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 Introduction and purpose : Gastrointestinal cancers are among the most frequently occurring cancers worldwide. Environmental and inherited factors could be contributed to the etiology of these cancers. Lifestyle factors such as dietary habits, physical activity and smoking may play an important role in the occurrence of these types of cancer. Gastric cancer is the fourth most common cancer and second leading cause of cancer death worldwide. Nisin is an antimicrobial peptide with 34 amino acids and due to having the Lantionin amino acid categorized as Lantibiotic peptides family. The purpose of this study is to evaluate the nisin effect on cell cytotoxicity of gastric cancer.  

 Method : For evaluation of nisin cytotoxic effect on AGS cell line, they were cultured in 96-well plates at a density of 1×104 cells per well and incubated for overnight 37°C. After 24 h, cells were treated in a triplicate manner with different concentrations of nisin including 0, 10, 20, 40, 60 and 80 micromolar and for each concentration was repeated 3 times. The cytotoxic effect of nisin on cells in the intervals 24, 48 and 72 h after treatment were investigated. 

 Results : In each interval with concentration increase, cells viability reduction was observed, In addition, Cytotoxicity increased in longer time treatment. 

 Discussion: Many peptides having biological activities are used as therapeutic agents. These peptides, including nisin, which causes death in AGS cells, Cytotoxicity effect of nisin on cells is concentration and time depended.

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Background & aim: Gastro-intestinal cancers are the most common kind of cancers all over the world. They are multifactorial disease and both genetical and environmental factors are involved in their progression. Adenocarcinoma is the most common type of stomach cancers. Brevinin-2R is a novel antimicrobial and anticancer peptide that is isolated from the skin secretions of a family of frogs called Rana. The 25-amino acid long peptide shows anticancer activity and induces antimicrobial activity. Brevinin-2R is a 25 amino acid long cationic peptide that shows very low hemolytic activity against red blood cells. In this paper we study cytotoxicity of brevinin-2R onto AGS cell line.

Material and Methods: AGS cell line incubated with different concentrations of peptide and different period of time, cytotoxicity of peptide and viability of AGS cell line assessed by MTT-assay. The experiment repeated three times and the average viability values were calculated.

Results: Findings shows that viability of treated cells decreased consistent with increasing concentrations and period of time.

Conclusion: Because of low hemolytic activity, Brevinin-2R is a good specimen in drug designing. Brevinin-2R triggers cell death by means of activation of autophagy and shows anticancer activity against AGS malignant cell lines.

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Materials and methods: AGS cells were transfused using lipofactamine solution and plasmid carrying the tagD gene encoding Helicobacter pylori or empty plasmid (control). RNA extraction was then performed from cultured cells and cDNA synthesis was performed, and then the eukaryotic expression of Helicobacter pylori gene tagD in AGS cells was investigated by RT-PCR method. The expression of GPR83 genes was evaluated by Real Time PCR method. It should be noted that the enoxin kit was used to evaluate apoptosis, and finally the expression of each gene was evaluated using SPSS software and t-test Indepent statistical tests.
Results: Results: The findings from gene expression analysis showed that the expression of GPR83 gene in AGS cells treated with tagD increased compared to control cells, but this increase in expression was not statistically significant (P = 0.0888).
Conclusion: Overall, the data obtained from this study showed that GPR83 gene expression is altered in cells treated with the Helicobacter pylori tagD gene and seems to play a role in the expression of Helicobacter pylori

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Aim and Background: Brassica napus has one of the most important oilseed crops in the world, which has undergone extensive genome reconstruction following an interspecies hybridization of Brassica rapa and Brassica oleracea. In order to understand the functional changes of B. napus genome during the evolution, comparison of gene expression was performed in three species of Brassica.
Materials and Methods: Seed preliminary data of three Brassica libraries were collected from the Harvard university database. To find similarities between three libraries, all EST sequences were assembled using EGassembler software. Then, all contigs were analyzed by X-blast using CLC Protein workbench software against nonredundant proteins of gene bank. IDEG6 software was used to identify genes with different expression between libraries. MapMan comparative classification tool was used to classify functional catalogs.
Results: Comparison of gene expression between the three species showed that 23 genes in 5 functional groups including fatty acids, storage proteins, amino acids, transcriptional regulation and signaling were statistically significant.
Conclusion: While B. rapa and B. oleracea encode the largest number of ESTs involved in the biosynthesis of erucic acid and linolenic acid, genome in B. napus has evolved to produce more oleic acid and linoleic acid, which may have resulted from the deletion or duplication of the genome during evolution. In addition, Cruciferin transcripts accounted for 40% of total seed storage protein transcripts. This study paves the way for further research on the genetic consequences of polyploidy during canola breeding evolution.

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Aim and Background: The use of affinity tags is a conventional method for purifying recombinant proteins. However, their removal in later stages is mandatory for therapeutic peptides or proteins, which not only prolongs the purification process but also imposes significant costs on the producer. A peptide sequence with an affinity for hydroxyapatite allows for the purification of recombinant peptides or proteins while enabling their binding to hydroxyapatite-containing structures such as teeth, bones, and even bone grafts. This can play a significant role in biomaterials, tissue engineering, surgery, and dental implants. The goal of this study is to utilize affinity sequences that eliminate the need for removal after purifying the desired protein using affinity chromatography columns, which is a priority in biotechnology and therapeutics.
Material and Methods: In this study, a fusion peptide derived from platelet-derived growth factor (PDGF-BB) was designed, containing a hydroxyapatite-binding sequence and His6x tag. To remove the histidine tag, the sequence was designed with primers containing XhoI and NdeI restriction sites and was subsequently cloned into the pET21a (+) vector. Polymerase chain reaction (PCR) and double enzymatic digestion were performed. The designed fusion peptide was expressed in Escherichia coli, confirmed through SDS-PAGE electrophoresis, and verified using Western blotting. The recombinant fusion peptide was purified using hydroxyapatite resin. To evaluate peptide binding to the scaffold, a release test was conducted, which was assessed using the Bradford protein assay and curve analysis. Cellular viability, proliferation, and growth were examined via the MTT assay.
Results: Expression of the designed fusion peptide in Escherichia coli was optimized. Cloning in the pET21a(+) vector was confirmed after PCR and double enzymatic digestion through gene sequencing. The expression was validated by SDS-PAGE and Western blotting, showing a peptide band at approximately 17 kDa. The peptide release assay demonstrated that the PDGF-BB fusion peptide binds stably to the hydroxyapatite scaffold, preventing complete peptide release on the first day in SBF (Simulated Body Fluid). On the second day, approximately 40% of the peptide was released, followed by stabilization (plateau). The MTT assay revealed cell viability and proliferation over 24 hours, with maximum growth observed at a concentration of 2.9 µg/mL compared to the control group.
Conclusion: In this study, a novel peptide derived from PDGF-BB with stable performance was designed, expressed, and purified using hydroxyapatite resin. The dual-purpose use of the hydroxyapatite-binding affinity tag not only enhances its efficiency in purification processes using hydroxyapatite-based ceramic affinity columns but also serves as an affinity factor for bone scaffolds in tissue engineering.