ABSTRACT In 2019, a subgroup of carbamate agents was added to the Schedules to the Chemical Weapons Convention, which are characterized by two positively charged amino groups with either one carbamate moiety for quaternaries or two carbamate moieties for bisquaternaries of dimethylcarbamoyloxypyridines. Limited data can be found in the open literature regarding these carbamates. We conducted an in vitro study to investigate the inhibition kinetics of human AChE as well as the effect of oximes on carbamylation and decarbamylation. The results confirmed these carbamates as potent inhibitors of human AChE showing second‐order inhibition rate constants ( k i ) ranging from 2.59 ± 0.19 × 10 8 (mol/L) −1 min −1 to 13.37 ± 0.24 × 10 8 (mol/L) −1 min −1 . The carbamates experienced a spectrum of effects in the presence of oximes resulting either in an increase or reduction of the k i values. For example, HLö‐7 had a significant effect on the inhibition kinetics of 1a (2.9‐fold). In addition, some oximes had a statistically relevant effect on the decarbamylation kinetics. Obidoxime or HLö‐7 significantly altered the decarbamylation kinetics of 1c , leading to increases by either a factor of 1.9 or 3.0. Furthermore, there was a decrease in decarbamylation for 1b in the presence of 2‐PAM and HI‐6. Despite these changes, the variation in decarbamylation kinetics might not significantly impact the overall effectiveness of carbamate prophylaxis. In conclusion, the interactions of AChE, the newly scheduled carbamates and oximes depend on small structural changes. The administration of HLö‐7 to humans poisoned by the carbamates cannot be recommended and the effect of pralidoxime, obidoxime, and HI‐6 on the carbamylation and decarbamylation have to be assessed for the individual combination of the carbamate and the oxime.
Indolinones are compounds with recognized antineoplastic properties and can act as inhibitors of multiple kinases. However, the antitumor effects of 2-carboxy-2-heptano-indolin-3-one (IDC) have not yet been investigated in cervical cancer models. This study investigated the cytotoxic and pro-apoptotic effects of IDC in HeLa cells, with emphasis on a three-dimensional spheroid model, and evaluated its effects on spheroid growth, cell cycle distribution, apoptosis, and the expression of genes associated with cell death and DNA damage responses. Cell viability was assessed in monolayer cultures using the resazurin assay, while spheroid growth and morphology were evaluated by microscopy and volumetric analysis. Apoptosis and cell cycle distribution were investigated by flow cytometry, and gene expression was assessed by RT-qPCR. IDC reduced cell viability by up to 80% in monolayer cultures and significantly inhibited spheroid growth, with loss of structural integrity and absence of recovery after treatment withdrawal. Flow cytometry revealed 81.7-83.6% apoptotic cells following IDC treatment, compared with 35.8% in the vehicle control. No significant changes in G1, S, or G2/M cell cycle distribution were observed. RT-qPCR showed increased mRNA levels of CASP8, CASP9, CASP3, BBC3, and GADD45A and decreased levels of TP53, CDKN1A, and MYC. These transcriptional changes suggest the involvement of apoptotic signaling and DNA damage response mechanisms. Overall, IDC exhibited cytotoxic and pro-apoptotic effects in HeLa cells and impaired three-dimensional spheroid growth and integrity, supporting further investigation of its antineoplastic potential in cervical cancer.
ABSTRACT Arsenic (As) contamination in groundwater has been reported in many countries and is a major risk factor for liver injury. While the impact of arsenic exposure on gut microbiota and its role in liver diseases through the gut‐liver axis has been documented, the underlying mechanism remains unclear. In this study, we established a chronic arsenic exposure rat model by administering sodium arsenite (NaAsO 2 ) at concentrations of 30 and 100 mg/L through drinking water until 62 weeks of age. Subsequently, high As‐exposed rats were subjected to fecal microbiota transplantation (FMT), arsenic cessation, or combined FMT and arsenic cessation interventions for 2 months. Liver pathological changes, hepatocyte proliferation, intestinal microbiota composition, fecal butyrate levels, and the expression of butyrate‐related molecular markers were evaluated using hematoxylin–eosin staining, immunohistochemistry, 16S rRNA gene sequencing, gas chromatography, and quantitative real‐time PCR. Chronic arsenic exposure increased hepatocyte proliferation, as evidenced by elevated PCNA and Ki‐67 expression in liver tissues. Microbiota analysis revealed that arsenic exposure significantly altered gut microbial community structure and reduced the abundance of butyrate‐producing bacteria, particularly Lachnospiraceae and Blautia . Consistently, fecal butyrate levels showed a decreasing trend after arsenic exposure. Furthermore, arsenic exposure significantly suppressed hepatic miR‐22 expression, accompanied by increased expression of Sirt1 and Ctnnb1 and decreased expression of Gsk3b , suggesting activation of a proliferation‐related signaling pathway. Intervention with FMT and/or arsenic cessation partially restored gut microbiota composition, alleviated miR‐22 suppression, and improved arsenic‐induced molecular alterations. Collectively, these findings demonstrate that chronic arsenic exposure promotes hepatocyte proliferation through disruption of gut microbiota and reduction of microbiota‐derived butyrate, which may regulate the miR‐22/Sirt1 signaling pathway. Restoration of intestinal microbiota by FMT or cessation of arsenic exposure may provide potential strategies for mitigating arsenic‐induced hepatic abnormalities.
Small cell carcinoma of the ovary, hypercalcemic type (SCCOHT) is a rare and highly aggressive ovarian malignancy with poorly understood environmental modifiers. Although benzophenone (BP) is a widely used environmental chemical with reported estrogenic activity, its effects on SCCOHT remain unknown. Here, we investigated whether BP alters malignant phenotypes and signaling and epigenetic programs in COV434 cells, a SCCOHT-derived cell line. Cells were exposed to BP (1, 10, or 100 μM), and estrogen receptor signaling, proliferation, migration, clonogenicity, and three-dimensional spheroid invasion were evaluated together with transcriptional and epigenetic changes. BP-induced ERα nuclear translocation to a level comparable with estradiol and enhanced proliferation, migration, colony formation, and spheroid invasion. These phenotypic changes were accompanied by increased expression of genes involved in GPER/ERα/PI3K/mTOR signaling and in cell cycle progression, metastasis, and angiogenesis. BP also increased DNMT1, DNMT3A, and DNMT3B expression, elevated H3K27me3 and H3K36me3, and was associated with increased HOXA9 methylation. Together, these findings show that BP can elicit estrogen-like responses and promote aggressive phenotypes in SCCOHT cells, accompanied by alterations in oncogenic signaling and epigenetic remodeling. More broadly, this study highlights the need to further examine whether environmental exposure to endocrine-disrupting chemicals can influence SCCOHT progression.
