Preparation and characterization of lipid nanoparticle/pDNA complexes for STAT3 downregulation and overcoming chemotherapy resistance in lung cancer cells

Developments in the field of molecular oncology have revealed that resistance to chemotherapeutics is acqured through several mechanisms including overexpression of common oncogenic proteins. Signal Transducer and Activator of Transcription 3 (STAT3) is one of these oncogenes that is overexpressed in many cancer types. RNA interference (RNAi) is proven powerful tool for downregulating STAT3, allowing re-sensitization of resistant cancer cells. However, delivery of RNA interference-mediating molecules for STAT3 downregulation in lung cancer cells is limited to a small number of studies most of which employ commercially available transfection kits. The aim of this study was to develop and evaluate cationic solid lipid nanoparticles for delivery of RNAi-mediating plasmid DNA in order to down regulate STAT3 in cisplatin resistant lung cancer cells. We focused on obtaining cSLN:plasmid DNA complexes with size below or equal to 100nm, and a positive zeta potential. Two successful candidate cSLN:plasmid DNA complexes (K2 and K3) were selected for in vitro tests and cell culture studies. These formulations have particle sizes of 98 and 93nm, and zeta potential values of 10.5 and 8.9mV, respectively. Plasmid DNA in these complexes was protected against DNaseI and serum-mediated degradation. Substantial part of DNA retained its supercoiled and circular conformation. TEM images showed nearly spherical complex structure. Both formulations reduced STAT3 expression by approx. 5-fold in cisplatin resistant Calu1 cell line and increased the sensitivity of cells to cisplatin.

Extracellular Vesicles as Natural Nanosized Delivery Systems for Small-Molecule Drugs and Genetic Material: Steps towards the Future Nanomedicines

A new platform for drug, gene and peptide-protein delivery is emerging, under the common name of “extracellular vesicles”. Extracellular vesicles (EVs) are 30-1000 nm-sized cell-derived, liposome-like vesicles. Current research on EVs as nano-delivery systems for small-molecule drugs and genetic material, reveal that these tiny, biologically-derived vesicles carry a great potential to boost the efficacy of many therapeutic protocols. Several features of EVs; from efficacy to safety, from passive to active targeting ability, the opportunity to be biologically or chemically labelled, and most importantly, their eobiotic origin make them promising candidate for development of the next generation personalized nanomedicines. The aim of this article is to provide a view on the current research in which EVs are used as drug/genetic material delivery systems. Their application areas, drug loading and targeting strategies, and biodistribution properties are discussed.This article is open to POST-PUBLICATION REVIEW. Registered readers (see “For Readers”) may comment by clicking on ABSTRACT on the issue’s contents page.

Identification of Y chromosome microdeletions in infertile Turkish men

OBJECTIVE

The aim of this study was to determine the frequencies of Y chromosome microdeletions in infertile azoospermic and oligozoospermic Turkish men and in healthy control subjects.

MATERIAL AND METHODS

Sixty-four azoospermic and 51 oligozoospermic patients infertile patients, and 70 healthy men who had a child without the aid of assisted reproductive technologies were included in this study. DNA was extracted from peripheral blood samples collected from the patients. Following multiplex PCR performed with 15 different primer sequences, Y chromosome AZFa, AZFb, AZFc and AZFd region microdeletions were determined by agarose gel electrophoresis.

RESULTS

Y chromosome microdeletions were detected in 8 (12.5%) patients in the azoospermia group and 3 (5.9%) patients in the oligozoospermia group. The overall frequency of Y chromosome microdeletions in all infertile cases was 9.6%. Y chromosome microdeletions were not found in the healthy control group. Among the infertile cases, there were 4 (3.48%) AZFa, 2 (1.74%) AZFb, 3 (2.61%) AZFc and 7 (6.09%) AZFd region microdeletions. Y chromosome microdeletions were not found among healthy men in the control group.

CONCLUSION

The presence of Y chromosome microdeletions among azoospermic and oligozoospermic infertile males suggests that routine genetic testing and genetic counseling prior to the use of assisted reproduction techniques are necessary.

miR-15a enhances the anticancer effects of cisplatin in the resistant non-small cell lung cancer cells

Platinum-based chemotherapies have long been used as a standard treatment in non-small cell lung cancer. However, cisplatin resistance is a major problem that restricts the use of cisplatin. Deregulated cell death mechanisms including apoptosis and autophagy could be responsible for the development of cisplatin resistance and miRNAs are the key regulators of these mechanisms. We aimed to analyse the effects of selected miRNAs in the development of cisplatin resistance and found that hsa-miR-15a-3p was one of the most significantly downregulated miRNAs conferring resistance to cisplatin in Calu1 epidermoid lung carcinoma cells. Only hsa-miR-15a-3p mimic transfection did not affect cell proliferation or cell death, though decreased cell viability was found when combined with cisplatin. We found that induced expression of hsa-miR-15a-3p via mimic transfection sensitised cisplatin-resistant cells to apoptosis and autophagy. Our results demonstrated that the apoptosis- and autophagy-inducing effects of hsa-miR-15a-3p might be due to suppression of BCL2, which exhibits a major connection with cell death mechanisms. This study provides new insights into the mechanism of cisplatin resistance due to silencing of the tumour suppressor hsa-miR-15a-3p and its possible contribution to apoptosis, autophagy and cisplatin resistance, which are the devil's triangle in determining cancer cell fate.

Beta-myosin heavy-chain mutations R403QLW, V606M, K615N and R663H in patients with hypertrophic cardiomyopathy

OBJECTIVE

Hypertrophic cardiomyopathy (HCM) is a disease of the myocardium with an autosomal-dominant pattern of inheritance mainly caused by single heterozygous mutations in sarcomere genes. In this study we aimed to detect the presence of R403QLW, V606M, K615N, and R663H mutations in beta-myosin heavy-chain gene (MYH7) and figure out the genotype-phenotype correlations in Turkish patients with HCM.

METHODS

This case-control study based on genotype-phenotype correlation included 69 patients (mean age, years: 50±13.16) diagnosed with HCM constituting the study group and 50 healthy individuals (mean age, years: 52±1.4) constituting the control group. DNA was extracted from peripheral blood and the genotyping of mutations was performed by real-time PCR technique and high resolution melting analysis. Associations between categoric variables were determined using chi-square tests. Differences between two groups were compared with unpaired Student's t-test for continuous variables.

RESULTS

None of the patients in the HCM group were carrying the index mutations. One healthy individual was found to be heterozygous for the R663H mutation with mildly abnormal IVS and LVPW thickness. The allele frequency for R663H (G>A) mutation was found to be 0.01% in control group.

CONCLUSION

We performed a mutational screening of 6 HCM-associated mutations in 69 Turkish HCM patients (not previously studied except R403Q). There was no significant difference in the prevalence of the mutations between the patients with HCM and the healthy controls (p>0.05).

Suppression of STAT5A and STAT5B chronic myeloid leukemia cells via siRNA and antisense-oligonucleotide applications with the induction of apoptosis

Signal transducers and activators of transcription (STAT) proteins function in the JAK/STAT signaling pathway and are activated by phosphorylation. As a result of this signaling event, they affect many cellular processes including cell growth, proliferation, differentiation, and survival. Increases in the expressions of STAT5A and STAT5B play a remarkable role in the development of leukemia in which leukemic cells gain uncontrolled proliferation and angiogenesis ability. At the same time, these cells acquire ability to escape from apoptosis and host immune system. In this study, we aimed to suppress STAT-5A and -5B genes in K562 CML cells by siRNA transfection and antisense oligonucleotides (ODN) targeting and then to evaluate apoptosis rate. Finally, we compared the transfection efficiencies of these approaches. Quantitative RT-PCR and Western blot results indicated that STAT expressions were downregulated at both mRNA and protein levels following siRNA transfection. However, electroporation mediated ODN transfection could only provide limited suppression rates at mRNA and protein levels. Moreover, it was displayed that apoptosis were significantly induced in siRNA treated leukemic cells as compared to ODN treated cells. As a conclusion, siRNA applications were found to be more effective in terms of gene silencing when compared to ODN treatment based on the higher apoptosis and mRNA suppression rates. siRNA application could be a new and alternative curative method as a supporting therapy in CML patients.

Evaluation of the Effects of STZ-Induced Diabetes on In Vitro Fertilization and Early Embryogenesis Processes

The aim of this study was to investigate the effects of experimentally induced diabetes on (a) germ cells, (b) in vitro fertilization (IVF) success rate, and (c) gap junction and cell adhesion molecule gene and protein expressions during the early blastocyst period. Germ cells were obtained from healthy and diabetic rats, analyzed for number, motility, and morphology, and used for IVF. After reaching the early blastocyst stage, the expressions of genes encoding gap junction proteins and cell adhesion molecules were analyzed by quantitative RT-PCR. Histomorphologically and immunohistochemically analyses were also performed. Diabetes significantly affected sperm number and motility and the development of oocytes. Gene expressions of β -catenin and connexin family members and protein expressions of E-cadherin and connexin-43 significantly decreased in groups including germ cells isolated from diabetic rats. Connective tissue growth factor expression increased in groups that included sperm cells isolated from diabetic male rats, whereas mucin-1 expression increased in the group that included oocytes isolated from diabetic female rats paired with sperm cells isolated from healthy male rats. In summary, experimentally induced diabetes was found to influence gap junctions, cell adhesion molecules, and associated proteins which all have important roles in germ cell maturation, fertilization, and development.