Bisphenol A-induced DNA damages promote to lymphoma progression in human lymphoblastoid cells through aberrant CTNNB1 signaling pathway

Lymphoma is a group of blood cancers that develop from the immune system, and one of the main risk factors is associated with exposure to environmental chemicals. Bisphenol A (BPA) is a common chemical used in the manufacture of materials in polycarbonate and epoxy plastic products and can interfere with the immune system. BPA is considered to possibly induce lymphoma development by affecting the immune system, but its potential mechanisms have not been well established. This study performed a gene-network analysis of microarray data sets in human lymphoma tissues as well as in human cells with BPA exposure to explore module genes and construct the potential pathway for lymphomagenesis in response to BPA. This study provided evidence that BPA exposure resulted in disrupted cell cycle and DNA damage by activating CTNNB1, the initiator of the aberrant constructed CTNNB1-NFKB1-AR-IGF1-TWIST1 pathway, which may potentially lead to lymphomagenesis.

Zinc supplementation augments the suppressive effects of repurposed NF-κB inhibitors on ACE2 expression in human lung cell lines

Aims

Angiotensin-converting enzyme 2 (ACE2) is a key negative regulator of the renin-angiotensin system and also a major receptor for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Here, we reveal a role for NF-κB in human lung cell expression of ACE2, and we further explore the potential utility of repurposing NF-κB inhibitors to downregulate ACE2.

Main methods

Expression of ACE2 was assessed by Western blotting and RT-qPCR in multiple human lung cell lines with or without NF-κB inhibitor treatment. Surface ACE2 expression and intracellular reactive oxygen species (ROS) levels were measured with flow cytometry. p50 was knocked down with siRNA. Cytotoxicity was monitored by PARP cleavage and MTS assay.

Key findings

Pyrrolidine dithiocarbamate (PDTC), an NF-κB inhibitor, suppressed endogenous ACE2 mRNA and protein expression in H322M and Calu-3 cells. The ROS level in H322M cells was increased after PDTC treatment, and pretreatment with N-acetyl-cysteine (NAC) reversed PDTC-induced ACE2 suppression. Meanwhile, treatment with hydrogen peroxide augmented ACE2 suppression in H322M cells with p50 knockdown. Two repurposed NF-κB inhibitors, the anthelmintic drug triclabendazole and the antiprotozoal drug emetine, also reduced ACE2 mRNA and protein levels. Moreover, zinc supplementation augmented the suppressive effects of triclabendazole and emetine on ACE2 expression in H322M and Calu-3 cells.

Significance

These results suggest that ACE2 expression is modulated by ROS and NF-κB signaling in human lung cells, and the combination of zinc with triclabendazole or emetine shows promise for clinical treatment of ACE2-related disease.

Niclosamide inhibits the cell proliferation and enhances the responsiveness of esophageal cancer cells to chemotherapeutic agents

Niclosamide is an FDA-approved anthelmintic drug, and may elicit antineoplastic effects through direct STAT3 inhibition, which has been revealed in numerous human cancer cells. Chemotherapy is the standard treatment for advanced esophageal cancers, but also causes severe systemic side effects. The present study represents the first study evaluating the anticancer efficacy of niclosamide in esophageal cancers. Through western blot assay, it was demonstrated that niclosamide suppressed the STAT3 signaling pathway in esophageal adenocarcinoma cells (BE3) and esophageal squamous cell carcinoma cells (CE48T and CE81T). In addition, niclosamide inhibited cell proliferation as determined by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay and soft agar colony forming assay, and induced cell apoptosis as determined by Annexin V and PI staining. The induction of p21 and G1 arrest of the cell cycle also was revealed in niclosamide-treated CE81T cells by qPCR and flow cytometric assays, respectively. Furthermore, in the combination analysis of niclosamide and chemotherapeutic agents by MTS assay, low IC₅₀ values were detected in cells co-treated with niclosamide, with the exception of cisplatin-treated CE81T cells. To confirm the results using an apoptosis assay, the apoptotic enhancement of niclosamide was only demonstrated in CE48T cells co-treated with 5-FU, cisplatin, or paclitaxel, and in BE3 cells co-treated with paclitaxel, but not in CE81T cells. These findings indicate a future clinical application of niclosamide in esophageal cancers.

Magnetic response of an ultrathin cobalt film in contact with an organic pentacene layer

To emulate the interfacial regimes of a Co/Pc/Co spin-valve structure, we fabricated ultrathin pentacene/cobalt (Pc/Co) and cobalt/pentacene (Co/Pc) bilayers. Through measurement of the magneto-optical Kerr effect, we found the Co layer has its magnetic properties depend strongly upon the order of deposition. Further x-ray spectroscopy and microscopy investigation indicated Co/Pc was chemically stable, whereas Pc/Co was reactive and exhibited complex magnetization pattern. The different chemistry and magnetic configurations at interfaces could cause additional complication for spin injection.

Erythrocyte spectrin's chimeric E2/E3 ubiquitin conjugating/ligating activity

Spectrin is important for the shape and the physical properties of the red blood cell, such as deformability and resistance to mechanical stress. Previous findings from our laboratory indicated that human erythrocyte alpha-spectrin can facilitate formation of ubiquitin-spectrin adducts and conjugates. Computer analysis revealed domains that contained significant homologies to known consensus catalytic E2 and E3 sequences, and allowed us to develop a model for alpha-spectrin ubiquitin conjugating enzyme (E2) and ubiquitin protein ligase (E3) enzymatic activities. In order to identify the precise E2/E3 site(s), in the present study, a GST-fusion alpha-spectrin (2005-2415) recombinant protein was tested using a cell free in vitro ubiquitination assay. We found that cysteine 2071 and cysteine 2100 are critical for alpha-spectrin (2005-2415) E2/E3 activity. Furthermore, together with testing an additional 13 site-specific mutants, we also demonstrated that both Cys2071 and Cys2100 are capable of transferring ubiquitin from an E1 enzyme to target sites within alpha-spectrin (2005-2415).

Molecular orientation of evaporated pentacene films on gold: alignment effect of self-assembled monolayer

Pentacene films deposited on self-assembled monolayers (SAMs) bearing different terminal functional groups have been studied by reflection-absorption IR, grazing angle XRD, NEXAFS, AFM, and SEM analyses. A film with pentacene molecules nearly perpendicularly oriented was observed on Au surfaces covered with an SAM of alkanethiol derivative of X-(CH2)(n)-SH, with X = -CH(3), -COOH, -OH, -CN, -NH(2), C(60), or an aromatic thiol p-terphenylmethanethiol. On the other hand, a film with the pentacene molecular plane nearly parallel to the substrate surface was found on bare Au surface. A similar molecular orientation was found in thinner ( approximately 5 nm) and thicker (100 nm) deposited films. Films deposited on different surfaces exhibit distinct morphologies: with apparently smaller and rod-shaped grains on clean bare Au surface but larger and islandlike crystals on SAM-modified surfaces. X-ray photoemission electron microscopy (X-PEEM) was used to analyze the orientation of pentacene molecules deposited on a SAM-patterned Au surface. With the micro-NEXAFS spectra and PEEM image analysis, the microarea-selective orientation control on Au was characterized. The ability to control the packing orientation in organic molecular crystals is of great interest in fabricating organic field effect transistors because of the anisotropic nature of charge transport in organic semiconducting materials.

Direct molecular interaction of a conserved yolk granule protein in sea urchins

The regulation of yolk storage in oocytes and subsequent utilization in embryos is critical for embryogenesis. In sea urchins, the major yolk protein is made in the intestines, transported to the ovaries and accumulated in developing oocytes within membrane-bound vesicles comprising approximately 10% of the mass of an egg. Here, a non-yolk protein that accumulates specifically in yolk granules is reported. This protein was identified by cDNA cloning and, by use of antibodies to the recombinant protein, it was shown that this molecule is stored selectively in yolk granules of oocytes and embryos. No accumulation was seen in the accessory cells, testis, or intestines. In situ ribonucleic acid (RNA) hybridizations showed that the transcript accumulated only in oocytes, and was more highly concentrated in young oocytes. However, later in oogenesis, the messenger ribonucleic acid (mRNA) levels decreased significantly so that no signal was detectable in mature haploid eggs or at any later stage in development. However, by immunofluorescence and western blot analysis, the 30 kDa band was present throughout development. The predicted sequence of this protein shows that it is a member of the bep, HLC-32, EBP family of sea urchin proteins, but as it does not accumulate at the cell surface, nor in the hyaline layer in the two species studied here, as do other members of the family, it has been referred to as YP30 (30 kDa protein of the yolk platelet). To address its potential function, yeast two-hybrid analysis was performed to screen for proteins that potentially interact with YP30. It was found that it binds itself, and forms strongly interacting dimers. It is hypothesized that YP30 participates in the packaging and storage of major yolk protein during oogenesis, or in the utilization of the major yolk protein in development.

The absence of neuromas in beaks of adult hens after conservative trimming at hatch

OBJECTIVE

To determine the effects of the amount of break removed and cauterisation time on neuroma formation in hens.

DESIGN

A pathology study with controls.

ANIMALS

Twenty domestic fowl were beak-trimmed. Three non-beak-trimmed domestic fowl were used as controls.

PROCEDURE

Beaks of two age groups with two levels of beak removal and either 2 s or 4 s cauterisation, were investigated macroscopically and microscopically for deformities.

RESULTS

Scattered trauma-associated neuromas were present in the beaks of pullets 10 weeks after moderate trimming at hatch. Neuromas were not present in beaks of adult hens that had been similarly trimmed. Sensory corpuscles were present 10 and 70 weeks after moderate trimming, though fewer in number than in intact control hens. In contrast, trauma-associated neuromas persisted in beaks of 70-week-old hens that had been severely trimmed at hatch. A range of deformities that were absent in moderately trimmed hens, were observed in hens with severely trimmed beaks. Receptors were not seen in severely trimmed beaks.

CONCLUSION

Beak-trimming at hatch induces the formation of neuromas, regardless of the amount of tissue removed. There is a critical amount of beak tissue that can be removed, beyond which trauma-associated neuromas will not resolve, but will persist in mature hens.