New insights into the roles and regulation of SphK2 as a therapeutic target in cancer chemoresistance

Chemoresistance is a complicated process developed by most cancers and accounts for the majority of relapse and metastasis in cancer. The main mechanisms of chemoresistance phenotype include increased expression and/or activated drug efflux pumps, altered DNA repair, altered metabolism of therapeutics as well as impaired apoptotic signaling pathways. Aberrant sphingolipid signaling has also recently received considerable attention in chemoresistance. Sphingolipid metabolites regulate main biological processes such as apoptosis, cell survival, proliferation, and differentiation. Two sphingosine kinases, SphK1 and SphK2, convert sphingosine to sphingosine-1-phosphate, an antiapoptotic bioactive lipid mediator. Numerous evidence has revealed the involvement of activated SphK1 in tumorigenesis and resistance, however, contradictory results have been found for the role of SphK2 in these functions. In some studies, overexpression of SphK2 suppressed cell growth and induced apoptosis. In contrast, some others have shown cell proliferation and tumor promotion effect for SphK2. Our understanding of the role of SphK2 in cancer does not have a sufficient integrity. The main focus of this review will be on the re-evaluation of the role of SphK2 in cell death and chemoresistance in light of our new understanding of molecular targeted therapy. We will also highlight the connections between SphK2 and the DNA damage response. Finally, we will provide our insight into the regulatory mechanisms of SphKs by two main categories, micro and long, noncoding RNAs as the novel players of cancer chemoresistance.     

A Facile Approach to Distinct Unusual Sucrose in Honey by Titanium Oxide Nanoparticles

In this study, we present a new approach to distinguish original honey from sucrose-overdosed one by a colloid of oxygen-deficient TiO₂ nanoparticles (NPs). Results show that the original honey does not affect the colloidal NPs while sucrose-overdosed one precipitates it in a few seconds. Our studies show that the precipitating time has a non-linear dependence on absorption peak intensity, and the settling rate increases up to 0.185 cm min^?1 by increasing sucrose in honey. Our results show that sucrose in honey can enhance the hydrodynamic radius of NPs up to 482.9 nm by suppressing zeta potential besides agglomerating the NPs and a blue shift in the absorption peak (up to 20 eV). The macroscopic behavior of the honey-solved colloid can be applied to determine the quality of honey according to the settling rate in a few minutes.

     

Evaluation of Antioxidant and Antimicrobial Activity of Water-Soluble Peptides Extracted from Iranian Traditional Kefir

International Journal of Peptide Research and Therapeutics - Kefir, a traditional fermented milk product, is considered as a rich source of biofunctional compounds like peptides that are beneficial...     

Recent advances of dendrimer in targeted delivery of drugs and genes to stem cells as cellular vehicles

Stem cells can be used to repair dysfunctional and injured (or cancerous) tissues by delivering therapeutics. However, in comparison with other cells, it is harder to transfect drugs or genes into stem cells. Dendrimers have been considered as efficient vectors to deliver both genes and drugs to stem cells due to their unique properties including adjustable molecular weight and size, low toxicity, high loading capacity, and having multiple peripheral chemical agents which can be functionalized to improve deliverance efficiency. In this review, we discuss dendrimer-mediated drug and gene delivery to stem cells as cellular vehicles and the role of this strategy in treating a variety of disorders via regenerative medicine approaches.     

Sodium Hydrosulfide Modulates Membrane Integrity,Cation Homeostasis,and Accumulation of Phenolics and Osmolytes in Zucchini Under Nickel Stress

Journal of Plant Growth Regulation - In this study, the role of hydrogen sulfide (H2S) in growth and metabolism of zucchini (Cucurbita pepo L.) was explored in a hydroponic culture system under...     

Fish genomics and its impact on fundamental and applied research of vertebrate biology

Reviews in Fish Biology and Fisheries - The living fishes span a unique and interesting set of animals because of their vast diversity, morphology, ecology, genetics and genomics, and higher...     

Enhancement of galegine production in cell suspension culture of Galega officinalis through elicitation

In Vitro Cellular & Developmental Biology - Plant - Galega officinalis L. is known for its dominant secondary metabolite “galegine” a guanidine derivative used in the synthesis of...