Study of microRNA expression profiling as biomarkers for colorectal cancer patients in Lebanon.

The high incidence and mortality rates of colorectal cancer (CRC) reveal its hazardous effect globally. Thus, it is important to diagnose CRC at an early stage to decrease its burden and improve survival rates. Previous studies have investigated the role of short non-coding microRNAs (miRNAs or miRs) in numerous types of cancer, including CRC. Previous studies have been performed to investigate the role of miRNAs as biomarkers in diagnosis, prognosis and prediction of CRC development. The aim of the present retrospective study was to identify the expression levels of miR-31, miR-145, miR-146b and miR-186 to highlight their role in CRC diagnosis and progression at different stages of the disease (precancerous polyp, adenoma and adenocarcinoma) in a Lebanese population. The expression levels of miRNAs was revealed using TaqMan reverse transcription-quantitative PCR on formalin-fixed paraffin-embedded tissues from Lebanese patients at different stages; their diagnostic value was determined using a receiver operating characteristics curve. Compared with healthy controls, miR-31 was upregulated (P<0.0001) at all stages. By contrast, miR-145, miR-186, and miR-146b were significantly downregulated at all stages (P<0.0001, P=0.0009 and P=0.0241, respectively). Of the four miRNAs studied, miR-31 and miR-145 were identified as potentially useful diagnostic factors, with an area under the curve of 0.7771 and 0.8269 and diagnostic accuracy of 71.3 and 78.5%, respectively. These data suggested that miR-31 and miR-145, upon further clinical validation, may be used as potential diagnostic biomarkers for the early detection of CRC at the polyp stage.

Cell Proteins Interacting with the Human Immunodeficiency Virus in Immunoblotting can be Detected by R5- or X4- Tropic Human Immunodeficiency Virus Particles.

INTRODUCTION: The present study reported a new immunoblot assay, with revelation by R5- or X4-whole free human immunodeficiency virus (HIV) particles or recombinant gp160. MATERIALS AND METHODS: The assay was optimized to identify cell proteins interacting with HIV. Whole cell lysates were prepared from peripheral blood lymphocytes (PBLs), dendritic cells (DC), monocyte-derived macrophage (MDM), and Henrietta Lacks (Hela, wild-type or transfected with DC-specific intracellular adhesion molecule-3-Grabbing Non-Integrin, HeLa) and Human endometrial cells (HEC-1A) lines; HIV particles used were the R5-tropic HIV-1JRCSF and the X4-tropic HIV-1NDK. RESULTS: Experiments with PBL lysates and both viruses demonstrated different bands, including a unique band at 105-117 kDa in addition to nonspecific bands. The 105-117 kDa band migrated at the same level of that observed in controls using total PBL lysate and anti-CD4 mAb for detection and thus likely corresponds to the cluster difference (CD) 4 complex. Blots using lysates of DCs, MDM, HeLa cell line, and HEC-1A cell line allowed identifying several bands that positions were similar to that seen by recombinant gp160 or whole R5- or X4-HIV particles. CONCLUSION: Blot of whole lysates of various HIV target cells is recognized by free HIV particles and allows identifying a wide range of HIV-interacting cell proteins. Such optimized assay could be useful to recognize new cellular HIV attachment proteins.

Pyocyanin, a Metabolite of Pseudomonas Aeruginosa, Exhibits Antifungal Drug Activity Through Inhibition of a Pleiotropic Drug Resistance Subfamily FgABC3.

The fungus Fusarium graminearum is the causative agent of economically significant plant diseases such as Fusarium Healed Blight (FHB) of cereals, its mycotoxins as deoxynivalenol (DON), Nivalenol (NIV) and Zearalenone (ZEN) contaminate wheat and other grains. The objectives of the present study were to determine the mechanism by which the bacterium Pseudomonas aeruginosa inhibits the growth of F. graminearum. Our results indicate that P. aeruginosa metabolites as pyocyanin has effective antifungal properties. Pyocyanin was produced by P. aeruginosa when cultured on mineral salt medium and reached a maximum concentration after 72 h. Pyocyanin significantly decreased mycotoxins of F. graminearum, a 25 mg/ml of pyocyanin for 72 h decreased DON by 68.7% and NIV by 57.7%.Real-Time PCR analysis demonstrated that the antifungal effect is mediated by downregulation of the Pleiotropic Drug Resistance (PDR) subfamily FgABC3. 25 mg/ml of pyocyanin decreased FgABC3-mRNA by 60%, inhibited the fungal growth and decreased the area of mycelial growth at 12, 24, 36 and 72 h post incubation by 40-50%. Deletion of FgABC3 led to enhanced accumulation of DON and NIV by 40 and 60%, respectively.The data presented in this report may have significance in understanding mechanism by which certain bacterial metabolites exert a beneficial effect and for developing antifungal drugs.

Oleic acid increases uptake and decreases the P-gp-mediated efflux of the veterinary anthelmintic Ivermectin.

The bioavailability of ivermectin is modulated by lipid-based formulations and membrane efflux transporters such as Breast Cancer Resistance Protein and P-glycoprotein (BCRP and P-gp). We have investigated the effect of oleic acid on the uptake of ivermectin in vitro using Caco-2 cells and in vivo in the intestines of wild-type mice. Complex micelles (M) with oleic acid induced a significant increase (e. g. for M3 was 7-fold, p≤0.001) in the uptake of the drug in a time-dependent manner with no involvement of cholesterol in the mechanism. In vivo results showed a significant increase in the concentration of plasma and intestinal mucosa ivermectin (p≤0.01) in mice receiving oleic acid-based drug formulation. We also examined the expression of the drug efflux transporter, BCRP and P-gp in Caco-2 cells and found a significant decrease (p≤0.001) in their level in the presence of 5 mM oleic acid. Treatment of mice with oleic acid-based formulation showed a significant decrease in the activity of P-gp in the intestinal mucosa (p≤0.01). This study highlighted the effect of oleic acid in decreasing the expression and the activity of P-gp-mediated ivermectin efflux and in limiting the drug absorption by increasing its uptake and bioavailability in Caco-2 cells and intestine, respectively.

Mycoplasma capricolum subsp. capripneumoniae, the cause of contagious caprine pleuropneumonia, comprises two distinct biochemical groups.

Mycoplasma capricolum subsp. capripneumoniae, the cause of the World Organisation of Animal Health- listed contagious caprine pleuropneumonia, is a member of the Mycoplasma mycoides cluster which comprises five pathogenic mycoplasmas of ruminants. These mycoplasmas are closely related immunologically and genetically which can lead to difficulties for differential diagnosis. The patterns of substrate metabolism of strains of M. c. capripneumoniae, gathered from diverse geographic regions, were studied by measurement of oxygen uptake rates. The strains fell into two major biochemical groups: one which only oxidised organic acids and glycerol and the other which could additionally metabolise sugars. Furthermore when DNA-DNA hybridisation tests were carried out these two groups of strains could be separated by their degree of DNA homology, the mean hybridisation value between members of the two groups was 86% well above the value of 70% normally used to indicate separate species. DNA-DNA hybridisation was also carried out between M. c. capripneumoniae strains and other members of the M. mycoides cluster. These experiments used labelled DNA from two representative subsp. capripneumoniae strains; these were 7/1a (organic acid-oxidising) and 4/2 LC (glucose-oxidising). The results showed a particularly close relationship of the glucose-oxidising strain to M leachii strains.

Antitumor activity of the synthetic retinoid ST1926 on primary effusion lymphoma in vitro and in vivo models.

Primary effusion lymphoma (PEL) is a rare B-cell neoplasm, associated with Kaposi sarcoma-associated herpes virus/human herpes virus-8 (KSHV/HHV-8), arising as malignant effusions in body cavities. PEL cells do not harbor conventional genetic cancer mutations; however, their oncogenesis is mainly attributed to HHV-8 latent genes. Treatment strategies are inefficient resulting in poor prognosis of PEL patients, stressing the need for new effective therapy. ST1926 is a synthetic retinoid with favorable antitumor properties and no cross-resistance with the natural retinoid, all-trans retinoic acid. ST1926 has shown potent apoptotic activities on a variety of solid tumors and hematologic malignancies in in vitro and in vivo models. In the present study we elucidated the antitumor activities and underlying molecular mechanism of ST1926 using in vitro, ex vivo, and in vivo PEL preclinical models. ST1926, at sub­micromolar concentrations, displayed potent antiproliferative effects on PEL cell lines and malignant ascites. Furthermore, ST1926 treatment of PEL cells and ascites resulted in their accumulation in the sub-G1 region, S phase cell cycle arrest, early DNA damage, PARP cleavage and p53 activation including the upregulation of its target genes p21 and Bax. However, ST1926 did not significantly modulate HHV-8 latent viral transcripts. Importantly, ST1926 delayed formation of ascites and enhanced survival of PEL mice. These results highlight the therapeutic potential of ST1926 in combination with drugs that target HHV-8 in PEL patients.

Close genetic and phenotypic relatedness between mycoplasma ovine/caprine serogroup 11 and Mycoplasma bovigenitalium.

Strains of Mycoplasma ovine/caprine serogroup 11, isolated from infertile sheep, were compared to the type strain, 2D, and to strains of the cattle pathogen M. bovigenitalium, including the type strain, PG11. Examination of these strains by growth inhibition and immune fluorescence tests showed strong serological cross reactivity between M. serogroup 11 and M. bovigenitalium but not with other ruminant mycoplasmas. Substrate oxidation and growth studies did not show any consistent differences between M. serogroup 11 and M. bovigenitalium strains; all strains assigned to both groups were adapted to the utilisation of a small range of organic acids as energy sources. DNA:DNA hybridisation, carried out between DIG labelled reference strains of M. serogroup 11 and M. bovigenitalium and field isolates of these two mycoplasmas showed a particularly close relationship with hybridisation rates all greater than 70% and, mostly, closer to 90%. Sequencing of the 16S ribosomal RNA gene region of the M. serogroup 11 and M. bovigenitalium strains as well as the respective type strains revealed very high overall homologies of 99.5%. In summary, the results showed a very close phenotypic and genotypic relatedness between these two ruminant mycoplasmas which justifies their classification into a single species.