Developmental potency of human ES cell-derived mesenchymal stem cells revealed in mouse embryos following blastocyst injection

Mesenchymal stem cells (MSCs) are present in almost all the tissues in the body, critical for their homeostasis and regeneration. However, the stemness of MSCs is mainly an in vitro observation, and lacking exclusive markers for endogenous MSCs makes it difficult to study the multipotency of MSCs in vivo, especially for human MSCs. To address this hurdle, we injected GFP-tagged human embryonic stem cell (hESC)-derived MSCs (EMSCs) into mouse blastocysts. EMSCs survived well and penetrated both the inner cell mass and trophectoderm, correlating to the higher anti-apoptotic capability of EMSCs than hESCs. Injected EMSCs contributed to skeletal, dermal, and extraembryonic tissues in the resultant chimera and partially rescued skeletal defects in Sox9+/- mouse fetuses. Thus, this study provides evidence for the stemness and developmental capability of human MSCs through chimerization with the mouse blastocyst, serving as a model for studying human mesenchymal and skeletal development.

Engineered Selenium/Human Serum Albumin Nanoparticles for Efficient Targeted Treatment of Parkinson's Disease via Oral Gavage

Parkinson's disease (PD) is a neurodegenerative disorder characterized by the degeneration of dopamine (DA) neurons in the midbrain substantia nigra pars compacta (SNpc). While existing therapeutic strategies can alleviate PD symptoms, they cannot inhibit DA neuron loss. Herein, a tailor-made human serum albumin (HSA)-based selenium nanosystem (HSA/Se nanoparticles, HSA/Se NPs) to treat PD that can overcome the intestinal epithelial barrier (IEB) and blood-brain barrier (BBB) is described. HSA, a transporter for drug delivery, has superior biological characteristics that make it an ideal potential drug delivery substance. Findings reveal that HSA/Se NPs have lower toxicity and higher efficacy than other selenium species and the ability to overcome the IEB and BBB to enrich DA neurons, which then protect MN9D cells from MPP+-induced neurotoxicity and ameliorate both behavioral deficits and DA neuronal death in MPTP-model mice. Thus, a therapeutic drug delivery system composed of orally gavaged HSA/Se NPs for the treatment of PD is described.

Definitive Endodermal Cells Supply an in vitro Source of Mesenchymal Stem/Stromal Cells

Mesenchymal stem/Stromal cells (MSCs) have great therapeutic potentials, and they have been isolated from various tissues and organs including definitive endoderm (DE) organs, such as the lung, liver and intestine. MSCs have been induced from human pluripotent stem cells (hPSCs) through multiple embryonic lineages, including the mesoderm, neural crest, and extraembryonic cells. However, it remains unclear whether hPSCs could give rise to MSCs in vitro through the endodermal lineage. Here, we report that hPSC-derived, SOX17⁺ definitive endoderm progenitors can further differentiate to cells expressing classic MSC markers, which we name definitive endoderm-derived MSCs (DE-MSCs). Single cell RNA sequencing demonstrates the stepwise emergence of DE-MSCs, while endoderm-specific gene expression can be elevated by signaling modulation. DE-MSCs display multipotency and immunomodulatory activity in vitro and possess therapeutic effects in a mouse ulcerative colitis model. This study reveals that, in addition to the other germ layers, the definitive endoderm can also contribute to MSCs and DE-MSCs could be a cell source for regenerative medicine.

Tumor-associated macrophages-educated reparative macrophages promote diabetic wound healing

Nonhealing diabetic wounds, with persistent inflammation and damaged vasculature, have failed conventional treatments and require comprehensive interference. Here, inspired by tumor-associated macrophages (TAMs) that produce abundant immunosuppressive and proliferative factors in tumor development, we generate macrophages to recapitulate TAMs' reparative functions, by culturing normal macrophages with TAMs' conditional medium (TAMs-CM). These TAMs-educated macrophages (TAMEMs) outperform major macrophage phenotypes (M0, M1, or M2) in suppressing inflammation, stimulating angiogenesis, and activating fibroblasts in vitro. When delivered to skin wounds in diabetic mice, TAMEMs efficiently promote healing. Based on TAMs-CM's composition, we further reconstitute a nine-factor cocktail to train human primary monocytes into TAMEMs^C-h , which fully resemble TAMEMs' functions without using tumor components, thereby having increased safety and enabling the preparation of autologous cells. Our study demonstrates that recapitulating TAMs' unique reparative activities in nontumor cells can lead to an effective cell therapeutic approach with high translational potential for regenerative medicine.

[Correlation analysis of smell and taste loss with COVID-19 outbreak trend based on big data of internet]

Objective: To analyze the correlation between loss of smell/taste and the number of real confirmed cases of coronavirus disease 2019 (COVID-19) worldwide based on Google Trends data, and to explore the guiding role of smell/taste loss for the COVID-19 prevention and control. Methods: "Loss of smell" and "loss of taste" related keywords were searched in the Google Trends platform, the data were obtained from Jan. 1 2019 to Jul. 11 2021. The daily and newly confirmed COVID-19 case number were collected from World Health Organization (WHO) since Dec. 30 2019. All data were statistically analyzed by SPSS 23.0 software. The correlation was finally tested by Spearman correlation analysis. Results: A total of data from 80 weeks were collected. The retrospective analysis was performed on the new trend of COVID-19 confirmed cases in a total of 186 292 441 cases worldwide. Since the epidemic of COVID-19 was recorded on the WHO website, the relative searches related to loss of smell/taste in the Google Trends platform had been increasing globally. The global relative search volumes of "loss of smell" and "loss of taste" on Google Trends was 10.23±2.58 and 16.33±2.47 before the record of epidemic while 80.25±39.81 and 80.45±40.04 after (t value was 8.67, 14.43, respectively, both P<0.001). In the United States and India, the relative searches for "loss of smell" and "loss of taste" after the record of epidemic were also much higher than before (all P<0.001). The correlation coefficients between the trend of weekly new COVID-19 cases and the Google Trends of "loss of smell" in the global, United States, and India was 0.53, 0.76, and 0.82 respectively (all P<0.001), the correlation coefficients with Google Trends of "loss of taste" was 0.54, 0.78, and 0.82 respectively (all P<0.001). The lowest and highest point of loss of smell/taste search curves of Google Trends in different periods appeared 7 to 14 days earlier than that of the weekly newly COVID-19 confirmed cases curves, respectively. Conclusions: There is a significant positive correlation between the number of newly confirmed cases of COVID-19 worldwide and the amount of keywords, such as "loss of smell" and "loss of taste", retrieved in Google Trends. The trend of big data based on Google Trends might predict the outbreak trend of COVID-19 in advance.

Transcriptome analysis of non human primate-induced pluripotent stem cell-derived cardiomyocytes in 2D monolayer culture vs. 3D engineered heart tissue

AIMS

Stem cell therapy has shown promise for treating myocardial infarction via re-muscularization and paracrine signalling in both small and large animals. Non-human primates (NHPs), such as rhesus macaques (Macaca mulatta), are primarily utilized in preclinical trials due to their similarity to humans, both genetically and physiologically. Currently, induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) are delivered into the infarcted myocardium by either direct cell injection or an engineered tissue patch. Although both approaches have advantages in terms of sample preparation, cell-host interaction, and engraftment, how the iPSC-CMs respond to ischaemic conditions in the infarcted heart under these two different delivery approaches remains unclear. Here, we aim to gain a better understanding of the effects of hypoxia on iPSC-CMs at the transcriptome level.

METHODS AND RESULTS

NHP iPSC-CMs in both monolayer culture (2D) and engineered heart tissue (EHT) (3D) format were exposed to hypoxic conditions to serve as surrogates of direct cell injection and tissue implantation in vivo, respectively. Outcomes were compared at the transcriptome level. We found the 3D EHT model was more sensitive to ischaemic conditions and similar to the native in vivo myocardium in terms of cell-extracellular matrix/cell-cell interactions, energy metabolism, and paracrine signalling.

CONCLUSION

By exposing NHP iPSC-CMs to different culture conditions, transcriptome profiling improves our understanding of the mechanism of ischaemic injury.

Time Series Forecasting of US COVID-19 Transmission

CONTEXT

The increasing number of confirmed cases of COVID-19 globally is shocking every day. US daily deaths have numbered over one-thousand people per day for nearly 3 days (from November 18, 2020 to November 20, 2020), and total deaths have exceeded 250 000 as of November 21, 2020, which drives the medical community to search for trends to provide an early warning of rising numbers of cases and to prevent future increases.

OBJECTIVE

The study intended to evaluate available US COVID-19 data to determine the possibility of predicting the spread of COVID-19 in the USA.

DESIGN

The research team collected US COVID-19 data from a time-series view and established a seasonal autoregressive integrated moving average (SARIMA) model to predict trends.

RESULTS

According to the spatial and temporal distribution of cumulative confirmed cases, US COVID-19 cases are mainly concentrated in areas with high population density, with that variable having a positive correlation to the number of confirmed cases and deaths. The correlation coefficients are 0.95 and 0.817, respectively, indicating that the transmission of COVID-19 in the USA is characterized by agglomeration. After exploring the impact of population density, the research team established a SARIMA model to predict the trends, finding that US COVID-19 cases will continue to go up.

CONCLUSIONS

By combining knowledge of the statistical features of the virus with modeling findings, the study determined a method that can improve understanding of the serious pandemic, paving the way toward the development of predictive and preventative solutions.

Integrated Co-functional Network Analysis on the Resistance and Virulence Features in Acinetobacter baumannii

Acinetobacter baumannii is one of the most troublesome bacterial pathogens that pose major public health threats due to its rapidly increasing drug resistance property. It is not only derived from clinic setting but also emerges from aquaculture as a fish pathogen, which could pass the resistant genes in the food chain. Understanding the mechanism of antibiotic resistance development and pathogenesis will aid our battle with the infections caused by A. baumannii. In this study, we constructed a co-functional network by integrating multiple sources of data from A. baumannii and then used the k-shell decomposition to analyze the co-functional network. We found that genes involving in basic cellular physiological function, including genes for antibiotic resistance, tended to have high k-shell values and locate in the internal layer of our network. In contrast, the non-essential genes, such as genes associated with virulence, tended to have lower k-shell values and locate in the external layer. This finding allows us to fish out the potential antibiotic resistance factors and virulence factors. In addition, we constructed an online platform ABviresDB (https://acba.shinyapps.io/ABviresDB/) for visualization of the network and features of each gene in A. baumannii. The network analysis in this study will not only aid the study on A. baumannii but also could be referenced for the research of antibiotic resistance and pathogenesis in other bacteria.

Patients With Lung Cancer Have High Susceptibility of COVID-19: A Retrospective Study in Wuhan, China

Patients with lung cancer are presumed to be at high risk from COVID-19 infection due to underlying malignancy. A total of 31 COVID-19 patients with pre-diagnosed lung cancer and 186 age and sex matched COVID-19 patients without cancer in 6 hospitals in Wuhan, China were identified in our study. There was a significantly higher level of IL-6 in lung cancer group showed by multifactorial analysis. The restricted mean survival time in 10, 20, and 53 days in COVID-19 patients with lung cancer were ealier than non-cancer COVID-19 patients in the same observation time (all P values < 0.05). Our results indicated that pre-diagnosed lung cancer was associated with higher morbidity and mortality in COVID-19 patients.

Abstract 276: NOTCH1 is Essential for Ventricular Cardiomyocyte Differentiation of Human Induced Pluripotent Stem Cells

Pathogenic variants in NOTCH1 have been implicated in multiple types of congenital heart defects, such as bicuspid aortic valve, Tetralogy of Fallot, and hypoplastic left heart syndrome (HLHS). However, the mechanisms by which NOTCH1 pathogenic variants cause abnormalities in human embryonic heart development are largely unknown. Here, we used CRISPR/Cas9-mediated genome editing to genetically delete NOTCH1 in human induced pluripotent stem cells (iPSCs). We found that NOTCH1 was dispensable for mesodermal and vascular endothelial differentiation of human iPSCs. Disruption of NOTCH activity promoted venous-specific gene expression but suppressed arterial-specific gene expression in iPSC-derived endothelial cells (iPSC-ECs). Intriguingly, NOTCH1 deletion significantly impaired the cardiac differentiation efficiency. In NOTCH1 homozygous knockout ( NOTCH1 -/- ) iPSC-derived cardiomyocytes (iPSC-CMs), atrial-specific genes ( NR2F2, KCNJ3 , and MYL7 ) were upregulated whereas ventricular-specific genes ( MYL2, IRX4 , and MYH7 ) were downregulated. Electrophysiological analysis by patch clamp and optical mapping indicated that atrial-like cardiomyocytes were dominant whereas the percentage of ventricular-like iPSC-CMs was dramatically reduced (<1%) in NOTCH1 -/- iPSC-CMs. In addition, mitochondrial respiration was reduced in NOTCH1 deficient iPSC-CMs compared to wild-type controls, which was likely attributed to the reduction of ventricular cardiomyocytes in NOTCH1 -/- iPSC-CMs. As NOTCH1 is primarily expressed in endothelial cells rather than cardiomyocytes, we conclude that NOTCH1 affects ventricular cardiomyocyte lineage commitment possibly through controlling cell fate determination of cardiac progenitors during human iPSC differentiation. Our study may provide novel insights into the mechanisms by which NOTCH1 mutations lead to left ventricular hypoplasia in HLHS patients.

Tacrolimus alleviates Ox-LDL damage through inducing vascular endothelial autophagy

OBJECTIVE

To study the protective effect of tacrolimus on vascular endothelium injured by oxidized low-density lipoprotein (ox-LDL) and its mechanism.

MATERIALS AND METHODS

Human umbilical vein endothelial cells were used as objects of study, and divided into control group, tacrolimus group and autophagy inhibition group. Control group received no ox-LDL, while tacrolimus group and autophagy inhibition group were treated with ox-LDL (100 μg/mL) for 3 h. Tacrolimus group was pre-treated with tacrolimus (100 nM) for 0.5 h, and the autophagy inhibition group was pre-treated with 3-methyladenine (3-MA) (10 mM) and tacrolimus (100 nM) for 0.5 h. The cell viability was detected via cell counting kit 8 (CCK8) assay, the cell apoptosis ratio was detected via flow cytometry and Hoechst staining, and the releases of superoxide dismutase (SOD), reactive oxygen species (ROS) and other cytokines were detected using the kit. Moreover, the autophagy level was detected via LC3 fluorescence staining, and the autophagy- and apoptosis-related molecules were detected via polymerase chain reaction (PCR) and Western blotting.

RESULTS

In the absence of ox-LDL, neither tacrolimus nor 3-MA had an effect on the cell viability. After the addition of ox-LDL, the cell viability was significantly decreased, whereas tacrolimus could alleviate such damage to cells. Flow cytometry and Hoechst staining proved that tacrolimus could reduce the proportion of apoptotic cells induced by ox-LDL, while PCR and Western blotting confirmed the decreased expression of apoptosis-related proteins in tacrolimus group. 3-MA could up-regulate the ratio of apoptosis and the expressions of apoptosis-related proteins. The detection of SOD and ROS showed that ox-LDL could induce the cell oxidative stress injury, whereas tacrolimus could inhibit such an effect. The addition of 3-MA inhibited the effect of tacrolimus. Besides, LC3 fluorescence staining, PCR and Western blotting revealed that ox-LDL could induce the autophagy, while tacrolimus could enhance the autophagy. After the addition of 3-MA, the intracellular autophagy level was significantly inhibited.

CONCLUSIONS

Tacrolimus protects vascular endothelial cells from ox-LDL damage through inducing the autophagy.

Abstract 217: TBX5 Clover2 /NKX2-5 TagRFP hiPSCs for Simultaneously Isolating Lineage-Specific Cardiovascular Cells

In vertebrate, the heart is the first organ to develop, comprises multiple highly specialized cell types arising from different lineages. Early animal studies have identified two cardiac lineages: the first and second heart fields which contribute to the four-chamber heart formation. These cardiac progenitor cells develop into different parts of the heart and any perturbation of them frequently leads to congenital heart disease. However, given the difficulty in studying human embryology, current understanding of the hierarchy of cardiac lineages is primarily based on mouse models. The recent breakthrough in generation of human induced pluripotent stem cells (hiPSCs) from somatic cells and de novo differentiation into cardiomyocytes offers an unprecedented opportunity to investigate the genetic control of the cellular process of the heart development and investigate cardiac lineages under human genetic background. Despite the prominent advantages of hiPSCs in cardiac research, heterogeneity of hiPSC-derived cardiomyocytes (hiPSC-CMs) significantly impede their applications in regenerative medicine, disease modeling, and personalized drug testing. Using CRISPR/Cas9 genome-editing technology, I have generated a dual-color iPSC reporter line by targeting fluorescent protein sequences to two transcription factors (TBX5 and NKX2.5) which play a critical role in cardiac differentiation. Using this novel reporter line, I was able to simultaneously isolate four distinct subpopulations which exhibited different gene expression patterns. Continuous culture after isolation, it was found that TBX5 + NKX2.5 + subpopulation primarily differentiated into ventricular myocytes (90% purity), whereas TBX5 - NKX2.5 + subpopulation differentiated into atrial myocytes (80% purity). Moreover the TBX5 + NKX2.5 - subpopulation exhibited the epicardial lineage characteristics and contributed to nodal myocytes (80% purity). However, TBX5 - NKX2.5 - subpopulation developed into endothelial cells. In conclusion, using this reporter line, different lineage subpopulations can be identified and isolated from a heterogeneous pool of cardiac cells. These purified myocyte subtypes hold the potential for precise disease modeling and drug testing.

Long-term follow-up of hepatic adenoma and adenomatosis: analysis of size change on imaging with histopathological correlation

AIM

To analyse the change in size on follow-up of hepatic adenomas (HAs) and adenomatosis, and to investigate the relationship of imaging features with size change.

MATERIALS AND METHODS

The study included 44 patients (142 lesions) who underwent magnetic resonance imaging (MRI) or computed tomography (CT) for diagnosis and follow-up of HA. The imaging features and percentage change in maximum tumour dimension were observed over a follow-up duration of up to 139 months.

RESULTS

With an average follow-up of 43 months, 37% lesions decreased in size, 58% were stable, 4% increased; one lesion regressed completely. Adenomas were stratified into size groups (<3, 3-5, and ≥5 cm). Size change among the three groups was similar (p>0.05). Percent size change was different for lesions followed for ≤12 months (-7.2%) compared with lesions followed for 13-60 months (-20.5%), and those followed for ≥60 months (-23.5%; p<0.05); there was no difference between lesions followed for 13-60 months and ≥60 months (p=0.523). Baseline size and percent size change was similar between the hepatocyte nuclear factor 1α-inactivated HA (HA-H) and inflammatory HA (HA-I) subtype (p>0.05).

CONCLUSION

Most adenomas were either stable or regressed on follow-up. Size change was independent of baseline size. After an initial size decrease within 5 years, no further size reduction was noted on extended follow-up. The percent size change in the HA-H and HA-I subtype was similar.

LncRNA MALAT1 promotes proliferation and metastasis in epithelial ovarian cancer via the PI3K-AKT pathway

OBJECTIVE

The metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is a long non-coding RNA (lncRNA) that plays a key role in the malignant phenotype of tumors. Although abnormal regulation of lncRNA MALAT1 impacts clinical prognostic and tumor metastasis, its function remains unclear in ovarian cancer.

PATIENTS AND METHODS

We collected 64 samples of surgical EOC tissues and 30 samples of normal ovarian tissues at the Department of Gynecology of Harbin Medical University (Harbin, China). The 30 control samples of ovarian surface epithelial tissues were obtained from patients diagnosed with uterine fibroids and scheduled hysterectomy with oophorectomy.

RESULTS

The present study discovered that MALAT1 was upregulated in tumor tissues and ovarian cancer cell lines. Further, the 5-year overall survival was higher in the lower expression of the MALAT1 group. MALAT1 inhibition impeded cell proliferation, invasion and metastasis, and promoted cell apoptosis in both in vivo and in vitro. Furthermore, silencing of MALAT1 hindered the expression of epithelial-to-mesenchymal transition (EMT)-related genes and MMPS. The evidence showed that MALAT1 induce EMT via PI3K/AKT pathway.

CONCLUSIONS

Our research suggests that MALAT1 transforms metastasis in EOC and may be a prospective therapeutic target.

Transcriptome Profiling of Patient-Specific Human iPSC-Cardiomyocytes Predicts Individual Drug Safety and Efficacy Responses In Vitro

Understanding individual susceptibility to drug-induced cardiotoxicity is key to improving patient safety and preventing drug attrition. Human induced pluripotent stem cells (hiPSCs) enable the study of pharmacological and toxicological responses in patient-specific cardiomyocytes (CMs) and may serve as preclinical platforms for precision medicine. Transcriptome profiling in hiPSC-CMs from seven individuals lacking known cardiovascular disease-associated mutations and in three isogenic human heart tissue and hiPSC-CM pairs showed greater inter-patient variation than intra-patient variation, verifying that reprogramming and differentiation preserve patient-specific gene expression, particularly in metabolic and stress-response genes. Transcriptome-based toxicology analysis predicted and risk-stratified patient-specific susceptibility to cardiotoxicity, and functional assays in hiPSC-CMs using tacrolimus and rosiglitazone, drugs targeting pathways predicted to produce cardiotoxicity, validated inter-patient differential responses. CRISPR/Cas9-mediated pathway correction prevented drug-induced cardiotoxicity. Our data suggest that hiPSC-CMs can be used in vitro to predict and validate patient-specific drug safety and efficacy, potentially enabling future clinical approaches to precision medicine.

Changes in snoRNA and snRNA Abundance in the Human, Chimpanzee, Macaque, and Mouse Brain

Small nuclear and nucleolar RNAs (snRNAs and snoRNAs) are known to be functionally and evolutionarily conserved elements of transcript processing machinery. Here, we investigated the expression evolution of snRNAs and snoRNAs by measuring their abundance in the frontal cortex of humans, chimpanzees, rhesus monkeys, and mice. Although snRNA expression is largely conserved, 44% of the 185 measured snoRNA and 40% of the 134 snoRNA families showed significant expression divergence among species. The snRNA and snoRNA expression divergence included drastic changes unique to humans: A 10-fold elevated expression of U1 snRNA and a 1,000-fold drop in expression of SNORA29. The decreased expression of SNORA29 might be due to two mutations that affect secondary structure stability. Using in situ hybridization, we further localized SNORA29 expression to nucleolar regions of neuronal cells. Our study presents the first observation of snoRNA abundance changes specific to the human lineage and suggests a possible mechanism underlying these changes.

High pretreatment neutrophil-lymphocyte ratio predicts recurrence and poor prognosis for combined small cell lung cancer

BACKGROUNDS

Compared to pure small cell lung cancer (SCLC), combined small cell lung cancer (C-SCLC) has its own characteristics. High neutrophil to lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR) have been shown to be related to poor prognosis in several types of tumors. The aim of this study was to explore the prognosis value of NLR and PLR in patients with C-SCLC.

METHODS

A total of 112 patients diagnosed with C-SCLC between January 2000 and March 2009 were enrolled in the study. The clinicopathological parameters, laboratory analyses, and survival time were collected and analyzed. The correlation between NLR, PLR, and clinicopathological characters was analyzed. Univariate and multivariate analyses were performed to investigate the prognostic significance of these parameters for C-SCLC.

RESULTS

The pretreatment NLR was elevated in 37.5 % patients (NLR ≥ 4.15; n = 42; H-NLR). NLR was significantly related to disease stage (p = 0.033) and tumor recurrence (p = 0.014). The median overall survival (OS) and progression-free survival (PFS) were significantly worse in the H-NLR group (OS: 22.0 months vs 11.7 months, p = 0.001; PFS: 11.1 vs 6.0 months, p < 0.001). However, PLR at diagnosis was not associated with OS or PFS. Multivariate analyses indicated elevated NLR (HR = 1.6; p = 0.001), disease stage (HR = 1.6; p = 0.001), and performance status (HR = 1.8; p = 0.015) as independent prognostic factors.

CONCLUSIONS

High pretreatment NLR (≥4.15) is a potential useful indicator for C-SCLC recurrence and predicts a poor long-term prognosis for C-SCLC, which should be considered in defining the prognosis with other well-known prognosticators in C-SCLC patients.

Tex10 Coordinates Epigenetic Control of Super-Enhancer Activity in Pluripotency and Reprogramming

Super-enhancers (SEs) are large clusters of transcriptional enhancers that are co-occupied by multiple lineage-specific transcription factors driving expression of genes that define cell identity. In embryonic stem cells (ESCs), SEs are highly enriched for the core pluripotency factors Oct4, Sox2, and Nanog. In this study, we sought to dissect the molecular control mechanism of SE activity in pluripotency and reprogramming. Starting from a protein interaction network surrounding Sox2, we identified Tex10 as a key pluripotency factor that plays a functionally significant role in ESC self-renewal, early embryo development, and reprogramming. Tex10 is enriched at SEs in a Sox2-dependent manner and coordinates histone acetylation and DNA demethylation at SEs. Tex10 activity is also important for pluripotency and reprogramming in human cells. Our study therefore highlights Tex10 as a core component of the pluripotency network and sheds light on its role in epigenetic control of SE activity for cell fate determination.

Role of Tet1 and 5-hydroxymethylcytosine in cocaine action

Ten-eleven translocation (TET) enzymes mediate the conversion of 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC), which is enriched in brain, and its ultimate DNA demethylation. However, the influence of TET and 5hmC on gene transcription in brain remains elusive. We found that ten-eleven translocation protein 1 (TET1) was downregulated in mouse nucleus accumbens (NAc), a key brain reward structure, by repeated cocaine administration, which enhanced behavioral responses to cocaine. We then identified 5hmC induction in putative enhancers and coding regions of genes that have pivotal roles in drug addiction. Such induction of 5hmC, which occurred similarly following TET1 knockdown alone, correlated with increased expression of these genes as well as with their alternative splicing in response to cocaine administration. In addition, 5hmC alterations at certain loci persisted for at least 1 month after cocaine exposure. Together, these reveal a previously unknown epigenetic mechanism of cocaine action and provide new insight into how 5hmC regulates transcription in brain in vivo.

Analytical tools and current challenges in the modern era of neuroepigenomics

Over the past decade, rapid advances in epigenomics research have extensively characterized critical roles for chromatin regulatory events during normal periods of eukaryotic cell development and plasticity, as well as part of aberrant processes implicated in human disease. Application of such approaches to studies of the CNS, however, is more recent. Here we provide a comprehensive overview of available tools for analyzing neuroepigenomics data, as well as a discussion of pending challenges specific to the field of neuroscience. Integration of numerous unbiased genome-wide and proteomic approaches will be necessary to fully understand the neuroepigenome and the extraordinarily complex nature of the human brain. This will be critical to the development of future diagnostic and therapeutic strategies aimed at alleviating the vast array of heterogeneous and genetically distinct disorders of the CNS.

Chronic cocaine-regulated epigenomic changes in mouse nucleus accumbens

BACKGROUND

Increasing evidence supports a role for altered gene expression in mediating the lasting effects of cocaine on the brain, and recent work has demonstrated the involvement of chromatin modifications in these alterations. However, all such studies to date have been restricted by their reliance on microarray technologies that have intrinsic limitations.

RESULTS

We use next generation sequencing methods, RNA-seq and ChIP-seq for RNA polymerase II and several histone methylation marks, to obtain a more complete view of cocaine-induced changes in gene expression and associated adaptations in numerous modes of chromatin regulation in the mouse nucleus accumbens, a key brain reward region. We demonstrate an unexpectedly large number of pre-mRNA splicing alterations in response to repeated cocaine treatment. In addition, we identify combinations of chromatin changes, or signatures, that correlate with cocaine-dependent regulation of gene expression, including those involving pre-mRNA alternative splicing. Through bioinformatic prediction and biological validation, we identify one particular splicing factor, A2BP1(Rbfox1/Fox-1), which is enriched at genes that display certain chromatin signatures and contributes to drug-induced behavioral abnormalities. Together, this delineation of the cocaine-induced epigenome in the nucleus accumbens reveals several novel modes of regulation by which cocaine alters the brain.

CONCLUSIONS

We establish combinatorial chromatin and transcriptional profiles in mouse nucleus accumbens after repeated cocaine treatment. These results serve as an important resource for the field and provide a template for the analysis of other systems to reveal new transcriptional and epigenetic mechanisms of neuronal regulation.

ngs.plot: Quick mining and visualization of next-generation sequencing data by integrating genomic databases

BACKGROUND

Understanding the relationship between the millions of functional DNA elements and their protein regulators, and how they work in conjunction to manifest diverse phenotypes, is key to advancing our understanding of the mammalian genome. Next-generation sequencing technology is now used widely to probe these protein-DNA interactions and to profile gene expression at a genome-wide scale. As the cost of DNA sequencing continues to fall, the interpretation of the ever increasing amount of data generated represents a considerable challenge.

RESULTS

We have developed ngs.plot - a standalone program to visualize enrichment patterns of DNA-interacting proteins at functionally important regions based on next-generation sequencing data. We demonstrate that ngs.plot is not only efficient but also scalable. We use a few examples to demonstrate that ngs.plot is easy to use and yet very powerful to generate figures that are publication ready.

CONCLUSIONS

We conclude that ngs.plot is a useful tool to help fill the gap between massive datasets and genomic information in this era of big sequencing data.

The efficacy and safety of zibotentan in the treatment of castration-resistant prostate cancer: a meta-analysis

OBJECTIVE

Recently, novel endothelins like zibotentan and atrasentan and other novel taxanes have been introduced to treat prostate cancer. This study reviews zibotentan in the treatment of castration-resistant prostate cancer (CRPC) and derives a more precise estimate of their effect of treatment.

MATERIALS AND METHODS

Two reviewers searched and extracted data of the published trials and review articles on zibotentan for prostate cancer using the Medline, Embase and Cochrane Controlled Trials Register database. We used hazard ratios (HRs) to assess the effects on overall survival (OS), progression-free survival (PFS), or time to PSA progression (TTP), and relative risk (RR) for the different types of toxicity. Four randomized controlled trials were identified.

RESULTS

The pooled HR showed that zibotentan did not improve OS and PFS (HR = 0.92, 95%CI = 0.82-1.03, p = 0.161, HR = 0.98, 95% CI = 0.89-1.08, p = 0.714). Zibotentan had modest benefits on TTP (HR = 0.94, 95% CI = 0.91-0.97, p = 0.001). In addition, zibotentan led to more peripheral edema, anemia, cardiac failure and pneumonia.

CONCLUSIONS

Our study concludes that zibotentan is not an attractive option for CRPC patients. However, additional studies on other novel therapies are needed to improve patient outcomes.

Targeting microRNAs to modulate TRAIL-induced apoptosis of cancer cells

MicroRNAs (miRNAs) are endogenously expressed small non-coding RNAs, which are evolutionarily conserved and function as regulators of gene expression. These molecules are involved in numerous biological processes including differentiation, development, proliferation and apoptosis. Further investigation identifies that miRNAs may act as either potent oncogenes or tumor-suppressor genes, linking to cancer initiation and progression. Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL), as a member of the TNF family, is an attractive therapeutic target in cancer because it directly induces tumor cell apoptosis and has no cytotoxicity to normal cell types in vitro or in vivo. However, the resistance to TRAIL-induced apoptosis limits its clinical effectiveness. Interestingly, several studies convincingly demonstrate a role of miRNAs in modulating sensitive/resistant phenotypes to TRAIL. Here, we review the current findings about miRNAs involved in TRAIL-induced apoptosis in different cancers.

IL-10 polymorphisms and prostate cancer risk: a meta-analysis

Evidence is accumulating that chronic inflammation may have an important role in prostate cancer (PCa). Three common polymorphisms in the promoter of interleukin-10 (IL-10) gene, -1082 A>G, -819 C>T and -592 C>A, have been implicated to alter the risk of PCa, but the results of relative studies are inconclusive or controversial. To derive a more precise estimation of the relationship, we performed an updated meta-analysis on the basis of 10 studies. A comprehensive search was conducted to examine all the eligible studies of IL-10 polymorphism and PCa risk. We used odds ratios (ORs) to assess the strength of the association, and 95% confidence intervals (CIs) give a sense of the precision of the estimate. Overall, there were no significant associations between increased risk of PCa and IL-10 -1082 A>G, -819 C>T and -592 C>A polymorphisms. However, meta-analysis suggested that IL-10 -819 C>T and -592 C>A polymorphisms might be modestly associated with PCa aggressiveness (T versus C, OR=1.162, 95% CI: 1.035-1.305, P=0.011; A versus C, OR=1.131, 95% CI: 1.012-1.264, P=0.030; respectively). IL-10 -819 C>T and -592 C>A polymorphisms might impact PCa progression. Variant alleles at both -819 and -592 were modestly associated with advanced stages of PCa. Additional well-designed studies are warranted to validate these findings.

BRCA1a has antitumor activity in TN breast, ovarian and prostate cancers

Breast cancer gene 1 (BRCA1) mutations predispose women to breast and ovarian cancers and men to increased risks for prostate cancer. We have previously showed BRCA1 splice variant BRCA1a/p110 to induce apoptosis of human breast cancer cells. In the current study, stable expression of BRCA1a/p110 resulted in inhibition of growth of estrogen receptor (ER)-positive and triple-negative (TN) human breast, ovarian, prostate and colon cancer cells and mouse fibroblast cells. Similar to wild-type BRCA1, only those cells with wild-type Rb were sensitive to BRCA1a-induced growth suppression and the status of p53 did not affect the ability of BRCA1a to suppress growth of tumor cells. BRCA1a also significantly inhibited tumor mass in nude mice bearing human CAL-51 TN breast cancer, ES-2 ovarian cancer and PC-3 prostate cancer xenografts. These results suggest that the majority of exon 11 sequences (residues 263-1365) are not required for the tumor suppressor function of BRCA1 proteins. This is the first report demonstrating antitumor activity of BRCA1a in human ER-positive and TN breast, hormone-independent ovarian and prostate cancer cells. Currently, there are no effective treatments against TN breast cancers and results from these studies will provide new treatments for one of the biggest needs in breast cancer research.

Structures and relative stability of medium-sized silicon clusters. V. Low-lying endohedral fullerenelike clusters Si31–Si40 and Si45

We have performed unconstrained search for low-lying structures of medium-sized silicon clusters Si(31)-Si(40) and Si(45), by means of the minimum-hopping global optimization method coupled with a density-functional based tight-binding model of silicon. Subsequent geometric optimization by using density-functional theory with the PBE, BLYP, and B3LYP functionals was carried out to determine the relative stability of various candidate low-lying silicon clusters obtained from the unconstrained search. The low-lying characteristics of these clusters can be affirmed by comparing the binding energies per atom of these clusters with previously determined lowest-energy clusters(Si(n)) in the size range of 21</=n</=30. In view of the fact that there exist numerous low-lying "endohedral fullerenelike" isomers for each size in the range 30</=n</=40, we used the homologue carbon-fullerene cage to classify different families of isomers. This structural classification allows us to focus on generic features of various isomers and to group many apparently different isomers into a single family. In addition, we report a new family of low-lying clusters which have "Y-shaped three-arm" structures. Isomers in this "handmade" family can be energetically competitive as the endohedral fullerene isomers when the total energies are calculated with the BLYP or B3LYP functional.

The regulation of cell migration by PTEN

In vertebrates, the tumour suppressor PTEN (phosphatase and tensin homologue deleted on chromosome 10) regulates many cellular processes through its PtdIns(3,4,5)P3 lipid phosphatase activity, antagonizing PI3K (phosphoinositide 3-kinase) signalling. Given the important role of PI3Ks in the regulation of directed cell migration and the role of PTEN as an inhibitor of migration, it is somewhat surprising that data now indicate that PTEN is able to regulate cell migration independent of its lipid phosphatase activity. Here, we discuss the role of PTEN in the regulation of cell migration.

[Effects of selective RAR or/and RXR retinoids on the proliferation and differentiation of NB4 cells and their mechanisms]

OBJECTIVE

To investigate the effects of RARbeta selective agonist and RARalpha antagonist (RARbeta +/RARalpha -) BMS453 in combination with RXR selective agonist (RXR+) BMS649 on the proliferation and differentiation of NB4 cells, and illustrate the mechanism.

METHODS

The proliferation and differentiation of NB4 cells were detected by cell count, morphological observation, NBT reduction assay, immunofluorescence analysis, flow cytometry and RT-PCR.

RESULTS

BMS453 in combination with BMS649 could significantly inhibited the growth of NB4 cell in the manner of dose and time dependence. NB4 cells treated with BMS453 and BMS649 were irreversibly committed to morphologically and functionally more differentiated granulocytic cells. When NB4 cells were treated with BMS453 and BMS649 for 0, 1, 3, 12, 24 and 48 h, RARalpha, RARbeta and RXRalpha expressions were up regulated at 1 h and 3h, respectively. As compared to ATRA, the situations had no significant difference. In contrast, BMS453 or BMS649 alone was ineffective on NB4 cells.

CONCLUSION

BMS453 (RARbeta+/RARalpha-) in combination with BMS649 (RXR+) significantly and synergistically inhibit proliferation of NB4 cells and induce them into granulocytic differentiation, the mechanism of which may be mediated by the AF-2 activity of RXR.

Identification of the subcellular localization of daunorubicin in multidrug-resistant K562 cell line

We examined the subcellular distribution of daunorubicin (DNR) in resistant K562 cell line which overexpress the P-glycoprotein by confocal laser scanning microscopy. Three fluorescent probes - Rhodamine123, neutral red, NBD-ceramide, which stain the mitochondria, lysosomes, Golgi apparatus respectively, were used to identify the nature of the subcellular compartment sequestering daunorubicin. In sensitive k562 cell line, nuclear and cytoplasmic DNR fluorescence was intense and diffuse. In contrast, resistant K562 cell line showed a different DNR distribution. A bright fluorescence signal was located in the perinuclear region and peripheral plasma, the nucleus and other cytoplasmic region appear as empty, as suggested by the distribution of fluorescent probe Rhodamine123 specifically for mitochondria. Verapamil, an effective resistance modulator in P-glycoprotein MDR cells, restored the DNR distribution closer to that in the parent cells. Golgic inhibitor brefeldin A and lysosomotropic agent chloroquine had little effect on drug sequestration. Our studies demonstrate that daunorubicin may be sequestered in mitochondrial compartment in the resistant cells and P-glycoprotein plays an important role on mediating DNR transport.

[Altered subcellular distribution of daunorubicin in the non-P-glycoprotein-mediated multidrug-resistant cell line HL-60/ADR]

OBJECTIVE

To investigate DNR subcellular distribution in the non-P-glycoprotein-mediated multidrug-resistant cell line HL-60/ADR and its relation to multidrug resistance.

METHODS

DNR subcellular disposition was studied by confocal scanning laser microscopy, fluorescent methods, MTT and RT-PCR. The effects of verapamil, brefeldin A, chloroquine were also examined.

RESULTS

In the drug-sensitive cell line HL-60 DNR fluorescence distributed evenly in the nucleus and cytoplasm, while in the resistant cell line DNR distributed in a punctate pattern in the cytoplasm and was reduced in the nucleus. Verapamil, brefeldin A, but not chloroquine could recover the intracellular distribution of DNR from punctate to even in the resistant cell line.

CONCLUSION

Altered subcellular disposition of DNR in resistant cell line was involved in the mechanism of multidrug resistance.

A clinical study of yi zhi capsules in prevention of vascular dementia

The raised score in the revised Hasegawa dementia scales (HDS) demonstrated that the effect of Yi Zhi Capsules (YZC) in treating loss of intellectual function after cerebrovascular diseases was significantly better than that of the western drug Piracetam [symbol: see text] (P < 0.01). The morbidity of vascular dementia was much lower in the treatment group than that of the control group (P < 0.05) after a one-year follow-up; and the blood lipid level and some indexes in rheological examinations were also improved significantly (P < 0.05, or < 0.01). The data indicate that YZC is a relatively good preparation for prevention of vascular dementia.

[Experimental study on multi-infarct dementia treated with reinforcing essence to refresh mental activity method]

OBJECTIVE

To explore the mechanism of multi-infarct dementia (MID) treated with reinforcing essence to refresh mental activity method (RERM).

METHODS

MID rat models were established by injecting sterile dry blood clots into common carotid artery and screening by the first jumping-off latency of diving platform reflex. Effect of RERM on model rats in learning, memory, serum and brain malondialdehyde (MDA), superoxide dismutase (SOD) level, brain monoamine neurotransmitter content, and brain morphosis were observed.

RESULTS

Obvious malfunction of learning and memory was found in MID rat models, and there were also significant decreasing of monoamine neurotransmitters content in partial brain zones, decreasing of SOD activity in brain and increasing of MDA content in serum and brain. RERM could obviously improve learning and memory, raise SOD activity and monoamine neurotransmitters content in brain tissue, lower MDA content in serum and brain of MID rat models, protect brain morphosis of multi-infarction rats.

CONCLUSION

RERM might treat MID by restraining lipid peroxidation, improving monoamine neurotransmitters content in partial brain zones and decreasing ischemic damage of brain tissue.

The second BRCT domain of BRCA1 proteins interacts with p53 and stimulates transcription from the p21WAF1/CIP1 promoter

Inherited mutations in the breast and ovarian cancer susceptibility gene BRCA1 are associated with high risk for developing breast and ovarian cancers. Several studies link BRCA1 to transcriptional regulation, DNA repair, apoptosis and growth/tumor suppression. BRCA1 associates with p53 and stimulates transcription in both p53 dependent and p53-independent manners. BRCA1 splice variants BRCA1a (p110) and BRCA1b (p100) associates with CBP/p300 co-activators. Here we show that BRCA1a and BRCA1b proteins stimulate p53-dependent transcription from the p21WAF1/CIP1 promoter. In addition, the C-terminal second BRCA1 (BRCT) domain is sufficient for p53 mediated transactivation of the p21 promoter. Previous studies emphasized the importance of the BRCT domain, which shows homology with p53 binding protein (53BP1), in transcriptional activation, growth inhibition and tumor suppression. Our findings demonstrate an additional function for this domain in protein-protein interaction and co-activation of p53. We also found that BRCA1a and BRCA1b proteins interact with p53 in vitro and in vivo. The p53 interaction domain of BRCA1a/1b maps, in vitro, to the second BRCT domain (aa 1760-1863). The BRCT domain binds to the central domain of p53 which is required for sequence specific DNA binding. These results demonstrate for the first time the presence of a second p53 interaction domain in BRCA1 proteins and suggests that BRCA1a and BRCA1b proteins, like BRCA1, function as p53 co-activators. This BRCT domain also binds in vitro to CBP. These results suggest that one of the mechanisms by which BRCA1 proteins function is through recruitment of CBP/p300 associated HAT/FAT activity for acetylation of p53 to specific promoters resulting in transcriptional activation.

Induction of apoptosis by Elk-1 and deltaElk-1 proteins

Elk-1, an ets related gene codes for at least two splice variants Elk-1, which regulates c-fos transcription and deltaElk-1, both of which function as transcriptional activators. To investigate the role of Elk-1 and deltaElk-1 proteins in apoptosis; we have developed rat fibroblast cell lines and human breast cancer cell lines expressing Elk-1 and deltaElk-1. The expression of Elk-1 and deltaElk-1 proteins in the Elk-1/deltaElk-1 transfectants were analysed by immunofluorescence, immunohistochemistry, and Western blot analysis. The Elk-1 unlike deltaElk-1 transfectants showed a shortened and flattened morphology compared to the parental cells. We have found that calcium ionophore treatment of Rat-1 Elk-1, MCF-7 Elk-1, Rat-1 deltaElk-1 and MCF-7 deltaElk-1 transfectants resulted in programmed cell death. These results indicate that constitutive expression of Elk-1 and deltaElk-1 proteins triggers apoptosis in Rat-1 fibroblasts and breast cancer cells when treated with calcium ionophore.

BRCA1 splice variants BRCA1a and BRCA1b associate with CBP co-activator

The tumor suppressor gene BRCA1, is a nuclear phosphoprotein which associates with RNA polymerase II holoenzyme. CBP is a component of the holoenzyme. Previously, we have characterized two new BRCA1 splice variants BRCA1a/p110 and BRCA1b/p100. In the present study, the carboxy-terminal domain of transcription factor CBP interacts both in vivo and in vitro with full length BRCA1a and BRCA1b proteins as demonstrated by mammalian two- hybrid assays, co-immunoprecipitation/western blot studies, GST binding assays and histone acetyl transferase (HAT) assays of BRCA1 immunoprecipitates from human breast cancer cells. Our results suggest that one of the mechanisms by which BRCA1 proteins function is through recruitment of CBP associated HAT/FAT (transcription factor acetyl-transferase) activity for acetylation of either themselves or general transcription factors or both to specific promoters resulting in transcriptional activation.

BRCA1 proteins are transported to the nucleus in the absence of serum and splice variants BRCA1a, BRCA1b are tyrosine phosphoproteins that associate with E2F, cyclins and cyclin dependent kinases

BRCA1, a familial breast and ovarian cancer susceptibility gene encodes nuclear phosphoproteins that function as tumor suppressors in human breast cancer cells. Previously, we have shown that overexpression of a BRCA1 splice variant BRCA1a accelerates apoptosis in human breast cancer cells. In an attempt to determine whether the subcellular localization of BRCA1 is cell cycle regulated, we have studied the subcellular distribution of BRCA1 in asynchronous and growth arrested normal, breast and ovarian cancer cells using different BRCA1 antibodies by immunofluorescence and immunohistochemical staining. Upon serum starvation of NIH3T3, some breast and ovarian cancer cells, most of the BRCA1 protein redistributed to the nucleus revealing a new type of regulation that may modulate the activity of BRCA1 gene. We have also characterized two new variant BRCA1 proteins (BRCA1a/p110 and BRCA1b/ p100) which are phosphoproteins containing phosphotyrosine. Immunofluorescence and Western blotting analysis indicate cytoplasmic and nuclear localization of BRCA1a and BRCA1b proteins. To elucidate the biological function of BRCA1, we created a bacterial fusion protein of glutathione-transferase (GST) and BRCA1 zinc finger domain and detected two cellular proteins with molecular weights of approximately 32 and 65 kD, one of which contains phosphotyrosine designated p32 and p65 BRCA1 interacting proteins (BIP) that specifically interact with BRCA1. Western blot analysis of BIP with cyclins/CDKs and E2F antisera indicated association with cdc2, cdk2, cdk4, cyclin B, cyclin D, cyclin A and E2F-4 but not with cdk3, cdk5, cdk6, E2F-1, E2F-2, E2F-3, E2F-5 and cyclin E. Furthermore, we have also demonstrated a direct interaction of in vitro translated BRCA1a and BRCA1b proteins with recombinant cyclin A, cyclin B1, cyclin D1, cdc2, cdk2 and E2F fusion proteins in vitro. Taken together these results seem to suggest that BRCA1 could be an important negative regulator of cell cycle that functions through interaction with E2F transcriptional factors and phosphorylation by cyclins/cdk complexes with the zinc ring finger functioning as a major protein-protein interaction domain. If the interactions we observe in vitro is also seen in vivo then it may be possible that lack or impaired binding of the disrupted BRCA1 proteins to E2F, cyclins/CDKs in patients with mutations in the zinc finger domain could deprive the cell of an important mechanism for braking cell proliferation leading to the development of breast and ovarian cancers.

Induction of apoptosis by the tumor suppressor protein BRCA1

The breast and ovarian cancer susceptibility gene BRCA1, is a nuclear phosphoprotein which functions as a tumor suppressor. To investigate the role of BRCA1 in apoptosis, we have developed mouse fibroblast cell lines and human breast cancer cell lines expressing BRCA1. The expression of BRCA1 protein in the BRCA1 transfectants were analysed by immunofluorescence and immunohistochemistry. The BRCA1 transfectants showed a flattened morphology compared to the parental cells. We show that serum deprivation or calcium ionophore treatment of BRCA1 transfectants resulted in programmed cell death. These results indicate that BRCA1 genes may play a critical role in the regulation of apoptosis. Thus, since a wide variety of human malignancies like breast and ovarian cancers have a decreased ability to undergo apoptosis, this could be due to lack/decreased levels of functional BRCA1 proteins. Treatments that are aimed at increasing the apoptotic threshold by BRCA1 gene therapy may have the potential to prevent the progression of these malignancies.

Antisense RNA to the putative tumor suppressor gene BRCA1 transforms mouse fibroblasts

Recently, BRCA1, a familial breast and ovarian cancer susceptible gene has been cloned and shown to be either lost or mutated in families with breast and ovarian cancers. BRCA1 has been postulated to encode a tumor suppressor, a protein that acts as a negative regulator of tumor growth. We have characterized the BRCA1 gene products by Western blot and immunoprecipitation analysis in mouse and tumor cells. Multiple BRCA1 polypeptides of approximately 225, 185, 160, 145, 100, 52 and 38 kD were identified in these cells. BRCA1 proteins were found to be localized mainly in the nucleus of normal Rat1 cells and human breast cancer cells. In order to understand the role of BRCA1 in cell transformation, we have established a stable NIH3T3 cell line expressing BRCA1 antisense RNA. The inhibition of expression of endogenous BRCA1 protein was detected in NIH3T3 transfectants by Western blot analysis. The antisense BRCA1 expressing NIH3T3 cells showed accelerated growth rate, anchorage independent growth and tumorigenicity in nude mice unlike the parental and sense transfectants. These results provide the first direct biological evidence for the possible function of BRCA1 as a tumor suppressor gene.

The study of health effects of vinyl chloride air pollution on population

A series of indicators, including serum lysozyme activity, G-banding chromosome aberration (G-banding CA) analysis, sister chromatid exchanges (SCEs), chromosome aberration (CA), T-lymphocyte transformation rate (TcTR), gamma-GT, GPT and AKP, were employed in the present survey among occupationally vinyl chloride (VC) exposed workers and inhabitants living in VC polluted area in a polyvinyl chloride (PVC) factory. The results showed that the serum lysozyme (S-LZM) activities in Group 3 (adult inhabitants exposed to 0.20 mg/m3 VC for at least 8 years), Group 2 (workers exposed to 4.1 mg/m3 for at least 7 years occupationally), Group 1 (workers exposed to 25.7 mg/m3 for at least 2 years) were significantly higher than control. G-banding CA analysis showed that the total chromosome breakage rates in both Groups 1 and 2 were higher, but no difference existed between Group 3 and control. Only Group 1 was observed having higher SCEs, CA level and lower TcTR than control. AKP levels in Groups 1 and 2 were higher than control, but no gamm-GT and GPT differences were found among groups. The study also suggests that G-banding CA analysis is more sensitive than CA and SCEs.

Heparin potentiation of the effect of acidic fibroblast growth factor on astrocytes and neurons

Acidic fibroblast growth factor (aFGF) could stimulate the proliferation of astrocytes and promote the survival of neurons from newborn rat brain in vitro. The effects of aFGF on both astrocytes and neurons were significantly potentiated by heparin. The effect of aFGF (2 ng/ml) with heparin (10 mu g/ml) on the survival of neurons was a hundredfold more potent than that of aFGF (200 ng/ml) without heparin.

7S nerve growth factor has different biological activity from 2.5S nerve growth factor in vitro

It is considered that two molecular forms of nerve growth factor (NGF), that is 7S NGF and 2.5S NGF have the identical neurotrophic effect on neurons. We now report that 7S NGF has different biological activities from 2.5S NGF in vitro. 7S NGF could promote the survival and neurite outgrowth of neurons from newborn rat hippocampus, cortex and cerebellum and stimulate the proliferation of astrocytes in vitro, but 2.5S NGF had no such effect.