Bromodomain inhibition of the coactivators CBP/EP300 facilitate cellular reprogramming.

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.

NANOG gene suppression and replacement of let-7 modulate the stemness, invasion, and apoptosis in breast cancer.

In the treatment of breast cancer (BC), as an important type of cancer in women, the specific cells, called cancer stem cells (CSCs), are the reason of failure and metastasis. So, targeting CSCs can be used as a novel strategy in cancer therapy in addition to common therapeutic strategies. According to the importance of CSCs, we tried to find a correlation between stemness and metastatic characteristics of BC cells, to address whether CSCs are a potential target for cancer therapy. Here, we evaluated the NANOG inhibition by siRNA and the increase of Let-7a levels by miRNA mimic in breast cancer cells and the effects of these changes on biologic aspects like cell apoptosis, stemness and invasion. Our results showed that the inhibition of NANOG combined with Let-7a restoration contributed to significant decrease in malignant phenotypes and stemness feature of BC cells. In conclusion, these findings showed that the combination of Let-7a miRNA mimic and Nanog siRNA could be exploited as a new treatment strategy to improve the cancer therapy outcome.

The role of miRNAs in the regulation of autophagy in autoimmune diseases.

Autoimmune diseases (AD), which are classified as chronic injuries, are caused by a specific auto-reactive reaction. The etiology of most ADs is not well understood. Meanwhile, Autophagy is a protective response defining as a catabolic method by lysosomes tending to maintain homeostasis acts by recycling and discrediting cell compartments. Autophagy plays a crucial role in controlling immune homeostasis by eliminating intracellular pathogens and presenting antigens to immune cognition. MicroRNAs are commonly known as endogenous non-coding small RNAs, which span 18-25 nt and take part in the gene expression at the post-transcriptional level regulation. miRNAs play important roles in different processes like, cell differentiation, duplicating, and apoptosis. Moreover, miRNAs are the critical molecules for the regular function of the immune system by modulating immune tolerance mechanisms and autoimmunity. Recent findings support the role of dysregulated miRNAs in the pathogenesis of ADs and in the regulation of autophagy. In this review, we will focus on the role of the miRNAs in the regulation of autophagy and then will explain the role of dysregulated miRNAs in the initiation of the ADs by modulating autophagy.

Recent Advances in Targeting of Breast Cancer Stem Cells Based on Biological Concepts and Drug Delivery System Modification.

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 used to treat breast cancer effectively. The aim of this review is focus on CSCs as a potential target of cancer therapy, to overcome the limitation and problems of current therapeutic strategies in cancer.

Somatic cell reprogramming as a tool for neurodegenerative diseases.

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 potentials of umbilical cord-derived mesenchymal stem cells in the treatment of multiple sclerosis.

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.

Leptin treatment of in vitro cultured embryos increases outgrowth rate of inner cell mass during embryonic stem cell derivation.

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 61.24 % (54/88), 84.96 % (42/50), 81.79 % (61/76), and 85.78 % (56/67), 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.

Telomerase activity and telomere on stem progeny senescence.

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.

Transgene-Free Disease-Specific iPSC Generation from Fibroblasts and Peripheral Blood Mononuclear Cells.

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.

Generation of integration-free induced pluripotent stem cells from a patient with Familial Mediterranean Fever (FMF).

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.

Genotyping of Human Papillomavirus and TP53 Mutaions at Exons 5 to 7 in Lung Cancer Patients from Iran.

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.