Breast cancer with various biological diversity known as the common reason of death in the world ... more Breast cancer with various biological diversity known as the common reason of death in the world and despite progress in novel therapeutic approaches, it faced with failure and recurrence in general. Recent clinical and preclinical statistics support cancer stem cells (CSCs) hypothesis and its similarities with normal stem cells. Evaluation of related paper conclude in significance finding in the further characterization of CSCs biology such as surface biomarkers, microenvironment regulatory molecules, cell signaling pathways, cell to cell transition and drug efflux pumps to overcome multidrug resistance and effective therapy. Emerging novel data indicate biological concepts in the base of unsuccessful treatment. A powerful understanding of the cell signaling pathways in cancer and CSCs topics can be led us to define and control treatment problems in cancer. More recently nano medicine based on drug delivery system modification and new implications on combinatorial therapy have been...
Introduction: Failure and recurrence in breast cancer treatment cause a great obstacle in cancer ... more Introduction: Failure and recurrence in breast cancer treatment cause a great obstacle in cancer therapy and identification of cell population named cancer stem cells (CSCs) in the tumor can be led us to define it as target in novel therapeutic strategy. Objectives: The aim of this study is the finding of correlation between stemness and metastatic characteristic, also knowing CSCs as a potential target of therapy because of its developmental behavior and similarities with normal stem cells. Materials and Methods: Here, we focus on the expression of NANOG in breast CSCs, a key molecule in the physiological process of stem cells and the Let-7a that is involved in the differentiation of the cells. Results: In this work, we found that NANOG was highly expressed in SKBR3 and down-regulation of let-7a, as a differentiation miRNA, was found in MDA-MB-468 cells. Conclusion: It will be critical for the developing of effective anti-tumor drugs, utilizing mentioned concepts. Inhibition of NAN...
Stem cell therapy has indicated a promising treatment capacity for tissue regeneration. Multiple ... more Stem cell therapy has indicated a promising treatment capacity for tissue regeneration. Multiple sclerosis is an autoimmune-based chronic disease, in which the myelin sheath of the central nervous system is destructed. Scientists have not discovered any cure for multiple sclerosis, and most of the treatments are rather palliative. The pursuit of a versatile treatment option, therefore, seems essential. The immunoregulatory and non-chronic rejection characteristics of mesenchymal stem cells, as well as their homing properties, recommend them as a prospective treatment option for multiple sclerosis. Different sources of mesenchymal stem cells have distinct characteristics and functional properties; in this regard, choosing the most suitable cell therapy approach seems to be challenging. In this review, we will discuss umbilical cord/blood-derived mesenchymal stem cells, their identified exclusive properties compared to another adult mesenchymal stem cells, and the expectations of thei...
M aintenance of cellular identity relies on the expression of cell type-specific transcription fa... more M aintenance of cellular identity relies on the expression of cell type-specific transcription factors and the underlying state of the epigenome. During somatic cell reprogramming , lineage-committed cells can be converted into iPSCs on expression of critical transcriptional regulators of embryonic stem cells; namely, OCT4, SOX2, KLF4 and MYC (OSKM) 1. This process results in a complete change in cellular identity, and involves extensive transcriptional and epigenome-wide changes 2. The state of an epigenome is determined by the activities of chromatin writer, reader and eraser proteins. Therefore, chromatin regulators have emerged as important factors of cell identity and can act as facilita-tors or barriers to reprogramming 3. Inhibition of a number of major chromatin-related pathways can facilitate reprogramming, such as DNA methylation 4 , histone deacetylation 5 , histone H3 lysine 9 methylation 6,7 , CAF-1 complex 8 and NCoR/SMRT corepressors 9. These factors safeguard cellular identity mainly by preventing the activation of pluripotency genes. However, chromatin factors also safeguard cellular identity by perpetuating active somatic-specific gene transcription programs or by preventing the silencing of such genes on OSKM expression. Recent work has indicated that loss of the 'active' histone H3 lysine 27 acet-ylation (H3K27) mark from the enhancers of somatic-specific genes is an early step in reprogramming 10. An important remaining question is which chromatin factors counteract the OSKM-mediated silencing of lineage-specific gene expression in reprogramming. We had previously identified DOT1L-mediated histone H3 lysine 79 methylation as one of the key barriers to reprogramming that counteracts the silencing of lineage-specific genes 6. DOT1L inhibition could also replace KLF4 and MYC in human iPSC generation. In subsequent studies, inhibition of DOT1L activity has been shown to increase reprogramming efficiency in a wide range of systems 11,12. Importantly, DOT1L inhibitors facilitate the derivation of chemically induced pluripotent stem cells (ciPSCs) from mouse somatic cells 13. However, the generation of ciPSCs from human cells has not been achieved so far, suggesting that additional barriers exist for human cell reprogramming. The CBP and EP300 proteins are closely related histone acetyl-transferases (HATs) that act as transcriptional coactivators 14. CBP and EP300 (also known as KAT3A and KAT3B, respectively) are large, multi-domain proteins, which in addition to their catalytic HAT domain, contain bromodomains that bind acetylated histones and are required for chromatin binding 15-17. Localization of CBP/ EP300 in the genome has been used to identify cell type-specific enhancers in mice and humans 18,19. These coactivators also occupy super-enhancer regions, which have an important role in maintaining cell identity 20,21. Both coactivators are required for early embry-onic development and proper differentiation of a wide range of cell types 22. However, the role of these two major coactivators in reprogramming remains largely unknown. In this study, we carried out a chromatin-focused chemical screen to identify epigenetic regulators that can collaborate with DOT1L inhibition in reprogramming. We discover that CBP/EP300 bromodomain inhibition enhances reprogramming to pluripotency by facilitating the silencing of the somatic gene expression program. Results A chromatin-focused chemical screen for reprogramming. We carried out a reprogramming screen in the presence of inhibitors Silencing of the somatic cell type-specific genes is a critical yet poorly understood step in reprogramming. To uncover pathways that maintain cell identity, we performed a reprogramming screen using inhibitors of chromatin factors. Here, we identify acetyl-lysine competitive inhibitors targeting the bromodomains of coactivators CREB (cyclic-AMP response element binding protein) binding protein (CBP) and E1A binding protein of 300 kDa (EP300) as potent enhancers of reprogramming. These inhibitors accelerate reprogramming, are critical during its early stages and, when combined with DOT1L inhibition, enable efficient derivation of human induced pluripotent stem cells (iPSCs) with OCT4 and SOX2. In contrast, catalytic inhibition of CBP/EP300 prevents iPSC formation, suggesting distinct functions for different coactivator domains in reprogramming. CBP/EP300 bromodomain inhibition decreases somatic-specific gene expression, histone H3 lysine 27 acetylation (H3K27Ac) and chromatin accessibility at target promoters and enhancers. The master mesenchymal transcription factor PRRX1 is one such functionally important target of CBP/EP300 bromodomain inhibition. Collectively, these results show that CBP/EP300 bromodomains sustain cell-type-specific gene expression and maintain cell identity. NATURE ChEMiCAl BiOlOGy | VOL 15 | MAY 2019 | 519-528 | www.nature.com/naturechemicalbiology 519
The utilization of embryonic stem cells has ethical problems regarding the use of embryos in cell... more The utilization of embryonic stem cells has ethical problems regarding the use of embryos in cell therapy and regenerative medicine, especially in neurodegenerative diseases. To overcome these ethical issues, induced Pluripotent Stem Cells and then transdifferentiation have presented to the science world which can be a good shortcut and solution to the ethical issues of traditional methods. Neurodegenerative diseases are difficult puzzles to combine and with modeling of these diseases by somatic cells reprogramming such as induced pluripotent stem cells induction or direct differentiation techniques, this could be solved. In the present study, we briefly review the techniques which used for neurodegenerative diseases' researches.
The Peroxisome proliferator-activated receptor-gamma (PPARγ) is a member of the nuclear receptor ... more The Peroxisome proliferator-activated receptor-gamma (PPARγ) is a member of the nuclear receptor family of transcription factors. In addition to its role in lipid and glucose metabolisms, PPARγ has possible roles in tumor suppression. One of the most common variations in PPARγ is the Pro12Ala polymorphism. It is the change of proline amino acid to alanine amino acid by the conversion of cytosin (C) to guanine (G) at 34th nucleotide of the 12th codon PPARγ gene. Several recent studies have shown that Pro12Ala polymorphism may be associated with many diseases, such as obesity, diabetes, and some types of cancer. Moreover, Pro12Ala polimorphism has been shown to affect PPARγ mRNA expression in the context of obesity. However, there have been no studies investigating the relationship Pro12Ala polymorphism and PPARγ mRNA expression in cancer. In this study, Pro12Ala polymorphism in PPARγ gene was investigated in cancer and normal cell lines via using restriction fragment length polymorphism and Sanger Sequencing. Depending on the Pro12Ala status, the effect of the polymorphism on PPARγ mRNA expression was investigated via using Real Time Polymerase Chain Reaction. In conclusion; amongst 13 cell lines that were screened, heterozygous Pro12Ala polymorphism was detected only in AGS and Caki-1 cancer cell lines. PPARγ mRNA expression in these cell lines was found to be lower than PPARγ mRNA expression in cell lines without Pro12Ala polymorphism such as MCF10A, SK-BR-3, MDA-MB-468. Taken together, Pro12Ala polymorphism may modulate the mRNA expression level of PPARγ. The role of this modulation in cancer should further be investigated.
Leptin, a metabolic hormone, regulates the reproductive functions responding to both nutritional ... more Leptin, a metabolic hormone, regulates the reproductive functions responding to both nutritional and body conditions. Embryonic stem cells play important roles in reproductive technology, but their derivation can be challenging. In this study, we evaluated the derivation rates of mouse embryonic stem cell (mESC) line from blastocysts developing in embryo culture media supplemented with different leptin concentrations. The results showed that addition of leptin into the embryo culture medium supported the in vitro development of mouse embryo. The mESC line derivation rates for media treated with 0, 10, 50, and 100 ng/ml of leptin were 60.61% (40/61), 80% (32/40), 82.93% (47/56), and 90.7% (29/37), respectively. In addition, leptin treatment of blastocysts upregulated the expression levels of the trophectoderm marker Cdx2, whereas inner cell mass markers Oct-4 and Nanog were not affected. mESC lines derived after leptin treatment demonstrated hallmarks of pluripotency, such as alkaline phosphatase activity, expression of, OCT4, NANOG, and SSEA1, as well as the ability to form embryoid bodies and well-differentiated teratomas. In conclusion, leptin has a positive effect on the derivation rate of mouse embryonic stem cell lines which may be, in part, due to its effects on the development of the trophectoderm cell lineage in the embryo. Keywords Leptin. Mouse. Embryo. Stem cell. Development Prior conference presentation of the submitted: Taskin AC, A Kocabay, TT Onder and A Ebrahimi. (2016) Effect of leptin on derivation rate of mouse embryonic stem (ES) cell line. In TRANSGENIC RESEARCH M
Stem cell therapy has indicated a promising treatment capacity for tissue regeneration. Multiple ... more Stem cell therapy has indicated a promising treatment capacity for tissue regeneration. Multiple sclerosis is an autoimmune-based chronic disease, in which the myelin sheath of the central nervous system is destructed. Scientists have not discovered any cure for multiple sclerosis, and most of the treatments are rather palliative. The pursuit of a versatile treatment option, therefore, seems essential. The immunoregulatory and non-chronic rejection characteristics of mesenchymal stem cells, as well as their homing properties, recommend them as a prospective treatment option for multiple sclerosis. Different sources of mesenchymal stem cells have distinct characteristics and functional properties; in this regard, choosing the most suitable cell therapy approach seems to be challenging. In this review, we will discuss umbilical cord/blood-derived mesenchymal stem cells, their identified exclusive properties compared to another adult mesenchymal stem cells, and the expectations of their potential roles in the treatment of multiple sclerosis.
The end of linear chromosomes is formed of a special nucleoprotein heterochromatin structure with... more The end of linear chromosomes is formed of a special nucleoprotein heterochromatin structure with repetitive TTAGGG sequences called telomere. Telomere length is regulated by a special enzyme called telomerase, a specific DNA polymerase that adds new telomeric sequences to the chromosome ends. Telomerase consists of two parts; the central protein part and the accessory part which is a RNA component transported by the central part. Regulation of telomere length by this enzyme is a multi-stage process. Telomere length elongation is strongly influenced by the level of telomerase and has a strong correlation with the activity of telomerase enzyme. Human Telomerase Reverse Transcriptase (hTERT) gene expression plays an important role in maintaining telomere length and high proliferative property of cells. Except a low activity of telomerase enzyme in hematopoietic and few types of stem cells, most of somatic cells didn't showed telomerase activity. Moreover, cytokines are secretory proteins that control many aspects of hematopoiesis, especially immune responses and inflammation. Also, the induction of hTERT gene expression by cytokines is organized through the PI3K/AKT and NF/kB signaling pathways. In this review we have tried to talk about effects of immune cell cytokines on telomerase expression/telomere length and the induction of telomerase expression by cytokines.
Fibroblasts from a Familial Mediterranean Fever (FMF) patient were reprogrammed with episomal vec... more Fibroblasts from a Familial Mediterranean Fever (FMF) patient were reprogrammed with episomal vectors by using the Neon Transfection System for the generation of integration-free induced pluripotent stem cells (iPSCs). The resulting iPSC line was characterized to determine the expression of pluripotency markers, proper differentiation into three germ layers, the presence of normal chromosomal structures as well as the lack of genomic integration. A homozygous missense mutation in the MEFV gene (p.Met694Val), which lead to typical FMF phenotype, was shown to be present in the generated iPSC line.
Introduction: There is a powerful relationship between high-risk human papillomaviruses and lung ... more Introduction: There is a powerful relationship between high-risk human papillomaviruses and lung cancer. In fact, inactivation of p53 is the most common genetic abnormality in lung cancer. Indeed, the frequency of HPV types and TP53 mutations in squamous cell carcinoma of lung, among patients from the northwest of Iran has been evaluated in this article. Methodes: Fifty Paraffin embedded blocks of lung SCC were selected for detection of HPV DNA by Nested PCR, and then DNA was sequenced for HPV typing. Equal numbers of positive and negative samples for the HPV DNA were examined for the presence of mutations in exons 5-7 of the TP53 gene by PCR and direct sequencing. Results: Overtly 9 (18%) of 50 samples presented the HPV DNA: eight were HPV-18 and one was HPV-6. TP53 mutations were found in 5 samples (27.7%). Of these, 4 cases showed mutations in exon 5 and one case contained a mutation in exon 7.The most frequent mutation in exon 5 was the C to G transversion (c.409C>G), and also the T to A tansversion (c.770T>A) in exon 7. Conclusion: This study showed that HPV-18 is more likely to conscequence in the development of lung cancer among some communities. Genetic alterations, alongside with environmental factors, all play a significant role in the pathogenesis of lung cancer.
Background: Human papilloma virus causes benign and malignant abnormalities in different part of ... more Background: Human papilloma virus causes benign and malignant abnormalities in different part of the body. The link between high risk types of HPV and some anogenital and aerodigestive tract cancer is well established. Oral HPV infection plays a role in developing oropharyngeal squamous cell carcinoma. We studied the prevalence of oral HPV in healthy individuals and its relative risk factors. Methods: Saliva samples of 114 healthy subjects were collected for HPV DNA analysis. Volunteers completed questionnaires and signed a written consent. For data analysis descriptive statistic, chi square test and odds ratio was used. Results: The frequency of oral HPV in healthy individuals was 6.1 %( seven participant).The most frequent type was HPV-18 in five of them.HPV-6 and HPV-66 each was detected in one case. Relation of oral HPV positivity to demographic features and risk factors was not statistically significant. Conclusions: The prevalence of oral HPV infection in our community is the same as many other communities of developing countries, stressing that HPV-18 were the dominant type.
Background: Epidemiologic and molecular evidences have established a strong link between high ris... more Background: Epidemiologic and molecular evidences have established a strong link between high risk types of Human Papilloma Virus and a subgroup of Head and Neck Squamous Cell Carcinomas (HNSCC). We evaluated the frequency of HPV positivity in HNSCC and its relationship to demographic and some risk factor variables in an open case-control study.
Although the diagnosis and treatment studies that can be developed by clarifying the pathology of... more Although the diagnosis and treatment studies that can be developed by clarifying the pathology of Alzheimer's disease (AD), which is one of the most common dementia in the world, have been studied intensively, an explicit result cannot be obtained. With new technologies developing every day, new approaches are being tried. The investigation of miRNA as a biomarker in the diagnosis of AD has recently started in this context. miRNAs are thought to have significant effects on the pathology of neural functions and hence neurological diseases. The ideal candidate for being a biomarker is a high rate of miRNAs in the brain and the circular system, and the key roles they play in the pathology of neurodegenerative diseases. In this chapter, the possible use of miRNAs as biological markers in AD is discussed.
Induced pluripotent stem cells (iPSCs) offer great promise as tools for basic biomedical research... more Induced pluripotent stem cells (iPSCs) offer great promise as tools for basic biomedical research, disease modeling, and drug screening. In this chapter, we describe the generation of patient-specific, transgene-free iPSCs from skin biopsies and peripheral blood mononuclear cells through electroporation of episomal vectors and growth under two different culture conditions. The resulting iPSC lines are characterized with respect to pluripotency marker expression through immunostaining, tested for transgene integration by PCR, and assayed for differentiation capacity via teratoma formation.
Breast cancer with various biological diversity known as the common reason of death in the world ... more Breast cancer with various biological diversity known as the common reason of death in the world and despite progress in novel therapeutic approaches, it faced with failure and recurrence in general. Recent clinical and preclinical statistics support cancer stem cells (CSCs) hypothesis and its similarities with normal stem cells. Evaluation of related paper conclude in significance finding in the further characterization of CSCs biology such as surface biomarkers, microenvironment regulatory molecules, cell signaling pathways, cell to cell transition and drug efflux pumps to overcome multidrug resistance and effective therapy. Emerging novel data indicate biological concepts in the base of unsuccessful treatment. A powerful understanding of the cell signaling pathways in cancer and CSCs topics can be led us to define and control treatment problems in cancer. More recently nano medicine based on drug delivery system modification and new implications on combinatorial therapy have been...
Introduction: Failure and recurrence in breast cancer treatment cause a great obstacle in cancer ... more Introduction: Failure and recurrence in breast cancer treatment cause a great obstacle in cancer therapy and identification of cell population named cancer stem cells (CSCs) in the tumor can be led us to define it as target in novel therapeutic strategy. Objectives: The aim of this study is the finding of correlation between stemness and metastatic characteristic, also knowing CSCs as a potential target of therapy because of its developmental behavior and similarities with normal stem cells. Materials and Methods: Here, we focus on the expression of NANOG in breast CSCs, a key molecule in the physiological process of stem cells and the Let-7a that is involved in the differentiation of the cells. Results: In this work, we found that NANOG was highly expressed in SKBR3 and down-regulation of let-7a, as a differentiation miRNA, was found in MDA-MB-468 cells. Conclusion: It will be critical for the developing of effective anti-tumor drugs, utilizing mentioned concepts. Inhibition of NAN...
Stem cell therapy has indicated a promising treatment capacity for tissue regeneration. Multiple ... more Stem cell therapy has indicated a promising treatment capacity for tissue regeneration. Multiple sclerosis is an autoimmune-based chronic disease, in which the myelin sheath of the central nervous system is destructed. Scientists have not discovered any cure for multiple sclerosis, and most of the treatments are rather palliative. The pursuit of a versatile treatment option, therefore, seems essential. The immunoregulatory and non-chronic rejection characteristics of mesenchymal stem cells, as well as their homing properties, recommend them as a prospective treatment option for multiple sclerosis. Different sources of mesenchymal stem cells have distinct characteristics and functional properties; in this regard, choosing the most suitable cell therapy approach seems to be challenging. In this review, we will discuss umbilical cord/blood-derived mesenchymal stem cells, their identified exclusive properties compared to another adult mesenchymal stem cells, and the expectations of thei...
M aintenance of cellular identity relies on the expression of cell type-specific transcription fa... more M aintenance of cellular identity relies on the expression of cell type-specific transcription factors and the underlying state of the epigenome. During somatic cell reprogramming , lineage-committed cells can be converted into iPSCs on expression of critical transcriptional regulators of embryonic stem cells; namely, OCT4, SOX2, KLF4 and MYC (OSKM) 1. This process results in a complete change in cellular identity, and involves extensive transcriptional and epigenome-wide changes 2. The state of an epigenome is determined by the activities of chromatin writer, reader and eraser proteins. Therefore, chromatin regulators have emerged as important factors of cell identity and can act as facilita-tors or barriers to reprogramming 3. Inhibition of a number of major chromatin-related pathways can facilitate reprogramming, such as DNA methylation 4 , histone deacetylation 5 , histone H3 lysine 9 methylation 6,7 , CAF-1 complex 8 and NCoR/SMRT corepressors 9. These factors safeguard cellular identity mainly by preventing the activation of pluripotency genes. However, chromatin factors also safeguard cellular identity by perpetuating active somatic-specific gene transcription programs or by preventing the silencing of such genes on OSKM expression. Recent work has indicated that loss of the 'active' histone H3 lysine 27 acet-ylation (H3K27) mark from the enhancers of somatic-specific genes is an early step in reprogramming 10. An important remaining question is which chromatin factors counteract the OSKM-mediated silencing of lineage-specific gene expression in reprogramming. We had previously identified DOT1L-mediated histone H3 lysine 79 methylation as one of the key barriers to reprogramming that counteracts the silencing of lineage-specific genes 6. DOT1L inhibition could also replace KLF4 and MYC in human iPSC generation. In subsequent studies, inhibition of DOT1L activity has been shown to increase reprogramming efficiency in a wide range of systems 11,12. Importantly, DOT1L inhibitors facilitate the derivation of chemically induced pluripotent stem cells (ciPSCs) from mouse somatic cells 13. However, the generation of ciPSCs from human cells has not been achieved so far, suggesting that additional barriers exist for human cell reprogramming. The CBP and EP300 proteins are closely related histone acetyl-transferases (HATs) that act as transcriptional coactivators 14. CBP and EP300 (also known as KAT3A and KAT3B, respectively) are large, multi-domain proteins, which in addition to their catalytic HAT domain, contain bromodomains that bind acetylated histones and are required for chromatin binding 15-17. Localization of CBP/ EP300 in the genome has been used to identify cell type-specific enhancers in mice and humans 18,19. These coactivators also occupy super-enhancer regions, which have an important role in maintaining cell identity 20,21. Both coactivators are required for early embry-onic development and proper differentiation of a wide range of cell types 22. However, the role of these two major coactivators in reprogramming remains largely unknown. In this study, we carried out a chromatin-focused chemical screen to identify epigenetic regulators that can collaborate with DOT1L inhibition in reprogramming. We discover that CBP/EP300 bromodomain inhibition enhances reprogramming to pluripotency by facilitating the silencing of the somatic gene expression program. Results A chromatin-focused chemical screen for reprogramming. We carried out a reprogramming screen in the presence of inhibitors Silencing of the somatic cell type-specific genes is a critical yet poorly understood step in reprogramming. To uncover pathways that maintain cell identity, we performed a reprogramming screen using inhibitors of chromatin factors. Here, we identify acetyl-lysine competitive inhibitors targeting the bromodomains of coactivators CREB (cyclic-AMP response element binding protein) binding protein (CBP) and E1A binding protein of 300 kDa (EP300) as potent enhancers of reprogramming. These inhibitors accelerate reprogramming, are critical during its early stages and, when combined with DOT1L inhibition, enable efficient derivation of human induced pluripotent stem cells (iPSCs) with OCT4 and SOX2. In contrast, catalytic inhibition of CBP/EP300 prevents iPSC formation, suggesting distinct functions for different coactivator domains in reprogramming. CBP/EP300 bromodomain inhibition decreases somatic-specific gene expression, histone H3 lysine 27 acetylation (H3K27Ac) and chromatin accessibility at target promoters and enhancers. The master mesenchymal transcription factor PRRX1 is one such functionally important target of CBP/EP300 bromodomain inhibition. Collectively, these results show that CBP/EP300 bromodomains sustain cell-type-specific gene expression and maintain cell identity. NATURE ChEMiCAl BiOlOGy | VOL 15 | MAY 2019 | 519-528 | www.nature.com/naturechemicalbiology 519
The utilization of embryonic stem cells has ethical problems regarding the use of embryos in cell... more The utilization of embryonic stem cells has ethical problems regarding the use of embryos in cell therapy and regenerative medicine, especially in neurodegenerative diseases. To overcome these ethical issues, induced Pluripotent Stem Cells and then transdifferentiation have presented to the science world which can be a good shortcut and solution to the ethical issues of traditional methods. Neurodegenerative diseases are difficult puzzles to combine and with modeling of these diseases by somatic cells reprogramming such as induced pluripotent stem cells induction or direct differentiation techniques, this could be solved. In the present study, we briefly review the techniques which used for neurodegenerative diseases' researches.
The Peroxisome proliferator-activated receptor-gamma (PPARγ) is a member of the nuclear receptor ... more The Peroxisome proliferator-activated receptor-gamma (PPARγ) is a member of the nuclear receptor family of transcription factors. In addition to its role in lipid and glucose metabolisms, PPARγ has possible roles in tumor suppression. One of the most common variations in PPARγ is the Pro12Ala polymorphism. It is the change of proline amino acid to alanine amino acid by the conversion of cytosin (C) to guanine (G) at 34th nucleotide of the 12th codon PPARγ gene. Several recent studies have shown that Pro12Ala polymorphism may be associated with many diseases, such as obesity, diabetes, and some types of cancer. Moreover, Pro12Ala polimorphism has been shown to affect PPARγ mRNA expression in the context of obesity. However, there have been no studies investigating the relationship Pro12Ala polymorphism and PPARγ mRNA expression in cancer. In this study, Pro12Ala polymorphism in PPARγ gene was investigated in cancer and normal cell lines via using restriction fragment length polymorphism and Sanger Sequencing. Depending on the Pro12Ala status, the effect of the polymorphism on PPARγ mRNA expression was investigated via using Real Time Polymerase Chain Reaction. In conclusion; amongst 13 cell lines that were screened, heterozygous Pro12Ala polymorphism was detected only in AGS and Caki-1 cancer cell lines. PPARγ mRNA expression in these cell lines was found to be lower than PPARγ mRNA expression in cell lines without Pro12Ala polymorphism such as MCF10A, SK-BR-3, MDA-MB-468. Taken together, Pro12Ala polymorphism may modulate the mRNA expression level of PPARγ. The role of this modulation in cancer should further be investigated.
Leptin, a metabolic hormone, regulates the reproductive functions responding to both nutritional ... more Leptin, a metabolic hormone, regulates the reproductive functions responding to both nutritional and body conditions. Embryonic stem cells play important roles in reproductive technology, but their derivation can be challenging. In this study, we evaluated the derivation rates of mouse embryonic stem cell (mESC) line from blastocysts developing in embryo culture media supplemented with different leptin concentrations. The results showed that addition of leptin into the embryo culture medium supported the in vitro development of mouse embryo. The mESC line derivation rates for media treated with 0, 10, 50, and 100 ng/ml of leptin were 60.61% (40/61), 80% (32/40), 82.93% (47/56), and 90.7% (29/37), respectively. In addition, leptin treatment of blastocysts upregulated the expression levels of the trophectoderm marker Cdx2, whereas inner cell mass markers Oct-4 and Nanog were not affected. mESC lines derived after leptin treatment demonstrated hallmarks of pluripotency, such as alkaline phosphatase activity, expression of, OCT4, NANOG, and SSEA1, as well as the ability to form embryoid bodies and well-differentiated teratomas. In conclusion, leptin has a positive effect on the derivation rate of mouse embryonic stem cell lines which may be, in part, due to its effects on the development of the trophectoderm cell lineage in the embryo. Keywords Leptin. Mouse. Embryo. Stem cell. Development Prior conference presentation of the submitted: Taskin AC, A Kocabay, TT Onder and A Ebrahimi. (2016) Effect of leptin on derivation rate of mouse embryonic stem (ES) cell line. In TRANSGENIC RESEARCH M
Stem cell therapy has indicated a promising treatment capacity for tissue regeneration. Multiple ... more Stem cell therapy has indicated a promising treatment capacity for tissue regeneration. Multiple sclerosis is an autoimmune-based chronic disease, in which the myelin sheath of the central nervous system is destructed. Scientists have not discovered any cure for multiple sclerosis, and most of the treatments are rather palliative. The pursuit of a versatile treatment option, therefore, seems essential. The immunoregulatory and non-chronic rejection characteristics of mesenchymal stem cells, as well as their homing properties, recommend them as a prospective treatment option for multiple sclerosis. Different sources of mesenchymal stem cells have distinct characteristics and functional properties; in this regard, choosing the most suitable cell therapy approach seems to be challenging. In this review, we will discuss umbilical cord/blood-derived mesenchymal stem cells, their identified exclusive properties compared to another adult mesenchymal stem cells, and the expectations of their potential roles in the treatment of multiple sclerosis.
The end of linear chromosomes is formed of a special nucleoprotein heterochromatin structure with... more The end of linear chromosomes is formed of a special nucleoprotein heterochromatin structure with repetitive TTAGGG sequences called telomere. Telomere length is regulated by a special enzyme called telomerase, a specific DNA polymerase that adds new telomeric sequences to the chromosome ends. Telomerase consists of two parts; the central protein part and the accessory part which is a RNA component transported by the central part. Regulation of telomere length by this enzyme is a multi-stage process. Telomere length elongation is strongly influenced by the level of telomerase and has a strong correlation with the activity of telomerase enzyme. Human Telomerase Reverse Transcriptase (hTERT) gene expression plays an important role in maintaining telomere length and high proliferative property of cells. Except a low activity of telomerase enzyme in hematopoietic and few types of stem cells, most of somatic cells didn't showed telomerase activity. Moreover, cytokines are secretory proteins that control many aspects of hematopoiesis, especially immune responses and inflammation. Also, the induction of hTERT gene expression by cytokines is organized through the PI3K/AKT and NF/kB signaling pathways. In this review we have tried to talk about effects of immune cell cytokines on telomerase expression/telomere length and the induction of telomerase expression by cytokines.
Fibroblasts from a Familial Mediterranean Fever (FMF) patient were reprogrammed with episomal vec... more Fibroblasts from a Familial Mediterranean Fever (FMF) patient were reprogrammed with episomal vectors by using the Neon Transfection System for the generation of integration-free induced pluripotent stem cells (iPSCs). The resulting iPSC line was characterized to determine the expression of pluripotency markers, proper differentiation into three germ layers, the presence of normal chromosomal structures as well as the lack of genomic integration. A homozygous missense mutation in the MEFV gene (p.Met694Val), which lead to typical FMF phenotype, was shown to be present in the generated iPSC line.
Introduction: There is a powerful relationship between high-risk human papillomaviruses and lung ... more Introduction: There is a powerful relationship between high-risk human papillomaviruses and lung cancer. In fact, inactivation of p53 is the most common genetic abnormality in lung cancer. Indeed, the frequency of HPV types and TP53 mutations in squamous cell carcinoma of lung, among patients from the northwest of Iran has been evaluated in this article. Methodes: Fifty Paraffin embedded blocks of lung SCC were selected for detection of HPV DNA by Nested PCR, and then DNA was sequenced for HPV typing. Equal numbers of positive and negative samples for the HPV DNA were examined for the presence of mutations in exons 5-7 of the TP53 gene by PCR and direct sequencing. Results: Overtly 9 (18%) of 50 samples presented the HPV DNA: eight were HPV-18 and one was HPV-6. TP53 mutations were found in 5 samples (27.7%). Of these, 4 cases showed mutations in exon 5 and one case contained a mutation in exon 7.The most frequent mutation in exon 5 was the C to G transversion (c.409C>G), and also the T to A tansversion (c.770T>A) in exon 7. Conclusion: This study showed that HPV-18 is more likely to conscequence in the development of lung cancer among some communities. Genetic alterations, alongside with environmental factors, all play a significant role in the pathogenesis of lung cancer.
Background: Human papilloma virus causes benign and malignant abnormalities in different part of ... more Background: Human papilloma virus causes benign and malignant abnormalities in different part of the body. The link between high risk types of HPV and some anogenital and aerodigestive tract cancer is well established. Oral HPV infection plays a role in developing oropharyngeal squamous cell carcinoma. We studied the prevalence of oral HPV in healthy individuals and its relative risk factors. Methods: Saliva samples of 114 healthy subjects were collected for HPV DNA analysis. Volunteers completed questionnaires and signed a written consent. For data analysis descriptive statistic, chi square test and odds ratio was used. Results: The frequency of oral HPV in healthy individuals was 6.1 %( seven participant).The most frequent type was HPV-18 in five of them.HPV-6 and HPV-66 each was detected in one case. Relation of oral HPV positivity to demographic features and risk factors was not statistically significant. Conclusions: The prevalence of oral HPV infection in our community is the same as many other communities of developing countries, stressing that HPV-18 were the dominant type.
Background: Epidemiologic and molecular evidences have established a strong link between high ris... more Background: Epidemiologic and molecular evidences have established a strong link between high risk types of Human Papilloma Virus and a subgroup of Head and Neck Squamous Cell Carcinomas (HNSCC). We evaluated the frequency of HPV positivity in HNSCC and its relationship to demographic and some risk factor variables in an open case-control study.
Although the diagnosis and treatment studies that can be developed by clarifying the pathology of... more Although the diagnosis and treatment studies that can be developed by clarifying the pathology of Alzheimer's disease (AD), which is one of the most common dementia in the world, have been studied intensively, an explicit result cannot be obtained. With new technologies developing every day, new approaches are being tried. The investigation of miRNA as a biomarker in the diagnosis of AD has recently started in this context. miRNAs are thought to have significant effects on the pathology of neural functions and hence neurological diseases. The ideal candidate for being a biomarker is a high rate of miRNAs in the brain and the circular system, and the key roles they play in the pathology of neurodegenerative diseases. In this chapter, the possible use of miRNAs as biological markers in AD is discussed.
Induced pluripotent stem cells (iPSCs) offer great promise as tools for basic biomedical research... more Induced pluripotent stem cells (iPSCs) offer great promise as tools for basic biomedical research, disease modeling, and drug screening. In this chapter, we describe the generation of patient-specific, transgene-free iPSCs from skin biopsies and peripheral blood mononuclear cells through electroporation of episomal vectors and growth under two different culture conditions. The resulting iPSC lines are characterized with respect to pluripotency marker expression through immunostaining, tested for transgene integration by PCR, and assayed for differentiation capacity via teratoma formation.
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Papers by Ayyub Ebrahimi
Methods: Saliva samples of 114 healthy subjects were collected for HPV DNA analysis. Volunteers completed questionnaires and signed a written consent. For data analysis descriptive statistic, chi square test and odds ratio was used. Results: The frequency of oral HPV in healthy individuals was 6.1 %( seven participant).The most frequent type was HPV-18 in five of them.HPV-6 and HPV-66 each was detected in one case. Relation of oral HPV positivity to demographic features and risk factors was not statistically significant. Conclusions: The prevalence of oral HPV infection in our community is the same as many other communities of developing countries, stressing that HPV-18 were the dominant type.
Books by Ayyub Ebrahimi
Methods: Saliva samples of 114 healthy subjects were collected for HPV DNA analysis. Volunteers completed questionnaires and signed a written consent. For data analysis descriptive statistic, chi square test and odds ratio was used. Results: The frequency of oral HPV in healthy individuals was 6.1 %( seven participant).The most frequent type was HPV-18 in five of them.HPV-6 and HPV-66 each was detected in one case. Relation of oral HPV positivity to demographic features and risk factors was not statistically significant. Conclusions: The prevalence of oral HPV infection in our community is the same as many other communities of developing countries, stressing that HPV-18 were the dominant type.