In silico evidence of high frequency of miRNA-related SNPs in Esophageal Squamous Cell Carcinoma

Esophageal squamous cell carcinoma (ESCC) is the dominant histological type of esophageal cancer significantly reported in developing nations. There is an increasing evidence suggesting that single nucleotide polymorphisms (SNPs) in the untranslated regions of genes (3′-UTRs) targeted by microRNAs (miRNAs) can change the target gene's expression and thereby affect the individual's cancer risk. Thus, in support of the role of SNPs occurring in miRNA target sites (miR-TS-SNPs) in the cancer, we analyzed the next generation sequencing data of 10 ESCC patients. In each patient, about 3,000 SNPs in 3′-UTRs were obtained in their whole-exome sequencing profiles. We applied two separate methods, manual and computational in silico approaches, to predict the miR-TS-SNPs with more effects on the miRNA–target interactions. dbSNP, 1000G, ExAC, Iranome, miRandb, miRCancer, TargetScan, Human, miRNASNP2 and miRBase databases were used for positive selection of miR-TS-SNPs and DIANA-miRPath v3.0 for pathway analysis. We identified six rare germline miR-TS-SNPs and two other ones with unknown miR-TS-SNPs. We interestingly observed all of these variants in only one patient, which can be evidence of the relationship between miR-TS-SNPs and cancer incidence. The study of cancer genetics including miR-TS-SNPs reveals miRNAs and their related pathways, which will be greatly useful in cancer research from noninvasive biomarkers to new treatments.     

Molten globule-like state of bovine carbonic anhydrase in the presence of acetonitrile

We have evaluated the effects of acetonitrile on the structure and function of bovine carbonic anhydrase II. The potential structural and functional changes in carbonic anhydrase in the presence of different acetonitrile/buffer ratios (0%, 17.5% and 47.5% v/v) were determined using a variety of methods. These included simple spectrophotometric methods to record enzyme velocity, fluorescence measurements and calculation of accessible surface area (ASA) to identify possible alterations in tertiary structure of the protein, CD measurements to search for secondary structure conversions, and thermal scanning to determine structural stability of the protein in different media. The Far-UV CD studies indicated that carbonic anhydrase, for the most part, retains its secondary structure in the presence of acetonitrile. Fluorescence measurements using iodide ion and ANS along with ASA calculations revealed that in the presence of acetonitrile some degree of conformational change occurs in the carbonic anhydrase structure. In addition to the hydrophobic pockets, two additional tryptophanyl residues become exposed to the solvent, thereby increasing the surface hydrophobicity of the protein. These alterations dramatically reduce the catalytic activity, thermal stability, and aggregation velocity of the enzyme. Thus, our results support a molten globule-like structure of carbonic anhydrase in the presence of acetonitrile.     

A Survey on Distribution of Aspergillus Section Flavi in Corn Field Soils in Iran: Population Patterns Based on Aflatoxins, Cyclopiazonic Acid and Sclerotia Production

Soil isolates of Aspergillus section Flavi from Mazandaran and Semnan provinces with totally different climatic conditions in Iran were examined for aflatoxins (AFs; B and G types), cyclopiazonic acid (CPA) and sclerotia production. A total of 66 Aspergillus flavus group strains were identified from three species viz. Aspergillus flavus, Aspergillus parasiticus and Aspergillus nomius in both locations. A. flavus (87.9%) was found to be the prominent species followed by A. nomius (9.1%) and A. parasiticus (3.0%). Only 27.5% of A. flavus isolates were aflatoxigenic (B₁ or B₁ and B₂), out of which approximately 75% were capable to producing CPA. All the A. parasiticus and A. nomius isolates produced AFs of both B (B₁ and B₂) and G (G₁ and G₂) types, but did not produce CPA. Sclerotia production was observed in only 4 isolates of A. flavus among all 66 isolates from three identified species. A. flavus isolates were classified into various chemotypes based on the ability to produce aflatoxins and CPA. In this study, a new naturally occurring toxigenic A. flavus chemotype comprising of two strains capable of producing more AFB₂ than AFB₁ has been identified. A relatively larger proportion of aflatoxigenic A. flavus strains were isolated from corn field soils of Mazandaran province which indicate a possible relationship between high levels of relative humidity and the incidence of aflatoxin-producing fungi. The importance of incidence of Aspergillus section Flavi in corn field soils regard to their mycotoxin production profiles and crop contamination with special reference to climatic conditions is discussed.     

Application of multiplex PCR with histopathologic features for detection of familial breast cancer in formalin-fixed,paraffin-embedded histological specimens

Breast cancer is the most common malignancy among females in the world. In Iran, age and family history are the major risk factors for the development of this disease. Mutations of BRCA1 and BRCA2 genes are associated with a greatly increased risk for familial breast cancer. The frequency of BRCA mutations was identified in familial breast cancers (FBCs) and nonfamilial breast cancers (NFBCs) by molecular genetics, and morphological and immunohistochemical methods. Thirty-four formalin-fixed, paraffin-embedded breast tissue tumors were analyzed from 16 patients with FBCs and 18 patients with NFBCs. Three 5382insC mutations were detected by multiplex PCR in 16 FBCs. The immunohistochemical method was used to detect estrogen receptors (ER), progesterona receptors (PR), and TP53. Comparison of ER, PR, and TP53 exhibited a high difference (P < 0.0001) in FBCs and NFBCs. Our results demonstrated that 5382insC mutation, ER, PR, TP53, mitotic activity, polymorphism, necrosis and tubules can serve as the major risk factors for FBC. The text was submitted by the authors in English.     

Tribe Eritrichieae (Boraginaceae s.str.) in West Asia: a molecular phylogenetic perspective

A selection of Boraginaceae genera was used to obtain a framework for the phylogenetic position of some tribes belong to subfamily Boraginoideae and genera within tribe Eritrichieae (Heterocaryum, Rochelia, Eritrichium, Lappula, Lepechiniella, and Asperugo) and related species. Our results were produced on the basis of nrDNA ITS and cpDNAtrnL-F sequences. The combined nrDNA ITS trnL-F data confirm four main clades of Boraginoideae comprising Echiochileae, Boragineae, Lithospermeae, and Cynoglosseae s. l. (including Eritrichieae, Cynoglosseae s. str., and Myosotideae). The tribe Eritrichieae itself at the current status is paraphyletic; some members, for example Asperugo procumbens, Lepechiniella inconspicua, Myosotidium hortensia, and Cryptantha flavoculata are placed out of the core tribe Eritrichieae. The genus Heterocaryum is monophyletic and allied with a subclade of genera Lappula, Lepechiniella, Eritrichium, and Rochelia. Rochelia is monophyletic, but Eritrichium and Lappula are non-monophyletic. Lepechiniella is nested among a group of Lappula species.     

Exogenous Melatonin Alleviates Heat‐Induced Oxidative Damage in Strawberry (Fragaria × ananassa Duch. cv. Ventana) Plant

Journal of Plant Growth Regulation - Melatonin is a signaling molecule that is involved in inducing plants? abiotic stress tolerance. To determine the possible effects of the melatonin...     

Competitive Inhibitory Effects of Acetazolamide upon Interactions with Bovine Carbonic Anhydrase II

Sulfonamide drugs mediate their main therapeutic effects through modulation of the activity of membrane and cytosolic carbonic anhydrases. How interactions of sulfonamide drugs impact structural properties and activity of carbonic anhydrases requires further study. Here the effect of acetazolamide on the structure and function of bovine carbonic anhydrase II (cytosolic form of the enzyme) was evaluated. The Far-UV CD studies indicated that carbonic anhydrase, for the most part, retains its secondary structure in the presence of acetazolamide. Fluorescence measurements using iodide ions and ANS, along with ASA calculations, revealed that in the presence of acetazolamide minimal conformational changes occurred in the carbonic anhydrase structure. These structural changes, which may involve spatial reorientation of Trp 4 and Trp 190 or some other related aminoacyl residues near the active site, considerably reduced the catalytic activity of the enzyme while its thermal stability was slightly increased. Our binding results indicated that binding of acetazolamide to the protein could occur with a 1:1 ratio, one mole of acetazolamide per one mole of the protein. However, the obtained kinetic results supported the existence of two acetazolamide binding sites on the protein structure. The occupation of each of these binding sites by acetazolamide completely inactivates the enzyme. Advanced analysis of the kinetic results revealed that there are two substrate (p-NPA) binding sites whose simultaneous occupation is required for full enzyme activity. Thus, these studies suggest that the two isoforms of CA II should exist in the medium, each of which contains one substrate binding site (catalytic site) and one acetazolamide binding site. The acetazolamide binding site is equivalent to the catalytic site, thus, inhibiting enzyme activity by a competitive mechanism.     

Identification of MiR-205 As a MicroRNA That Is Highly Expressed in Medullary Thymic Epithelial Cells

Thymic epithelial cells (TECs) support T cell development in the thymus. Cortical thymic epithelial cells (cTECs) facilitate positive selection of developing thymocytes whereas medullary thymic epithelial cells (mTECs) facilitate the deletion of self-reactive thymocytes in order to prevent autoimmunity. The mTEC compartment is highly dynamic with continuous maturation and turnover, but the genetic regulation of these processes remains poorly understood. MicroRNAs (miRNAs) are important regulators of TEC genetic programs since miRNA-deficient TECs are severely defective. However, the individual miRNAs important for TEC maintenance and function and their mechanisms of action remain unknown. Here, we demonstrate that miR-205 is highly and preferentially expressed in mTECs during both thymic ontogeny and in the postnatal thymus. This distinct expression is suggestive of functional importance for TEC biology. Genetic ablation of miR-205 in TECs, however, neither revealed a role for miR-205 in TEC function during homeostatic conditions nor during recovery from thymic stress conditions. Thus, despite its distinct expression, miR-205 on its own is largely dispensable for mTEC biology.