Epigenetic Effects of Benzene in Hematologic Neoplasms: The Altered Gene Expression

Risk assessment of Benzene, Toluene, Ethyl benzene, and Xylene (BTEX) in the atmospheric air around the world: A review

Volatile organic compounds, such as BTEX, have been the subject of numerous debates due to their detrimental effects on the environment and human health. Human beings have had a significant role in the emergence of this situation. Even though US EPA, WHO, and other health-related organizations have set standard limits as unhazardous levels, it has been observed that within or even below these limits, constant exposure to these toxic chemicals results in negative consequences as well. According to these facts, various studies have been carried out all over the world - 160 of which are collected within this review article, so that experts and governors may come up with effective solutions to manage and control these toxic chemicals. The outcome of this study will serve the society to evaluate and handle the risks of being exposed to BTEX. In this review article, the attempt was to collect the most accessible studies relevant to risk assessment of BTEX in the atmosphere, and for the article to contain least bias, it was reviewed and re-evaluated by all authors, who are from different institutions and backgrounds, so that the insights of the article remain unbiased. There may be some limitations to consistency or precision in some points due to the original sources, however the attempt was to minimize them as much as possible.

Therapy-Related Myeloid Neoplasms: Predisposition and Clonal Evolution

Therapy-related Myeloid Neoplasm (t-MN) represents one of the worst long-term consequences of cytotoxic therapy for primary tumors and autoimmune disease. Poor survival and refractoriness to current treatment strategies characterize affected patients from a clinical point of view. In our aging societies, where newer therapies and ameliorated cancer management protocols are improving the life expectancy of cancer patients, therapy-related Myeloid Neoplasms are an emerging problem. Although several research groups have contributed to characterizing the main risk factors in t-MN development, the multiplicity of primary tumors, in association with the different therapeutic strategies available and the new drugs in development, make interpreting the current data still complex. The main risk factors involved in t-MN pathogenesis can be subgrouped into patient-specific, inherited, and acquired predispositions. Although t-MN can occur at any age, the risk tends to increase with advancing age, and older patients, characterized by a higher number of comorbidities, are more likely to develop the disease. Thanks to the availability of deep sequencing techniques, germline variants have been reported in 15-20% of t-MN patients, highlighting their role in cancer predisposition. It is becoming increasingly evident that t-MN with driver gene mutations may arise in the background of Clonal Hematopoiesis of Indeterminate Potential (CHIP) under the positive selective pressure of chemo and/or radiation therapies. Although CHIP is generally considered benign, it has been associated with an increased risk of t-MN. In this context, the phenomenon of clonal evolution may be described as a dynamic process of expansion of preexisting clones, with or without acquisition of additional genetic alterations, that, by favoring the proliferation of more aggressive and/or resistant clones, may play a crucial role in the progression from preleukemic states to t-MN.

Coexistence of ETV6-RUNX1 and MLL aberration among pediatric acute lymphoblastic leukemia: case reports and a literature review

Background

It is known that ETV6-RUNX1 is usually related to favorable prognosis, but MLL aberration has been associated with poor prognosis among pediatric acute lymphoblastic leukemia (ALL). However, the outcome of coexistence of ETV6-RUNX1 and MLL aberration in pediatric ALL patients is unknown. Herein, we report 4 cases of the coexistence of ETV6-RUNX1 and MLL-partial tandem duplications (MLL-PTD) in pediatric ALL patients and show the favorable outcome, which was never reported before.

Case Description

The frequency of coexistence of ETV6-RUNX1 and MLL aberration at our children's medical center was calculated as 0.98% (4/410). All of them were ETV6/RUNX1-positive cases that exhibited MLL-PTD, and the 10-year event-free survival (EFS) and overall survival (OS) were both 75%. With the following keywords of "ETV6-RUNX1", "MLL", "children" and "acute lymphoblastic leukemia", a literature search of coexistence of ETV6-RUNX1 and MLL aberration was conducted in the database of PubMed, and 4 articles were retrieved finally, involving 16 cases of children. Among the 16 cases of pediatric ALL, the age ranged from 2 to 7 years old, including 9 males and 7 females and the white blood cell (WBC) count was (2.66-68.6)×109/L. In terms of fusion genes, they all had positive ETV6/RUNX1. Among them, MLL deletion was exhibited among 8 ETV6/RUNX1-positive patients, and 2 cases of der(21) duplication. MLL allelic deletions were shown among the remaining ETV6/RUNX1-positive patients. All patients showed a favorable outcome.

Conclusions

The results of our analysis primarily provide compelling evidence that cases with an MLL-PTD or other types of MLL aberration are in fact a distinct subentry among ETV6-RUNX1 B-cell ALL (B-ALL).

Benzene induces spleen injury through the B cell receptor signaling pathway

Benzene is a toxic environmental pollutant that disrupts the immune system in humans. Benzene exposure reduces the abundance of immune cells in multiple immune organs; however, the biological mechanisms underlying benzene-induced immunotoxicity has not been elucidated. In this study, benzene was used to develop mouse model for immune dysfunction. A significant decrease in IgG, IL-2 and IL-6 levels, an increase in oxidative stress and spleen injury were observed after benzene exposure in a dose-dependent manner. Quantitative proteomics revealed that benzene-induced immune dysfunction was associated with deregulation of the B cell receptor (BCR) signaling pathway. Benzene exposure suppressed the expression of CD22, BCL10 and NF-κb p65. Also, a significant decrease in proliferation and an increase in apoptosis of splenic lymphocytes were found after benzene exposure. Moreover, we found that benzene exposure increased mitochondrial reactive oxygen species (mito-ROS) and decreased adenosine triphosphate (ATP). Overall, we revealed the damaging effects of benzene on spleen-related immune function and the underlying biological mechanism, involving the disruption of BCR signaling pathway, NF-κB deactivation, and mitochondrial dysfunction.

Electrochemical and Optical Sensors for the Detection of Chemical Carcinogens Causing Leukemia

The incidence and mortality due to neoplastic diseases have shown an increasing tendency over the years. Based on GLOBOCAN 2020 published by the International Agency for Research on Cancer (IARC), leukemias are the thirteenth most commonly diagnosed cancer in the world, with 78.6% of leukemia cases diagnosed in countries with a very high or high Human Development Index (HDI). Carcinogenesis is a complex process initiated by a mutation in DNA that may be caused by chemical carcinogens present in polluted environments and human diet. The IARC has identified 122 human carcinogens, e.g., benzene, formaldehyde, pentachlorophenol, and 93 probable human carcinogens, e.g., styrene, diazinone. The aim of the following review is to present the chemical carcinogens involved or likely to be involved in the pathogenesis of leukemia and to summarize the latest reports on the possibility of detecting these compounds in the environment or food with the use of electrochemical sensors.

Effects of Benzene: Hematological and Hypersensitivity Manifestations in Resident Living in Oil Refinery Areas

Literature is teeming with publications on industrial pollution. Over the decades, the main industrial pollutants and their effects on human health have been widely framed. Among the various compounds involved, benzene plays a leading role in the onset of specific diseases. Two systems are mainly affected by the adverse health effects of benzene exposure, both acute and chronic: the respiratory and hematopoietic systems. The most suitable population targets for a proper damage assessment on these systems are oil refinery workers and residents near refining plants. Our work fits into this area of interest with the aim of reviewing the most relevant cases published in the literature related to the impairment of the aforementioned systems following benzene exposure. We perform an initial debate between the two clinical branches that see a high epidemiological expression in this slice of the population examined: residents near petroleum refinery areas worldwide. In addition, the discussion expands on highlighting the main immunological implications of benzene exposure, finding a common pathophysiological denominator in inflammation, oxidative stress, and DNA damage, thus helping to set the basis for an increasingly detailed characterization aimed at identifying common molecular patterns between the two clinical fields discussed.

Evaluating Phenotypic and Transcriptomic Responses Induced by Low-Level VOCs in Zebrafish: Benzene as an Example

Urban environments are plagued by complex mixtures of anthropogenic volatile organic compounds (VOCs), such as mixtures of benzene, toluene, ethylene, and xylene (BTEX). Sources of BTEX that drive human exposure include vehicle exhaust, industrial emissions, off-gassing of building material, as well as oil spillage and leakage. Among the BTEX mixture, benzene is the most volatile compound and has been linked to numerous adverse health outcomes. However, few studies have focused on the effects of low-level benzene on exposure during early development, which is a susceptible window when hematological, immune, metabolic, and detoxification systems are immature. In this study, we used zebrafish to conduct a VOC exposure model and evaluated phenotypic and transcriptomic responses following 0.1 and 1 ppm benzene exposure during the first five days of embryogenesis (n = 740 per treatment). The benzene body burden was 2 mg/kg in 1 ppm-exposed larval zebrafish pools and under the detection limit in 0.1 ppm-exposed fish. No observable phenotypic changes were found in both larvae except for significant skeletal deformities in 0.1 ppm-exposed fish (p = 0.01) compared with unexposed fish. Based on transcriptomic responses, 1 ppm benzene dysregulated genes that were implicated with the development of hematological system, and the regulation of oxidative stress response, fatty acid metabolism, immune system, and inflammatory response, including apob, nfkbiaa, serpinf1, foxa1, cyp2k6, and cyp2n13 from the cytochrome P450 gene family. Key genes including pik3c2b, pltp, and chia.2 were differentially expressed in both 1 and 0.1 ppm exposures. However, fewer transcriptomic changes were induced by 0.1 ppm compared with 1 ppm. Future studies are needed to determine if these transcriptomic responses during embryogenesis have long-term consequences at levels equal to or lower than 1 ppm.

Multiple Myeloma: Challenges Encountered and Future Options for Better Treatment

Multiple myeloma (MM) is a malignant hematological disease. The disease is characterized by the clonal proliferation of malignant plasma cells in the bone marrow. MM accounts for 1.3% of all malignancies and has been increasing in incidence all over the world. Various genetic abnormalities, mutations, and translocation, including epigenetic modifications, are known to contribute to the disease’s pathophysiology. The prognosis is good if detected early, or else the outcome is very bad if distant metastasis has already occurred. Conventional treatment with drugs poses a challenge when there is drug resistance. In the present review, we discuss multiple myeloma and its treatment, drug resistance, the molecular basis of epigenetic regulation, the role of natural products in epigenetic regulators, diet, physical activity, addiction, and environmental pollutants, which may be beneficial for clinicians and researchers.