LncRNAs as potential diagnostic and prognostic biomarkers in gastric cancer: A novel approach to personalized medicine

Gastric cancer is the third leading cause of cancer death with 5-year survival rate of about 30–35%. Since early detection is associated with decreased mortality, identification of novel biomarkers for early diagnosis and proper management of patients with the best response to therapy is urgently needed. Long noncoding RNAs (lncRNAs) due to their high specificity, easy accessibility in a noninvasive manner, as well as their aberrant expression under different pathological and physiological conditions, have received a great attention as potential diagnostic, prognostic, or predictive biomarkers. They may also serve as targets for treating gastric cancer. In this review, we highlighted the role of lncRNAs as tumor suppressors or oncogenes that make them potential biomarkers for the diagnosis and prognosis of gastric cancer. Relatively, lncRNAs such as H19, HOTAIR, UCA1, PVT1, tissue differentiation-inducing nonprotein coding, and LINC00152 could be potential diagnostic and prognostic markers in patients with gastric cancer. Also, the impact of lncRNAs such as ecCEBPA, MLK7-AS1, TUG1, HOXA11-AS, GAPLINC, LEIGC, multidrug resistance-related and upregulated lncRNA, PVT1 on gastric cancer epigenetic and drug resistance as well as their potential as therapeutic targets for personalized medicine was discussed.     

Shedding light on the EpCAM: An overview

The epithelial cell adhesion molecule (EpCAM) is a Type I transmembrane superficial glycoprotein antigen that is expressed on the surface of basolateral membrane of multiple epithelial cells with some exceptions such as epidermal keratinocytes, hepatocytes, thymic cortical epithelial cells, squamous stratified epithelial cells, and myoepithelial cells that do not express the molecule. The molecule plays a pivotal role in the structural integrity, adhesion of the epithelial tissues and their interaction with the underlying layers. EpCAM prevents claudin-7 and claudin-1 molecules from degradation, thereby, decreasing the number of tight junctions and cellular interconnections, and promoting the cells toward carcinogenic transformation. Moreover, the mutations in the EpCAM gene lead to congenital tufting enteropathy, severe intestinal epithelium homeostasis disorders, and Lynch and Lynch syndrome. Overexpression of EpCAM on stem cells of some cancers and the presence of this molecule on circulating tumor cells (CTCs) makes it a promising candidate for cancer diagnosis as well as tracing and isolation of CTCs.     

Copper (II) complexes with N,S donor pyrazole-based ligands as anticancer agents

BioMetals - A group of bidentate nitrogen and sulfur donor pyrazole derivative ligands abbreviated as Na[RNCS(Pz)], Na[RNCS(PzMe2)], Na[RNCS(PzMe3)], Na[RNCS(PzPhMe)], Na[RNCS(PzPh2)], where...     

Hippocampal AMPA-type receptor complexes containing GluR3 and GluR4 are paralleling training in the Multiple T-Maze

Although it is well-known that AMPA receptors are involved in spatial learning and memory, published data on GluR3 and GluR4 are limited. Moreover, there is no information about GluR3 and GluR4 receptor complex levels in spatial memory training. It was therefore the aim of the study to determine the above-mentioned receptor levels following training in the Multiple T-Maze (MTM). Results from the MTM and hippocampal membrane proteins from C57BL/6J mice were taken from an own previous study and GluR3 and GluR4 receptor complexes were run on blue native gel electrophoresis followed by immunoblotting and quantification of bands. Subsequently, GluR3 and GluR4 were identified under denaturing conditions from two-dimensional gels by mass spectrometry (nano-LC-ESI-MS/MS). Hippocampal levels of GluR3 containing complexes (apparent molecular weight between 480 and 720) were decreased while GluR4 containing complexes (apparent molecular weight between 480 and 720) were increased. GluR4 complex levels in trained mice were correlating with latency and speed. Mass spectrometry unambiguously identified the two receptor subunits. The findings show that GluR3 and GluR4 may have different functions in the processes of spatial memory training in the MTM and indeed, different neurobiological functions of the two receptor subunits have been already reported. GluR3 and GluR4 receptor complex rather than subunit levels are paralleling training in the MTM and GluR4 complex levels were even linked to memory training, which may be of relevance for understanding molecular memory processes, interpretation of previous work or for design of future AMPA receptor studies.     

Mass spectrometrical identification of hippocampal NMDA receptor subunits NR1, NR2A-D and five novel phosphorylation sites on NR2A and NR2B

The NMDA receptor (NMDA-R) is a key element in neural transmission and mediating a vast variety of physiological and pathological processes in the nervous system. It is well-known that phosphorylation is required for functioning of the NMDA-R, and we therefore decided to study this post-translational modification in subunits NR1 and NR2A-D. Immunoprecipitation with an antibody against NR1 was carried out from rat hippocampi and SDS-PAGEs were run. Bands were punched, destained, and digested with trypsin and chymotrypsin and peptides were identified by nano-LC-ESI-MS/MS using an ion trap (HCT). Proteins were identified using specific software. Phosphorylations were verified by phosphatase treatment and reanalysis by mass spectrometry. The NMDA-R subunits NR1 and 2A-D were identified. On NR2A, a novel phosphorylation site was observed at S511, and on NR2B, four novel phosphorylation sites were revealed at S886, S917, S1303, and S1323 by mass spectrometry and verified by phosphatase treatment with mass spectrometrical reanalysis. A series of NMDA-R phosphorylations have been reported and these serve different functions as receptor activation, localization, and protein-protein interactions. Herein, findings of novel phosphorylation sites are extending knowledge on chemical characterization of the NMDA-R and warrant studying function of site-specific receptor phosphorylation in health and disease.     

IL-35, a double-edged sword in cancer

Interleukin 35 (IL-35), a cytokine mainly produced by regulatory T cells (Treg cells), is composed of an Epstein-Barr virus–induced gene 3 β-chain and an IL-12 p35 α-chain. IL-35 causes tumorigenicity in cancer, protects cancer cells against apoptosis, and facilitates cancer progression. However, a few reports have referred to its contradictory roles in cancer prevention. Therefore, the exact purpose of this cytokine in cancer development has become a fundamental question that needs to be answered. In this review, we explain the structure of IL-35 and its receptors and their different signaling pathways. Finally, the function of IL-35 in some cancers and the possible application of this cytokine in approaches for cancer therapy have been discussed.     

Changes of several brain receptor complexes in the cerebral cortex of patients with Alzheimer disease: probable new potential pharmaceutical targets

Although Alzheimer disease (AD) has been linked to defects in major brain receptors, studies thus far have been limited to the determination of receptor subunits or specific ligand binding studies. However, the availability of current technology enables the determination and quantification of brain receptor complexes. Thus, we examined levels of native receptor complexes in the brains of patients with AD. Cortical tissue was obtained from control subjects (n = 12 females and 12 males) and patients with AD (n = 12 females and 12 males) within a 3-h postmortem time period. The tissues were kept frozen until further biochemical analyses. Membrane proteins were extracted and subsequently enriched by ultracentrifugation using a sucrose gradient. Membrane proteins were then electrophoresed onto native gels and immunoblotted using antibodies against individual brain receptors. We found that the levels were comparable for complexes containing GluR2, GluR3 and GluR4 as well as 5-HT1_A. Moreover, the levels of complexes containing muscarinic AChR M1, NR1 and GluR1 were significantly increased in male patients with AD. Nicotinic AChRs 4 and 7 as well as dopaminergic receptors D1 and D2 were also increased in males and females with AD. These findings reveal a pattern of altered receptor complex levels that may contribute to the deterioration of the concerted activity of these receptors and thus result in cognitive deficits observed in patients with AD. It should be emphasised that receptor complexes function as working units rather than individual subunits. Thus, the receptor deficits identified may be relevant for the design of experimental therapies. Therefore, specific pharmacological modulation of these receptors is within the pharmaceutical repertoire.     

Resveratrol mitigates genotoxicity induced by iodine-131 in primary human lymphocytes

The purpose of this study was to investigate the radioprotective effects of resveratrol as a natural product that protects against genotoxic actions of ¹³¹I in cultured human lymphocytes. Whole-blood samples from human volunteers were treated with resveratrol at doses of 0.5, 1, 5, and 50 μg/mL for 1 h, after which the lymphocytes were incubated with ¹³¹I (100 μCi/1.5 mL) for 2 h. The lymphocyte cultures were then mitogenically stimulated to enable evaluation of the number of micronuclei in cytokinesis-blocked binucleated cells. Incubation of lymphocytes with ¹³¹I induced genotoxicity, which was reflected by an increase in micronuclei frequency. At the doses tested, resveratrol significantly reduced micronuclei frequency. Maximal protective effects occurred at a dose of 1 μg/mL, with total micronuclei values being reduced by 65 % compared to controls. In conclusion, our results indicate protective effects of resveratrol at low doses against genetic damage and adverse effects induced by ¹³¹I administration.     

Mitochondrial Proliferation and Paradoxical Membrane Depolarization during Terminal Differentiation and Apoptosis in a Human Colon Carcinoma Cell Line

Herbimycin A, a tyrosine kinase inhibitor, induces cellular differentiation and delayed apoptosis in Colo-205 cells, a poorly differentiated human colon carcinoma cell line. Cell cycle analysis in conjunction with end labeling of DNA fragments revealed that G₂ arrest preceded apoptotic cell death. Ultrastructural examination of herbimycin-treated cells demonstrated morphologic features of epithelial differentiation, including formation of a microvillar apical membrane and lateral desmosome adhesions. A marked accumulation of mitochondria was also observed. Fluorometric analysis using the mitochondrial probes nonyl-acridine orange and JC-1 confirmed a progressive increase in mitochondrial mass. However these cells also demonstrated a progressive decline in unit mitochondrial transmembrane potential (ΔΨ_m) as determined by the ΔΨ_m-sensitive fluorescent probes rhodamine 123 and JC-1 analyzed for red fluorescence. In concert with these mitochondrial changes, Colo-205 cells treated with herbimycin A produced increased levels of reactive oxygen species as evidenced by oxidation of both dichlorodihydrofluorescein diacetate and dihydroethidium. Cell-free assays for apoptosis using rat-liver nuclei and extracts of Colo-205 cells at 24 h showed that apoptotic activity of Colo-205 lysates requires the early action of mitochondria. Morphological and functional mitochondrial changes were observed at early time points, preceding cleavage of poly (ADP-ribose) polymerase.

These results suggest that apoptosis in differentiated Colo-205 cells involves unrestrained mitochondrial proliferation and progressive membrane dysfunction, a novel mechanism in apoptosis.