Ferritin Heavy Chain (FHC) is Up-regulated in Papillomavirus-Associated Urothelial Tumours of the Urinary Bladder in Cattle

Comprehensive physiological and transcriptomic analysis revealing the responses of hybrid grouper (Epinephelus fuscoguttatus♀ × E. lanceolatus♂) to the replacement of fish meal with soy protein concentrate

Plant proteins are suitable and alternative to fish meals (FMs), with less cost compared with that of all other types of fish feeds. In recent years, soy protein concentrate (SPC) has emerged as a cost-effective alternative to FM; however, little is known regarding the effects of dietary SPC on general fish physiology and well-being. This study aimed to perform comprehensive physiological and transcriptomic analysis for testing the applicability of SPC as fish feeds in hybrid grouper (Epinephelus fuscoguttatus♀ × E. lanceolatus♂) [SPC replaced 0% (CK), 30% (SPC30), and 75% (SPC75) of FM protein]. Generally, SPC30 promoted fish survival and had less effects on the phenotype, while SPC75 reduced fish survival, promoted inflammation, and regulated multiple physiological responses. Thousands of differentially expressed genes (DEGs) by SPC were identified in the intestine, liver, and muscle, which were enriched in biological regulation, cellular process, metabolic process, single-organism process, cell, cell part, membrane, binding, and catalytic activity based on RNA-seq. Notably, some DEGs involved in amino acid and lipid metabolism in the digestive system highlighted the modulatory effect of SPC on these metabolic processes, consistent with the physiological responses including enzyme activities. The enriched aspects of these predominant DEGs might be directly related to the different effects of SPC30 and SPC75 on fish growth, digestibility, and underlying enzyme activities and histology. In conclusion, the comprehensive physiological and transcriptomic comparative analysis of CK, SPC30, and SPC75 was also effective in testing the applicability of SPC as fish feeds and in designing a proper diet with the best impact on the growth performance and health of fish in hybrid grouper.

Epithelial-to-mesenchymal transition in FHC-silenced cells: the role of CXCR4/CXCL12 axis

Background

Ferritin plays a central role in the intracellular iron metabolism; the molecule is a nanocage of 24 subunits of the heavy and light types. The heavy subunit (FHC) is provided of a ferroxidase activity and thus performs the key transformation of iron in a non-toxic form. Recently, it has been shown that FHC is also involved in additional not iron-related critical pathways including, among the others, p53 regulation, modulation of oncomiRNAs expression and chemokine signalling. Epithelial to mesenchymal transition (EMT) is a cellular mechanism by which the cell acquires a fibroblast-like phenotype along with a decreased adhesion and augmented motility. In this work we have focused our attention on the role of the FHC on EMT induction in the human cell lines MCF-7 and H460 to elucidate the underlying molecular mechanisms.

Methods

Targeted silencing of the FHC was performed by lentiviral-driven shRNA strategy. Reconstitution of the FHC gene product was obtained by full length FHC cDNA transfection with Lipofectamine 2000. MTT and cell count assays were used to evaluate cell viability and proliferation; cell migration capability was assayed by the wound-healing assay and transwell strategy. Quantification of the CXCR4 surface expression was performed by flow cytometry.

Results

Experimental data indicated that FHC-silenced MCF-7 and H460 cells (MCF-7^shFHC, H460^shFHC) acquire a mesenchymal phenotype, accompanied by a significant enhancement of their migratory and proliferative capacity. This shift is coupled to an increase in ROS production and by an activation of the CXCR4/CXCL12 signalling pathway. We present experimental data indicating that the cytosolic increase in ROS levels is responsible for the enhanced proliferation of FHC-silenced cells, while the higher migration rate is attributable to a dysregulation of the CXCR4/CXCL12 axis.

Conclusions

Our findings indicate that induction of EMT, increased migration and survival depend, in MCF-7 and H460 cells, on the release of FHC control on two pathways, namely the iron/ROS metabolism and CXCR4/CXCL12 axis. Besides constituting a further confirmation of the multifunctional nature of FHC, this data also suggest that the analysis of FHC amount/function might be an important additional tool to predict tumor aggressiveness.

Apoptotic effects of two COX-2 inhibitors on breast adenocarcinoma cells through COX-2 independent pathway

Recently, much effort has been directed toward the search for compounds that influence apoptosis and to understand their mechanisms of action. Cyclooxygenase (COX)-2 inhibitors may induce apoptosis through the COX-2-independent mechanism via a mitochondrial pathway. In view of the reported antiproliferative activities of two COX-2 inhibitor derivatives (1, 2) in breast cancer cells (MCF-7), the present study was undertaken to evaluate the potential of these compounds to induce apoptosis and unravel the associated mechanisms. The apoptotic activities of the two compounds were assessed using flow cytometry, fluorescence microscope, and Western blot analysis. Compounds 1 and 2-treated MCF-7 cells revealed the apoptotic cell death, as confirmed by the changes in nuclear morphology and the increased annexin-V/PI staining. Elevation of Bax to Bcl-2 ratio and activation of caspase-3 were found to be associated with the initiation of apoptosis induced by compound 1. Further investigation showed that compounds 1 and 2 inhibited NF-κB, FHC, and ERK activation, while no dramatic change was revealed in c-Myc and EGR-1 levels. Our data suggest that induction of apoptosis by compounds 1 and 2 is not associated with COX-2 expression and occurs through the NF-κB pathway, which sequentially inhibits P-ERK and FHC expression.

Tumor necrosis factor-α attenuates starvation-induced apoptosis through upregulation of ferritin heavy chain in hepatocellular carcinoma cells

BACKGROUND

Tumor microenviroment is characteristic of inflammation, ischemia and starvation of nutrient. TNF-α, which is an extraordinarily pleiotropic cytokine, could be an endogenous tumor promoter in some tumor types. The basic objective of this study was to investigate the effects of TNF-α on the cell viability and apoptosis of hepatocellular carcinoma cells under serum starvation, and to identify the molecular mechanisms involved.

METHODS

For this purpose, five different concentrations of TNF-α and two different serum settings (serum-cultured and serum-deprived) were used to investigate the effects of TNF-α on the cell viability and apoptosis of Hep3B and SMMC-7721 cells.

RESULTS

TNF-α (10 ng/ml) attenuated serum starvation-induced apoptosis of hepatocellular carcinoma cells, and autophagy conferred this process. BAY11-7082, a specific inhibitor of NF-κB, reversed the suppression of serum starvation-induced apoptosis by TNF-α. Moreover, TNF-α-induced NF-κB transactivation was suppressed by autophagy inhibitor 3-MA. In addition, TNF-α up-regulated Ferritin heavy chain (FHC) transiently by NF-κB activation and FHC levels were correlated with the TNF-α-induced protection against serum starvation-mediated apoptosis of hepatocellular carcinoma cells. Furthermore, FHC-mediated inhibition of apoptosis depended on suppressing ROS accumulation.

CONCLUSIONS

Our findings suggested that autophagy conferred the TNF-α protection against serum starvation-mediated apoptosis of hepatocellular carcinoma cells, the mechanism involved with the activation of the TNF-α/ NF-κB /FHC signaling pathway.

Bovine papillomavirus E5 and E7 oncoproteins in naturally occurring tumors: are two better than one?

Bovine papillomaviruses (BPVs) are oncogenic DNA viruses, which mainly induce benign lesions of cutaneous and/or mucosal epithelia in cattle. Thirteen (BPV 1-13) different viral genotypes have been characterized so far. BPVs are usually species-specific but BPV 1/2 may also infect equids as well as buffaloes and bison and cause tumors in these species. BPV-induced benign lesions usually regress, however occasionally they develop into cancer particularly in the presence of environmental carcinogenic co-factors. The major transforming protein of BPV is E5, a very short hydrophobic, transmembrane protein with many oncogenic activities. E5 contributes to cell transformation through the activation of the cellular β receptor for the platelet-derived growth factor (PDGFβ-r), it also decreases cell surface expression of major histocompatibility complex class I (MHCI) causing viral escape from immunosurveillance, and plays a role in the inhibition of the intracellular communication by means of aberrant connexin expression. E7 is considered as a weak transforming gene, it synergies with E5 in cell transformation during cancer development. E7 expression correlates in vivo with the over-expression of β1-integrin, which plays a role in the regulation of keratinocytes proliferation and differentiation. Additionally, E7 is involved in cell-mediated immune responses leading to tumour rejection, in anoikis process by direct binding to p600, and in invasion process by upregulation of Matrix metalloproteinase1 (MMP-1) expression. Studies on the role of BPV E5 and E7 oncoproteins in naturally occurring tumours are of scientific value, as they may shed new light on the biological role of these two oncogenes in cell transformation.

TP53 intronic mutations in bovine enzootic hematuria-associated urinary bladder tumors

Tumor protein 53 (TP53) is a tumor suppressor gene that is frequently mutated in urinary bladder tumors in both humans and animals. In cattle, urinary bladder tumors have been reported as occurring spontaneously as well as in conjunction with bracken fern consumption-induced bovine enzootic hematuria (BEH). The goal of this study was to evaluate various types of bovine urinary bladder neoplasms for the presence of TP53 alterations, using the polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) method. DNA was extracted from both epithelial and mesenchymal urinary bladder tumor samples in cattle, associated with the chronic consumption of bracken fern. PCR was performed using primers targeted to exons 5 to 8, following electrophoresis and isolation, and the products were assessed by SSCP. Tumors in which alterations in the electrophoresis patterns were noted included hemangiomas, papillomas, and carcinomas in situ. Exemplars of these tumor types were selected for sequencing, and although no changes were noted in the 5 to 8 exon range, on either side of the designed primers for exon 6, there was some portion of intron 6 in which sequencing demonstrated a deletion of the thyamine nucleotide at position 9332. In summary, although mutations were not observed within exons 5 to 8, this represents the first report of an intronic mutation in the TP53 gene in association with bovine urinary bladder tumors. Mutations within introns can predispose tissues to the development of cancer, and therefore, a possible association between mutations of the introns of TP53 and the development of urinary bladder tumors in cattle with BEH should be further investigated.

PBMCs are additional sites of productive infection of bovine papillomavirus type 2

Bovine papillomavirus type 2 (BPV-2) is an oncogenic virus infecting both epithelial and mesenchymal cells. Its life cycle, similar to other papillomaviruses (PVs), appears to be linked to epithelial differentiation. Human and bovine PVs have been known to reside in a latent, episomal form in PBMCs; therefore, it is believed that blood cells, like all mesenchymal cells, function as non-permissive carriers. Here, for the first time in veterinary and comparative medicine, the BPV-2 E5 oncoprotein and the major structural L1 capsid protein, known to be expressed only in productive infections, were shown to occur in defined subsets of PBMCs. E5 oncoprotein was detected in sorted T- and B-cells as well as in monocytes by flow cytometry and Western blot analysis. However, CD4(+) and CD8(+) lymphocytes appeared to be the main circulating targets of the virus, thus possibly representing the most important reservoir of active BPV-2 in blood. L1 protein was identified by flow cytometry in a population of blood cells recognized as lymphocytes by morphological scatter properties. Western blot analysis was performed on lysates obtained from the sorted subpopulations of PBMCs and detected L1 protein in CD4(+) and CD8(+) cells only. Thus, this study showed that CD4(+) and CD8(+) lymphocytes are permissive for BPV-2 and are new, hitherto unknown sites of productive PV infection. In light of these observations, the life cycle of PVs needs to be revisited to gain novel insights into the epidemiology of BPV infection and the pathogenesis of related diseases.

Sigma-2 receptor expression in bovine papillomavirus-associated urinary bladder tumours

The expression of sigma-2 receptors was investigated in nine urothelial tumours of the urinary bladder of cattle. Each tumour was associated with the presence of DNA of bovine papillomavirus type-2 (BPV-2) and expression of the E5 viral oncoprotein. Five tumours were classified as low-grade carcinoma on the basis of morphological criteria and calculation of mean nuclear area (MNA) and mean nuclear perimeter (MNP). Four tumours were classified as high-grade carcinoma. Sigma-2 receptors were overexpressed in both types of carcinoma. In control normal bovine bladder tissue the density of receptors (expressed as the B(max)) was 0.37 pmol/mg of protein. Low-grade carcinomas had a mean B(max) of 1.37+/-0.32 pmol/mg of protein (range 1.03-1.86) and in high-grade carcinomas the mean B(max) was 10.9+/-2.8 pmol/mg of protein (range 8.2-14). The difference in B(max) between low- and high-grade carcinomas was statistically significant (P=0.0001).