The Effect of MicroRNA-375 Overexpression, an Inhibitor of Helicobacter pylori-Induced Carcinogenesis, on lncRNA SOX2OT.

BACKGROUND: Helicobacter pylori is a major human pathogenic bacterium in gastric mucosa. Although the association between gastric cancer and H. pylori has been well-established, the molecular mechanisms underlying H. pylori-induced carcinogenesis are still under investigation. MicroRNAs (miRNAs) are small noncoding RNAs that modulate gene expression at the posttranscriptional level. Recently, studies have revealed that miRNAs are involved in immune response and host cell response to bacteria. Also, microRNA-375 (miR-375) is a key regulator of epithelial properties that are necessary for securing epithelium-immune system cross-talk. It has been recently reported that miR-375 acts as an inhibitor of H. pylori-induced gastric carcinogenesis. There are few reports on miRNA-mediated targeting long noncoding RNAs (lncRNAs). OBJECTIVES: This study aimed to examine the possible effect of miR-375 as an inhibitor of H. pylori-induced carcinogenesis on the expression of lncRNA SOX2 overlapping transcript (SOX2OT) and SOX2, a master regulator of pluripotency of cancer stem cells. MATERIALS AND METHODS: In a model cell line, NT-2 was transfected with the constructed expression vector pEGFP-C1 contained miR-375. The RNA isolations and cDNA synthesis were performed after 48 hours of transformation. Expression of miR-375 and SOX2OT and SOX2 were quantified using real-time polymerase chain reaction and compared with control cells transfected with pEGFP-C1-Mock clone. Cell cycle modification was also compared after transfections using the flow cytometry analysis. RESULTS: Following ectopic expression of miR-375, SOX2OT and SOX2 expression analysis revealed a significant decrease in their expression level (P < 0.05) in NT-2 cells compared to the control. Cell cycle analysis following ectopic expression of miR-375 in the NT-2 cells using propidium iodine staining revealed significant extension in sub-G1 cell cycle. CONCLUSIONS: This is the first report to show down-regulation of SOX2OT and SOX2 following induced expression of miR-375. This finding may suggest expression regulation potential between different classes of ncRNAs, for example between miR-375 and SOX2OT. This data not only extends our understanding of possible ncRNA interactions in cancers but also may open novel investigation lines towards elucidation of molecular mechanisms controlling H. pylori inflammation and carcinogenesis.

Molecular Characterization of Highly Susceptible Candida africana from Vulvovaginal Candidiasis.

Phylogenetic studies highlight Candida africana as an atypical variant within Candida albicans species complex which is dominantly recovered from vaginal specimens. This study aimed to characterize C. africana isolates from patients with vulvovaginal candidiasis (VVC) by molecular methods and in vitro susceptibilities. One hundred and fifty-six (48.44%) Candida strains were collected from 322 patients diagnosed with VVC. Of these, 114 (73.07%) were germ tube positive and presented green color on the chromogenic medium, thus classified as C. albicans species complex. One hundred and nine (95.61%) out of 114 isolates were identified as C. albicans, while five (4.38%) isolates were identical with C. africana based on hwp1 PCR. C. africana appeared to be highly susceptible to the tested antifungals. For all strains of C. africana, fluconazole MIC was 2-log2-dilution steps less active than amphotericin B, which in turn was 2-log2-dilution steps and 3-log2-dilution steps less active than other azoles and echinocandin agents, respectively. In conclusion, among the C. albicans species complex, C. albicans predominantly and C. africana rarely occur in vaginal mucosa. Due to limited information on molecular epidemiology of this novel yeast, more studies using molecular methods are needed to elucidate the inter- and intraspecific genomic variations of C. africana isolates.

Use of rolling circle amplification to rapidly identify species of Cladophialophora potentially causing human infection.

The genus Cladophialophora comprises etiologic agents of disease in immunocompetent patients, ranging from mild cutaneous colonization to cerebral encephalitis, in addition to saprobic species. Due to the high degree of phenotypic similarity between closely related species of the genus, identification problems are imminent. In the present study, we described rapid and sensitive rolling circle amplification (RCA) method based on species-specific padlock probes targeted for the internal transcribed spacer regions of rDNA. ITS regions of 12 Cladophialophora species were sequenced, and subsequently, 10 specific padlock probes were designed for the detection of single nucleotide polymorphisms. The majority of circularizable padlock probes were designed based on single nucleotide polymorphisms (SNPs), while for C. bantiana, C. immunda and C. devriesii were characterized by two or more nucleotides. Individual species-specific probes correctly identified in all ten Cladophialophora species correctly by visualization on 1.2 % agarose gels used to verify specificity of probe-template binding; no cross-reactivity was observed. Simplicity, sensitivity, robustness and low costs provide RCA a distinct place among isothermal techniques for DNA diagnostics. However, restriction and specificity and sensitivity should be lowered and increased, respectively, to be useful for a wide variety of clinical applications.

Veronaea botryosa: molecular identification with amplified fragment length polymorphism (AFLP) and in vitro antifungal susceptibility.

Inter- and intraspecific genomic variability of 18 isolates of Veronaea botryosa originating from clinical and environmental sources was studied using amplified fragment length polymorphism (AFLP). The species was originally described from the environment, but several severe cases of disseminated infection in apparently healthy individuals have been reported worldwide. All tested strains of V. botryosa, identified on the basis of sequencing and phenotypic and physiological criteria prior to our study, were confirmed by AFLP analysis, yielding a clear separation of V. botryosa as a rather homogeneous group from related species. In vitro antifungal susceptibility testing resulted in MIC90s across all strains in increasing order posaconazole (0.25 µg/ml), itraconazole (1 µg/ml), voriconazole (4 µg/ml), terbinafine (4 µg/ml), caspofungin (8 µg/ml), anidulafungin (8 µg/ml), isavuconazole (16 µg/ml), amphotericin B (16 µg/ml), and fluconazole (32 µg/ml). Overall, the isolates showed a uniform pattern of low MICs of itraconazole and posaconazole, but high MICs for remaining agents. The echinocandins (caspofungin and anidulafungin) had no activity against V. botryosa. There was no statistically significant difference between susceptibilities of environmental (n = 11) and clinical (n = 7) isolates of V. botryosa (P > 0.05).

Comparison of cell wall proteins in putative Candida albicans & Candida dubliniensis by using modified staining method & SDS-PAGE.

BACKGROUND: Candida species are among the most common causes of opportunistic fungal diseases. Among Candida species, Candida albicans is responsible for most infections. Having many strains, C. albicans is very polymorph. C. dubliniensis is very similar to albicans species both morphologically and physiologically. For an infection to occur, cell wall proteins play an important role as they enable yeast to adhere to host cells and begin pathogenesis. Therefore, we decided to extract these proteins and examine them through common molecular methods of protein analysis including SDS-PAGE. METHODS: Initially cell wall proteins of two C. albicans strains (CBS 562 and PTCC6027) and one C. dubliniensis strain (CBS7987) were extracted by using a solution of beta-mercaptoethanol and ammonium carbonate. After dialysis against Tris-HCL buffer, SDS gel electrophoresis was performed on the proteins extract. Bands were then visualized by using three different staining methods among which one method provided improved detection. RESULTS: By using Coomassie Brilliant Blue staining method, proteins with molecular weight of 42, 66.2 and 200 kDa were detected. By using Silver staining method, proteins with molecular weight of 21.5, 28.5 and 37 kDa were detected. However, using combined Coomassie Brilliant Blue & Sliver staining method visualized more bands resulting in improved detection. CONCLUSION: To answer many existing questions about fungal diseases, fungi cell wall proteins are necessary to be examined. To commence such examinations, a simple step may be an SDS-PAGE performance on as many strains as possible. A combined staining method can enhance bands detection.