Books on the topic 'Fos oncogenes'

This article focuses on the use of Bayesian concepts and methods in the trans-study projection of genomic biomarkers for the analysis of oncogene deregulation in breast cancer. The objective of the study is to determine the extent to which patterns of gene expression associated with experimentally induced oncogene pathway deregulation can be used to investigate oncogene pathway activity in real human cancers. This is often referred to as the in vitro to in vivo translation problem, which is addressed using Bayesian sparse factor regression analysis for model-based translation and refinement of in vitro generated signatures of oncogene pathway activity into the domain of human breast tumour tissue samples. The article first provides an overview of the role of oncogene pathway deregulation in human cancers before discussing the details of modelling and data analysis. It then considers the findings based on biological evaluation and Bayesian pathway annotation analysis.

It is obvious that the process of developing cancer—oncogenesis—is a multistep process. We know that smoking, obesity, and a family history are strong independent predictors of developing malignancy; yet, in clinics, we often see that some heavy smokers live into their nineties and that some people with close relatives affected by cancer spend many years worrying about a disease that, in the end, they never contract. For many centuries scientists have struggled to understand the process that make cancer cells different from normal cells. There were those in ancient times who believed that tumours were attributable to acts of the gods. Hippocrates suggested that cancer resulted from an imbalance between the black humour that came from the spleen, and the other three humours: blood, phlegm, and bile. It is only in the last 100 years that biologists have been able to characterize some of the pathways that lead to the uncontrolled replication seen in cancer, and subsequently examine exactly how these pathways evolve. The rampant nature by which cancer invades local and distant tissues, as well its apparent ability to spread between related individuals led some, such as Peyton Rous in 1910, to suggest that cancer was an infectious condition. He was awarded a Nobel Prize in 1966 for the 50 years of work into investigating a link between sarcoma in chickens and a retrovirus that became known as Rous sarcoma virus. He had shown how retroviruses are able to integrate sequences of DNA coding for errors in cellular replication control (oncogenes) by introducing into the human cell viral RNA together with a reverse transcriptase. Viruses are now implicated in many cancers, and in countries where viruses such as HIV and EBV are endemic, the high incidence of malignancies such as Kaposi’s sarcoma and Burkitt’s lymphoma is likely to be directly related. There are several families of viruses associated with cancer, broadly classed into DNA viruses, which mutate human genes using their own DNA, and retroviruses, like Rous sarcoma virus, which insert viral RNA into the cell, where it is then transcribed into genes. This link with viruses has not only led to an understanding that cancer originates from genetic mutations, but has also become a key focus in the design of new anticancer therapies. Traditional chemotherapies either alter DNA structure (as with cisplatin) or inhibit production of its component parts (as with 5-fluorouracil.) These broad-spectrum agents have many and varied side effects, largely due to their non-specific activity on replicating DNA throughout the body, not just in tumour cells. New vaccine therapies utilizing gene-coding viruses aim to restore deficient biological pathways or inhibit mutated ones specific to tumour cells. The hope is that these gene therapies will be effective and easily tolerated by patients, but development is currently progressing with caution. In a trial in France of ten children suffering from X-linked severe combined immunodeficiency and who were injected with a vector that coded for the gene product they lacked, two of the children subsequently died from leukaemia. Further analysis confirmed that the DNA from the viral vector had become integrated into an existing, but normally inactive, proto-oncogene, LM02, triggering its conversion into an active oncogene, and the development of life-threatening malignancy. To understand how a tiny change in genetic structure could lead to such tragic consequences, we need to understand the molecular biology of the cell and, in particular, to pay attention to the pathways of growth regulation that are necessary in all mammalian cell populations. Errors in six key regulatory pathways are known as the ‘hallmarks of cancer’ and will be discussed in the rest of this chapter.

Accumulating evidence indicates that cancer is a type of mitochondrial metabolic disease. Chronic damage to mitochondria causes a gradual shift in cellular energy metabolism from respiration to fermentation. Consequently, fermentable metabolites become the drivers of cancer. Mitochondrial injury can explain the long-standing “oncogenic paradox,” and all major hallmarks of cancer including genomic instability. Restriction of fermentable fuels therefore becomes a viable therapeutic strategy for cancer management. The ketogenic diet (KD) is a metabolic therapy that lowers blood glucose and elevates blood ketone bodies. Ketone bodies are a “super fuel” for functional mitochondria, but cannot be metabolized efficiently by tumor mitochondria. The efficacy of KDs for cancer management can be enhanced when used together with drugs and procedures (such as hyperbaric oxygen therapy) (that further target fermentation. Therapeutic ketosis can represent an alternative, nontoxic strategy for managing and preventing a broad range of cancers while reducing healthcare costs.

THE ROOTS of implementation science (IS) in cancer in some sense date back to the earliest days of uncovering cancer’s etiology, diagnosis, prevention, and treatment, although it was not called that. Indeed, unlocking the mysteries of cancer and determining effective ways to intervene began not in the lab but, rather, the clinic. As Mukherjee recounted in the seminal work, The Emperor of All Maladies, 1 cancer had been the subject of clinical examination for centuries, and the drive to optimize care began in those early days. As opposed to the largely separate worlds of research discovery and care delivery that exist today, scientific research and cancer treatment coexisted. In addition, epidemiologic observations of risk factors affecting oncogenesis developed targets for what types of prevention programs needed to be implemented. Naturally, the challenges of what exactly to implement and how best to implement have been with us throughout time.

This chapter discusses primary prevention measures that disrupt transmission of oncogenic infections. It begins by discussing vaccination against hepatitis B virus (HBV) and human papillomavirus (HPV), two major causes of cancer for which safe and effective vaccines are currently available. It briefly discusses the importance of treatment and prophylaxis against human immunodeficiency virus type 1 (HIV-1), which potentiates the virulence of other viral infections as well as directly increasing the incidence of non-Hodgkin lymphoma. It does not discuss the treatment of HBV or hepatitis C virus (HCV) infection, since these are considered in Chapters 25 and 33. Also beyond the scope of this chapter are the randomized clinical trials currently underway to assess the efficacy and feasibility of eradication of Helicobacter pylori (Chapters 24, 31), vaccination against Epstein-Barr virus (EBV) (Chapters 24, 26, 39), or the prevention of schistosomiasis and liver flukes (Chapters 24, 33, and 52).

Renal cell carcinoma (RCC) is the exemplar of how the understanding of the molecular pathogenesis of rare inherited disorders can inform an understanding of the key pathways involved in the pathogenesis of sporadic cancer. In this chapter we describe the clinical and pathological features of the inherited kidney cancer syndromes: von Hippel Lindau disease (VHL); Birt-Hogg-Dube syndrome; hereditary leiomyomatosis and renal cancer syndrome; succinate dehydrogenase disorders; hereditary papillary renal cancer; and translocation-associated kidney cancer. Though individually rare, recognition of individuals with familial kidney cancer is important as they present specific clinical challenges to the urological surgeon because of their propensity to develop multicentric/bilateral tumours. Furthermore, different familial RCC predisposition syndromes are associated with different extra renal clinical features and have specific surveillance needs. Despite differences in clinical features, there is some overlap in the molecular pathophysiology between the disorders and these highlight the key signalling pathways for RCC oncogenesis.

Any public debate about air pollution starts with the premise that air pollution cannot be good for you, so we should have less of it. However, it is much more difficult to determine how much is dangerous, and even more difficult to decide how much we are willing to pay for improvements in measured air pollution. Recent UK estimates suggest that fine particulate pollution causes about 6500 deaths per year, although it is not clear how many years of life are lost as a result. Some deaths may just be brought forward by a few days or weeks, while others may be truly premature. Globally, household pollution from cooking fuels may cause up to two million premature deaths per year in the developing world. The hazards of black smoke air pollution have been known since antiquity. The first descriptions of deaths caused by air pollution are those recorded after the eruption of Vesuvius in ad 79. In modern times, the infamous smogs of the early twentieth century in Belgium and London were clearly shown to trigger deaths in people with chronic bronchitis and heart disease. In mechanistic terms, black smoke and sulphur dioxide generated from industrial processes and domestic coal burning cause airway inflammation, exacerbation of chronic bronchitis, and consequent heart failure. Epidemiological analysis has confirmed that the deaths included both those who were likely to have died soon anyway and those who might well have survived for months or years if the pollution event had not occurred. Clean air legislation has dramatically reduced the levels of these traditional pollutants in the West, although these pollutants are still important in China, and smoke from solid cooking fuel continues to take a heavy toll amongst women in less developed parts of the world. New forms of air pollution have emerged, principally due to the increase in motor vehicle traffic since the 1950s. The combination of fine particulates and ground-level ozone causes ‘summer smogs’ which intensify over cities during summer periods of high barometric pressure. In Los Angeles and Mexico City, ozone concentrations commonly reach levels which are associated with adverse respiratory effects in normal and asthmatic subjects. Ozone directly affects the airways, causing reduced inspiratory capacity. This effect is more marked in patients with asthma and is clinically important, since epidemiological studies have found linear associations between ozone concentrations and admission rates for asthma and related respiratory diseases. Ozone induces an acute neutrophilic inflammatory response in both human and animal airways, together with release of chemokines (e.g. interleukin 8 and growth-related oncogene-alpha). Nitrogen oxides have less direct effect on human airways, but they increase the response to allergen challenge in patients with atopic asthma. Nitrogen oxide exposure also increases the risk of becoming ill after exposure to influenza. Alveolar macrophages are less able to inactivate influenza viruses and this leads to an increased probability of infection after experimental exposure to influenza. In the last two decades, major concerns have been raised about the effects of fine particulates. An association between fine particulate levels and cardiovascular and respiratory mortality and morbidity was first reported in 1993 and has since been confirmed in several other countries. Globally, about 90% of airborne particles are formed naturally, from sea spray, dust storms, volcanoes, and burning grass and forests. Human activity accounts for about 10% of aerosols (in terms of mass). This comes from transport, power stations, and various industrial processes. Diesel exhaust is the principal source of fine particulate pollution in Europe, while sea spray is the principal source in California, and agricultural activity is a major contributor in inland areas of the US. Dust storms are important sources in the Sahara, the Middle East, and parts of China. The mechanism of adverse health effects remains unclear but, unlike the case for ozone and nitrogen oxides, there is no safe threshold for the health effects of particulates. Since the 1990s, tax measures aimed at reducing greenhouse gas emissions have led to a rapid rise in the proportion of new cars with diesel engines. In the UK, this rose from 4% in 1990 to one-third of new cars in 2004 while, in France, over half of new vehicles have diesel engines. Diesel exhaust particles may increase the risk of sensitization to airborne allergens and cause airways inflammation both in vitro and in vivo. Extensive epidemiological work has confirmed that there is an association between increased exposure to environmental fine particulates and death from cardiovascular causes. Various mechanisms have been proposed: cardiac rhythm disturbance seems the most likely at present. It has also been proposed that high numbers of ultrafine particles may cause alveolar inflammation which then exacerbates preexisting cardiac and pulmonary disease. In support of this hypothesis, the metal content of ultrafine particles induces oxidative stress when alveolar macrophages are exposed to particles in vitro. While this is a plausible mechanism, in epidemiological studies it is difficult to separate the effects of ultrafine particles from those of other traffic-related pollutants.