FigurePurpose: Determining the MMR gene mutation careers in HNPCC families to prevent advanced disease by early diagnosis through recommended screening tests, decreasing both mortality and morbidity rates. Methods: 592 unselected colorectal cancer patients were screened for MMR mutations by immunohistochemical analysis. For patients with defects in expression of at least one of the MMR proteins, full mutational analysis was performed by PCR amplification of each exon of the respective gene, including the flanking intronic regions, follwed by bidirectional sequencing. Any variation in DNA sequence was confirmed on an independent PCR product. Paired tumoral and genomic DNA samples were used for microsatellite instability testing.Table: Clinical characteristics of 56 cases with colorectal cancer who met the Amsterdam II CriteriaResults: 56/592 families fulfilled the Amsterdam Criteria II. 47/592 patients had lack of expression of MMR protein(s); 17(36%) MLH1, 25(53%) MSH2 and 5(11%) PMS2. Among them, we have found 20 mutations in 18/47 families so far. 7 mutations were novel mutations and were reported to the GenBank (GenBank accession numbers: EF570785-EF570789, EF583852 and EF125076). Genetic tests were offered to at risk family members of these patients. Conclusion: Our results provide further insight into the mutational spectrum of MMR genes in Iranian HNPCC families.
Breast cancer is among the most prevalent mortal cancers in women worldwide. In the present study, an optimum formulation of letrozole, letrozole-loaded niosome, and empty niosome was developed, and the anticancer effect was assessed in in vitro MCF-7, MCF10A and MDA-MB-231 breast cancer cell lines.Various niosomal formulations of letrozole were fabricated through thin-film hydration method and characterized in terms of size, polydispersity index (PDI), morphology, entrapment efficiency (EE%), release kinetics, and stability. Optimized niosomal formulation of letrozole was achieved by response surface methodology (RSM). Antiproliferative activity and the mechanism were assessed by MTT assay, quantitative real-time PCR, and flow cytometry. Furthermore, cellular uptake of optimum formulation was evaluated by confocal electron microscopy.The formulated letrozole had a spherical shape and showed a slow-release profile of the drug after 72 h. The size, PDI, and eEE% of nanoparticles showed higher stability at 4°C compared with 25°C. The drug release from niosomes was in accordance with Korsmeyer-Peppa's kinetic model. Confocal microscopy revealed the localization of drug-loaded niosomes in the cancer cells. MTT assay revealed that all samples exhibited dose-dependent cytotoxicity against breast cancer cells. The IC50 of mixed formulation of letrozole with letrozole-loaded niosome (L + L3) is the lowest value among all prepared formulations. L+L3 influenced the gene expression in the tested breast cancer cell lines by down-regulating the expression of Bcl2 gene while up-regulating the expression of p53 and Bax genes. The flow cytometry results revealed that L + L3 enhanced the apoptosis rate in both MCF-7 and MDA-MB-231 cell lines compared with the letrozole (L), letrozole-loaded niosome (L3), and control sample.Results indicated that niosomes could be a promising drug carrier for the delivery of letrozole to breast cancer cells.
Background/aim: This study aimed to investigate the efficacy of pegylated liposomal etoposide nanoparticles (NPs) against T-47D and MCF-7 breast cancer cell lines. Materials and methods: Pegylated liposomal etoposide NPs were prepared by reverse phase evaporation method. The size, size distribution, and zeta potential of the NPs was measured by a Zetasizer instrument. The cytotoxicity of NPs was inspected by methyl thiazol tetrazolium assay. The release pattern of the drug from the vesicles was studied by the dialysis method. Drug loading and encapsulation efficiency (EE) were also measured. Results: The mean size, size distribution, and zeta potential of pegylated liposomal etoposide NPs were 491 ± 15.5 nm, 0.504 ± 0.14, and -35.8 ± 2.5 mV, respectively. Drug loading and EE were 10.3 ± 1.6% and 99.1 ± 2.8%, respectively. The etoposide release in the formulation was estimated at about 3.48% after 48 h. The cytotoxicity effect of etoposide NPs on T-47D and MCF-7 cell lines of breast cancer showed higher antitumor activity as compared with those of the free drug. Conclusion: Liposome-based NPs may hold great potential as a drug delivery system.
Introduction: We assessed whether 16S rDNA and gyrB gene sequences, alone or combined, were suitable for determining the phylogenetic relationship among Salmonella enterica strains isolated from Tehran, Iran. Patients over five years of age enrolled in an acute diarrheal surveillance project in Tehran province between May 2004 and October 2006 were selected as our study group. Methodology: 16S ribosomal DNA (rDNA) and gyrB genes from 40 Salmonella isolates obtained from patients with acute diarrhea were sequenced and the data was used to generate phylogenetic trees that facilitated isolate comparison. Results: Salmonella strains clustered into five to seven phylogenetic groups, dependent on analysis of 16S rDNA (1546 bp), gyrB (1256 bp) or a combination of the two genes. By 16S rDNA sequence analysis, only strains of Salmonella enterica serovar Typhi ( S. Typhi) clustered exclusively together. gyrB sequences permitted clustering of all the S. Typhi and S. Paratyphi A isolates, and clustering of S. Enteritidis into two separate but exclusive groups. Concatenation of the two data sets did not significantly improve the resolution of the strains compared to the gyrB gene. None of the analyses completely resolved S. enterica Paratyphi B and C into mutually exclusive groups. Conclusion: Sequencing of gyrB represents a potentially useful tool for determining the phylogenetic relationship of S. enterica strains in Tehran, Iran. Genetic analysis of the 16S rRNA gene alone or in combination with gyrB did not increase the resolution between serotypes of S. enterica. We speculate that inclusion of additional genetic markers would improve the sensitivity of the analysis.
Purpose: To encapsulate paclitaxel into nanoliposomes, followed by pegylatation, in order to improve its therapeutic index and reduce side effects in breast cancer.Methods: In order to prepare nanoliposomal paclitaxel, varying ratios of phosphatidylcholine, cholesterol and paclitaxel were mixed and the formulations pegylated with poly-ethylene glycol 2000 (PEG 2000) to enhance stability, efficiency, as well as solubility. The mean diameter of nanoliposomal paclitaxel and pegylated nanoliposomal paclitaxel were measured by Zeta sizer device and release of paclitaxel from both formulations was determined within 28 h by dialysis method. The cytotoxicity of nanoliposomal and pegylated nanoliposomal paclitaxel was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay.Results: The mean diameter of nanoliposomal paclitaxel and pegylated nanoliposomal paclitaxel was 421.4 and 369.1 nm, respectively, while encapsulation efficiency was 91.3 ± 5.7 and 95.2 ± 6.3 %, respectively. Paclitaxel released from both formulations in 28 h was 5.53 and 5.02 %, respectively. The cytotoxicity of pegylated nanoliposomal paclitaxel was significantly (p . 0.05) greater than that of nanoliposomal paclitaxel (their IC50 = 79.8±2.9 and 86.25±3.4 µg/ml, respectively).Conclusion: The release pattern and cytotoxicity of pegylated nanoliposomal paclitaxel show that the formulation is superior to nanoliposomal paclitaxel. Furthermore, the mean particle size of pegylatednanoliposome is smaller than that of the non-pegylated preparation.Keywords: Paclitaxel, Nanoliposome, Breast cancer, Pegylation, Drug delivery, Cytotoxicity
Received: 13/Feb/2008, Accepted: 5/Jun/2008 Objective: To determine the role of global genome methylation in gastritis lesion and its relation with clinicopathologic finding. Materials and Methods: The study was conducted on 44 gastritis and normal adjacent specimens using a technique composed of restriction enzyme digestion and pyrosequencing known as LUMA (LUminometric Methylation Assay). At first, DNA extracted from gastritis lesion and normal tissue was digested with HpaII (sensitive to methylation in recognition site) and MspI (insensitive). These enzymes leave an overhang after cutting which are then filled in a polymerase extension assay with stepwise addition of dNTPs using pyrosequencing. The comparison of the height of picks obtained form both enzymes provides the possibility to evaluate and compare global genome methylation level of normal and gastritis tissues. If the target site is fully methylated, the HpaII /MspI will approach toward zero .If not, this ratio will go around one. In the other conditions the ratio varies between 0-1. Results: According to our findings, gastritis tissue was significantly more hypomethylated (p=0.04) than the nornal tissue and Global genome methylation had no correlation with sex, age, microsatellite instability (MSI) and gastritis severity. Conclusion: Global DNA hypomethylation occurs in the gastritis lesion. Presumably the process of hypomethylation keeps falling in the next steps leading to gastric cancer.
To investigate the role of MYOC and CYP1B1 in Iranian juvenile open angle glaucoma (JOAG) patients.Twenty-three JOAG probands, their available affected and unaffected family members, and 100 ethnically matched control individuals without history of ocular disease were recruited. Clinical examinations of the probands included slit lamp biomicroscopy, intraocular pressure (IOP) measurement, gonioscopic evaluation, fundus examination, and perimetry measurement. Familial cases were classified according to the mode of inheritance. Exons of MYOC and CYP1B1 were sequenced, and novel variations assessed in the control individuals. Potential disease-associated variations were tested for segregation with disease status in available family members.The mode of inheritance of the disease in the families of four probands (17.4%) appeared to be autosomal dominant and in at least eight (34.8%) to be autosomal recessive. Four patients carried MYOC mutations, and an equal number carried CYP1B1 mutations. The MYOC mutations were heterozygous; two of them (p.C8X and p.L334P) are novel, and one codes for the shortest truncated protein so far reported. Autosomal recessive inheritance was consistent with inheritance observed in families of patients carrying CYP1B1 mutations. All these patients carried homozygous mutations.MYOC and CYP1B1 contributed equally to the disease status of the Iranian JOAG patients studied. The contribution of the two genes appeared to be independent in that no patient carried mutations in both genes. The fraction of Iranian patients carrying MYOC mutations was comparable to previously reported populations.
Vinblastine (VB), as a chemotherapeutic agent, is widely used in treatment of different types of cancer. However, its clinical application is limited due to its low water solubility, side effects, and multidrug resistance. The aim of this study was to increase the therapeutic efficacy of VB using drug delivery systems. For this purpose, a PEGylated niosomal formulation of vinblastine (Pn-VB) was prepared by thin film hydration method and physicochemically characterized. Drug release pattern was performed by dialysis diffusion method. The cytotoxicity of Pn-VB was investigated against murine lung cancer TC-1 cells using MTT assay and its tumor inhibitory effect was evaluated in lung tumor-bearing C57BL/6 mice. Mean particle size, zeta potential, entrapment, and loading efficiency of niosomes were obtained to be about 234.3 ± 11.4 nm, -34.6 ± 4.2 mV, 99.92 ± 1.6%, and 2.673 ± 0.30%, respectively. While, the mean particle size and zeta potential for non-PEGylated niosomes were obtained about 212.4 nm and -31.4 mV, respectively. The in vitro release pattern of drug from niosomes showed a sustained release behavior. Pn-VB indicated a significant increase in toxicity against TC-l cells as compared to free VB. In animal model, Pn-VB exhibited stronger tumor inhibitory effect and longer life time in comparison to free VB. In conclusion, Pn-VB showed appropriate stability, high-entrapment efficacy, lower releasing rate, and stronger cytotoxic activity against lung cancer TC-1 cells as compared to free drug. Thus, the Pn-VB could be a promising formulation for delivery of vinblastine to tumor cells with enhanced drug bioavailability and therapeutic efficacy.
Bacterial Celluloses (BC) are gaining importance in research and commerce due to numerous factors affecting the bacterial cellulose characteristics and application in different industries. The aim of the present study was to produce bacterial cellulose in different media using different cultivation vessels. Bacterial cellulose was produced by static cultivation of Glucanacetobacter xylinum ATCC 10245 in different culture media such as Brain Heart Agar, Luria Bertani Agar /Broth, Brain Heart Infusion, Hestrin-Schramm and medium no. 125. Cultivation of bacterium was conducted in various culture vessels with different surface area. The cellulose membrane was treated and purified with a 0.1 M NaOH solution at 90 degreesC for 30 min and dried by a freeze- drier at -40 degreesC to obtain BC. The prepared bacterial cellulose was characterized by scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy and X-ray diffraction (XRD). The amount of produced BC was related directly to the surface area of culture vessels.
Purpose: Hydroxyurea (HU) is a well-known chemotherapy drug with several side effects which limit its clinical application. This study was conducted to improve its therapeutic efficiency against breast cancer using liposomes as FDA-approved drug carriers. Methods: PEGylated nanoliposomes-containing HU (NL-HU) were made via a thin-film hydration method, and assessed in terms of zeta potential, size, morphology, release, stability, cellular uptake, and cytotoxicity. The particle size and zeta potential of NL-HU were specified by zeta-sizer. The drug release from liposomes was assessed by dialysis diffusion method. Cellular uptake was evaluated by flow cytometry. The cytotoxicity was designated by methyl thiazolyl diphenyl-tetrazolium bromide (MTT) test. Results: The size and zeta value of NL-HU were gotten as 85 nm and -27 mV, respectively. NL-HU were spherical.NL-HU vesicles were detected to be stable for two months. The slow drug release and Weibull kinetic model were obtained. Liposomes considerably enhanced the uptake of HU into BT-474 human breast cancer cells. The cytotoxicity of NL-HU on BT-474 cells was found to be significantly more than that of free HU. Conclusion: The results confirmed these PEGylated nanoliposomes containing drug are potentially suitable against in vitro model of breast cancer.
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