Strengthening desert plant biotechnology research in the United Arab Emirates: a viewpoint

The biotechnology of desert plants is a vast subject. The main applications in this broad field of study comprises of plant tissue culture, genetic engineering, molecular markers and others. Biotechnology applications have the potential to address biodiversity conservation as well as agricultural, medicinal, and environmental issues. There is a need to increase our knowledge of the genetic diversity through the use of molecular genetics and biotechnological approaches in desert plants in the Arabian Gulf region including those in the United Arab Emirates (UAE). This article provides a prospective research for the study of UAE desert plant diversity through DNA fingerprinting as well as understanding the mechanisms of both abiotic stress resistance (including salinity, drought and heat stresses) and biotic stress resistance (including disease and insect resistance). Special attention is given to the desert halophytes and their utilization to alleviate the salinity stress, which is one of the major challenges in agriculture. In addition, symbioses with microorganisms are thought to be hypothesized as important components of desert plant survival under stressful environmental conditions. Thus, factors shaping the diversity and functionality of plant microbiomes in desert ecosystems are also emphasized in this article. It is important to establish a critical mass for biotechnology research and applications while strengthening the channels for collaboration among research/academic institutions in the area of desert plant biotechnology.     

Overexpression of fatty acid synthase in Middle Eastern epithelial ovarian carcinoma activates AKT and Its inhibition potentiates cisplatin-induced apoptosis

Fatty acid synthase (FASN), the enzyme responsible for de novo synthesis of fatty acids, has been shown to be deregulated in several cancers, including epithelial ovarian carcinoma (EOC). In this study, we investigated the function of the FASN signaling pathway in a large series of Middle Eastern EOC patient samples, a panel of cell lines and nude mouse model. Using immunohistochemistry, we detected overexpression of FASN in 75.5% (114/151) of the tumor samples. Overexpression of FASN was associated significantly with tumor proliferative marker Ki-67 (P = 0.0009), activated AKT (P = 0.0117) and XIAP (P = 0.0046). Treatment of EOC cell lines with C-75, a selective inhibitor of FASN, caused inhibition of EOC cell viability via induction of apoptosis. Inhibition of FASN by C-75 led apoptosis via the mitochondrial pathway. FASN inhibition caused downregulation of activated AKT and its downstream targets. In addition, inhibition by FASN siRNA caused downregulation of FASN and activation of caspases, suggesting the role of FASN in C-75 mediated apoptosis. Furthermore, treatment of EOC cells with subtoxic doses of C-75 augmented the effect of cisplatin-mediated induction of apoptosis. Finally, treatment of EOC cell line xenografts with a combination of C-75 and cisplatin resulted in growth inhibition of tumors in nude mice through downregulation of FASN and activation of caspases. Altogether, our results show overexpression of FASN in Middle Eastern EOC, suggesting that FASN may be a potential therapeutic target in a subset of EOC, alone or in combination with other conventional chemotherapeutic agents.     

Resveratrol suppresses constitutive activation of AKT via generation of ROS and induces apoptosis in diffuse large B cell lymphoma cell lines

Background

We have recently shown that deregulation PI3-kinase/AKT survival pathway plays an important role in pathogenesis of diffuse large B cell lymphoma (DLBCL). In an attempt to identify newer therapeutic agents, we investigated the role of Resveratrol (trans-3,4′, 5-trihydroxystilbene), a naturally occurring polyphenolic compound on a panel of diffuse large B-cell lymphoma (DLBCL) cells in causing inhibition of cell viability and inducing apoptosis.

Methodology/Principal Findings

We investigated the action of Resveratrol on DLBCL cells and found that Resveratrol inhibited cell viability and induced apoptosis by inhibition of constitutively activated AKT and its downstream targets via generation of reactive oxygen species (ROS). Simultaneously, Resveratrol treatment of DLBCL cell lines also caused ROS dependent upregulation of DR5; and interestingly, co-treatment of DLBCL with sub-toxic doses of TRAIL and Resveratrol synergistically induced apoptosis via utilizing DR5, on the other hand, gene silencing of DR5 abolished this effect.

Conclusion/Significance

Altogether, these data suggest that Resveratrol acts as a suppressor of AKT/PKB pathway leading to apoptosis via generation of ROS and at the same time primes DLBCL cells via up-regulation of DR5 to TRAIL-mediated apoptosis. These data raise the possibility that Resveratrol may have a future therapeutic role in DLBCL and possibly other malignancies with constitutive activation of the AKT/PKB pathway.     

Genetic variability and haplotype profile of MDR1 in Saudi Arabian males

Polymorphisms in multidrug resistance (MDR1) gene play an important role in influencing the pharmacological action and toxicity profile of a large number of therapeutic agents, and in human susceptibility to various diseases. Because of genotypic variability, several studies were directed toward determination of the frequencies of MDR1 polymorphisms and/or haplotypes in different ethnic populations. In this study, we determined the frequencies of the most common three polymorphisms in the MDR1 gene (i.e., C1236T, G2677T, and C3435T) in Saudi Arabians and their haplotypes. Our results showed that the frequencies of 1236T, 2677T, and 3435T were 43.7?%, 40.2?%, and 42.2?%, respectively. In addition, the frequencies of the most common MDR1 haplotypes, C-G-C and T-T-T, were correspondent to 48.8 and 35.5?%. Furthermore, we identified moderate to strong linkage disequilibrium between the loci of these single nucleotide polymorphisms in the studied subjects. These identified frequencies in Saudi Arabians are different from that reported in the other ethnic groups.     

Phosphorylated IκBα Predicts Poor Prognosis in Activated B-Cell Lymphoma and Its Inhibition with Thymoquinone Induces Apoptosis via ROS Release

Activated B-cell lymphoma (ABC), one of the three subtypes of Diffuse Large B-cell Lymphoma (DLBCL) has the worst survival rate after upfront chemotherapy and is characterized by constitutively activated NFκB. We therefore studied the role of NFκB In a cohort of clinical DLBCL samples and ABC cell lines. In our clinical tissue microarray cohort of DLBCL samples, p-IκBα was detected in 38.3% of ABC DLBCL and was an independent prognostic marker for poor survival. In vitro, we found that Thymoquinone (TQ), a natural compound isolated from Nigella sativa caused release of ROS in ABC cells. TQ-mediated release of ROS in turn inhibited NFκB activity by dephosphorylating IκBα and decreased translocation of p65 subunit of NFκB in the nuclear compartment in ABC cell lines. This led to inhibition of cell viability and induction of mitochondrial dependent apoptosis in ABC-DLBCL cell lines. Additionally, TQ treatment also caused up-regulation of death receptor 5 (DR5), however, up-regulation of DR5 did not play a role in TQ-induced apoptosis. Finally, combination of sub-optimal doses of TQ and TRAIL induced efficient apoptosis in ABC-DLBCL cell lines. These data show that p-IκBα can be used as a prognostic marker and target for therapy in this aggressive sub-type of DLBCL and TQ may play an important role in the management of DLBCL in the future.     

Molecular detection of Epstein–Barr virus in different types of lymphoma

Molecular Biology Reports - Epstein-Barr virus (EBV) is a member of the γ herpesvirus subfamily. It is widely spread, potentially oncogenic and has been studied in different human cancers such...     

Thymoquinone suppresses growth and induces apoptosis via generation of reactive oxygen species in primary effusion lymphoma

We provide evidence that thymoquinone (TQ), a natural compound isolated from Nigella sativa, induces growth inhibition and apoptosis in several primary effusion lymphoma (PEL) cell lines. Our data demonstrate that TQ treatment results in down-regulation of constitutive activation of AKT via generation of reactive oxygen species (ROS) and it causes conformational changes in Bax protein, leading to loss of mitochondrial membrane potential and release of cytochrome c to the cytosol. This leads to activation of caspase-9, caspase-3, and polyadenosine 5'-diphosphate ribose polymerase cleavage, leading to caspase-dependent apoptosis. Pretreatment of PEL cells with N-acetylcysteine, a scavenger of ROS, prevented TQ-mediated effects. In addition, subtoxic doses of TQ sensitized PEL cells to TRAIL via up-regulation of DR5. Altogether, these findings demonstrate that TQ is a potent inducer of apoptosis in PEL cells via release of ROS. They also raise the possibility that incorporation of TQ in treatment regimens for primary effusion lymphomas may provide a novel approach to sensitizing malignant cells and provide a molecular basis for such future translational efforts.