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Carcinogenesis

About: Carcinogenesis is a research topic. Over the lifetime, 60368 publications have been published within this topic receiving 3192599 citations. The topic is also known as: oncogenesis & tumorigenesis.


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Journal ArticleDOI
TL;DR: Recent advances in the studies of the relation between oxidative stress, lipid peroxidation products, and cancer progression are focused on, with particular attention to the pro-oxidant anticancer agents and the drug-resistant mechanisms, which could be modulated to obtain a better response to cancer therapy.
Abstract: The generation of reactive oxygen species (ROS) and an altered redox status are common biochemical aspects in cancer cells. ROS can react with the polyunsaturated fatty acids of lipid membranes and induce lipid peroxidation. The end products of lipid peroxidation, 4-hydroxynonenal (HNE), have been considered to be a second messenger of oxidative stress. Beyond ROS involvement in carcinogenesis, increased ROS level can inhibit tumor cell growth. Indeed, in tumors in advanced stages, a further increase of oxidative stress, such as that occurs when using several anticancer drugs and radiation therapy, can overcome the antioxidant defenses of cancer cells and drive them to apoptosis. High concentrations of HNE can also induce apoptosis in cancer cells. However, some cells escape the apoptosis induced by chemical or radiation therapy through the adaptation to intrinsic oxidative stress which confers drug resistance. This paper is focused on recent advances in the studies of the relation between oxidative stress, lipid peroxidation products, and cancer progression with particular attention to the pro-oxidant anticancer agents and the drug-resistant mechanisms, which could be modulated to obtain a better response to cancer therapy.

623 citations

Journal Article
TL;DR: It is confirmed in a large sample that methylation is a frequent event in NSCLC, can also occur in smoking-damaged nonmalignant lung tissues, and may be the most common mechanism to inactivate cancer-related genes inNSCLC.
Abstract: Aberrant methylation of CpG islands acquired in tumor cells in promoter regions is one method for loss of gene function. We determined the frequency of aberrant promoter methylation (referred to as methylation) of the genes retinoic acid receptor beta-2 (RARbeta), tissue inhibitor of metalloproteinase 3 (TIMP-3), p16INK4a, O6-methylguanine-DNA-methyltransferase (MGMT), death-associated protein kinase (DAPK), E-cadherin (ECAD), p14ARF, and glutathione S-transferase P1 (GSTP1) in 107 resected primary non-small cell lung cancers (NSCLCs) and in 104 corresponding nonmalignant lung tissues by methylation-specific PCR. Methylation in the tumor samples was detected in 40% for RARbeta, 26% for TIMP-3, 25% for p16INK4a, 21% for MGMT, 19% for DAPK, 18% for ECAD, 8% for p14ARF, and 7% for GSTP1, whereas it was not seen in the vast majority of the corresponding nonmalignant tissues. Moreover, p16INK4a methylation was correlated with loss of p16INK4a expression by immunohistochemistry. A total of 82% of the NSCLCs had methylation of at least one of these genes; 37% of the NSCLCs had one gene methylated, 22% of the NSCLCs had two genes methylated, 13% of the NSCLCs had three genes methylated, 8% of the NSCLCs had four genes methylated, and 2% of the NSCLCs had five genes methylated. Methylation of these genes was correlated with some clinicopathological characteristics of the patients. In comparing the methylation patterns of tumors and nonmalignant lung tissues from the same patients, there were many discordancies where the genes methylated in nonmalignant tissues were not methylated in the corresponding tumors. This suggests that the methylation was occurring as a preneoplastic change. We conclude that these findings confirm in a large sample that methylation is a frequent event in NSCLC, can also occur in smoking-damaged nonmalignant lung tissues, and may be the most common mechanism to inactivate cancer-related genes in NSCLC.

622 citations

Journal ArticleDOI
TL;DR: Deregulation of [Ca2+] results in a number of phenomena from activation of signaling mechanisms and alterations in cellular structure to alterations in gene expression, all of which contribute to or play a critical role in cellular toxicity, including carcinogenesis and cell death.
Abstract: The effect of intracellular ion deregulation, particularly of [Ca2+], on the events following acute cell injury and the progression of change from initiation (reversible) to maintenance (reversible-irreversible) phases and finally to cell death has been the major thrust of experimentation in our laboratory for over 20 years. Cell death, which plays an important role in both normal and pathological phenomena, has been classified into two principal types, accidental and programmed. Recent exploration of programmed cell death (or apoptosis) has revealed extensive data showing it is an important mechanism for the normal maintenance and also differentiation of a variety of cell types and organs. From the results from our laboratory and those of others, we continue to expand and refine our working hypothesis: deregulation of [Ca2+] results in a number of phenomena from activation of signaling mechanisms and alterations in cellular structure to alterations in gene expression, all of which contribute to or play a critical role in cellular toxicity, including carcinogenesis and cell death. Therefore, although much more experimentation is needed to clarify some of these phenomena, the implications of such data for understanding the mechanisms and processes involved in carcinogenesis and the chemotherapeutic killing of cancer cells are extremely exciting. These relationships between [Ca2+], cell injury, and cell death are briefly reviewed here within the framework of our hypothesis.

621 citations

Journal ArticleDOI
TL;DR: Two case-control studies of incident breast cancer indicate that the HMMR locus is associated with higher risk of breast cancer in humans, and this network shows higher connectivity than expected by chance, suggesting that its components function in biologically related pathways.
Abstract: Many cancer-associated genes remain to be identified to clarify the underlying molecular mechanisms of cancer susceptibility and progression. Better understanding is also required of how mutations in cancer genes affect their products in the context of complex cellular networks. Here we have used a network modeling strategy to identify genes potentially associated with higher risk of breast cancer. Starting with four known genes encoding tumor suppressors of breast cancer, we combined gene expression profiling with functional genomic and proteomic (or 'omic') data from various species to generate a network containing 118 genes linked by 866 potential functional associations. This network shows higher connectivity than expected by chance, suggesting that its components function in biologically related pathways. One of the components of the network is HMMR, encoding a centrosome subunit, for which we demonstrate previously unknown functional associations with the breast cancer-associated gene BRCA1. Two case-control studies of incident breast cancer indicate that the HMMR locus is associated with higher risk of breast cancer in humans. Our network modeling strategy should be useful for the discovery of additional cancer-associated genes.

621 citations

Journal ArticleDOI
11 Dec 2015-Cancers
TL;DR: It is shown that CAFs are an important IL-6 source and that anti-IL-6 receptor antibody suppressed angiogenesis and inhibited tumor-stroma interactions, and CAFs contribute to drug-resistance acquisition in cancer cells.
Abstract: Cancer tissues are composed of cancer cells and the surrounding stromal cells (e.g., fibroblasts, vascular endothelial cells, and immune cells), in addition to the extracellular matrix. Most studies investigating carcinogenesis and the progression, invasion, metastasis, and angiogenesis of cancer have focused on alterations in cancer cells, including genetic and epigenetic changes. Recently, interactions between cancer cells and the stroma have attracted considerable attention, and increasing evidence has accumulated on this. Several researchers have gradually clarified the origins, features, and roles of cancer-associated fibroblasts (CAFs), a major component of the cancer stroma. CAFs function in a similar manner to myofibroblasts during wound healing. We previously reported the relationship between CAFs and angiogenesis. Interleukin-6 (IL-6), a multifunctional cytokine, plays a central role in regulating inflammatory and immune responses, and important roles in the progression, including proliferation, migration, and angiogenesis, of several cancers. We showed that CAFs are an important IL-6 source and that anti-IL-6 receptor antibody suppressed angiogenesis and inhibited tumor-stroma interactions. Furthermore, CAFs contribute to drug-resistance acquisition in cancer cells. The interaction between cancer cells and the stroma could be a potential target for anti-cancer therapy.

620 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20239,028
20227,271
20213,536
20203,486
20193,433
20183,073