Overexpression of reactive oxygen species modulator 1 is associated with advanced grades of bladder cancer

Molecular Biology Reports - Reactive Oxygen Species Modulator 1 (ROMO1) plays a pivotal role in the regulation of mitochondrial structure integrity, and the production of reactive oxygen species...     

Quantification of Ultrasonic Scattering Properties of In Vivo Tumor Cell Death in Mouse Models of Breast Cancer

INTRODUCTION: Quantitative ultrasound parameters based on form factor models were investigated as potential biomarkers of cell death in breast tumor (MDA-231) xenografts treated with chemotherapy. METHODS: Ultrasound backscatter radiofrequency data were acquired from MDA-231 breast cancer tumor–bearing mice (n = 20) before and after the administration of chemotherapy drugs at two ultrasound frequencies: 7 MHz and 20 MHz. Radiofrequency spectral analysis involved estimating the backscatter coefficient from regions of interest in the center of the tumor, to which form factor models were fitted, resulting in estimates of average scatterer diameter and average acoustic concentration (AAC). RESULTS: The ∆AAC parameter extracted from the spherical Gaussian model was found to be the most effective cell death biomarker (at the lower frequency range, r² = 0.40). At both frequencies, AAC in the treated tumors increased significantly (P = .026 and .035 at low and high frequencies, respectively) 24 hours after treatment compared with control tumors. Furthermore, stepwise multiple linear regression analysis of the low-frequency data revealed that a multiparameter quantitative ultrasound model was strongly correlated to cell death determined histologically posttreatment (r² = 0.74). CONCLUSION: The Gaussian form factor model–based scattering parameters can potentially be used to track the extent of cell death at clinically relevant frequencies (7 MHz). The 20-MHz results agreed with previous findings in which parameters related to the backscatter intensity (i.e., AAC) increased with cell death. The findings suggested that, in addition to the backscatter coefficient parameter ∆AAC, biological features including tumor heterogeneity and initial tumor volume were important factors in the prediction of cell death response.     

Effect of culture conditions on canthaxanthin production by Dietzia natronolimnaea HS-1

This study investigated the effects of various culture parameters (carbon sources, temperature, initial pH of culture, NaCl concentration, and light) on the growth and canthaxanthin production by Dietzia natronolimnaea HS-1. The results showed that the most effective carbon source for growth and canthaxantin production was glucose, and the best pH and temperature were 7 and 31 degrees C, respectively. In addition, the biomass and canthaxanthin production increased in a medium without NaCl and in the presence of light. Under the optimized conditions, the maximum biomass, total carotenoid, and canthaxanthin production were 6.12 +/- 0.21 g/l, 4.51 +/- 0.20 mg/l, and 4.28 +/- 0.15 mg/l, respectively, in an Erlenmeyer flask system, yet increased to 7.25 g/l, 5.48 mg/l, and 5.29 mg/l, respectively, in a batch fermenter system.     

Improved osteogenic differentiation of human induced pluripotent stem cells cultured on polyvinylidene fluoride/collagen/platelet-rich plasma composite nanofibers

Blood transfusion or blood products, such as plasma, have a long history in improving health, but today, platelet-rich plasma (PRP) is used in various medical areas such as surgery, orthopedics, and rheumatology in many ways. Considering the high efficiency of tissue engineering in repairing bone defects, in this study, we investigated the combined effect of nanofibrous scaffolds in combination with PRP on the osteogenic differentiation potential of human induced pluripotent stem cells (iPSCs). Electrospinning was used for fabricating nanofibrous scaffolds by polyvinylidene fluoride/collagen (PVDF/col) with and without PRP. After scaffold characterization, the osteoinductivity of the fabricated scaffolds was studied by culturing human iPSCs under osteogenic medium. The results showed that PRP has a considerable positive effect on the biocompatibility of the PVDF/col nanofibrous scaffold when examined by protein adsorption, cell attachment, and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays. In addition, the results obtained from alkaline phosphatase activity and calcium content assays demonstrated that nanofibers have higher osteoinductivity while grown on PRP-incorporated PVDF/col nanofibers. These results were also confirmed while the osteogenic differentiation of the iPSCs was more investigated by evaluating the most important bone-related genes expression level. According to the results, it can be concluded that PVDF/col/PRP has much more osteoinductivity while compared with the PVDF/col, and it can be introduced as a promising bone bio-implant for use in bone tissue engineering applications.     

Molecular cloning, expression and purification of recombinant soluble mouse endostatin as an anti-angiogenic protein in Escherichia coli

Inhibition of angiogenesis has become a particular interest for treatment of solid tumors. Endostatin, a C-terminal fragment of collagen XVIII, has been reported to exhibit potent inhibitory effect on endothelial cells proliferation, migration and tube formation. In this research, the cDNA library of endostatin was synthesized from mouse liver and inserted into the SacI and SalI enzyme-cutting sites of pUC18 cloning vector. The recombinant vector was transferred into Escherichia coli DH5a and the recombinant clone was selected on LB agar plate plus ampicillin. PCR analysis and DNA sequencing proved the presence of intact endostatin gene in pUC18. The endostatin gene subcloned into pET32a expression vector and the competent bacterial cells of E. coli BL21 were transformed by the vector harboring endostatin gene. In the optimum conditions, expression plasmid was induced with IPTG and recombinant soluble endostatin as a fusion with thioredoxin was purified with Ni–NTA (Ni²⁺-nitrilotriacetate) resin. The results showed that soluble recombinant endostatin as a fusion protein with thioredoxin is a homogenous polypeptide that inhibits angiogenesis (capillary tube formation) in human umbilical vein endothelial cells by 200 ng/ml.     

Detection and isolation of tick‐borne bacteria (Anaplasma spp., Rickettsia spp., and Borrelia spp.) in Amblyomma varanense ticks on lizard (Varanus salvator)

Ticks are one of the arthropods that play an important role in the transmission of numerous pathogens to livestock and humans. We investigated the presence of tick‐borne bacteria in 23 Amblyomma varanense that fed on a water monitor (Varanus salvator) in Indonesia. Anaplasmataceae and borreliae were detected by PCR in 17.4% and 95.7% of ticks, respectively. “Candidatus Rickettsia sepangensis”, spotted fever group of Rickettsia, was detected in 21.7% of ticks. The water monitor is a common reptile that is widely encountered in city areas in Asian countries. Our results suggested that Am. varanense on water monitor in Indonesia harbored several kinds of bacteria.     

DNA restriction--modification enzymes of phage P1 and plasmid p15B. Subunit functions and structural homologies

We have purified the type III restriction enzymes EcoP1 and EcoP15 to homogeneity from bacteria that contain the structural genes for the enzymes cloned on small, multicopy plasmids and which overproduce the enzymes. Both of the enzymes contain two different subunits. The molecular weights of the subunits are the same for both enzymes and antibodies prepared against one enzyme cross-react with both subunits of the other. Bacteria containing a plasmid derivative in which a large part of one of the structural genes has been deleted have a restriction- modification+ phenotype and contain only the smaller of the two subunits. This subunit therefore must be the one that both recognizes the specific DNA sequence and methylates it in the modification reaction (the restriction enzyme itself also acts as a modification methylase). We have purified the P1 and P15 modification subunits from these deletion derivatives and have shown that in vitro they have the expected properties: they are sequence-specific modification methylases. In addition, we have demonstrated that strains carrying the full restriction/modification system also contain a pool of free modification subunits that might be responsible for in vivo modification.     

Effect of alkylation with streptozotocin on the secondary structure of DNA

S₁ nuclease hydrolysis and hydroxyapatite chromatography were used to study the effect of the alkylating antibiotic, streptozotocin, on the secondary structure of DNA. Native calf thymus DNA was alkylatedin vitro with increasing concentrations of streptozotocin and subjected to S 1 nuclease hydrolysis. An increasing degree of DNA degradation was seen, suggesting a destabilization of the secondary structure. Indirect evidence, deduced from alkaline hydrolysis, effect of NaCl on S₁ nuclease hydrolysis, and hydroxyapatite chromatographic analysis of alkylated DNA, suggested a significant alkylation of DNA phosphates in addition to DNA bases. Nictotinamide has been reported to alter the cytotoxic and carcinogenic effects of streptozotocin. Our experiments indicate that in the presence of nicotinamide, streptozotocin causes the formation of a greater proportion of alkylated bases in relation to alkyl phosphotriesters. This may have significance in relation to the differential cytotoxicity of streptozotocin in the absence and presence of nicotinamide.