No abstract

Introduction: The oral tumor is the sixth most prevalent type of cancer worldwide and the second leading cause of cancer-related mortality. Although chemotherapy and immunotherapy are the main strategies for the treatment of oral cancer, an emergence of inevitable resistance to these treatment modalities is the major drawback that causes recurrence of the disease. Nowadays, probiotics have been suggested as adjunctive and complementary treatment modalities for improving the impacts of chemotherapy and immunotherapy agents. Probiotics, the friendly microflora in our bodies, contribute to the production of useful metabolites with positive effects on the immune system against various diseases such as cancer. Methods: Lactobacillus plantarum is one of the most important bacteria, which commensally live in the human oral system. In the current study, the impacts of L. plantarum on maintaining oral system health were investigated, and the molecular mechanisms of inhibition of oral cancer KB cells mediated by L. plantarum were evaluated using real-time polymerase chain reaction (PCR) and FACS flow cytometry analyses. Results: Our findings showed that L. plantarum is effective in the signal transduction of the oral cancer cells through upregulation and downregulation of PTEN and MAPK pathways, respectively. Conclusion: Based on the biological effects of oral candidate probiotics candidate bacterium L. plantarum on functional expression of PTEN and MAPK pathways, this microorganism seems to play a key role in controlling undesired cancer development in the oral system. Taken all, L. plantarum is proposed as a potential candidate for probiotics cancer therapy.

In this effort, we provided comparative study on optimization of transfection conditions for AGS human gastric cancer cell line using two commercial non-liposomal cationic lipids. Using reporter vector pEGFP-N1, transfection efficiency of Attractene™ and X-tremeGENE HP™ transfection reagents in terms of cell densities and DNA/reagent ratios was determined in AGS cells by flow cytometry and fluorescence microscopy. In addition, influence of transfection reagents on direct cytotoxicity and cell viability was respectively, measured using lactate dehydrogenase (LDH) leakage and MTT assays. Provided that the transfection rate of 29% and the mean fluorescence intensity of 437.5, the DNA/reagent ratio of 0.4/1.5 was selected as the optimal condition using Attractene™, whereas the optimum condition using X-tremeGENE HP™ was obtained by the ratio of 1/2 with a higher transfection rate of 36.9% and an MFI of 833. Very low direct cytotoxicity (<5% and 6-9% using Attractene™ and X-tremeGENE HP™, respectively) and high cell viability (74.5-95.5% versus 68-75%) showed the biodegradable attribute for both transfection reagents. Altogether, X-tremeGENE HP™ exhibited superiority over Attractene™ as a transfection reagent for AGS cells. In the present research, we have established the optimized protocols for efficient transfection of AGS cells with potential applications in gene function and expression studies as well as gene therapy.

The resistance of 220 coagulase-negative Staphylococci (CNS) (associated with animal disease) to 13 antibiotics were determined using the disk diffusion method. 35.9% of multidrug-resistant coagulase-negative Staphylococci (MR-CNS) exhibited resistance to five or more than five antibiotics; all of these bacteria were resistant to methicillin too. The new Streptomyces sp. ABRIINW111 was isolated from the Zagros Mountains Hamadan, Iran. The 16S rDNA sequence of the isolate indicated that it has 98% similarity to S. levis, but some mutations in the alpha and gamma regions of the 16S rDNA sequence emphasize the probability of the existence of a new species. Preliminary and secondary antibacterial screenings revealed that the isolate is active against gram negative and positive bacteria. The diethyl ether extracted metabolite of the Streptomyces sp. ABRIINW111 showed an effective antibacterial activity against MR-CNS. So the diethyl ether extract of the new Streptomyces sp. strain ABRIINW111 can inhibit the MR-CNS in vitro, and it can offer a new approach to treat MR-CNS infectious patients.