Cancer‐secreted miRNAs regulate amino‐acid‐induced mTORC1 signaling and fibroblast protein synthesis

Metabolic reprogramming of non‐cancer cells residing in a tumor microenvironment, as a result of the adaptations to cancer‐derived metabolic and non‐metabolic factors, is an emerging aspect of cancer–host interaction. We show that in normal and cancer‐associated fibroblasts, breast cancer‐secreted extracellular vesicles suppress mTOR signaling upon amino acid stimulation to globally reduce mRNA translation. This is through delivery of cancer‐derived miR‐105 and miR‐204, which target RAGC, a component of Rag GTPases that regulate mTORC1 signaling. Following amino acid starvation and subsequent re‐feeding, ¹³C‐arginine labeling of de novo synthesized proteins shows selective translation of proteins that cluster to specific cellular functional pathways. The repertoire of these newly synthesized proteins is altered in fibroblasts treated with cancer‐derived extracellular vesicles, in addition to the overall suppressed protein synthesis. In human breast tumors, RAGC protein levels are inversely correlated with miR‐105 in the stroma. Our results suggest that through educating fibroblasts to reduce and re‐prioritize mRNA translation, cancer cells rewire the metabolic fluxes of amino acid pool and dynamically regulate stroma‐produced proteins during periodic nutrient fluctuations.     

The effects of nickel oxide nanoparticles on structural changes,heme degradation,aggregation of hemoglobin and expression of apoptotic genes in lymphocytes

Abstract

Nickel oxide nanoparticles (NiO NPs) have received great interests in medical and biotechnological applications. However, their adverse impacts against biological systems have not been well-explored. Herein, the influence of NiO NPs on structural changes, heme degradation and aggregation of hemoglobin (Hb) was evaluated by UV-visible (Vis) spectroscopy, circular dichroism (CD) spectroscopy, fluorescence spectroscopy, transmission electron microscopy (TEM), and molecular modeling investigations. Also, the morphological changes and expression of Bax/Bcl-2 mRNA in human lymphocyte cell exposed to NiO NPs were assayed by DAPI staining and quantitative real-time PCR (qPCR), respectively. The UV-Vis study depicted that NiO NPs resulted in the displacement of aromatic residues and heme groups and production of the pro-aggregatory species. Intrinsic and Thioflavin T (ThT) fluorescence studies revealed that NiO NPs resulted in heme degradation and amorphous aggregation of Hb, respectively, which the latter result was also confirmed by TEM study. Moreover, far UV-CD study depicted that NiO NPs lead to substantial secondary structural changes of Hb. Furthermore, near UV-CD displayed that NiO NPs cause quaternary conformational changes of Hb as well as heme displacement. Molecular modelling study also approved that NiO NPs resulted in structural alterations of Hb and heme deformation. Moreover, morphological and genotoxicity assays revealed that the DNA fragmentation and expression ratio of Bax/Bcl-2 mRNA increased in lymphocyte cells treated with NiO NPs for 24?hr. In conclusion, this study indicates that NiO NPs may affect the biological media and their applications should be limited.

Communicated by Ramaswamy H. Sarma     

Molecular Detection of Campylobacter Species: Comparision of 16SrRNA with slyD,cadF, rpoA,and dnaJ Sequencing

Background: Campylobacter spp. are the main cause of human gastroenteritis. The 16SrRNA sequencing is one of fast molecualr method to detect this fastidious. In this study, we compared the sequencing of 16srRNA genewith four housekeeping genestodetect Campylobacter spp. in patients with diarrhea and healthy people.Methods:60 samples of Campylobacter DNA extracted from stool samples of 30 patients with diarrhea and 30 healthy people were used. In order to detect Campylobacter, we designed primers for proliferation of 16SrRNA, cadF, dnaJ, slyD , and rpoA genes using Primer 3, Mega 4.0 and Blast software. Then the PCR products were sequenced using ABI system.Results:The sequencing showed concordance of PCR-products with deposited sequences in the Gene Bank. Among diarrhea patients, 53.3% of samples were significantly (p< 0.05) positive for slyD and cadF genes and 50% of samples were positive using 16SrRNA, rpoA, and dnaJ genes by PCR assay. The average of sensitivity and specificity were found 53.33% and 83.33%, respectively.Conclusion:Due to various copies of repeated sequences of 16SrRNA gene, analyzing its amplicons on electrophoresis may be more difficult than the slyD and cadF genes. According to our results, among the 5 studied genes; the highest detection rate was related to slyD and cadF genes. Although, dnaJ and rpoA genes,instead of 16SrRNA gene, can be considered as appropriate genes for molecular detection of Campylobacter bacteria.     

Are the distributions of variations of circle of Willis different in different populations? – Results of an anatomical study and review of literature

Background  

Previous studies have proposed correlation between variants of the cerebral arterial circle (also known as circle of Willis) and some cerebrovascular diseases. Differences in the incidence of these diseases in different populations have also been investigated. The study of variations in the anatomy of the cerebral arterial circle may partially explain differences in the incidence of some of the cerebrovascular diseases in different ethnic or racial groups.     

Use of solvent mixtures for total lipid extraction of Chlorella vulgaris and gas chromatography FAME analysis

Bioprocess and Biosystems Engineering - Lipid extraction is the bottleneck step for algae-based biodiesel production. Herein, 12 solvent mixture systems (mixtures of three non-polar and two polar...     

Predicting doxorubicin drug delivery by single-walled carbon nanotube through cell membrane in the absence and presence of nicotine molecules: a molecular dynamics simulation study

Abstract

In order to study the interaction of the anticancer agent Doxorubicin with the single-walled carbon nanotubes with different diameters as drug delivery systems, the molecular dynamics (MD) simulations have been used. Also, for design and development of intracellular Doxorubicin drug delivery systems, a series of steered MD simulations are applied to explore the possibility of encapsulated Doxorubicin–carbon nanotube penetration through a lipid bilayer in presence and absence of Nicotine molecules at different pulling rates. Our simulation results showed that in spite of the adsorption of drug molecules on the outer sidewall of the nanotubes, the spontaneous localization of one Doxorubicin molecule into the cavity of the nanovectors with larger diameters is observed. It is found that the presence of Nicotine molecules in extracellular medium increases the required force for pulling nanotube-encapsulated drug as well as the required time for penetration process, especially at higher velocity. Also, the entering process of the Nicotine molecules into the carbon nanotube causes that the encapsulated drug molecule is fully released in the hydrophobic phase of the lipid bilayer.

Communicated by Ramaswamy H. Sarma     

Immune checkpoints in hematologic malignancies: What made the immune cells and clinicians exhausted!

Hematologic malignancies comprise a considerable part of cancers with high mortality at any age. Since the introduction of hematopoietic stem cell transplantation (HSCT), the overall survival of patients dramatically increased. The main goal of HSCT is the induction of a graft-versus-leukemia effect to eradicate the residual cancer cells and also reconstitute a healthy immune system for patients. However, relapse is a nettlesome challenge of HSCT. Like many other tumors, hematologic cancer cells induce immune exhaustion leading to immune escape and relapses after HSCT. Besides malignant cells, inhibitory cells such as tumor-associated macrophages and myeloid-derived suppressor cells express various inhibitory receptors capable of inducing exhaustion in immune cells, especially T and natural killer cells. The significance of immune checkpoint blocking in tumor regression in clinical trials led to the 2018 Nobel Prize in Physiology/Medicine. Here, we reviewed the clinical roles of immune checkpoints in hematologic malignancies and post-HSCT relapses.     

Age-specific reference intervals for routine biochemical parameters in healthy neonates,infants, and young children in Iran

Age and sex need to be considered in the establishment of reference intervals (RIs), especially in early life when there are dynamic physiological changes. Since data for important biomarkers in healthy neonates and infants are limited, particularly in Iranian populations, we have determined age-specific RIs for 7 laboratory biochemical parameters. This cross-sectional study comprised a total of 344 paediatric participants (males: 158, females: 186) between the ages of 3 days and 30 months (mean age: 12.91 ± 7.15 months). Serum levels of creatinine, urea, uric acid, calcium, phosphate, vitamin D and high-sensitivity C-reactive protein (hs-CRP) were measured using an Alpha classic-AT plus auto-analyser. We determined age-specific RIs using CLSI Ep28-A3 and C28-A3 guidelines. No sex partitioning was required for any of the biomarkers. Age partitioning was required for kidney function tests and phosphate. The serum concentration of urea and creatinine increased with age, while phosphate and uric acid decreased with age. Age partitioning was not required for serum calcium, vitamin D, and hs-CRP, which remained relatively constant throughout the age range. Age-specific RIs for 7 routine biochemical markers were determined to address critical gaps in RIs in early life to help improve clinical interpretation of blood test results in young children, including neonates. Established age partitions demonstrate the biochemical changes that take place during child growth and development. These novel data will ultimately better disease management in the Iranian paediatric population and can be of value to clinical and hospital laboratories with similar populations.