Theories of carcinogenesis. An up to date review of theories of carcinogenesis.

Theories of carcinogenesis. We will first compare the merits of what we consider the 2 main theories of carcinogenesis, namely, the still hegemonic SMT and the more recently proposed tissue organization field theory (TOFT) (see Table 1). Within this perspective, what matters both in morphogenesis and carcinogenesis is not only molecules, but also biophysical forces generated by cells and tissues. 1. Historical Perspective Apr 29, 2019 · The Multi-Stage Model of Carcinogenesis (MMC), developed in the 1950 s-70s, postulated carcinogenesis as a Darwinian somatic selection process. Apr 1, 2020 · Evaluating theories of carcinogenesis. These theories may be used to justify various alternative cancer treatments. We shall describe most of them, especially those pertain-ing to chemical carcinogenesis. According to the SMT, cancer is a cellular problem, and thus, the level of organization where it should be studied is the cellular level. The rationale for reducing the number of theories on carcinogenesis to 2 is due to the fact that The hypothesis of carcinogenesis as a multistep process proposes that neoplastic changes progress over time due to the accumulation of somatic mutations in a single cell line, resulting in the phenotypic progression from normal to hyperplastic cells to dysplastic, and finally to fully malignant phenotypes. that underlie them, it will be useful to identify the different types of human cancers that exist. From the humor theory that interpreted cancer as an excess of black bile to the three notions of initiation, promotion, and progression and the most recent definitions of hallmarks of cancer, we reviewed and discussed each of these steps to better understand the state of the art For many decades, a corollary to the contemporary understanding of the nature of cancer and of carcinogenesis has been the recognition of causative agents. Based on the observation that a carcinogenic aminoazo dye covalently bound liver proteins in animals undergoing early carcinogenesis, whereas little or no dye binding occurred to the proteins of Weber-Ch01. May 31, 2024 · The current theories of carcinogenesis are the result of a long succession of thoughts and beliefs since antiquity. 14 Michael Sporn, who defined the term Given their clinical importance and the magnitude of their incidence, our analysis will mainly concentrate on explanations on how known causative agents generate the sporadic variety of cancers. However, in this clonal evolution theory, even the definition of a “clone” is not unequivocal and straightforward and can be interpreted in more than one way [ 4 ]. A snapshot of theories of carcinogenesis, devised in the course of the last two centuries, reflects the progress of insight from the cellular level via biochemistry to an understanding of damaging influences and oncogenes, and to a more wholistic approach in the regulatory theory. Jun 30, 2021 · As the main theory of carcinogenesis, the Somatic Mutation Theory, increasingly presents difficulties to explain some experimental observations, different theories are being proposed. txt) or read online for free. The activation of protooncogenes and inactivation of tumor suppressor genes are mutational (more) Jul 24, 2023 · In this Review, Jassim et al. The MMC paradigm was later Jan 8, 2019 · This theory became the standard model of carcinogenesis and continues to spread, primarily because it is a simple and uncomplicated manner to explain a complex process. Since 1950 a number of different quantitative theories of carcinogenesis have been proposed. outline the various theories that have currently been proposed for cancer origins, and the determinants of cancer risk upon which they are based. Since the 1950s, many agents that contribute to the development of cancer have been categorized as initiators or promoters, on the basis of studies of chemical carcinogenesis in mouse skin (Berenblum and Shubik, 1947). The Atavistic Theory of Cancer (ATC) postulates that the hallmark capabilities of cancer pre-exist in normal human cells. First, there are those that are inherited through the germline of the carriers; they represent about 5% of the total incidence of human cancers. The cellular organization of tissues was then poorly understood, with almost nothing known about cancer drivers and stem cells. A major Sep 10, 2024 · In general, other theories of cancer, such as the cancer stem cell theory 267, the atavistic theory 268,269 and the wound that will not heal 270,271,272, describe the biological constraints and Apr 8, 2015 · The building of a global model of carcinogenesis is one of modern biology’s greatest challenges. com In this review we provide a critical analysis of the two main currents in cancer research, one centered at the cellular level of biological organization, the somatic mutation theory, which conceptualizes carcinogenesis as a problem of cell proliferation control, and the other centered at the tissue level, the tissue organization filed theory Multistage chemical carcinogenesis can be conceptually divided into four stages: tumor initiation, tumor promotion, malignant conversion, and tumor progression. An up to date review of theories of carcinogenesis. One many consider this process an active phenomenon induced by any one or several of a vari-ety of agents-chemical, physical, biological, or genetic. Jul 1, 2022 · The Tissue Organization Field Theory (TOFT) considers that proliferation is the default state of all cells and carcinogenesis is a disease of tissue organization comparable to organogenesis [135]. Pas-sive carcinogenesis may be equated with spontaneous car- Oct 2, 2024 · Carcinogenesis can be viewed as a series of genetic and epigenetic changes that gradually allow cells to acquire these hallmarks, ultimately leading to full cancer development. For a century, the somatic mutation theory (SMT) has been the prevalent theory to explain carcinogenesis. oup. Carcinogenesis can be actively induced by chemicals, radiation, infectious biological agents, transgenesis, or selective breeding. Oct 1, 2008 · In this review we provide a critical analysis of the two main currents in cancer research, one centered at the cellular level of biological organization, the somatic mutation theory, which conceptualizes carcinogenesis as a problem of cell proliferation control, and the other centered at the tissue level, the tissue organization filed theory Sep 13, 2017 · While there are a number of models of carcinogenesis, these have evolved through the interaction of several disciplines and can be grouped into two main theories: those that consider cancer to be a genetic disease, including SMT, multistage models, and evolutionary models that consider the development of cancer to be due to temporal changes p/asia carcinogenic agents multistage carcinogenesis CARCINOGENESIS IS A GENERAL term used to denote the de-velopment of neoplasia. According to TOFT, the original source of cancer is loss of tissue organization rather than genetic mutations. See full list on academic. qxd 14/8/07 5:19 PM Page 8 Theories of Carcinogenesis - Free download as PDF File (. Several of these theories are summarized in a 1961 review by Armitage and Doll [5]. Jan 1, 2022 · Conceptual views of carcinogenesis are formed by the piece-by-piece discovery of key elements of the complex biological puzzle that this disease entails; however, the search for a comprehensive theory of carcinogenesis has not been forthcoming, and investigation into several theories on the origin and pathogenesis of neoplasia still dominates Oct 1, 2008 · To avoid unnecessary confusions regarding the theories of carcinogenesis and the premises that underlie them, it will be useful to identify the different types of human cancers that exist. By presenting them in a unified manner we shall Apr 1, 2008 · To avoid unnecessary confusions regarding the theories of carcinogenesis and the premises. The traditional somatic mutation theory (SMT) is now supplemented by a new approach, called the Tissue Organization Field Theory (TOFT). Theories of carcinogenesis The somatic mutation theory (SMT) has been the prevailing one in cancer research for the last 50 years [2]. . Oct 1, 2008 · A single integrated framework for carcinogenesis has been developed, enabling existing theories to become compatible as alternative mechanisms, facilitating the integration of bioinformatics and providing a structure in which translational research can flow from both ‘benchtop to bedside’ and ‘bedside to benchtop’. In the human and o … This statement pronounced 15 years ago applies to the status of cancer research today, and thus justifies a brief historical note to introduce the two currently competing theories of carcinogenesis, namely, the somatic mutation theory and the tissue organization theory of carcinogenesis. In this paper, we study the argumentative Carcinogenesis can be induced experimentally by exposure to exogenous agents or it can occur spontaneously without intentional or active intervention. In this review we provide a critical analysis of the two main currents in cancer research, one centered at the cellular level of biological organization, the somatic mutation theory, which conceptualizes carcinogenesis as a problem of cell proliferation control, and the other centered at the tissue level, the tissue organization filed theory The theories of carcinogenesis can be grouped as follows: the genetic mutation theory, the aberrant differentiation theory, the viral theory and the cell selection theory. The protein deletion theory, an extension of the dedifferentiation theory, is an epigenetic model of cancer. A theory that is unanimously accepted at present is the multistage theory . Herein, we describe how the principles for a theory of organisms apply to the TOFT and thus to the study of carcinogenesis. qxd 14/8/07 5:19 PM Page 8 There are a number of theories of carcinogenesis and cancer treatment that fall outside the mainstream of scientific opinion, due to lack of scientific rationale, logic, or evidence base. pdf), Text File (. The carcinogenesis process involves multiple events of genetic DNA damage (mutations) and epigenetic modifications in gene expression that accumulate sequentially.

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