The Cesare Maltoni Cancer Research Center of the European Ramazzini Foundation has conducted a long-term bioassay on aspartame (APM), a widely used artificial sweetener. APM was administered with feed to 8-week-old Sprague-Dawley rats (100–150/sex/group), ...
1 September 2007 in Environmental Health Perspectives
Background: In a previous study conducted at the Cesare Maltoni Cancer Research Center of the European Ramazzini Foundation (CMCRC/ERF), we demonstrated for the first time that aspartame (APM) is a multipotent carcinogenic agent when various doses are administered with feed to Sprague-Dawley rats from 8 weeks of age throughout the life span. Objective: The aim of this second study is to better quantify the carcinogenic risk of APM, beginning treatment during fetal life. Methods: We studied groups of 70–95 male and female Sprague-Dawley rats administered APM (2,000, 400, or 0 ppm) with feed from the 12th day of fetal life until natural death. Results: Our results show a) a significant dose-related increase of malignant tumor–bearing animals in males (p < 0.01), particularly in the group treated with 2,000 ppm APM (p < 0.01); b) a significant increase in incidence of lymphomas/leukemias in males treated with 2,000 ppm (p < 0.05) and a significant dose-related increase in incidence of lymphomas/leukemias in females (p < 0.01), particularly in the 2,000-ppm group (p < 0.01); and c) a significant dose-related increase in incidence of mammary cancer in females (p < 0.05), particularly in the 2,000-ppm group (p < 0.05). Conclusions: The results of this carcinogenicity bioassay confirm and reinforce the first experimental demonstration of APM’s multipotential carcinogenicity at a dose level close to the acceptable daily intake for humans. Furthermore, the study demonstrates that when life-span exposure to APM begins during fetal life, its carcinogenic effects are increased.
Intrinsic and acquired chemoresistance are frequent causes of cancer eradication failure. Thus, long-term cis-diaminedichloroplatine(II) (CDDP) or cisplatin treatment is known to promote tumor cell resistance to apoptosis induction via multiple mechanisms involving gene expression modulation of oncogenes, tumor suppressors and blockade of pro-apoptotic mitochondrial membrane permeabilization. Here, we demonstrate that CDDP-resistant non-small lung cancer cells undergo profound remodeling of their endoplasmic reticulum (ER) proteome (>80 proteins identified by proteomics) and exhibit a dramatic overexpression of two protein disulfide isomerases, PDIA4 and PDIA6, without any alteration in ER-cytosol Ca2+ fluxes. Using pharmacological and genetic inhibition, we show that inactivation of both proteins directly stimulates CDDP-induced cell death by different cellular signaling pathways. PDIA4 inactivation restores a classical mitochondrial apoptosis pathway, while knockdown of PDIA6 favors a non-canonical cell death pathway sharing some necroptosis features. Overexpression of both proteins has also been found in lung adenocarcinoma patients, suggesting a clinical importance of these proteins in chemoresistance.
The liver is one of the richest organs in terms of number and density of mitochondria. Most chronic liver diseases are associated with the accumulation of damaged mitochondria. Hepatic mitochondria have unique features compared to other organs' mitochondria, since they are the hub that integrates hepatic metabolism of carbohydrates, lipids and proteins. Mitochondria are also essential in hepatocyte survival as mediator of apoptosis and necrosis. Hepatocytes have developed different mechanisms to keep mitochondrial integrity or to prevent the effects of mitochondrial lesions, in particular regulating organelle biogenesis and degradation. In this paper, we will focus on the role of mitochondria in liver physiology, such as hepatic metabolism, reactive oxygen species homeostasis and cell survival. We will also focus on chronic liver pathologies, especially those linked to alcohol, virus, drugs or metabolic syndrome and we will discuss how mitochondria could provide a promising therapeutic target in these contexts.
Anthropogenic pollutants are found worldwide. Their fate and effects on human and ecosystem health must be appropriately monitored. Today, ecotoxicology is focused on the development of new methods to assess the impact of pollutant toxicity on living organisms and ecosystems. In situ biomonitoring often uses sentinel animals for which, ideally, molecular biomarkers have been defined thanks to which environmental quality can be assessed. In this context, high-throughput proteomics methods offer an attractive approach to study the early molecular responses of organisms to environmental stressors. This approach can be used to identify toxicity pathways, to quantify more precisely novel biomarkers, and to draw the possible adverse outcome pathways. In this review, we discuss the major advances in ecotoxicoproteomics made over the last decade and present the current state of knowledge, emphasizing the technological and conceptual advancements that allowed major breakthroughs in this field, which aims to "make our planet great again". SIGNIFICANCE: Ecotoxicoproteomics is a protein-centric methodology that is useful for ecotoxicology and could have future applications as part of chemical risk assessment and environmental monitoring. Ecotoxicology employing non-model sentinel organisms with highly divergent phylogenetic backgrounds aims to preserve the functioning of ecosystems and the overall range of biological species supporting them. The classical proteomics workflow involves protein identification, functional annotation, and extrapolation of toxicity across species. Thus, it is essential to develop multi-omics approaches in order to unravel molecular information and construct the most suitable databases for protein identification and pathway analysis in non-model species. Current instrumentation and available software allow relevant combined transcriptomic/proteomic studies to be performed for almost any species. This review summarizes these approaches and illustrates how they can be implemented in ecotoxicology for routine biomonitoring.