Journal of Epigenetics
Volume:1 Issue: 1, Winter 2019

Substance abuse is known as a relapsing and chronic disorder. Drug abuse has a significant role in the dopaminergic system in which dopamine is an important neurotransmitter.  Binding dopamine and dopamine receptors could activate major intracellular signalling through protein kinase A (PKA). Activation of intracellular signalling such CREB affect gene expression of some genes. As dopamine and dopaminergic system have an important regulation role in the inhibition of immune system we analysed the effects of drug addiction on the DNA methylation and expression of cytotoxic T-lymphocyte antigen 4 (CTLA-4). We evaluate promoter methylation and mRNA expression of CTLA-4 in individual with drug addiction. DNA was extracted from blood of 74 patients with drug addiction and 59 healthy controls. Methylation of CTLA-4 promoter was assessed using a methylation-specific PCR technique. In addition the expression level of CTLA-4 was also indicated in 17 individuals with drug addiction and 18 people of controls. Although Promoter Methylation of CTLA-4 was not significantly different between these two groups, expression of CTLA-4 was remarkably different among them. We observed that each one of the drugs can increase the mRNA expression of CTLA_4. Therefore, we suggest that further research for other epigenetic factors is required to detect the underlying cause of changing gene expression.

Trastuzumab has been applied widely in the treatment of breast cancer. The majority of initial responders display disease progression again within one year. Regardless of the high resistance rate, the molecular mechanisms affected this disease are not well understood. MicroRNAs are small, non-coding RNA molecules that involved in gene regulation. There is evidence that promotes miRNAs as potential candidates to mediate therapeutic actions by targeting genes involved in drug response. The purpose of this study is to evaluate miR-885-3p in HER2 positive breast cancer chemoresistance. Trastuzumab-resistant BT-474 cells were generated by in vitro culture of BT-474 cells continuously in the presence of trastuzumab about 9 months. The relative expression of miR-885-3p to U6 RNA was evaluated in trastuzumab-resistant and sensitive cells using Relative Real-Time PCR. The Mann-Whitney test is used to compare the differences between the two groups. The MTT assay showed that BT-474 breast cancer cells were resistant to this drug under long-term culturing with trastuzumab (p < 0.05). MiR-885-3p expression was also significantly downregulated in trastuzumab-resistant cells in comparison with the parent cells (p < 0.05).:  As the relative expression of candidate microRNAs was statistically different in trastuzumab-resistant and sensitive cells, we hypothesize that miR-885-3p downregulation as a possible mechanism of trastuzumab resistance.

The present study was carried out to detect Salmonella enterica in meat samples of commercial boilers (CB) and the spent hens (SH) in Ardabil, Iran. Metallo-β-lactamase (MBL) enzyme produced by Salmonella enterica strains isolated from poultry meat samples were detected by both biochemical and molecular methods. The study included 20 positive samples for Salmonella  enterica from boilers (CB) and spent hens (SH). The prevalence of Salmonella enterica for CB was 22% (11/50) and for SH was 18% (9/50). The antibiotic susceptibility testing for both CB and SH showed maximum number of Salmonella enterica isolates were resistant against Augmentin (30 μg), Cotrimaxazole (25 μg) and Tetracycline (25 μg) and susceptible against Ofloxacin (5 μg) and Gentamicin (10 μg). Screening phenotypic confirmatory test for Metallo-β-lactamase (MBL) for CB, (n= 11, 100%) were positive for MBL while for SH (n= 8, 88.88%) samples were positive for MBL. The results showed that MBL positive Salmonella enterica isolates from CB and SH meat samples contained gene blaVIM (n=11, 57.89%), blaIMP (n=6, 31.57%) and blaSPM-1(n=2, 10.52%). Since Salmonella infections in poultry are high due to large demand and antibiotic resistance to strains, so the purpose of the current study is to focus on the detection of MBL enzyme produced by Salmonella enterica isolates.

Aberrant DNA methylation is an epigenetic event that occurs by methyltransferases. DNMT3A and DNMT3B are responsible for de novo methylation that plays important roles in normal development and disease. A number of reports on methylation of various genes in endometrial cancer have been published, but most of these studies focused on tumor suppressor genes. In this study, we determined the promoter methylation pattern of DNMT3A and DNMT3B genes; also we analyzed correlations between methylation statuses with clinicopathological parameters. 28 patients and 22 healthy controls were studied. Isolation of genomic DNA from FFPE and peripheral blood was performed and Methylation-Specific PCR (MSP) was applied for analysis the promoter CpG methylation status of DNMT3A and DNMT3Bgenes in the studied population. A significant difference was found between the study groups and the presence of promoter CpG hypermethylation status in the DNMT3A (P=0.04) gene. Furthermore methylation status between tissue and blood samples of DNMT3A genewas not significant (p=0.78). Our results indicated correlation between age and menopausal state with DNMT3B promoter methylation, but there were no significant relationships between parameters such as tumor grade, type of tumor, amount of metastasis and myometrium invasion, furthermore diabetes (p = 0.01) and obesity (p = 0.027) were two important items in endometrial cancer incidence. In our study hypermethylation of DNMT3A gene was found as an important event in carcinogenesis of endometrial cancer. The inactivation epigenetic of methylation regulation genes is a common occurrence in many cancers, including endometrial cancer.

Plant epigenetic has become one of the key research topics not only as the subject of basic research, but also as a new source of useful traits for plant breeding. Epigenetic regulation is necessary for the production of differentiated cells throughout plant development, as well as maintaining the stability and integrity of the gene expression profiles. Although epigenetic processes are essential for natural growth, they can become misdirected led to abnormal phenotypes and diseases. Epigenetics is the study of heritable phenotype changes that do not involve alterations in the DNA sequence. The microstructure (not code) of DNA itself or the associated chromatin proteins may be modified, causing activation or silencing. This mechanism enables differentiated cells in a multicellular organism to express only the genes which are necessary for their own activity. In this review, our goal is to introduce epigenetics and its different applications in plants, especially in production of transgenic plants, plants tolerate to biotic and abiotic stresses and understanding the mechanisms of gene silencing. Also, in this review, we have referred to the role of transposons in epigenetic, epigenetic engineering methods, epigenetic fingerprinting and ultimately methods for epigenetic data analysis and related databases.

Epigenetic in insects is an important origin of biodiversity that can convert environmental stimuli into heritable phenotypic changes and biological variation without mutations and independent changes in the DNA sequence, by variation of gene expression levels. Epigenetic may play important roles in the parameters such as development, longevity, reproduction, gender-specific phenotypic variation, immunity and evolution of both insect-plant and insect-microbe interactions. To investigate the molecular bases of epigenetic, social insects like ants provide a natural experimental system.  In social insects, multiple phenotypes and distinct types of individuals arise from a single genome. The existence of alternative phenotypes encoded by the same genome is known as polyphenism. Caste polyphenism is originated from molecular information that once established can be later maintained through epigenetic inheritance. As well as, Host–parasite interactions are intimate epigenetic relationships. Insect Epigenetic mechanisms are divided in to before transcription and post-transcriptional gene regulation. DNA methylation and histone acetylation/deacetylation are before transcription and small non-coding RNAs known as microRNAs are referred to as post-transcriptional gene regulation. Methylation is common throughout the genome and it is reported as origin of differential gene expression in social insect castes. In general, insects possess relatively low levels of DNA methylation, compared to mammalian systems. Epigenetic studies in insects are not only progressing, but also promising to find a solution for pesticide resistance.

Hypnea species were found in southern coasts of Iran. This genus is an important red alga which comprises about 53 species world-wide and has a wide geographical distribution on the tropical shores around the world. In Iran, about 10 species of this genus has been reported from subtidal zone of Persian Gulf and Gulf of Oman coasts. The present study considers assessment of genetic diversity of 10 populations of 3 species of Hypnea by using 6 ISSR primers. Genetic diversity parameters were determined among populations. The genetic divergence of the studied populations was checked by Neighbor Joining (NJ) and Principal component analysis (PCA). Genetic differentiation of the studied species and populations was studied by AMOVA (Analysis of molecular variance) test. The Mantel test was performed to study association between molecular distance and geographical distance of the studied populations. Grouping of the populations by NJ clustering separated the studied species in 2 distinct clusters. The most populations of  H. musciformis formed a separate cluster and were placed far from the other species. H. ecklonii and H. cornuta showed some degree of relationship and were placed close to each other. AMOVA test showed significant genetic difference among populations. The Mantel test did not show correlation between the genetic distance and geographical distance of these populations.