EXTH-48. GALECTIN-1 INHIBITION SENSITIZES RADIATION TREATMENT IN A PRE-CLINICAL MODEL OF GLIOBLASTOMA

Radioresistance remains a major clinical challenge in glioblastoma (GB) therapy. However, the mechanism for the development of radioresistance in GB is unclear. Mounting evidence suggests that Galectin-1 (Gal1: a carbohydrate-binding protein galectin-1) contributes to the radioresistance of GB tumors. Recently, several Gal1-targeting compounds have emerged. OTX008 is a calixarene derivative designed to bind the Gal1 amphipathic β-sheet conformation. Our study aimed to reduce galectin-1 expression using OTX008 in a human GB pre-clinical model. For these studies an in vivo GL261 murine models of GB were utilized to assess efficacy of treatment with radiation plus OTX008. Our results demonstrated that inhibition of Gal-1 with OTX008 plus radiation showed significantly decrease in GB growth rate and improved survival in in vivo. OTX008 treatment plus radiation was associated with downregulation of Gal1 and Ki67 in treated tumors, as well as decreased microvessel density and VEGFR2 expression. Finally, combination studies showed OTX008 synergy with radiation therapies, principally when OTX008 was administered first. This study provides insights of Gal-1inhibitory effects of OTX008 and its enhancement of the efficacy of radiotherapy in mouse models of GB suggest that further studies are warranted.

A novel immobilization matrix for the biosensing of phenol: self assembled monolayers of calixarenes

Aim:The development of calixarene based phenol biosensor.Methods:This study describes the application of a calixarene derivative, 5,17-diamino-25,27-bis(3-thiol-1-oxypropane)-26,28-dihydroxycalix[4]arene (HS-Calix-NHResults:The linearity was observed in the range of 0.1–100 μM and 1.0–100 μM for catechol and phenol, respectively. The potential use of the biosensor was investigated for phenol analysis in artificial samples which simulate the industrial waste water, which is highly acidic and composed of concentrated salt, without needing any sample pre-treatment step.Conclusion:The prepared Lac biosensor has a potential for rapid, selective and easy detection of phenolic contaminations in samples.

The colorimetric assay of diamine oxidase activity with high sensitivity based on calixarene derivative-capped gold nanoparticles

Diamine oxidase (DAO) is involved in regulating ingested or endogenous histamine, several types of human cancer, and the cell mass during embryonic development.

A novel architecture based on a conducting polymer and calixarene derivative: its synthesis and biosensor construction

An amperometric biosensor based on a selenium comprising conducting polymer and newly synthesized calixarene derivative with gold nanoparticles was constructed for the detection of glucose.