Circular RNAs and Its Biological Functions in Health and Disease

Circular RNAs (circRNAs) belong to the family of long noncoding RNAs (lncRNA) that, unlike linear RNAs, are characterized by a covalently closed circular RNA structure lacking 5′ cap and 3′ poly-adenylated tails. circRNAs have a role in epigenetic regulation of downstream targets. circRNAs play a crucial role in regulating gene and protein expressions by acting as a microRNA (miRNA) sponge and RNA binding protein (RBP) sponge and interact with proteins to affect cell behavior. circRNA expression profiles differ between physiological and pathological states. Moreover, the expression patterns of circRNAs exhibit differences in a tissue-specific manner. Although investigations on circRNAs have been exploding nowadays, yet only a limited number of circRNAs are identified. Furthermore, further researches are needed to shed light on their functions and targets. Therefore, circRNAs are becoming vital as potential biomarkers that may be used for the diagnosis and treatment of diseases. In this chapter, we review the current advancement of cirRNAs with regard to their biogenesis, biological functions, gene regulatory mechanisms, and implications in human diseases and summarize the recent studies on circRNAs as potential diagnostic and prognostic biomarkers based on existing knowledge

Phenoxodiol sensitizes metastatic colorectal cancer cells to 5-fluorouracil- and oxaliplatin-induced apoptosis through intrinsic pathway

Colorectal cancer (CRC) is one of the most common types of cancer seen in the world. 5-Fluorouracil (5-Fu) plus Oxaliplatin (1-OHP) remains the backbone of CRC chemotherapeutics, but with limited success. Phenoxodiol (Pxd) is an isoflavone analog with antitumor activity against various types of cancers, and sensitizes chemoresistant cancer cells to chemotherapeutics including platinum and taxanes. This study was, therefore, undertaken to examine whether Pxd pre-treatment with conventional chemotherapeutic agent(s) 5-Fu and 1-OHP co-administration be a therapeutic strategy for CRC. Cell viability and cytotoxicity were evaluated using dimethyl-thiazolyl diphenyl tetrazolium bromide (MTT) and lactate dehydrogenase assays. The percentage of apoptotic and necrotic cells were determined by fluorescence microscopy analysis. Besides, active Caspase-3 levels by ELISA and relative mRNA levels of Caspase 3 (CASP3), CASP8 and CASP9 genes were determined by quantitative real-time PCR (qPCR) analysis. The pre-treatment of Pxd followed by 5-Fu and 1-OHP co-administration was more effective at inhibiting cell viability than either chemotherapeutic agents treatment alone. When compared to 5-Fu with 1-OHP alone treatment, Pxd pre-treatment overwhelmingly increased apoptotic Caspase-3 activity levels in CRC cells. Moreover, qPCR analyses showed that CASP3 and CASP9 mRNA levels significantly increased after pre-treatment with Pxd followed by 5-Fu and 1-OHP treatments, compared to 5-Fu with 1-OHP alone. Our results suggested that Pxd enhanced the in vitro antitumor activity of 5-Fu and 1-OHP. Our study also suggested that Pxd may be a potential candidate agent in advanced CRC and inclusion of Pxd to the conventional chemotherapeutic agent(s) could be an effective therapeutic strategy for CRC

HDAC inhibitors, MS-275 and salermide, potentiates the anticancer effect of EF24 in human pancreatic cancer cells

Histone deacetylases (HDACs) play a major role in the regulation of chromatin structure and gene expression by changing acetylation status of histone and non-histone proteins. MS-275 (entinostat, MS) is a well-known benzamide-based HDACI and Salermide (SAL), a reverse amide compound HDACI, have antiproliferative effects on several human cancer cells. In this study, we aimed to investigate the effects of HDACIs (MS and SAL) alone and/or combined use with EF24 (EF), a novel synthetic curcumin analog, on human pancreatic cancer cell line (BxPC-3). In vitro, BxPC-3 cells were exposed to varying concentrations of MS, SAL with or without EF, and their effects on cell viability, acetylated Histone H3 and H4 levels, cytotoxicity, and cleaved caspase 3 levels, and cell cycle distribution were measured. The viability of BxPC-3 cells decreased significantly after treatment with EF, MS and SAL treatments. MS and SAL treatment increased the acetylation of histone H3 and H4 in a dose dependent manner. MS and SAL alone or combined with EF were increased the number of cells in G1 phase. In addition, treatment with agents significantly decreased the ratio of cell in G2/M phase. There were significant dose-dependent increases at cleaved Caspase 3 levels after MS treatment but not after SAL treatment. Our results showed that HDAC inhibitors (MS and SAL), when combined with EF, may effectively reduce pancreatic cancer cell (BxPC-3) progression and stop the cell cycle at G1 phase. Further molecular analyses are needed to understand the fundamental molecular consequences of HDAC inhibition in pancreas cancer cells

Flavopiridol Induces Apoptosis via Mitochondrial Pathway in B16F10 Murine Melanoma Cells and a Subcutaneous Melanoma Tumor Model

Flavopiridol is a cyclin-dependent kinase (CDK) inhibitor that promotes cell cycle arrest. We aimed to examine the anti-proliferative effects of the flavopiridol and oxaliplatin combination on p16INK4A deficient melanoma cells B16F10 and also its apoptotic effects on a subcutaneously injected B16F10 allograft melanoma tumor model. Flavopiridol and oxaliplatin treated B16F10 cell viability was determined by MTT assay. C57BL6 mice were injected with B16F10 cells and treated with flavopiridol after tumor implantation. BRAF and BCL2L1 mRNA expression levels were measured using reverse transcription-polymerase chain reaction (RT-PCR). Caspase 9 and caspase 3/7 activity were determined by activity assay kits. Proliferating cell nuclear antigen (PCNA) and B-cell lymphoma 2 (BCL-2) protein expression levels were analyzed immunohistochemically. Flavopiridol and oxaliplatin decreased cell death. Flavopiridol enhanced caspase 3/7 and caspase 9 activities in vitro and in vivo in a dose dependent manner via the mitochondrial apoptotic pathway. Even though there was a significant increase in Bcl-2 staining, PCNA staining was decreased in flavopiridol-administered mice. Decreased PCNA expression showed antiproliferative effects of flavopiridol which might be the result of cell-cycle arrest. Flavopiridol can be used as a cell cycle inhibitor, which induced apoptosis through the mitochondrial pathway, independently from BCL2 in B16F10 cells and B16F10 injected C57BL6 allografts. </p

PHENOXODIOL SENSITIZES METASTATIC COLORECTAL CANCER CELLS TO 5-FLUOROURACIL-AND OXALIPLATIN-INDUCED APOPTOSIS THROUGH INTRINSIC PATHWAY

Colorectal cancer (CRC) is one of the most common types of cancer seen in the world. 5-Fluorouracil (5-Fu) plus Oxaliplatin (1-OHP) remains the backbone of CRC chemotherapeutics, but with limited success. Phenoxodiol (Pxd) is an isoflavone analog with antitumor activity against various types of cancers, and sensitizes chemoresistant cancer cells to chemotherapeutics including platinum and taxanes. This study was, therefore, undertaken to examine whether Pxd pre-treatment with conventional chemotherapeutic agent(s) 5-Fu and 1-OHP co-administration be a therapeutic strategy for CRC. Cell viability and cytotoxicity were evaluated using dimethyl-thiazolyl diphenyl tetrazolium bromide (MTT) and lactate dehydrogenase assays. The percentage of apoptotic and necrotic cells were determined by fluorescence microscopy analysis. Besides, active Caspase-3 levels by ELISA and relative mRNA levels of Caspase 3 (CASP3), CASP8 and CASP9 genes were determined by quantitative real-time PCR (qPCR) analysis. The pre-treatment of Pxd followed by 5-Fu and 1-OHP co-administration was more effective at inhibiting cell viability than either chemotherapeutic agents treatment alone. When compared to 5 -Fu with 1-OHP alone treatment, Pxd pre-treatment overwhelmingly increased apoptotic Caspase-3 activity levels in CRC cells. Moreover, qPCR analyses showed that CASP3 and CASP9 mRNA levels significantly increased after pretreatment with Pxd followed by 5-Fu and 1-OHP treatments, compared to 5-Fu with 1-OHP alone. Our results suggested that Pxd enhanced the in vitro antitumor activity of 5-Fu and 1-OHP. Our study also suggested that Pxd may be a potential candidate agent in advanced CRC and inclusion of Pxd to the conventional chemotherapeutic agent(s) could be an effective therapeutic strategy for CRC

Effects of Meloxicam, Alone and in Combination With Chemotherapeutic Agents on the Raf/Mek/Erk Pathway in Raji Cells

WOS: 000344634100027Background: Non-steroidal anti-inflammatory drugs (NSAIDs) have been reported to induce apoptosis and inhibit cell proliferation in tumor cells when combined with conventional chemotherapeutic agents. We aimed to investigate the effect of NSAIDs (meloxicam and lornoxicam) plus conventional chemotherapeutic agents on RAF/MEK/ERK pathway in Burkitt's lymphoma cell line (Raji). Methods: Raji cells were treated with meloxicam, lornoxicam, carboplatin, gemcitabine and 5-fluorourasil (5-FU) for 24h. Then, the cells were treated with selected low and high doses of meloxicam alone or in combination with two different gemcitabine concentrations. Presence of apoptotic cells were assessed using fluorescence microscopy. mRNA expression levels of RAF1, MEK1, ERK1 and ERK2 genes were analyzed with quantitative real time PCR. Results: Apoptotic and anti-proliferative effects were not observed by carboplatin, 5-FU and lornoxicam. However, meloxicam and gemcitabine treatment resulted in a decrease in viability. Therefore, we examined the effects of low and high doses of meloxicam, gemcitabine and their combinations on this pathway. The antiproliferative effects of gemcitabine were not significantly enhanced in the presence of meloxicam. Furthermore, mRNA expression levels of RAF1, MEK1 and ERK1/2 genes were downregulated in gemcitabine alone and upregulated in meloxicam alone. Interestingly, the decrease shown in low and high doses of gemcitabine alone reversed in low dose meloxicam plus gemcitabine treatment. Conversely, downregulation of these genes by high dose gemcitabine did not change with meloxicam treatment. Conclusion: We believe that it may be fundamental to further evaluate this inhibitory drug interaction

Carboxylesterase1, alpha 2a adrenergic receptor and noradrenalin transporter gene polymorphisms and their clinical effects in attention deficit hyperactivity disorder in Turkish children

tas torun, yasemin/0000-0002-4922-7594WOS: 000433193600010The objective of this study was to examine the association between ADHD and G1287A polymorphism in the NET1 gene, C1291G polymorphism in the ADRA2A gene on the adrenergic pathway and Gly143Glu polymorphism in the CES1 gene on the metabolic pathway, and their clinical effects. The study population included 114 children with ADHD and 83 healthy controls. 103 patients are followed for 6 months, their scale points are recorded and side effects are questioned in each interview. Every patient in both control and ADHD group are found to have GG genotype when Gly143Glu polymorphism in the CES1 gene is examined, thus we came to a conclusion that Turkish population is homozygote in the mentioned polymorphism. No significant association between NET1 gene G1287A polymorphism genotypes and ADHD was found. It was found that ADRA2A C1291G polymorphism C allele and CC genotype is a risk factor for ADHD (p= 0.003, OR: 2.17, CI: 12.8-37.0) and the risk is higher in males (p= 0.013, OR: 2.43, CI: 12.0-49.5). There was no significant relation between ADRA2A C1291G polymorphism and clinical parameters but it was found that individuals with NET1 G1287A polymorphism AA genotype have less concurrent Oppositional Defiant Disorder diagnosis (18.8% vs. 81.2%, p= 0.039), their initial CTRS-attention deficit points are higher (17.47 +/- 3.73 vs. 16.15 +/- 4.58, p= 0.045). In conclusion, our study showed that the ADRA2A C1291G polymorphism C allele and CC genotype is associated with ADHD. NET1 G1287A polymorphism AA genotype is mainly associated with attention deficit cluster.Turkish Psychiatry Society's Ankara branch office [11/2014]This research has been supported by Turkish Psychiatry Society's (grant number: 11/2014, grant date: 20.01.2014) Ankara branch office

The Impact of Gene Polymorphisms on the Success of Anticholinergic Treatment in Children with Overactive Bladder

Aim. To determine the impact of gene polymorphisms on detrusor contraction-relaxation harmony in children with lower urinary tract symptoms (LUTS). Materials and Methods. Toilet trained children older than 5 years of age with LUTS and normal neurological examination underwent videourodynamic study. The control group was composed of age matched children with no voiding complaints. The study group who filled out the voiding dysfunction symptom score before and after the treatment received standard oxybutynin treatment and was reevaluated 1 year after treatment. Genomic DNA was isolated from all patients and subjected to PCR for amplification. Genotyping of ARGHEF10, ROCK2, ADRB3, and CYP3A4 was carried out with Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) method. Results. 34 (45%) and 42 (55%) patients were enrolled in the study and control group, respectively. ARGEF10 GG, ADRB3 TC, and CYP3A4 AG genotype patients displayed insignificant difference between pre-and posttreatment voiding dysfunction symptom score and bladder volumes. Conclusions. The polymorphism of genes in the cholinergic pathway did not significantly differ clinical parameters. On the other hand, polymorphic patients in the adrenergic pathway seemed to suffer from clinical disappointment. For this reason, we think that the neglected adrenergic pathway could be a new therapeutic target for the treatment of anticholinergic resistant LUTS in children