Profiling of the silica-induced molecular events in lung epithelial cells using the RNA-Seq approach.

Silicosis is a prolonged, irreversible and incurable occupational disease, and there is a significant number of newly diagnosed cases every year in Hong Kong. Due to the long latency of the disease, the diagnosis can be missed until detailed clinical examination at a later stage. For a better control of this deadly disease, detailing the pro-inflammatory and fibrotic events in the macrophage would be instrumental in understanding the pathogenesis of the disease and essential for the significant biomarkers discovery. In this in vitro study, human cell line model A549 lung epithelial cells were used. The immediate molecular events underneath the activation of quartz silica polymorphs were followed in a time course of 0, 0.5, 2, 8, 16 and 24 h. The transcriptome library was prepared and subjected to RNA-Seq analysis. Data analysis was performed by pathway analysis tools and verified by real-time PCR. The results showed that triggered genes were mainly found in the immune response and inflammatory pathways. An interesting finding was the association of the DNA-binding protein inhibitor (ID) family in the silica exposure to lung cells. The linkage of ID1, ID2 and ID3 to cancer may rationalize themselves to be the markers indicating an early response of silicosis. However, further studies are required to consolidate the roles of these genes in silicosis. Copyright © 2017 John Wiley & Sons, Ltd.

Rhodamine B-conjugated encrypted vipericidin nonapeptide is a potent toxin to zebrafish and associated with in vitro cytotoxicity.

BACKGROUND: Animal venoms contain a diverse array of proteins and enzymes that are toxic toward various physiological systems. However, there are also some practical medicinal uses for these toxins including use as anti-bacterial and anti-tumor agents. METHODS: In this study, we identified a nine-residue cryptic oligopeptide, KRFKKFFKK (EVP50) that is repeatedly encoded in tandem within vipericidin sequences. RESULTS: EVP50 displayed in vivo potent lethal toxicity to zebrafish larvae (LD50=6 µM) when the peptide's N-terminus was chemically conjugated to rhodamine B (RhoB). In vitro, RhoB-conjugated EVP50 (RhoB-EVP50) exhibited a concentration-dependent cytotoxic effect toward MCF-7 and MDA-MB-231 breast cancer cells. In MCF-7 cells, the RhoB-EVP50 nonapeptide accumulated inside the cells within minutes. In the cytoplasm, the RhoB-EVP50 induced extracellular calcium influx and intracellular calcium release. Membrane budding was also observed after incubation with micromolar concentrations of the fluorescent EVP50 conjugate. CONCLUSIONS: The conjugate's interference with calcium homeostasis, its intracellular accumulation and its induced membrane dysfunction (budding and vacuolization) seem to act in concert to disrupt the cell circuitry. Contrastively, unconjugated EVP50 peptide did not display neither toxic nor cytotoxic activities in our in vivo and in vitro models. GENERAL SIGNIFICANCE: The synergic mechanism of toxicity was restricted to the structurally modified encrypted vipericidin nonapeptide.

Association of genetic polymorphisms with psychological symptoms in cancer: A systematic review.

Cancer patients suffer from a repertoire of symptoms, including such psychological and psychiatric symptoms as anxiety, depression, and posttraumatic stress. Exploration of genetic factors that modify the risk and severity of these symptoms may facilitate the development of personalised care plans for managing these symptoms. This review aims to provide an overview on the variations in genes that may contribute to the occurrence and severity of anxiety, depression, and posttraumatic stress disorder (PTSD) among cancer patients. Literature search was performed in nine English and Chinese electronic databases, and extracted data are presented narratively. The reporting quality of the included studies was assessed using selected items of The STrengthening the REporting of Genetic Association (STREGA) checklist. Twenty-nine studies were included in the review. Most studies involved breast cancer patients, while patients of other cancer types appeared to be understudied. A number of studies reported the association between genes involved in inflammatory pathways and depression and anxiety. Other genes found to show associations with anxiety, depression, and PTSD among cancer patients are those involved in neurotrophic signalling, serotonergic signalling, regulation of stress response, antioxidation, dopamine catabolism and cellular apoptosis, despite some inconsistencies in findings between studies. Our review highlighted a need for further research for enhancing our knowledge on the association between genetic variations and anxiety, depression, and PTSD of patients of various cancer types. Future studies examining such associations in patients of various cancers should utilise standardised instruments for outcome assessments and stratify the patients based on their age for analysis.

Effects of a Rice Bran Dietary Intervention on the Composition of the Intestinal Microbiota of Adults with a High Risk of Colorectal Cancer: A Pilot Randomised-Controlled Trial.

Rice bran exhibits chemopreventive properties that may help to prevent colorectal cancer (CRC), and a short-term rice bran dietary intervention may promote intestinal health via modification of the intestinal microbiota. We conducted a pilot, double-blind, randomised placebo-controlled trial to assess the feasibility of implementing a long-term (24-week) rice bran dietary intervention in Chinese subjects with a high risk of CRC, and to examine its effects on the composition of their intestinal microbiota. Forty subjects were randomised into the intervention group (n = 19) or the control group (n = 20). The intervention participants consumed 30 g of rice bran over 24-h intervals for 24 weeks, whilst the control participants consumed 30 g of rice powder on the same schedule. High rates of retention (97.5%) and compliance (≥91.3%) were observed. No adverse effects were reported. The intervention significantly enhanced the intestinal abundance of Firmicutes and Lactobacillus, and tended to increase the Firmicutes/Bacteroidetes ratio and the intestinal abundance of Prevotella_9 and the health-promoting Lactobacillales and Bifidobacteria, but had no effect on bacterial diversity. Overall, a 24-week rice bran dietary intervention was feasible, and may increase intestinal health by inducing health-promoting modification of the intestinal microbiota. Further larger-scale studies involving a longer intervention duration and multiple follow-up outcome assessments are recommended.

Role of oxidative stress in clofazimine-induced cardiac dysfunction in a zebrafish model.

BACKGROUND: Clofazimine (CFZ), a riminophenazine, is now commonly used in the treatment of multidrug-resistant tuberculosis. However, its use may be potentially associated with cardiac dysfunction in some individuals. In this study, the zebrafish heart, by merit of its developmental and genetic characteristics being in homology with that of human, was chosen as an animal model for evaluation of such dysfunction. METHODS: Morphological and physiological parameters were used to assess cardiac dysfunction. Transcriptome analysis was performed, followed by validation with real-time quantitative PCR, for delineation of the relevant genomics. RESULTS: Exposure of 2 dpf zebrafish to 4 mg/L CFZ for 2 days, adversely affected cardiac functions including significant decreases in HR, SV, CO, and FS, with observable pathophysiological developments of pericardial effusion and blood accumulation in the heart, in comparison with the control group. In addition, genes which respond to xenobiotic stimulus, related to oxygen transport, glutathione metabolism and extracellular matrix -receptor interactions, were significantly enriched among the differentially up-regulated genes. Antioxidant response element motif was enriched in the 5000 base pair upstream regions of the differentially expressed genes. Co-administration of N-acetylcysteine was shown to protect zebrafish against the development of CFZ-induced cardiac dysfunction. CONCLUSIONS: This study suggests an important role of oxidative stress as a major pathogenetic mechanism of riminophenazine-induced cardiac dysfunction.

Process Evaluation and Experience Sharing on Utilizing Information Communication Technologies and Digital Games in a Large Community Family Health Event: Hong Kong Jockey Club SMART Family-Link Project.

Background: Information communication technologies (ICT) are increasingly used in health promotion, but integration is challenging and involves complex processes. Large community health promotion events are often held but the experiences and processes have rarely been evaluated and published. No reports have described and systematically evaluated an ICT-supported health promotion event using digital games. Objective: We evaluated the development and implementation of a large community family health promotion event with ICT integration to promote family happiness with collaboration between academia (The University of Hong Kong) and the social (family) service sector, and collected feedback from participants and social service workers. Methods: We (i) conducted a systematic process evaluation, (ii) administered an on-site questionnaire survey on participant satisfaction and feedback, and (iii) collected post-event qualitative feedback from social workers on using new technologies, digital game design and overall experiences. Results: Fourteen digital games were designed and run in booths at the event by 12 non-governmental social service organizations and academia. Four gaming technologies were utilized: chroma key (green screen), somatosensory (kinect and leap motion techniques), augmented reality and virtual reality. 1,365 participants joined the event, in which 1,257 from 454 families were recruited and pre-registered through 12 NGOs. About 39.3% were male and more than half (53.3%) were aged 18 years and above. About 3,487 game booth headcounts were recorded. Games using virtual reality, kinect motion and green screen technologies were most liked. The average game satisfaction score was high (4.5 out of 5). Social service workers reported positive experiences with using new technologies in health promotion, and interests in future collaborations involving more ICT. Conclusions: Our systematic evaluation showed successful integration of ICT components in the health promotion event. This event, most likely the first of its kind, served as a capacity building and knowledge transfer platform for interdisciplinary co-sharing and co-learning of new technologies. It provided a solid foundation for further academic and social service partnerships and should be a useful model for similar community events and their evaluation. Further development and integration of ICT for health promotion among social service organizations with comprehensive evaluation are warranted.

RNA-Seq revealed ATF3-regulated inflammation induced by silica.

BACKGROUND: Millions of workers are exposed to dust containing silica. Chronic and over-exposure to silica will lead to silicosis, which is an irreversible and sometimes fatal lung disease. The disordered physiological processes of silicosis consist of accumulation of silica particles in the alveoli of the lung. Then, the ingestion of the silica particles by macrophages was followed by an inflammatory response. Up till now, the chest radiographs remain the key tool in diagnosing and assessing the extent of silicosis. However, concerns exist regarding the sensitivity and specificity of the technique. Therefore, there is still a need to develop a biomarker for silicosis for early detection of silicosis. METHOD: In this study, RNA-Seq was applied to detect the gene expression changes when silica was exposed to macrophages at different time intervals. RNA-Seq provides a broader dynamic range, increased specificity and sensitivity, and easier detection of rare and low-abundance transcripts. Bioinformatics tools such as the Database for Annotation, Visualization and Integrated Discovery (DAVID) and Gene Functional Classification Tool and Search Tool for the Retrieval of Interacting Genes (STRING) were applied for data analysis. Quantitative PCR was used to validate the results. RESULTS: Our results showed that regulation of transcription factors was the dominant activated pathway in early exposure of silica to macrophages, followed by inflammatory responses which were the main mechanisms in silicosis. One of the findings was the upregulation of activating transcription factor 3 (ATF3) during silica exposure. When ATF3 expression was inhibited by siRNA, the production of cytokines IL-1ß, IL-6 and TNF was further increased. CONCLUSION: This indicated that ATF3 may be a potential early diagnostic biomarker for silicosis and ATF3 acts as a repressor in inflammatory responses induced by silica.

Suppression of cell proliferation and regulation of estrogen receptor alpha signaling pathway by arsenic trioxide on human breast cancer MCF-7 cells.

In recent years, breast cancers have aroused much concern. Together with a growing incidence all over the world, the development of drug resistance to tamoxifen, the most commonly prescribed chemotherapeutic drug for breast cancer patients, has highlighted the importance of developing a new chemotherapeutic drug in combating breast cancer. With the aim of treating breast cancers, the anti-tumor effects of arsenic trioxide in MCF-7 cells have been studied. MCF-7 cells are estrogen responsive cells which mimic breast cancers at the early stage. 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay and direct cell counting were used to measure cell proliferation. The mechanisms of action were elucidated through the measurement of estrogen receptor (ER) binding, mRNA and protein levels of ERalpha and its activity. We have demonstrated that arsenic trioxide was capable of reducing cell survival in MCF-7 cells via the suppression of the estrogen-induced growth stimulatory effects in MCF-7 cells. Arsenic trioxide was shown to suppress the action of estrogen through the regulation of the ERalpha signaling pathway. Arsenic trioxide could down-regulate ERalpha mRNA and protein levels without competing with estrogen for ERalpha binding. Arsenic trioxide also inhibited the transcription activity mediated by the ERalpha signaling pathway and ultimately it down-regulated c-myc protein expression and inhibited cell entry to S phase under estrogen's stimulation. In conclusion, arsenic trioxide could inhibit the growth of MCF-7 cells by reducing the growth stimulatory effect of estrogen. As estrogen is a primary risk factor in promoting the growth of breast tumor cells, the anti-estrogenicity exhibited by arsenic trioxide sheds light on the therapy of breast cancer.

Effect of arsenic trioxide on human hepatocellular carcinoma HepG2 cells: inhibition of proliferation and induction of apoptosis.

Arsenic trioxide (As(2)O(3)), a major ingredient of Traditional Chinese Medicine (TCM), is found to be an effective anticancer drug in acute promyelocytic leukemia (APL). The present study explored the use of As(2)O(3) on human hepatocellular carcinoma by in vitro study. The study showed that the clinically achievable concentration of As(2)O(3), i.e. 2 microM, inhibited the cell proliferation of human hepatocellular carcinoma cell line, HepG2, in a time-dependent manner. The mechanistic study showed that 2 microM of As(2)O(3) acted through induction of apoptosis in which caspase-3 was activated. The results also suggested that mitochondria did not take part in As(2)O(3)-induced apoptosis.

Distribution of melamine in rat foetuses and neonates.

Pharmacokinetics of melamine has not been studied in pregnancies despite of the many reports on the effect on renal damage in adult and neonates. In this study, Sprague-Dawley rats have been used as a model to study the single-dose effect of melamine administration in late pregnancy and in neonates within 24h. Melamine concentrations in maternal serum, breast milk, whole foetus, amniotic fluid, neonatal serum and neonatal kidney was measured by liquid chromatography coupled with mass spectrometry. Melamine was detected in all the samples, including foetal rats and amniotic fluid in utero. Melamine was able to pass through placenta and reach the foetus, and to accumulate in lactating mammary gland and neonatal kidney. Moreover, melamine was eliminated through the placenta of the foetus and the kidneys of the neonates, and later excreted into the amniotic fluid. The study characterised for the first time the distribution of melamine in foetuses and neonates, providing reference for toxicological study of melamine during pregnancy.

The 3a protein of severe acute respiratory syndrome-associated coronavirus induces apoptosis in Vero E6 cells.

An outbreak of severe acute respiratory syndrome (SARS) occurred in China and the first case emerged in mid-November 2002. The aetiological agent of this disease was found to be a previously unknown coronavirus, SARS-associated coronavirus (SARS-CoV). The detailed pathology of SARS-CoV infection and the host response to the viral infection are still not known. The 3a gene encodes a non-structural viral protein, which is predicted to be a transmembrane protein. In this study, it was shown that the 3a protein was expressed in the lungs and intestinal tissues of SARS patients and that the protein localized to the endoplasmic reticulum in 3a-transfected monkey kidney Vero E6 cells. In vitro experiments of chromatin condensation and DNA fragmentation suggested that the 3a protein may trigger apoptosis. These data showed that overexpression of a single SARS-CoV protein can induce apoptosis in vitro.

Inhibition of cell proliferation in human breast tumor cells by antisense oligonucleotides against facilitative glucose transporter 5.

In recent years, successful examples of antisense oligonucleotide (AS) therapy for genetic diseases have stimulated scientists to investigate its application on cancer diseases. AS can be used to down-regulate the mRNA and protein expression by annealing to specific region of the target mRNA which is responsible for the malignancy. Glucose transporter 5 (Glut5) is a tissue specific transporter that can be found on breast cancer tissues but not on normal breast tissues. Therefore, it is of clinical interest to investigate whether AS against Glut5 mRNA can tackle breast cancer. In this study, two cell lines, MCF-7 which is estrogen-receptor positive and MDA-MB-231 which is estrogen-receptor negative, were used to mimic breast cancer tissues at early and late stages, respectively. A 15-base sequence around the start codon of Glut5 was used. It was found that AS against Glut5 exerted anti-proliferative effect on both of these two breast tumor cell lines and seemed to exert its effect via the suppression of expression of Glut5 proteins in the cells. AS against Glut5 exhibited no effect on human hepatoma HepG2 cells which do not possess any Glut5. The results imply an alternative way in treating breast tumor as the AS against Glut5, unlike tamoxifen, takes effect on breast tumor cells via suppressing the expression of Glut5 that they specifically possess, and regardless whether the breast tumors are estrogen dependent or not.

Inhibition of cell proliferation and the action mechanisms of arsenic trioxide (As2O3) on human breast cancer cells.

Arsenic trioxide (As(2)O(3)) is one of the arsenic compounds found in nature. As(2)O(3) has recently been used to treat patients suffering from retinoic acid receptor (AML). It is of clinical interest to investigate whether As(2)O(3) is also effective in treating solid tumors. Here, we report that As(2)O(3) exhibited inhibitory effects on the proliferation of human breast cancer MCF-7 cells in a dose- and time-dependent manner. The 50% inhibitory concentration (IC(50)) of As(2)O(3) in inhibiting proliferation of MCF-7 cells were 8, 1.8, and 1.2 microM upon 1-, 2-, and 3-day treatment, respectively. In elucidating the underlying action mechanisms, the results of experiments concerning DNA fragmentation and externalization indicated that As(2)O(3) exerted its action on MCF-7 cells via apoptosis, whereas the result of flow cytometry also indicated that As(2)O(3) could induce mitochondrial mediated cell-cycle arrest at G(1) phase. Further studies by Western blot analysis indicated that As(2)O(3) regulated apoptosis and the expression of cell-cycle-related proteins as it upregulated p53 protein level and downregulated bcl-2 protein level. Results in present study indicated that As(2)O(3) might also be a good candidate for treating breast cancer.