Although the in silico predictive ability of the Ames test results has recently made remarkable progress, there are still some chemical classes for which the predictive ability is not yet sufficient due to a lack of Ames test data. These classes include simple heterocyclic compounds. This study aimed to investigate the mutagenicity and structure-mutagenicity relationships for some heterocycles in the Ames test. In the present study, we selected 12 quinoline analogues containing one or two nitrogen atoms in the naphthalene ring and 12 indole analogues containing one to three nitrogen atoms in the indole ring, without any side moiety.

Primary aromatic amines (PAAs) present significant challenges in the prediction of mutagenicity using current standard quantitative structure activity relationship (QSAR) systems, which are knowledge-based and statistics-based, because of their low positive prediction values (PPVs). Previous studies have suggested that PAAs are metabolized into genotoxic nitrenium ions. Moreover, ddE, a relative-energy based index derived from quantum chemistry calculations that measures the stability nitrenium ions, has been correlated with mutagenicity. This study aims to further examine the ability of the ddE-based approach in improving QSAR mutagenicity predictions for PAAs and to develop a refined method to decrease false positive predictions.

The rose ketone β-damascone (β-Dam) elicits positive results in the in vitro micronucleus (MN) assay using human lymphocytes, but shows negative outcomes in the Ames test and combined in vivo MN and comet assays. This has led to the interpretation that the in vitro MN result is a misleading positive result. Oxidative stress has been suggested as an indirect mode of action (MoA) for in vitro MN formation, with the α, β-unsaturated carbonyl moiety of the β-Dam chemical structure expected to cause misleading positive results through this MoA. In this study, we investigated the role of oxidative stress in β-Dam-induced in vitro MN formation by co-treatment with the antioxidant N-acetyl-L-cysteine (NAC), thereby highlighting a possible link between mitochondrial dysfunction and aneugenicity.

The Escherichia coli MutT (NudA) protein catalyzes the hydrolysis of an oxidized form of dGTP, 8-oxo-7,8-dihydro-dGTP (8-hydroxy-dGTP), and the spontaneous mutation frequency is elevated in E. coli cells deficient in the mutT gene.

Error-corrected next-generation sequencing (ecNGS) technologies have enabled the direct evaluation of genome-wide mutations after exposure to mutagens. Previously, we reported an ecNGS methodology, Hawk-Seq™, and demonstrated its utility in evaluating mutagenicity. The evaluation of technical transferability is essential to further evaluate the reliability of ecNGS-based assays. However, cutting-edge sequencing platforms are continually evolving, which can affect the sensitivity of ecNGS. Therefore, the effect of differences in sequencing instruments on mutation data quality should be evaluated.

Both mutation induction and clonal expansion of mutated cells cause cancer. The probability of cancer development depends on mutations, clonal growth rates, and carcinogenic mechanisms. A recent study showed cases of occupational cholangiocarcinomas that originate multifocally, with higher mutation burden levels than those in common cholangiocarcinomas. This study aimed to identify the effect of clonal expansion on and estimate the risk of occupational and common intrahepatic cholangiocarcinomas (ICCs) using a multistage model modified to include the effect of cell expansion at any carcinogenic stage.

We previously investigated methods for separating mutagenic contaminants from aqueous solutions using cellulose-bearing covalently bound trisulfo-Cu-phthalocyanine (blue cotton and blue rayon). Mutagenic contaminants with three or more fused aromatic rings in their structures were adsorbed onto blue cotton and rayon. Since Cu-phthalocyanine is considered an unsuitable absorption ligand for byproducts of water chlorination, such as 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (Mutagen X or MX), we investigated the development of a new material for the elimination of MX from aqueous solvents.

Poly(ADP-ribose) polymerase-1 (PARP-1) is a pan nuclear protein that utilizes NAD as a substrate for poly(ADP-ribosyl)ation reaction (PARylation), resulting in both auto-modification and the modification of its accepter proteins. Earlier reports suggested that several nucleolar proteins interact and colocalize with PARP-1, leading to their PARylation. However, whether PARP-1 has any role in nucleolar biogenesis and the functional relevance of such a role is still obscure.

Di(2-ethylhexyl) phthalate (DEHP) is a plasticizer commonly used in a wide variety of products, including medical devices. It is rapidly metabolized in the liver into various metabolites upon absorption through oral ingestion, dermal absorption, and inhalation. DEHP is classified as a non-genotoxic hepatocarcinogen in rodents, as its chronic exposure has been associated with the development of liver cancer in these animals, but most genotoxicity studies have been negative. Epidemiologic studies in humans suggest that long-term high intakes of DEHP may be a risk factor for liver dysfunction. The repeated-dose liver micronucleus (RDLMN) assay is a well-established method for assessing chromosomal changes caused by hepatic genotoxins and/or carcinogens. It is particularly valuable for detecting substances that undergo metabolic activation, especially when the metabolite has a short half-life or does not reach the bone marrow effectively. Therefore, we investigated whether the RDLMN assay could detect DEHP-induced micronucleus formation in the liver following a 14 or 28-day treatment.

Exposure to chemical mixtures inherent in air pollution, has been shown to be associated with the risk of breast and lung cancers. However, studies on the molecular mechanisms of exposure to a mixture of these pollutants, such as hydrocarbons, in the development of breast and lung cancers are scarce. We utilized in silico toxicogenomic analysis to elucidate the molecular pathways linked to both cancers that are influenced by exposure to a mixture of selected hydrocarbons. The Comparative Toxicogenomics Database and Cytoscape software were used for data mining and visualization.

Rosmarinic acid (RA) has a wide range of beneficial effects on human health. On the other hand, RA has been reported to induce metal-mediated reactive oxygen species (ROS) generation and DNA damage. However, its mechanism remains unknown. In this study, to clarify the underlying mechanism, we analyzed metal-mediated DNA damage in isolated DNA treated with RA and its analog isorinic acid.

Long non-coding RNA (lncRNA) is a group of RNA transcripts that contribute to tumor development by post-transcriptionally regulating cancer-related genes. Nasopharyngeal carcinoma (NPC) is an epithelial tumor that occurs in the nasopharynx and is common in North Africa and Southeast Asia. The study investigated the functions of lncRNA TMPO-AS1 in NPC cell proliferation and apoptosis as well as its related competing endogenous RNA (ceRNA) mechanism.

Sinonasal adenocarcinoma is a rare cancer, encompassing two different entities, the intestinal-type sinonasal adenocarcinoma (ITAC) and the non-intestinal-type sinonasal adenocarcinoma (non-ITAC). Occurrence of ITAC is strongly associated with exposure to hardwood dusts. In countries with predominant exposure to softwood dust the occurrence of sinonasal adenocarcinomas is lower and the relative amount of non-ITACs to ITACs is higher. The molecular mechanisms behind the tumorigenic effects of wood dust remain largely unknown.

As a natural extraction, astaxanthin is gaining increasing attention because of its safety and anti-tumor properties. It has been reported to participate in the progression of various types of cancer such as gastric cancer and ovarian cancer. Nevertheless, the role of astaxanthin in nasopharyngeal carcinoma (NPC) has not been investigated.

An in vitro micronucleus assay is a standard genotoxicity test. Although the technique and interpretation of the results are simple, manual counting of the total and micronucleus-containing cells in a microscopic field is tedious. To address this issue, several systems have been developed for quick and efficient micronucleus counting, including flow cytometry and automated detection based on specialized software and detection systems that analyze images.

Gastric cancer is the sixth most frequently diagnosed cancer and third in causing cancer-related death globally. The most frequently mutated gene in human cancers is TP53, which plays a pivotal role in cancer initiation and progression. In Africa, particularly in Rwanda, data on TP53 mutations are lacking. Therefore, this study intended to obtain TP53 mutation status in Rwandan patients with gastric cancer.

The prevalence of cancer is increasing globally, and Malaysia is no exception. The exposome represents a paradigm shift in cancer research, emphasizing the importance of a holistic approach that considers the cumulative effect of diverse exposures encountered throughout life. The exposures include dietary factors, air and water pollutants, occupational hazards, lifestyle choices, infectious agents and social determinants of health. The exposome concept acknowledges that each individual's cancer risk is shaped by not only their genetic makeup but also their unique life experiences and environmental interactions. This comprehensive review was conducted by systematically searching scientific databases such as PubMed, Scopus and Google Scholar, by using the keywords "exposomes (environmental exposures AND/OR physical exposures AND/OR chemical exposures) AND cancer risk AND Malaysia", for relevant articles published between 2010 and 2023. Articles addressing the relationship between exposomes and cancer risk in the Malaysian population were critically evaluated and summarized. This review aims to provide an update on the epidemiological evidence linking exposomes with cancer risk in Malaysia. This review will provide an update for current findings and research in Malaysia related to identified exposomes-omics interaction and gap in research area related to the subject matter. Understanding the interplay between complex exposomes and carcinogenesis holds the potential to unveil novel preventive strategies that may be beneficial for public health.

Carbendazim (methyl 2-benzimidazolecarbamate, CASRN: 10605-21-7) exhibits spindle poisoning effects and is widely used as a fungicide. With respect to genotoxicity, carbendazim is deemed to be non-mutagenic in vitro, but it causes indicative DNA damage in vivo and chromosome aberrations in vitro and in vivo. In this study, we examined the mutagenicity of carbendazim in vivo.