Information and biospecimens were collected before ART treatment, embryo transfer, at early, second, third trimester and delivery, and at 42 days, 6, 12 and 36 months after birth. Results: By June 2020, CNBC had included 27 044 families with ART conception and 29 589 families with spontaneous conception. The majority of the participants are urban residents. Among the families with ART conception, 65.5% of the men and 63.7% of the women had college degrees or higher. The mean age distribution of men and women was (33.83±5.52) and (32.38±4.67) years. 83.2% of women were primiparas, and the prevalence rates of current regular smokers and current alcohol drinkers were 0.8% and 2.1% in women. Among the families with spontaneous conception, 81.5% of the men and 86.5% of the women had college degrees or higher. The mean age distribution of men and women was (32.06±5.09) and (30.40±4.27) years. 67.2% of women were primiparas, and the prevalence rates of current regular smokers and current alcohol drinkers were 0.1% and 2.2% in women. The baseline characteristics were different between the families with ART conception and spontaneous conception in different regions. Conclusion: CNBC provides a powerful and rich resource in studying the impact of genetic, environmental factors and interactions in early life and ART treatment on the health of offspring after birth.

[Profile of China National Birth Cohort]

With the rapid changes in lifestyle, natural and social environment, the reproductive health status of couples in childbearing age continues to decline, and long-term outcomes of the rapidly increasing offspring conceived by assisted reproductive technology (ART) needs to be evaluated urgently. Therefore, the focus of research now needs to be extended from death and severe diseases to full life cycle and full disease spectrum. In order to meet the demand for such research, we launched the China National Birth Cohort (CNBC) study, an ongoing prospective and longitudinal study aiming to recruit 30 000 families underwent ART and 30 000 families with spontaneous pregnancies. Long-term follow-up programs will be conducted for both spouses and their offspring. Data of couples and their offspring, such as environmental exposure, reproductive history, psychological and behavioral status, will be collected during follow-up. Peripheral blood, urine, umbilical blood, follicular fluid, semen were also collected at different follow-up nodes. Based on high-quality data and biological samples, CNBC will play an extremely important supporting role and have a far-reaching impact on maternal and children's health care and reproductive health in China. This paper is exactly a brief introduction to the construction and basic design of CNBC.

[A sub-cohort study design of the maternal and infant microbes in China National Birth Cohort]

The importance of gut microbes to human health has gradually attracted attention. With the use of animal models, it has been revealed that maternal microbes during pregnancy could influence their children's health outcomes through shaping their microbial composition and regulating the development of their metabolic and immune system. However, the physiological mechanism of the human body is more complex and is affected by the interaction of multiple factors. The research results obtained from animal models are often inconsistent with human studies. At present, the influence of maternal intestinal microbes during pregnancy on the microbial colonization in their offspring and on a series of children's health outcomes is still unclear. Establishing a sub-cohort to detect the microbiome of the women across pregnancy and of their offspring, and further to integrate with variety of environmental and behavioral exposures can better provide reliable support for the research on the mechanism of children's health and diseases. This paper briefly introduces the research objectives, content, progress, strength and limitations of the sub-cohort study.

[The Autism Spectrum Disorder Cohort-the sub-cohort of China National Birth Cohort]

Autism spectrum disorder (ASD), a representative disease of children's neurodevelopmental disorders, brings huge pressure and financial burden to families and society. It is of great significance to explore its etiology and pathogenesis. Therefore, we established an ASD Cohort based on the existing China National Birth Cohort (CNBC), which applied parallel design to recruit and follow up families who achieved pregnancy after receiving assisted reproductive technologies (ART) and families with spontaneous conception. The main aims of this study are to compare the incidence of ASD among children born after ART with those born under spontaneous pregnancy, and to evaluate the impact of ART on the neurobehavioral development of offspring. Additionally, with a variety of clinical and behavioral related information collected during pregnancy and at early life of offspring, we are able to investigate the risk factors associated with ASD comprehensively. This article briefly introduces the objectives, contents, preliminary progress, strength and limitations, as well as further prospects of the ASD cohort study, mainly focusing on the overall design and current progress.

[Application of cloud-based information platform in China National Birth Cohort]

Birth cohort is an important observational study which can continuously and dynamically collect the exposure changes and health outcomes from gametophyte development to adolescence and even old age. However, because of its complex design and difficult implementation, how to construct birth cohort with high quality and high efficiency is the main difficulty faced by epidemiologists at home and abroad. In 2016, China National Birth Cohort was officially launched. The network and information technology were used to explore, and a set of "cloud-based information platform" was established to support this queue construction, containing 16 units in China. After four years of development, the platform has formed a complete set of programs about the construction of cohort information platform, which including recruitment and follow-up management of participants, real-time data interaction, queue quality control, multi-level authority management and function division. The relevant design framework and functional elements provide the references to the future information construction of large-scale birth cohort and even population-based research in China.

[Quality control and measures of China National Birth Cohort]

Birth cohort is an effective method to explore the relationship between various prepregnant and pregnant exposures and the health of fetuses, infants and young children. It is a long construction period to build a birth cohort and the quality of research may be affected by many factors. This paper reviews the quality assurance and quality control measures in the process of China National Birth Cohort (CNBC), and summarizes the construction experience. We aim to provide experience for related cohort studies, which could improve the quality of cohort studies through removing the impact of related factors. CNBC adopted a series of measures to ensure the quality of research in the top-level design of quality assurance, including screening research center, developing member management system, formulating standard operating procedures and training staff by it. In terms of quality control, it includes real-time, timely and timing quality control for the process of data generation, full-cycle quality control for biological sample collection, processing, storage and comprehensive three-dimensional quality control for staff training, supervision and quantitative assessment.

[Polygenic risk score in personalized screening of lung cancer: a prospective cohort study in Chinese]

Objective: To explore how to personalize lung cancer screening programs for prevention in Chinese populations based on individual genetic risk score. Methods: We constructed the lung cancer polygenic genetic risk score (PRS-19) based on the 19 previously published genetic variations, using 100 615 participants with genotyping data from the China Kadoorie Biobank (CKB). Using the 5-year absolute risk of lung cancer in a population (55 years old with at least 30-pack-year history of smoking) as reference, the trend of 5-year absolute risk in different genetic risk groups was calculated in smokers and non-smokers, respectively. Distribution curves of 5-year absolute risk were also described to determine the theoretical age or smoking dose when different genetic risk groups reached the reference values. Given the overall findings, the specific start age for lung cancer screening were suggested for different genetic risk groups. Results: The 5-year absolute risk of lung cancer was 0.67% in 55-year-old smokers with 30 packs per year in the CKB. Among smokers, 5-year absolute risk of participants increased as the genetic risk increased. Hence, it was recommended that people at high genetic risk should start screening earlier. For the highest genetic risk populations (the top 1% of PRS), the start age might be changed to 50 years old. If the start age remained at 55-year-old, the smoking dose should be set lowered in high genetic risk populations. For the highest genetic risk populations, they should be included in lung cancer screening regardless of the cumulative smoking exposure. Among nonsmokers, it was also valuable to screen people with high genetic risk, considering the start age of 62 for the highest genetic risk populations and 74 for the lowest genetic risk populations (the bottom 5% of PRS). Conclusions: PRS-19 can be effectively used in developing lung cancer screening program for individualized prevention in China. For smokers with high genetic risk, the recommended starting age and smoking dose could be lowered for lung cancer screening, and non-smokers with high genetic risk could also be included in the screening programs.

[Epidemiological research in the big data era: opportunities, challenges and prospectives]

Recent years with the rapid progress in high-throughput omics techniques, the accumulation of population cohorts and biobanks, great advances in internet and information technology, and the emerging tools for big data utilization, health care big data provide abundant data resources and broad research platforms for epidemiological research. We aimed to review the opportunities and challenges of epidemiological research in the era of big data, and explore the future development of epidemiology. Epidemiology should seize the opportunities, open up new directions, develop new methods, and promote the translation of research results into public health and clinical medicine, which will eventually realize the vision of "Healthy China".

[Observation and analysis of systemic reactions to house dust mite subcutaneous immunotherapy in 362 patients with allergic rhinitis]

Objective: To investigate the frequency and severity of systemic reactions (SRs) to standardized house dust mite subcutaneous immunotherapy (SCIT) in patients with perennial allergic rhinitis (AR), and to analyze the clinical risk factors. Methods: The clinical data of 362 patients including 209 males and 153 females, aged from 5 to 55 years old receiving SCIT at the Department of Otorhinolaryngology, the Third People's Hospital of Changzhou were collected from May 2014 to July 2017. The SRs were classified as early-onset and delayed-onset, and 4 grades (grade Ⅰ to Ⅳ) to assess severity. The records of SRs were retrospectively analyzed, including the numbers/frequencies, symptoms and signs, onset of reaction and treatment. And the relationships between SRs and patient's age, gender, allergen injection dose, accompanied allergic diseases were explored. All the statistical analyses were conducted using SPSS 19.0. Results: There were 57 cases (15.75%) of SRs in 362 patients. All the patients received a total of 12 308 injections and 111 SRs (0.90%) were observed. Among them, 31 (27.93%) were early-onset reactions and 80 (72.07%) were delayed-onset reactions; most of the SRs were grade Ⅰ reactions (n=83, 74.78%), followed by grade Ⅱ (n=25, 22.52%), grade Ⅲ (n=3, 2.70%), and no fatal reactions occurred. The incidence of SRs in patients>14 years old was higher than that in patients ≤14 years old according to the number of cases and injections (35.14% vs 13.54%, 2.34% vs 0.76%, χ(2) value was 11.679, 28.162, respectively, all P<0.05), but no significant differences of SRs were observed in gender (18.66% vs 11.76%, 5.98% vs 5.62%, χ(2) value was 3.166, 0.095, respectively, all P>0.05). Fifteen SRs (13.51%) occurred during the build-up phase and 96 (86.49%) during the maintenance phases. SRs could occur in lots of dose phases, and 95 (85.59%) were distributed at high concentrations more than 40 000 SQ-U. The incidence of SRs in patients with multiple allergic diseases was significantly higher than that in patients with AR alone, with asthma or atopic dermatitis (30.67% vs 11.85%, χ(2)=15.875, P<0.001). Meanwhile, the incidence of SRs in patients with pure AR was also significantly lower than that in patients with other allergic diseases (5.26% vs 20.56%, χ(2)=13.783, P<0.001). Conclusions: The incidence of SRs is less than 1% according to the injection times, the severity of SRs is mostly slight, and the safety and tolerance are good during standardized house dust mite SCIT in perennial AR patients. Delayed-onset SRs are more common. The incidence of SRs is significantly correlated with age, high dose of allergen vaccine injection, and concomitant other allergic diseases (asthma, atopic dermatitis, etc).

[Effects of estradiol on the day of human chorionic gonadotropin administration on adverse perinatal outcomes]

Objective: To investigate the association between estradiol on the day of human chorionic gonadotropin (HCG) administration and birth outcomes among singleton live births following fresh embryo transfers. Methods: Based on the clinical reproduction medicine management system of the First Affiliated Hospital of Nanjing Medical University, this retrospective cohort study collected data of fresh embryo transfer cycles during January 2013 and December 2016, including pregnant women's age, body mass index (BMI), type and cause of infertility, assisted reproductive therapy indicators (fertilization mode, ovulation stimulation protocol, estradiol levels on HCG administration day), adverse birth outcomes[small for gestational age (SGA), premature and low birth weight (LBW)], etc.. A total of 2 060 women with singleton pregnancy (2 061 fresh embryo transfer cycles) were enrolled. Multivariate logistic regression was used to analyze the association between estradiol on HCG administration day and singletons' adverse birth outcomes. Results: The age and BMI of the 2 060 pregnant women were (29.63±3.92) years old and (22.29±2.86) kg/m². Incidences of SGA, premature and LBW were 9.8% (201/2 061), 6.9% (143/2 061) and 3.5% (73/2 061), respectively. After adjusting for confounders, the risk of LBW in 4 000-4 499 pg/ml group was significantly elevated when compared to estradiol<1 500 pg/ml group [OR (95%CI): 4.42 (1.13-17.24)]. A protective effect of premature was observed in estradiol≥4 500 pg/ml group [OR (95%CI): 0.50 (0.25-0.97)]. Conclusion: The high level of estradiol on HCG administration day might be a risk factor for LBW, but a protective factor for premature.

[Thoughts on the reform of preventive medicine education in the context of new medicine]

Talent training is the core and foundation of public health system construction. Shortage of talents in the field of disease prevention and public health exposed by COVID-19 pandemic highlights the importance of developing preventive medical education. This article analyzes the challenges of medical education in the dilemma of "separation of medical treatment and prevention", and the new requirements for preventive medical education in the construction of New Medicine under the Healthy China strategy. Four aspects including stepping up the resource allocation and investment, educating responsible public health professionals, the education of all medical students who implement the core competence of public health, and the establishment of a continuing education system for preventive medicine have been considered. A series of specific suggestions are put forward including the establishment of a full-chain closed-loop research system to support the cultivation of top-notch innovative public health talents, strengthening the assessment of core public health capabilities for clinical medical professional admission, formulating a "medical and preventive integration" training program for primary health personnel, and implementing "combination of peace and war" public health personnel reserve system, with the purpose of providing reference for the reform and development of preventive medical education in China.

[Estimation on the individual treatment effect among heterogeneous population, using the Causal Forests method]

Objective: This project aimed to explore the effectiveness of estimating individual treatment effect on real data, among the heterogeneous population, with Causal Forests (CF) method, to find out the characteristics of heterogeneous population. Methods: We designed and conducted four computer simulation schemes to verify the effect of estimating on individual treatment, using the CF under four different environments of the treatment effects. Real data was then analyzed for the catheterization on right heart. Results: Results from the simulation process showed that the values on individual treatment effect that were estimated by causal forests were consistent with the population effect as well as in line with the expected distribution under the setting of four different effect values. Results of real data analysis showed that values of individual treatment effect among most patients appeared positive, so the use of RHC could cause an increase of the '180-day mortality rate' in the sampled population. Patients with lower predicted probability of 2-mo survival and albumin were more likely to have a lower risk of death after using the RHC. Conclusion: CF method could be effectively used to estimate the individual treatment effect and helping the individuals to make decision on the receipt of treatment.

[Study on genetic structure differences and adjustment strategies in different areas of China]

Objective: To describe the genetic structure of populations in different areas of China, and explore the effects of different strategies to control the confounding factors of the genetic structure in cohort studies. Methods: By using the genome-wide association study (GWAS) on data of 4 500 samples from 10 areas of the China Kadoorie Biobank (CKB), we performed principal components analysis to extract the first and second principal components of the samples for the component two-dimensional diagram generation, and then compared them with the source of sample area to analyze the characteristics of genetic structure of the samples from different areas of China. Based on the CKB cohort data, a simulation data set with cluster sample characteristics such as genetic structure differences and extensive kinship was generated; and the effects of different analysis strategies including traditional analysis scheme and mixed linear model on the inflation factor (λ) were evaluated. Results: There were significant genetic structure differences in different areas of China. Distribution of the principal components of the population genetic structure was basically consistent with the geographical distribution of the project area. The first principal component corresponds to the latitude of different areas, and the second principal component corresponds to the longitude of different areas. The generated simulation data showed high false positive rate (λ=1.16), even if the principal components of the genetic structure was adjusted or the area specific subgroup analysis was performed, λ could not be effectively controlled (λ>1.05); while, by using a mixed linear model adjusting for the kinship matrix, λ was effectively controlled regardless of whether the genetic structure principal component was further adjusted (λ=0.99). Conclusions: There were large differences in genetic structure among populations in different areas of China. In molecular epidemiology studies, bias caused by population genetic structure needs to be carefully treated. For large cohort data with complex genetic structure and extensive kinship, it is necessary to use a mixed linear model for association analysis.

[Data management and quality control strategies for population based cohort study]

Large-scale cohort study has unique advantages in the field of etiology research for its large sample size a multi-time point data, but it also brings great difficulty in data management and quality control at the same time. Recently, China has initiated a number of large-scale population cohort studies, posing enormous challenges to the management and quality control of related cohort data. This paper summarizes the existing experience and consensus in the field of cohort study in China from the characteristics of the cohort data, aiming at the types and main forms of the four main sources of questionnaire data, clinical diagnosis and treatment data, biological sample detection data and observation outcome data, from the data storage, circulation and transmission work.The contents and methods of queue data management are comprehensively summarized. Corresponding data quality control strategies are advised in the questionnaire evaluation, data logic verification, survey object sampling and multi-database review, etc. The goal of this review is to provide guidance for the management of data and the formulation of quality control strategies in the cohort study in China.

Serum hepatitis B surface antigen correlates with fibrosis and necroinflammation: A multicentre perspective in China

The kinetics of serum hepatitis B surface antigen (HBsAg) during the natural history of hepatitis B virus (HBV) infection has been studied, but the factors affecting them remain unclear. We aimed to investigate the factors affecting HBsAg titres, using data from multicentre, large-sized clinical trials in China. The baseline data of 1795 patients in 3 multicentre trials were studied, and the patients were classified into 3 groups: hepatitis B early antigen (HBeAg)-positive chronic HBV infection (n = 588), HBeAg-positive chronic hepatitis B (n = 596), and HBeAg-negative chronic hepatitis B (n = 611). HBsAg titres in the different phases were compared, and multiple linear progression analyses were performed to investigate the implicated factors. HBsAg titres varied significantly in different phases (P = .000), with the highest (4.60 log10 IU/mL [10%-90% confidence interval: 3.52 log10 IU/mL-4.99 log10 IU/mL]) in patients with HBeAg-positive chronic HBV infection. In all phases, age and HBV DNA were correlated with serum HBsAg level. In HBeAg-positive chronic hepatitis B patients, a negative correlation between HBsAg titres and fibrosis stage was observed. Alanine amonitransferase or necroinflammatory activity was also correlated with HBsAg titres in HBeAg-negative chronic hepatitis B patients. In conclusion, decreased HBsAg titres may be associated with advancing fibrosis in HBeAg-positive chronic hepatitis B patients or increased necroinflammation in those with HBeAg-negative chronic hepatitis B. Our findings may help clinicians better understand the kinetics of HBsAg and provide useful insights into the management of this disease.

[Epidemiological characteristics of HBeAg reversion in chronic hepatitis B patients with HBeAg seroconversion in Jiangsu province, 2012-2014]

Objective: To understand characteristics and influencing factors of reversion of HBeAg in chronic hepatitis B patients with HBeAg sero-conversion, and provide epidemiological evidence for the regular management of chronic hepatitis B patients. Methods: From 2012 to 2014, a cohort study was conducted among the chronic hepatitis B patients with sero-conversion of HBeAg in Jiangsu province. Association between participants' demographics, ALT, HBV DNA and incidence of HBeAg reversion was analyzed by Cox regression model. HBV DNA changing trend between patients with HBeAg reversion and patients with persistent HBeAg sero-conversion was compared by repeated measure data variance analysis. Results: In 2012, there were 5 068 HBeAg seroconverted chronic hepatitis B patients aged (51.9 ± 12.8) years enrolled. By 2014, HBeAg had reversed in 121 cases with the rate of 1.3/100 person-years. The probability of HBeAg reversion decreased with the age of the patients. By Cox regression analysis, HBV DNA level was an important influencing factor for the progress of HBeAg reversion. The patients with HBV DNA≥200 000 IU/ml had a higher HBeAg reversion rate DNA (3.8/100 person-years) than those with HBV DNA <2 000 IU/ml (1.1 person-years) (HR=3.44, 95% CI: 1.91-6.20, P=0.000). Compared with the persistent HBeAg sero-conversion group, HBV DNA and ALT showed a more dramatic increase in the HBeAg reversion group (P=0.000). Conclusions: There was a certain HBeAg reversion rate in chronic hepatitis B patients with HBeAg sero-conversion. Younger chronic CHB patients with HBeAg sero-conversion and those with higher HBV DNA lever had higher HBeAg reversion rate. Following up and management of chronic CHB patients with HBeAg sero-conversion is important and helpful for the control of hepatitis B.

[DNA damage associated genetic variants contribute to lung cancer susceptibility in a Han Chinese population]

OBJECTIVE

To explore the association between DNA damage-related genetic variants and lung cancer susceptibility in a Han Chinese population.

METHODS

This case-control study enrolled patients from the Cancer Hospital of Jiangsu Province and Jiangsu Province Hospital from 2003 to 2009. Controls were randomly selected from individuals who visited the same hospital or a community-based health examination program during the same time period. A 5 ml venous blood sample was obtained from each participant and epidemiological information was collected on a standard questionnaire. Illumina Infinium(®) BeadChip was used for genotyping of 35 DNA damage-related single nucleotide variations (SNVs), which were identified in our previous study. Multivariate and binary logistic regressions were used to calculate the OR and 95%CI for lung cancer risk. HaploReg V4.1 and Regulome DB were used to understand functional annotation on important SNV.

RESULTS

The distributions of age (61.06±10.15) vs. (61.32±11.07) years; t=-0.72, P=0.473) and sex (χ(2)=1.81, P=0.179) were similar between cases and controls. However, the case group had a higher frequency of smokers (61.08% vs. 48.54%; χ(2)=50.04, P<0.001) and heavy smokers (42.28% vs. 24.07%; χ(2)=122.32, P<0.001). Among the 34 SNVs that passed quality control, two SNVs were significantly associated with lung cancer risk after adjustments for age, sex and cumulative smoking dose: rs9267576 C>A (CA genotype/CC genotype, OR=1.56, 95% CI: 1.01-2.40) and rs3130683 A>G (AG genotype/AA genotype, OR=1.87, 95%CI: 1.13-3.09). After step-wise logistic regression analysis, only the rs3130683 SNV was retained in the model, indicating that the association between rs9267576 and lung cancer may be due to the effect of rs3130683. Functional annotation indicated that rs3130683 was located in the promoter and enhancer regions, and was an expression quantitative trait loci of HLA. The Cancer Genome Atlas indicated that expression of HLA-C, DQB1, DRB1 and DRB5 in lung cancer tissue was significantly lower than in paired normal tumor-adjacent tissue, with down-regulation of the four respective genes in 81.3%, 88.8%, 90.7% and 90.7% of lung cancer tissues (P-values were 6.68×10(-15), 2.21×10(-13), 2.20×10(-16), 2.58×10(-13), respectively).

CONCLUSIONS

The SNV rs3130683 (A>G) was associated with the risk of lung cancer in a Han Chinese population. This SNV may affect the risk of lung cancer by regulating HLA expression.

[A cohort study on the epidemiological characteristics of HBeAg sero-clearance in HBeAg positive chronic hepatitis B patients in Jiangsu province from 2012 to 2014]

Objective: To understand the epidemiological characteristics and influencing factors related to HBeAg sero-clearance in chronic hepatitis B patients so as to provide evidence for regular management on chronic HBV patients. Methods: From 2012 to 2014, a cohort study was conducted among HBeAg positive chronic HBV patients in Jiangsu province. Association between the characteristics and incidence of HBeAg sero-clearance was analyzed by Cox regression method. The changing trend on HBV DNA between patients with HBeAg sero-clearance and those with persistent HBeAg positive status was compared by repeated measure data variance analysis method. Results: In 2012, there were 721 HBeAg positive hepatitis B patients aged (45.2 ± 14.2) years enrolled in this study. By 2014, the follow-up observation period was 1 058 person-years, and 393 cases had lost their HBeAg status, with the rate as 37.2/100 person-years. The HBeAg sero-clearance rate was 32.4/100 person-years in hepatitis B patients who received antiviral treatment. The probability of HBeAg clearance in HBeAg positive hepatitis B patients aged ≥60 year (62.0/100 person-years) was higher than those of aged <20 year (7.0/100 person-years). The rate of HBeAg sero-clearance in HBeAg positive patients with HBV DNA <20 000 IU/ml (75.8/100 person-years) was higher than those whose HBV DNA were ≥200 000 IU/ml (16.1/100 person-years). By Cox regression analysis, the HBV DNA level was an important influencing factor on the progress of HBeAg sero-clearance. Patients with HBV DNA levle as ≥200 000 IU/ml, had a lower HBeAg clearance rate (HR=0.18, 95%CI: 0.13-0.23, P<0.001). Compared to the persistent HBeAg positive group, HBV DNA showed a more dramatic fall in the HBeAg-lost group (P<0.001). Conclusion: The rate of HBeAg sero-clearance among HBeAg positive hepatitis B patients was correlated with age and HBV DNA status of the patients that called for comprehensive management and intervention programs to develop for the HBeAg positive hepatitis B patients with different characteristics.

[Clinical value of classified detection of circulating tumor cells in peripheral blood of NSCLC patients]

OBJECTIVE

To investigate the clinical value of detection of circulating tumor cells (CTCs) classified by epithelial cell adhesion molecule (EpCAM) in peripheral blood of patients with non-small cell lung cancer (NSCLC).

METHODS

Peripheral blood samples (7.5 ml each time) were collected from 47 NSCLC patients. Among them, blood samples were collected at the end of each therapy-cycle in three patients for longitudinal monitoring of CTCs. CTCs were enriched by the depletion of leucocytes using a magnetic bead separation technique, stained with EpCAM, cytokeratin 7/8 and their isotypic control antibodies, respectively, and then identified and counted by multi-parameter flow cytometry.

RESULTS

In the blood samples from 47 patients, EpCAM-positive CTCs were detected in 64.3%(9/14), 40.0%(4/10) and 43.5%(10/23) of patients in stages Ⅰ-Ⅱ, Ⅲ and Ⅳ, respectively. EpCAM-negative CTCs were detected in 78.6%(11/14), 90.0%(9/10) and 91.3%(21/23) of patients in stage Ⅰ-Ⅱ, Ⅲ, and Ⅳ, respectively. The total detection rates of EpCAM-positive and EpCAM-negative CTCs were 48.9%(23/47) and 87.2%(41/47), respectively, showing a statistically significant difference between them (P<0.001). According to the stage of the cancer, there was a significant difference between the detection rates of the two types of CTCs in patients of stage Ⅳ(P=0.001), but not in stage Ⅰ-Ⅱ and Ⅲ (P>0.05). The number of EpCAM-negative CTCs was significantly higher than that of EpCAM-positive CTCs in all stages (P<0.05). The frequency of patients with the percentage of EpCAM-negative CTCs >90% was significantly higher in stage Ⅳ patients than that in stage Ⅰ-Ⅱ cases (P=0.030), while the frequency of patients with the percentage of EpCAM-negative CTCs between 50%~90% was significantly lower in the stage Ⅳ than that in the stage Ⅰ-Ⅱ patients (P=0.001). The treatment of most patients with EpCAM-negative CTCs >50% showed to be ineffective (P=0.033).

CONCLUSION

Detection of CTCs classified by EpCAM in peripheral blood is helpful in evaluating the distant metastasis and treatment effectiveness of NSCLC patients.

[Association between genetic variants in microRNA biosynthesis genes and the risk of head and neck squamous cell carcinoma]

OBJECTIVE

To investigate the association between genetic variants in microRNA biosynthesis genes and the risk of head and neck squamous cell carcinoma (HNSCC).

METHODS

A case-control study was conducted with 576 HNSCC patients and 1 552 healthy controls matched by factors as age-(±5 years) and sex. Eight potentially functional single nucleotide polymorphism loci in microRNA biosynthesis genes (DICER1, GEMIN3, and PIWIL1) were genotyped using the Illumina Infinium BeadChip platform. Univariate and multivariate logistic regression models were performed to assess the association between genotypes and HNSCC risk.

RESULTS

The allele frequencies of rs1106042 (G> A) in PIWIL1 were significantly different between the cases and controls (P=0.011). After controlling for factors as age, sex, smoking and alcohol intake, the A allele of rs1106042 showed a decreased risk of HNSCC (additive model: adjusted OR=0.73, 95% CI: 0.57-0.93, P=0.011). RESULTS from the stratification analysis by age, sex, smoking, alcohol intake and tumor sites showed that the effect of rs1106042 A allele on HNSCC risk was significant in older age groups (≥60), females, nonsmokers, non-alcohol drinkers, and subjects with oral cavity cancer (P<0.05).

CONCLUSION

Potentially, functional single nucleotide polymorphism in PIWIL1 might modify the risk of HNSCC in China.

Environmental impacts of the shelter forests in Horqin Sandy land, northeast China

Assessing environmental effects of shelter forests is primarily necessary for realizing their greatest protective benefits. The Three-North Shelter Forest Program (TNSFP), the largest ecological afforestation program in the world, has been operated for three decades in China but so far lacks comprehensive assessment of its environmental impacts. Horqin Sandy Land (HSL) in Northeast China is one of the key areas in the TNSFP implementation. To identify the principal contributors to environmental changes in HSL, we evaluated impacts of variations in landscape features, shelter forest areas, climatic factors, and social factors on changes in sandy land areas from 1978 to 2007, by using Gray Relational Analysis. Our analysis showed that during the period 1978 to 2007, the sandy land area decreased by 3.9% in low aeolian dunes, 14.5% in low mountains and hills, and 98.9% in high elevation alluvial flats of HSL. Factors with Gray Correlation Degrees >0.9 were identified as the patch shape index (PSI) and the landscape isolation index (LII) of grasses in low aeolian dunes, PSI of grasses in mountains and hills, and area of broadleaved forests and LII of shrubs in alluvial flats. It is concluded that establishment of the shelter forests has played a significant role in controlling the expansion of sandy land in HSL. To sustain the long-term environmental benefits of the shelter forests in the remaining period for TNSFP construction, suitable tree species should be selected and planted at appropriate densities based on the local precipitation, groundwater and landform conditions, and the system stability of the total landscape.

Sulfated beta-glucan derived from oat bran with potent anti-HIV activity

China is a major producer of oats; the annual harvested area of 350,000 ha yields approximately 465,000 tons, giving an average yield of 1.33 tons/ha. The bran is not used for animal feed as it is of poor digestibility and low nutritive content and is considered a waste byproduct. Therefore, it is advantageous to produce a value-added product from the bran. We extracted the native polysaccharide, a linear (1-3)-, (1-4)-linked beta-glucan (OBG) from the oat bran and synthesized a sulfated derivative OBGS containing 36.5% sulfate. OBGS had potent activity against a primary isolate of human immunodeficiency virus (HIV-1) in peripheral blood mononuclear cells at a concentration (EC(50)=5.98 x 10(-4) microM) approximately 15,000 times below its cytotoxic concentration. OBGS was also active postinfection (EC(50)=5.3 x 10(-4) microM) and protected pretreated peripheral mononuclear cells (EC(50)=5.2 x 10(-2) microM) washed free of the compounds prior to infection. Thus, OBGS has potential as a vaginal microbicide and is the first such report for oat bran derived sulfated beta-glucan.

Palmatine, a protoberberine alkaloid, inhibits both Ca(2+)- and cAMP-activated Cl(-) secretion in isolated rat distal colon

BACKGROUND AND PURPOSE

The protoberberine alkaloid berberine has been reported to inhibit colonic Cl(-) secretion. However, it is not known if other protoberberine alkaloids share these effects. We have therefore selected another protoberberine alkaloid, palmatine, to assess its effects on active ion transport across rat colonic epithelium.

EXPERIMENTAL APPROACH

Rat colonic mucosa was mounted in Ussing chambers and short circuit current (I (SC)), apical Cl(-) current and basolateral K(+) current were recorded. Intracellular cAMP content was determined by an enzyme immunoassay. Intracellular Ca(2+) concentration was measured with Fura-2 AM.

KEY RESULTS

Palmatine inhibited carbachol-induced Ca(2+)-activated Cl(-) secretion and the carbachol-induced increase of intracellular Ca(2+) concentration. Palmatine also inhibited cAMP-activated Cl(-) secretion induced by prostaglandin E(2) (PGE(2)) or forskolin. Palmatine prevented the elevation of intracellular cAMP by forskolin. Determination of apical Cl(-) currents showed that palmatine suppressed the forskolin-stimulated, apical cAMP-activated Cl(-) current but not the carbachol-stimulated apical Ca(2+)-activated Cl(-) current. Following permeabilization of apical membranes with nystatin, we found that palmatine inhibited a carbachol-stimulated basolateral K(+) current that was sensitive to charybdotoxin and resistant to chromanol 293B. However, the forskolin-stimulated basolateral K(+) current inhibited by palmatine was specifically blocked by chromanol 293B and not by charybdotoxin.

CONCLUSIONS AND IMPLICATIONS

Palmatine attenuated Ca(2+)-activated Cl(-) secretion through inhibiting basolateral charybdotoxin-sensitive, SK4 K(+) channels, whereas it inhibited cAMP-activated Cl(-) secretion by inhibiting apical CFTR Cl(-) channels and basolateral chromanol 293B-sensitive, KvLQT1 K(+) channels.

Structural features and anti-HIV-1 activity of novel polysaccharides from red algae Grateloupia longifolia and Grateloupia filicina

Since sulphated polysaccharides have antiviral activity in vitro, we examined the structure and antiretroviral activity of native sulphated galactans extracted from the red algae, Grateloupia filicina (GFP) and Grateloupia longifolia (GLP). The sulphate contents of GFP and GLPE (the 1,4-alpha-d-glucan-glucanohydrolase digest of GLP) were 25.7 and 18.5%, respectively. The sulphate ester groups were located at carbon 2 for GFP and at carbon 2 and 6 for GLPE. Antiretroviral activity was investigated with a primary isolate (PI) of HIV-1 and human peripheral blood mononuclear cells (PBMCs) rather than T-cell line adapted (TCLA) HIV-1 and T-cell lines because it is more representative of the in vivo situation. Both compounds and their derivatives had potent anti-HIV-1 activity when added at the time of infection, and 2h post-infection (EC50s 0.010-0.003microM, EC(90s) 0.87-0.33microM) and low cytotoxicity. Their potential medical application as virucidal vaginal formulations is discussed.

Astragaloside IV and polysaccharide production by hairy roots of Astragalus membranaceus in bioreactors

Hairy roots of Astragalus membranaceus were grown in bioreactors up to 30 l for 20 d. Cultures from a 30 l airlift bioreactor gave 11.5 g l dry wt with 1.4 mg g(-1) astragaloside IV, similar to cultures from 250 ml and 1 l flasks, but greater than yields from a 10 l bioreactor (dry wt 9.4 g l(-1), astragaloside IV 0.9 mg g(-1)). Polysaccharide yields were similar amongst the different bioreactors (range 25-32 mg g(-1)). The active constituent content of the cells approached that of plant extracts, indicating that large scale hairy root cultures of A. membranaceus has the potential to provide an alternative to plant crops without compromising yield or pharmacological potential.

[Effect of satragaloside IV on the increase of microvascular permeability induced by histamine in pial microvessels of rat]

OBJECTIVE

To study the effect of satragaloside IV on the microvascular permeability induced by histamine in pial microvessels.

METHOD

The microvascular permeability was expressed by changes in the transendothelial electrical resistance which was measured with technique using microelectrode impaled into the vascular lumen and based on cable analysis of vessels in rat.

RESULT

The transendothelial electrical resistance of microvessels superfused with artificial cerebrospinal fluid was about 2500 omega.cm2, indicating a tight barrier with extremely low ion permeability, and application of 10(-4) mol.L-1 histamine in superfusate caused a rapid and reversible decrease in transendothelial electrical resistance. In paired experiment, the decrease of transendothelial electrical resistance induced by 10(-4) mol.L-1 histamine was inhibited by adding 0.8 x 10(-4) mol.L-1 satragaloside IV in superfusate.

CONCLUSION

The results indicated that increases in the microvascular permeability induced by histamine, and satragaloside IV can inhibit the increases in the microvascular permeability induced by histamine. It is necessary that the cellular mechanism of permeability response induced by satragaloside IV be further elucidated.

[Studies on the chemical constituents of Evodia rutaecarpa (Juss.) Benth. var. officinalis (Dode) Huang]

AIM

To study the chemical constituents of the unriped fruits from Evodia rutaecarpa (Juss.) Benth. var. officinalis (Dode) Huang.

METHODS

Various chromatographic techniques were used to separate and purify the constituents. Their structures were elucidated on the physico-chemical properties and spectral data.

RESULTS

A lot of compounds were isolated of the unriped fruits from Evodia rutaecarpa (Juss.) Benth. var. officinalis (Dode) Huang. This paper reports mainly compounds identified as shihulimonin A, emodin, physcion, chrysophanol and limonin.

CONCLUSION

Shihulimonin A is a new compound. Emodin, physcion and chrysophanol were isolated from the Evodia for the first time.

[Studies on constituents in Uncaria macrophylla Wall]

OBJECTIVE

To study the chemical constituents of Uncaria macrophylla.

METHOD

Compounds were isolated by Columu Chromatography, and the structures were identified by NMR spectral data and other methods.

RESULT AND CONCLUSION

Six compounds were isolated and identified as ursolic acid, 3 beta-6 beta-23-trihydroxyurs-12-en-28-oic acid, 3 beta, 6 beta, 19 alpha-trihydroxyurs-12-en-28-oic acid, epicatechin, beta-sitosterol and daucosterin. All the compounds were isolated for the first time from the plant.

[Effects of components isolated from Astragalus membranaceus Bunge on cardiac function injured by myocardial ischemia reperfusion in rats]

OBJECTIVE

To investigate the effects of components isolated from Astragalus membranaceus on myocardial ischemia reperfusion injury.

METHODS

The myocardial ischemia reperfusion injury model was created by the left anterior descending coronary artery occlusion from the oracotouated rats, and the total saponins, total flavonids and astragaloside i.v. isolated from A. membranaceus on hemodynamics during acute myocardial ischemia, Na(+)-K(+)-ATPase activity, cAMP and malondialdehyede (MDA) contents in the ischemic myocardium were observed.

RESULTS

The total saponins, total flavonids and astragaloside i.v. attenuated the declines of the amplitudes of LVSP and +/- LVdp/dtmax in rat heart injured by ischemia reperfusion in vivo, and decreased Na(+)-K(+)-ATPase activity in the ischemic myocardium. Otherwise, the total saponins increased the cAMP content and the total flavonids decreased the level of MDA production in the ischemic myocardium.

CONCLUSION

The effects of different components isolated from A. membranaceus on protecting the cardiac function in the process of ischemia reperfusion may be related to the mechanism of improving energy metabolism, scavenging the oxygen free radicals and inhibiting the production of free radicals in the ischemic myocardium.

Regulation of drug sensitivity by ribosomal protein S3a

When bcl-2 is immunoprecipitated from (32)P-labeled cell extracts of all-trans retinoic acid (ATRA)-treated acute myeloblastic leukemia (AML) blasts, a phosphorylated protein of approximately 30 kd is coprecipitated. This protein has been identified as ribosomal protein S3a. The biologic effects of S3a include favoring apoptosis and enhancing the malignant phenotype. We sought to determine whether S3a, like bcl-2, influenced the response of cells to chemotherapeutic drugs and ATRA. Cell lines were studied in which S3a was genetically increased or disrupted; increased S3a was regularly associated with increased plating efficiency and increased sensitivity to either cytosine arabinoside (ara-C) or doxorubicin (DNR). S3a did not affect the sensitivity of cells to paclitaxel. Pulse exposures to either (3)HTdR or ara-C showed a greater percentage of clonogenic cells in the S phase of the cell cycle in cells with increased S3a than in controls. Cells with increased S3a responded to ATRA by increased ara-C or DNR sensitivity, whereas cells with reduced S3a protein were either protected by ATRA or not affected. We studied cryopreserved blast cells from patients with AML or chronic myelomonocytic leukemia (CMML). S3a protein levels were heterogeneous in these populations. In 32 cryopreserved blast populations, S3a levels were significantly correlated with both bcl-2 and with cell growth in culture. As in cell lines, high S3a in cryopreserved blasts was associated with ATRA-induced sensitization to ara-C. No significant association was seen between S3a levels and response to treatment.

p53 alterations in human leukemia-lymphoma cell lines: in vitroartifact or prerequisite for cell immortalization?

Alteration of the p53 gene is one of the most frequent events in human tumorigenesis. The inactivation of p53 tumor suppressor function can be caused by chromosome deletion, gene deletion, or mainly by point mutations. p53 mutations occur moderately often in hematopoietic malignancies. A significantly higher frequency of p53 alterations in cell lines vs primary samples has been observed for all types of malignant hematopoietic cell lines. It has been postulated that p53 gene abnormalities arise in cell lines during in vitro establishment of the culture or prolonged culture; but it is also conceivable that those cases that carry p53 mutations may be more suitable for in vitro establishment as permanent cell lines. We analyzed data on the p53 gene status in a panel of matched primary hematopoietic tumor cells and the respective cell lines derived from this original material. In 85% (53/62) of the pairs of matched primary cells and cell lines, the in vivo and in vitro data were identical (both with p53 wild-type or both with the same p53 mutation). In some instances, serial clinical samples (eg at presentation and relapse) and serial sister cell lines were available. These cases showed that a clinical sample at presentation often had a p53 wild-type configuration whereas the derived cell line and a relapse specimen carried an identical p53 point mutation. These findings suggest that a minor clone, at first undetectable by standard analysis, represents a reservoir for the outgrowth of resistant cells in vivo and also a pool of cells with a growth advantage in vitro, providing a significantly higher chance of immortalization in culture. This was further supported by studies employing mutant allele-specific gene amplifications, a technique which is significantly more sensitive (100- to 1000-fold) than the commonly applied SSCP assay with a sensitivity threshold of about 10% mutated cells within a pool of wild-type cells. Taken together, this analysis confirms the usefulness of human hematopoietic cell lines as in vitro model systems for the study of the biology of hematopoietic malignancies. It further underlines the notion that p53 gene alterations confer a survival advantage to, at least some, malignant cells in vitro and presumably also in vivo; however, it is highly unlikely that a p53 mutation alone would suffice for the immortalization of a cell line in vitro or tumor development in vivo. Leukemia (2000) 14, 198-206.

Phosphorylation of BCL-2 after exposure of human leukemic cells to retinoic acid

Serine phosphorylation of bcl-2 has been reported after treatment of cells with protein kinase C, okadaic acid, taxol, and other chemotherapeutic agents that attack microtubules. We report here that bcl-2 is phosphorylated on serine in acute myeloblastic leukemia (AML) blasts exposed to all trans retinoic acid (ATRA). Two-dimension gels (isoelectric focusing followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis [SDS-PAGE]) disclosed a novel acidic isoform of bcl-2 in ATRA-treated blast cells from a continuous line and from two AML patients; when the cell lysates were digested with lambda-phosphatase, bcl-2 reverted to the control position, indicating that it was phosphorylated. Metabolic labeling experiments using 32Pi showed that, while control bcl-2 was labeled, incorporation was greatly increased when cells were treated with ATRA. A comparison of bcl-2 from blasts treated with ATRA or taxol showed that bcl-2 was phosphorylated on serine in cells treated with either agent; however, both qualitative and quantitative differences were seen. Qualitatively, the phosphorylated isoform from taxol-treated cells was slightly larger than the native isoform and could be distinguished on 10% to 20% SDS-polyacrylamide gradient gels, while the phosphorylated bcl-2 after ATRA ran as a single band on gradient gels at the same position as control bcl-2. Quantitatively, all bcl-2 from ATRA-treated cells was in the phosphorylated isoform, while after taxol, both phosphorylated and native bcl-2 was present; incorporation of 32Pi into bcl-2 was stimulated to greater extent in ATRA-treated compared with taxol-treated cells. We used immunoprecipitation experiments to ask if bcl-2 phosphorylated after ATRA or taxol had altered capacity to dimerize with bax. No change in dimerization was demonstrated. We conclude that: bcl-2 is phosphorylated on serine after treatment of AML blasts with ATRA; bcl-2 phosphorylation after ATRA is different from that seen after taxol; bcl-2 phosphorylated after either agent retains capacity to dimerize with bax. The ATRA or taxol-induced phosphorylation of bcl-2 can also be seen in blast cells obtained from AML patients.

In vitro culture studies of childhood myelodysplastic syndrome: establishment of the cell line MUTZ-1

Myelodysplastic syndrome (MDS) in childhood is considered to be very rare and detailed pathobiological data are scarce. More biological information regarding MDS in children is clearly needed and in vitro culture studies provide one possibility for gaining further pathophysiological insights into this malignancy. Here, we incubated bone marrow samples from 30 children with MDS in liquid suspension culture in order to grow the transformed cells in vitro. In most cultures, the hematopoietic cells died quickly and only fibroblastic (stromal) background layers proliferated temporarily; several normal Epstein-Barr virus (EBV)-transformed B-lymphoblastoid cell lines (B-LCL) were established. Only in one instance, albeit from the peripheral blood and not from the bone marrow, could we establish a cell line, termed MUTZ-1, from the malignant cells of a 5-year-old girl with MDS (FAB subtype refractory anemia with excess of blasts). The MDS arose from a pre-existing Fanconi anemia and progressed quickly to an acute myeloid leukemia (FAB M2). Despite positivity for EBV, MUTZ-1 is not an EBV + B-LCL and further characterization of MUTZ-1 confirmed the derivation from the transformed clonal cells. Immunophenotyping showed a pre B-cell surface marker profile (CD10+ CD19+ cytoplasmic IgM+); receptor gene rearrangement analyses underlined the clonal B-cell nature of MUTZ-1 cells. MUTZ-1 cells exhibit a highly rearranged, unstable karyotype with a high frequency of spontaneous chromatid breaks and exchanges; del(5q) and additional rearrangements involving chromosome 5 [der(15)t(5;15)] were detected. The present data and results from a few other MDS-derived cell lines suggest that the transforming event in MDS seems to occur in an immature pluripotent progenitor cell. The new MDS-derived continuous cell line MUTZ-1 provides a useful in vitro model system for studies on the pathogenetic events leading to MDS.

MUTZ-3, a monocytic model cell line for interleukin-4 and lipopolysaccharide studies

The human monocytic cell lines MUTZ-3 and MONO-MAC-6 express the lipopolysaccharide (LPS) receptor CD14. Paralleling the situation in peripheral blood monocytes (PBMo), recombinant human interleukin-4 (IL-4) down-regulated the expression of CD14 on the cell surface of MUTZ-3, but not that of MONO-MAC-6 cells. In addition, preincubation with IL-4 prevented the LPS-induced up-regulation of IL-1 beta mRNA levels in MUTZ-3, but not in MONO-MAC-6 cells. We examined whether the differential responsiveness of the cell lines was due to the missing expression of the IL-4 receptor (IL-4R) alpha or gamma c chain in MONO-MAC-6 cells. Flow cytometric and immunoprecipitation analysis revealed expression of both IL-4R chains in both cell lines. In addition, short-term stimulation with IL-4 induced tyrosine-phosphorylation of the gamma c chain. As both cell lines also expressed signal transducer and activator of transcription 6 (STAT 6), our data suggested that the differential reaction patterns of MUTZ-3 and MONO-MAC-6 cells were not due to a generally defective IL-4R complex. Interestingly, long-term (48 hr) treatment with LPS rendered MONO-MAC-6 cells sensitive to IL-4. LPS up-regulated expression of monocyte-specific esterase (MSE) mRNA as well as CD14 protein in MONO-MAC-6 cells; both effects were inhibited by IL-4. This stimulation was not paralleled by an increase of IL-4R mRNA or protein expression supporting the above hypothesis of a constitutively present and active IL-4R. We discuss possible causes for the differential reaction patterns of MUTZ-3 and MONO-MAC-6 cells to IL-4.

Regulation of the synthesis of bcl-2 protein by growth factors

The sensitivity of AML blast stem cells can be measured in cell culture, using a clonogenic assay to determine survival after each of a graded series of drug concentrations. For cytosine arabinoside, the dose-response curve is a simple negative exponential that can be described by a D10 value, a measure of slope. This D10 value can be affected by regulatory molecules added to the cultures. All-trans retinoic acid (ATRA) usually sensitizes cells, while hydrocortisone (HC) is protective. Growth factor responsive cells are more Ara-C sensitive in G-CSF than in GM-CSF or IL-3. The proto-oncogene bcl-2 may be part of the mechanism by which drug sensitivity is regulated. Previous work has shown that ATRA decreases bcl-2 RNA expression and the half-life of the protein; in contrast, the protein from cells treated with HC is more stable than controls. Growth factors were not shown to change either expression of bcl-2 RNA or the stability of its protein. In this paper, we describe experiments where OCI/AML-1 cells were grown in G-CSF and then transferred to medium containing both G-CSF and the GM-CSF-IL-3 fusion protein pIXY. Steady-state levels of bcl-2 protein were measured by Western blot and synthesis by incorporation of 35S methionine into protein. We observed that both measures doubled within 12-24 h after transfer from G-CSF in G-CSF with pIXY, but promptly returned to the previous state when pIXY was withdrawn. We conclude that growth factors regulate that activity of bcl-2 post-transcriptionally by altering the rate of synthesis of the protein.

Cohabiting t(12;22) and inv(3) primary rearrangements in an acute myelomonocytic leukemia (FAB M4) cell line

We describe the cytogenetic characterization of MUTZ-3, the first continuous cell line to be established from acute myelomonocytic leukemia (FAB M4) cells, exhibiting recurrent chromosomal rearrangements associated with this disease category. MUTZ-3 was established from peripheral blood taken at presentation from a 29-year-old male patient and carries the t(12;22)(p13.2;q11.2) associated with acute myelomonocytic leukemia (AMMoL), the inv(3)(q21.2q26.3) associated with multilineage acute myeloid leukemias (AML), and the inv(7)(p 14q35) associated with ataxia telangiectasia (A-T). There was no evidence that the patient was an A-T heterozygote. The breakpoint on chromosome 22 mapped between 5' BCR and D22S39, consistent with the G-banding assignment. Both inversions were translocation-associated and may be further examples of an association previously described in AML FAB M4eo with inv(16). We suggest that the combination of inv(3)/t(3;3) with t(12;22) may represent a new, nonrandom association in AML.

Esterase isoenzyme profiles of 255 leukemia-lymphoma cell lines from all hematopoietic cell lineages

Carboxylic esterase isoenzymes isolated from a panel of well-characterized continuous human leukemia-lymphoma cell lines were separated by isoelectric focusing. Typical isoenzyme patterns designated Mono 1/Mono 2 (for monocyte-associated), My 1/My 2 (for myeloid or myeloma), Lym 1/Lym 2 (for lymphoid) and Und (for undifferentiated) could be reproducibly discerned. The Mono patterns contained one unique isoenzyme encoded by the monocyte-specific esterase gene. This comparative analysis of 255 leukemia-lymphoma cell lines covered the major cell lineage that are affected by hematological neoplasias. The results showed that (except for myelomas) lymphoid-derived malignancies, both leukemias and lymphomas, expressed primarily the Und and Lym esterase isoenzyme profiles. In contrast, myeloid leukemia cells and the related erythroid and megakaryocytic cell lines displayed mainly the My patterns. The Mono patterns were detected predominantly in monocyte-derived leukemias. As the B-lymphocytic hierarchy progresses from pre B-cells via B-cells to plasma cells, number and intensity of the isoenzymes increased as well from the Und pattern to the My isoenzyme profile. Hodgkin's disease and anaplastic large cell lymphoma lines displayed heterogenous isoenzyme profiles consistent with their heterogenous cellular origin. The present study using continuous leukemia-lymphoma cell lines as model systems provides a biochemical characterization of different hematopoietic cell lineages and stages of differentiation.

Establishment and characterization of two novel cytokine-responsive acute myeloid and monocytic leukemia cell lines, MUTZ-2 and MUTZ-3

Human permanent leukemia cell lines represent powerful research tools in a multitude of investigations. The two new continuous leukemia cell lines MUTZ-2 and MUTZ-3 were derived from the peripheral blood of patients with acute myeloid leukemia (AML) FAB M2 and AML FAB M4. MUTZ-2 and MUTZ-3 cells have morphological and immunophenotypical features of myeloid and monocytic cells, respectively. While MUTZ-2 is negative, MUTZ-3 cells express the monocytic surface marker CD14, albeit weakly. The monocytic nature of MUTZ-3 cells is underlined by the expression of the monocyte-specific esterase (MSE), myeloperoxidase (MPO) and tartrateresistant acid phosphatase (TRAP) enzymes; MUTZ-2 is negative for MSE and TRAP, but expresses MPO. For sustained cell growth, both cell lines require constitutively the addition of cytokines to the culture medium and retain an absolute dependence on conditioned medium or recombinant growth factors for proliferation and survival. Incubation with single recombinant cytokines from a broad spectrum of growth factors established that the strongest proliferation response of MUTZ-2 cells was elicited by FLT-3 ligand, granulocyte colony-stimulating factor (G-CSF), macrophage CSF (M-CSF), interferon-gamma (IFN-gamma) and stem cell factor (SCF), whereas granulocyte-macrophage CSF (GM-CSF), M-CSF, interleukin-3 (IL-3) and SCF were the most effective growth factors in inducing proliferation of MUTZ-3. Both cell lines were proliferatively responsive to several further cytokines, however, to a lesser extent. Exposure to phorbol ester 12-O-tetradecanoyl-phorbol-13-acetate (TPA) or the physiological all-trans retinoic acid (ATRA) had growth-inhibitory and differentiation-inducing effects on both cell lines. Using a clonogenic cell recovery assay, both cell lines were found to be sensitive to the chemotherapeutic drugs cytosine arabinoside (Ara-C) and daunorubicin (DNR), MUTZ-2 cells being more sensitive to both Ara-C and DNR treatment than MUTZ-3 cells. Chromosomal trisomies 8 and 10 were found in MUTZ-2 cells without any additional structural abnormalities. MUTZ-3 carries the rare, but recurrent AML-associated translocation (12;22)(p13;q11-q12) reflecting the karyotype of the original tumor. The main characteristics of these cell lines remained the same during about 1 year of continuous culture as well as after freezing and thawing. In summary, we established and characterized two new leukemia cell lines with myeloid or monocytic features which are growth factor-responsive, one of them carrying a unique chromosomal translocation. These cells will be of particular value for investigating the complex cytokine network and molecular events caused by chromosomal aberrations.

Post-transcriptional regulation of bcl-2 in acute myeloblastic leukemia: significance for response to chemotherapy

The blast stem cells of acute myeloblastic leukemia become more sensitive in culture to the chemotherapeutic agents cytosine arabinoside (Ara-C) and daunorubicin (DNR) when exposed to all-trans retinoic acid (ATRA) after drug. We have proposed that down regulation of bcl-2 by ATRA is part of the mechanism of sensitization. The hypothesis is based on reduced expression of bcl-2 mRNA, as seen in Northern blots, after ATRA. Nuclear run on experiments, however, failed to account completely for the effect at the transcriptional level. Accordingly, we looked for post-transcriptional effects of ATRA on bcl-2, using metabolic labelling of the protein to measure stability. We found that the half-life of bcl-2 protein is markedly shortened after treatment with ATRA. Hydrocortisone (HC) protects cells against the toxic effects of Ara-C or DNR when given before drug. HC does not alter bcl-2 expression at the level of mRNA; however, metabolic labelling shows that newly synthesized bcl-2 protein is stabilized in blast cells treated with HC. Response to Ara-C by growth factor responsive blast cells is influenced by the factor in the cultures; cells are more sensitive in cultures with G-CSF and less sensitive when GM-CSF is present. We compared two blast cell lines, OCI/AML-5, primarily responsive to GM-CSF, and OCI/AML-10, primarily responsive to G-CSF. Growth factor did not influence the stability of bcl-2 protein in either line. In contrast, Western blots showed that the amount of bcl-2 protein was greater in cultures with GM-CSF or GM-CSF in combination with G-CSF than in cultures with G-CSF or no added factor. This pattern was seen regardless of the mitogenic response to G-CSF or GM-CSF. We interpret our findings as indicating that bcl-2 protein is transcriptionally activated; that the stability of the protein is decreased after ATRA and increased after HC; that the amount of bcl-2 protein is greater in cultures with GM-CSF than in cultures with G-CSF, regardless of which factor gives the greater mitogenic response. We propose that these post-transcriptional modifications of transcriptionally activated bcl-2 account, in part, for the regulation of drug sensitivity by ATRA, HC and growth factors.

Leukemia cell lines: in vitro models for the study of acute promyelocytic leukemia

Acute promyelocytic leukemia (APL) serves as a paradigm in clinical and biological leukemia research. Firstly, APL represents a model for the new therapeutic approach of differentiation therapy, taking advantage of the ability of APL cells to respond to retinoic acid treatment by terminal differentiation. Secondly, the 15;17 chromosomal translocation specific for APL leads at the molecular genetic level to a chimeric gene fusing the PML and RAR alpha genes and appears to be an instrumental, if not actually the causative event, in the neoplastic process. These unique characteristics of an otherwise rather rare disease have recently attracted intense research interest. As in other types of leukemia where continuous cell lines are powerful research tools, studies using APL-derived cell lines have contributed a large body of relevant data in efforts to unravel the pathobiology and leukemogenesis of APL. Three cell lines have been reported to be derived from patients with APL: HL-60, NB-4 and PL-21. Both HL-60 and PL-21 lack t(15;17) while NB-4 carries this cytogenetic hallmark pathognomonic for APL. Morphological and immunophenotypical examinations of the cell lines do not permit a clear assignment to any stage of myelomonocytic differentiation. Some additional data, such as expression of myeloperoxidase, monocyte-specific esterase and annexin VIII, together with the cytogenetic and molecular biological information, suggest that NB-4 is the only genuine promyelocytic leukemia cell line, whereas HL-60 may represent a discrete stage of differentiation between the late myeloblasts and the promyelocyte; PL-21 has distinct features associated with monocytic cells. These cell lines provide unique in vitro model systems for studying the cellular and molecular events involved in the proliferation and differentiation of normal and leukemic myelomonocytic cells.

Direct evidence for the participation of bcl-2 in the regulation by retinoic acid of the Ara-C sensitivity of leukemic stem cells

All-trans retinoic acid (ATRA) increases the sensitivity of AML blast cells to cytosine arabinoside (Ara-C) or daunorubicin (DNR) when ATRA is given after drug. We have proposed that down-regulation of bcl-2 is part of the mechanism by which ATRA regulates drug sensitivity. To test this hypothesis cDNA encoding bcl-2 was transfected into cells of the continuous lines OCI/AML-2 and OCI/AML-5. Four transfectant lines were isolated; three contained transfected bcl-2 in the sense orientation (AML5-BCL2sa, AML5-BCL2sb and 2-bcl2) and one with anti-sense bcl-2(AML5-bcl2as). The presence of the transfected gene was demonstrated by Northern blot; translation of the sense transfected genes into protein was demonstrated by Western blotting. Lines with sense-oriented transfected bcl-2 were significantly less sensitive to Ara-C or H2O2 than the parental lines; the cells with anti-sense transfected genes were more sensitive than their parent but the difference did not reach statistical significance. The effect of ATRA on bcl-2 expression was compared in sense-transfected cells and their parents; by Northern blotting it was shown that the endogenous but not the transfected genes were down-regulated after ATRA exposure. The capacity of cells with transfected genes to respond to ATRA was tested by obtaining Ara-C survival curves for ATRA-treated cells. Compared to controls not exposed to ATRA, the transfected cells showed little or statistically insignificant changes in Ara-C sensitivity after ATRA treatment. We conclude that data from the transfectants provides evidence that expression of bcl-2 is a determinant of sensitivity to Ara-C and H2O2; and that the effect of ATRA on sensitivity requires the presence of bcl-2 genes in association with regulatory elements.

Mechanism of cytosine arabinoside toxicity to the blast cells of acute myeloblastic leukemia: involvement of free radicals

Retinoic acid and hydrocortisone (HC) have been shown to regulate the drug sensitivity of the blast cells of acute myeloblastic leukemia (AML). We asked if the proto-oncogene bcl-2 played a role in this regulation. As target cells we used the continuous lines, OCI/AML-1, OCI/AML-2 or OCI/AML-5; expression of bcl-2 can be detected by Northern analysis of RNA from OCI/AML-2 or OCI/AML-5 cells; bcl-2 expression can be found in OCI/AML-1 cells only by using RT-PCR. Exposure of OCI/AML-2 or OCI/AML-5 cells to retinoic acid (all-trans retinoic acid, ATRA) led to a down-regulation of bcl-2 expression that was first seen after 2 h of exposure and was complete after a day. The down-regulation could be prevented by exposing the cells to ara-C either before or after ATRA; decrease in bcl-2 protein was moderate and only obvious after 36 h of ATRA treatment. Nuclear run-on experiments provided evidence that bcl-2 down-regulation was occurring at transcriptional and post-translational levels. Since bcl-2 is considered to have anti-oxidant activity, we tested the sensitivity of the three cell lines to H2O2; we found that OCI/AML-1, the line with very low bcl-2 expression, was a 100-fold more H2O2-sensitive than OCI/AML-2 or OCI/AML-5, where bcl-2 expression can be detected readily. We then asked if H2O2 sensitivity could be regulated. We found that exposure of cells to HC before H2O2 was protective while ATRA after peroxide treatment increased killing; this is the same pattern of regulation observed when AML blasts are exposed to HC before, or ATRA after ara-C. Finally, we asked whether N-acetylcysteine (NAC), a known radical scavenger would protect cells against ara-C killing. Significant protection was observed when NAC was given before drug, but not if given after drug. NAC protection against ara-C killing was seen for OCI/AML-1 and 2 cells, but not for OCI/AML-5 cells. We interpret the results as follows: ara-C kills cells in two ways: first, directly, by incorporation into DNA and chain termination; second, indirectly, by inducing the production of toxic radicals. Bcl-2 reduces the oxidant activity of such radicals, and is protective. ATRA regulates ara-C toxicity by its action on bcl-2. Left unexplained are the action of HC, which does not affect bcl-2 expression and the mechanism by which ara-C prevents down-regulation of bcl-2 by ATRA.