Preventing cancer through tobacco and infection control: how many lives can we save in the next 10 years?

Virome assembly and annotation in brain tissue based on next-generation sequencing

The glioblastoma multiforme (GBM) is one of the deadliest tumors. It has been speculated that virus plays a role in GBM but the evidences are controversy. Published researches are mainly limited to studies on the presence of human cytomegalovirus (HCMV) in GBM. No comprehensive assessment of the brain virome, the collection of viral material in the brain, based on recently sequenced data has been performed. Here, we characterized the virome from 111 GBM samples and 57 normal brain samples from eight projects in the SRA database by a tested and comprehensive assembly approach. The annotation of the assembled contigs showed that most viral sequences in the brain belong to the viral family Retroviridae. In some GBM samples, we also detected full genome sequence of a novel picornavirus recently discovered in invertebrates. Unlike previous reports, our study did not detect herpes virus such as HCMV in GBM from the data we used. However, some contigs that cannot be annotated with any known genes exhibited antibody epitopes in their sequences. These findings provide several avenues for potential cancer therapy: the newly discovered picornavirus could be a starting point to engineer novel oncolytic virus; and the exhibited antibody epitopes could be a source to explore potential drug targets for immune cancer therapy. By characterizing the virosphere in GBM and normal brain at a global level, the results from this study strengthen the link between GBM and viral infection which warrants the further investigation.

Statistical projection methods for lung cancer incidence and mortality: a systematic review

OBJECTIVES

To identify and summarise all studies using statistical methods to project lung cancer incidence or mortality rates more than 5 years into the future.

STUDY TYPE

Systematic review.

METHODS

We performed a systematic literature search in multiple electronic databases to identify studies published from 1 January 1988 to 14 August 2018, which used statistical methods to project lung cancer incidence and/or mortality rates. Reference lists of relevant articles were checked for additional potentially relevant articles. We developed an organisational framework to classify methods into groups according to the type of data and the statistical models used. Included studies were critically appraised using prespecified criteria.

RESULTS

One hundred and one studies met the inclusion criteria; six studies used more than one statistical method. The number of studies reporting statistical projections for lung cancer increased substantially over time. Eighty-eight studies used projection methods, which did not incorporate data on smoking in the population, and 16 studies used a method which did incorporate data on smoking. Age-period-cohort models (44 studies) were the most commonly used methods, followed by other generalised linear models (35 studies). The majority of models were developed using observed rates for more than 10 years and used data that were considered to be good quality. A quarter of studies provided comparisons of fitted and observed rates. While validation by withholding the most recent observed data from the model and then comparing the projected and observed rates for the most recent period provides important information on the model's performance, only 12 studies reported doing this.

CONCLUSION

This systematic review provides an up-to-date summary of the statistical methods used in published lung cancer incidence or mortality projections. The assessment of the strengths of existing methods will help researchers to better apply and develop statistical methods for projecting lung cancer rates. Some of the common methods described in this review can be applied to the projection of rates for other cancer types or other non-infectious diseases.

Chemical Constituents of Thai Citrus hystrix and Their Antiausterity Activity against the PANC-1 Human Pancreatic Cancer Cell Line

Human pancreatic cancer cells have an extreme tolerance to nutrition starvation, enabling them to survive in a hypovascular tumor microenvironment. Searching for agents that preferentially inhibit cancer cell viability under nutrition starvation conditions is a novel antiausterity strategy in anticancer drug discovery. In the present study, a hexane extract of the peels of Citrus hystrix fruits showed preferential cytotoxicity against PANC-1 human pancreatic cancer cells using a nutrient-deprived medium. Phytochemical investigation of this bioactive extract led to the isolation of 10 coumarins (1-10) including a new furanocoumarin (1). The isolated compounds were tested for their preferential cytotoxic activity against three different human pancreatic cancer cell lines [PANC-1, MIA PaCa-2, and PSN-1]. Among these, bergamottin (7) was identified as the most active constituent. In real-time live imaging, 7 was found to induce cell shrinkage, membrane blebbing, and disintegration of organelles in PANC-1 cells. Bergamottin (7) was also found to inhibit PANC-1 cell migration and colony formation. Mechanistically, 7 inhibited key survival proteins in the Akt/mTOR signaling pathway. Bergamottin (7) and related compounds are potential antiausterity candidates for drug development against pancreatic cancer.

Bioassay-Guided Isolation and Evaluation of Antiproliferative Effects of (Z)-Ethylidene-4, 6-Dimethoxycoumaran-3-One from Pogostemon Quadrifolius (Benth.)

The aim of the study was to isolate and identify the major cytotoxic principle from plant leaves of Pogostemon quadrifolius (Benth.) and evaluate its antiproliferative potential against human cancer cells. Plant leaves were extracted sequentially with a soxhlet apparatus, using petroleum ether, chloroform and methanol solvents. Petroleum ether and chloroform extracts exhibited antiproliferative properties against Caco-2, HeLa, THP-1, MCF-7 and Jurkat E6-1cancer cell lines tested, but methanol extracts failed to exhibit such activity. The major antiproliferative principle from petroleum ether and chloroform extracts was isolated with the help of bioassay guided column chromatography. This cytotoxic compound was further analysed by UV, TLC, HPLC, LC-MS, GC-MS and NMR analyses and was identified to be novel: (Z)-ethylidene-4,6-dimethoxycoumaran-3-one (Compound 1). The half-maximal inhibitory concentrations for proliferation (IC₅₀) exhibited by compound 1 were 19.4, 23.1, 22.1, 35.9 and 8.32 µM against Caco-2, HeLa, THP-1, MCF-7 and Jurkat E6-1 cancer cell lines, respectively. Further experiments revealed that compound 1 triggered the apoptosis mode of cell death in cancer cell lines. Thus, the present study allowed isolation and identification of a novel cytotoxic natural compound, (Z)-ethylidene-4,6-dimethoxycoumaran-3-one, from plant leaves of P. quadrifolius (Benth.). Our pre-clinical study also indicated that compound 1 is particularly active in the acute T cell leukemia cell line (Jurkat E6-1) with potential for application as a chemotherapeutic agent in the future.

Mathematical Modeling in Tobacco Control Research: Initial Results From a Systematic Review

OBJECTIVES

The US Food and Drug Administration has expressed interest in using mathematical models to evaluate potential tobacco policies. The goal of this systematic review was to synthesize data from tobacco control studies that employ mathematical models.

METHODS

We searched five electronic databases on July 1, 2013 to identify published studies that used a mathematical model to project a tobacco-related outcome and developed a data extraction form based on the ISPOR-SMDM Modeling Good Research Practices. We developed an organizational framework to categorize these studies and identify models employed across multiple papers. We synthesized results qualitatively, providing a descriptive synthesis of included studies.

RESULTS

The 263 studies in this review were heterogeneous with regard to their methodologies and aims. We used the organizational framework to categorize each study according to its objective and map the objective to a model outcome. We identified two types of study objectives (trend and policy/intervention) and three types of model outcomes (change in tobacco use behavior, change in tobacco-related morbidity or mortality, and economic impact). Eighteen models were used across 118 studies.

CONCLUSIONS

This paper extends conventional systematic review methods to characterize a body of literature on mathematical modeling in tobacco control. The findings of this synthesis can inform the development of new models and the improvement of existing models, strengthening the ability of researchers to accurately project future tobacco-related trends and evaluate potential tobacco control policies and interventions. These findings can also help decision-makers to identify and become oriented with models relevant to their work.

Effects of High Doses of Vitamin C on Cancer Patients in Singapore: Nine Cases

Introduction Intravenous high-dose vitamin C therapy is widely used in naturopathic and integrative oncology; however, a study reviewing its effects has never been performed in Singapore. This article serves to document administration of supportive vitamin C therapy for cancer patients in Singapore.

METHODS

The clinical response of 9 cancer patients of differing stages to the regular administration of large doses (25-100 g/d) of intravenous vitamin C (IVC; ascorbic acid) is outlined. Tumor pathology and patient health were verified by doctors who do not practice vitamin C treatment.

RESULTS

Cases suggesting survival beyond prognosis, improvement in quality of life, safe coadministration with and improved tolerance of conventional therapy, and deterioration in clinical condition following withdrawal of vitamin C therapy are documented clinically. Some patients experience the Jarisch-Herxheimer reaction-the release of endotoxin from microorganism death resulting in pimples, fever, and body odor-for a few hours after the therapy, but these are resolved quickly with no lasting effects.

CONCLUSION

Randomized trials of IVC therapy are recommended because it has minimal side effects and has shown promising results.

Cytomegalovirus and glioma: putting the cart before the horse

In 1908, Oluf Bang and Vilhelm Ellerman laid the foundation for theory of oncoviruses by demonstrating that the avian erythroblastosis (a form of chicken leukaemia) could be transmitted by cell-free extracts. Since then, it has been shown very convincingly that viruses can directly cause several human cancers by various mechanisms. Epidemiological data imply that viruses are the second most important risk factor for cancer development in humans, exceeded only by tobacco consumption. Although the ability of certain viruses (hepatitis B and C, human papillomavirus, etc) to cause cancer has been time tested and proven scientifically, there are several other potential viral candidates whose role in oncogenesis is more controversial. One such controversial scenario involves the role of cytomegalovirus (CMV) in malignant gliomas, the most common form of primary brain tumour. CMV first attracted attention about a decade ago when CMV gene products were found in glioma tissue but not in normal brain. Since this initial observation, several different groups have shown an oncomodulatory effect of CMV; however, direct association between CMV infection and incidence of glioma is lacking. In this review, we will evaluate the evidence, both preclinical and clinical, regarding the possible role of CMV in gliomagenesis and maintenance. We will also critically evaluate the rationale for using antiviral drugs in the treatment of patients with glioma.

The landscape of viral expression and host gene fusion and adaptation in human cancer

Viruses cause 10–15% of all human cancers. Massively parallel sequencing has recently proved effective for uncovering novel viruses and virus–tumour associations, but this approach has not yet been applied to comprehensive patient cohorts. Here we screen a diverse landscape of human cancer, encompassing 4,433 tumours and 19 cancer types, for known and novel expressed viruses based on >700 billion transcriptome sequencing reads from The Cancer Genome Atlas Research Network. The resulting map confirms and extends current knowledge. We observe recurrent fusion events, including human papillomavirus insertions in RAD51B and ERBB2. Patterns of coadaptation between host and viral gene expression give clues to papillomavirus oncogene function. Importantly, our analysis argues strongly against viral aetiology in several cancers where this has frequently been proposed. We provide a virus–tumour map of unprecedented scale that constitutes a reference for future studies of tumour-associated viruses using transcriptome sequencing data.

Viruses contribute to the pathogenesis of certain cancers. Using massively parallel sequencing data from The Cancer Genome Atlas to analyse viral expression in 19 tumour types, Tang et al. both confirm and reject previously described viral associations and present new information on viral integration and host interaction.

Evaluating stem and cancerous biomarkers in CD15+CD44+ KYSE30 cells

Digestive system cancers are listed among the ten top causes of cancer-related death worldwide. Cancer stem cells (CSCs) are malignant cells that share some of their characteristics with normal stem cells, including self-renewal and multipotency, and also cancer cells, such as drug resistance and metastasis. Despite many reports on CSCs with digestive system origin, identification and characterization of esophageal CSCs have remained elusive. To examine the validity of routine SC, cancer cell and CSC markers in KYSE30 cells, derived from esophageal carcinoma, cells were first characterized by immunofluorescence and RT-PCR techniques, and then the significance of candidate biomarkers was evaluated in retinoic acid-treated cells by flow cytometry and/or real-time RT-PCR. Meanwhile, to study CD15 (a newly introduced CSC marker) expression in digestive tract cancers, human normal and tumoral tissues of esophagus, stomach, and colon were analyzed by immunohistochemistry. Using several experimental approaches, we show that CD44, but not CD15, could serve as a reliable marker for undifferentiated malignant squamous cells of esophagus. In conclusion, our study confirms the role of CD44 as a CSC marker in KYSE30 cells, an esophageal squamous cell carcinoma cell line, and for the first time indicates the expression of CD15 in non-neural stem-like cancer cells. Although the importance of CD15 was not indicated in diagnosis of digestive cancers, further studies are needed to better understand the biological identity and function of this molecule in non-neural malignancies.

Health of the world's adolescents: a synthesis of internationally comparable data

Adolescence and young adulthood offer opportunities for health gains both through prevention and early clinical intervention. Yet development of health information systems to support this work has been weak and so far lagged behind those for early childhood and adulthood. With falls in the number of deaths in earlier childhood in many countries and a shifting emphasis to non-communicable disease risks, injuries, and mental health, there are good reasons to assess the present sources of health information for young people. We derive indicators from the conceptual framework for the Series on adolescent health and assess the available data to describe them. We selected indicators for their public health importance and their coverage of major health outcomes in young people, health risk behaviours and states, risk and protective factors, social role transitions relevant to health, and health service inputs. We then specify definitions that maximise international comparability. Even with this optimisation of data usage, only seven of the 25 indicators, covered at least 50% of the world's adolescents. The worst adolescent health profiles are in sub-Saharan Africa, with persisting high mortality from maternal and infectious causes. Risks for non-communicable diseases are spreading rapidly, with the highest rates of tobacco use and overweight, and lowest rates of physical activity, predominantly in adolescents living in low-income and middle-income countries. Even for present global health agendas, such as HIV infection and maternal mortality, data sources are incomplete for adolescents. We propose a series of steps that include better coordination and use of data collected across countries, greater harmonisation of school-based surveys, further development of strategies for socially marginalised youth, targeted research into the validity and use of these health indicators, advocating for adolescent-health information within new global health initiatives, and a recommendation that every country produce a regular report on the health of its adolescents.

Perspectives for cancer prevention with natural compounds

Cancer is the second leading cause of death in the United States. Despite the estimated 565,650 deaths in 2008 of Americans as a result of cancer, it is mostly a preventable disease. Simply by modification of diet, maintenance of optimum body weight, and regular physical activity, 30% to 40% of all instances of cancer could be prevented. Modification of diet alone by increasing vegetable and fruit intake could prevent 20% or more of all cases of cancer and may potentially prevent approximately 200,000 cancer-related deaths annually. Because of their safety, low toxicity, antioxidant properties, and general acceptance as dietary supplements, fruits, vegetables, and other dietary elements (phytochemicals and minerals) are being investigated for the prevention of cancer. Extensive research over the past several decades has identified numerous dietary and botanical natural compounds that have chemopreventive potential. In this review, we discuss promising natural chemopreventive compounds, their molecular targets, and their mechanisms, which may help the further design and conduct of preclinical and clinical trials.