Uptake of fluorescent D- and L-glucose analogues, 2-NBDG and 2-NBDLG, into human osteosarcoma U2OS cells in a phloretin-inhibitable manner

The roles of glycolysis in osteosarcoma

Metabolic reprogramming is of great significance in the progression of various cancers and is critical for cancer progression, diagnosis, and treatment. Cellular metabolic pathways mainly include glycolysis, fat metabolism, glutamine decomposition, and oxidative phosphorylation. In cancer cells, reprogramming metabolic pathways is used to meet the massive energy requirement for tumorigenesis and development. Metabolisms are also altered in malignant osteosarcoma (OS) cells. Among reprogrammed metabolisms, alterations in aerobic glycolysis are key to the massive biosynthesis and energy demands of OS cells to sustain their growth and metastasis. Numerous studies have demonstrated that compared to normal cells, glycolysis in OS cells under aerobic conditions is substantially enhanced to promote malignant behaviors such as proliferation, invasion, metastasis, and drug resistance of OS. Glycolysis in OS is closely related to various oncogenes and tumor suppressor genes, and numerous signaling pathways have been reported to be involved in the regulation of glycolysis. In recent years, a vast number of inhibitors and natural products have been discovered to inhibit OS progression by targeting glycolysis-related proteins. These potential inhibitors and natural products may be ideal candidates for the treatment of osteosarcoma following hundreds of preclinical and clinical trials. In this article, we explore key pathways, glycolysis enzymes, non-coding RNAs, inhibitors, and natural products regulating aerobic glycolysis in OS cells to gain a deeper understanding of the relationship between glycolysis and the progression of OS and discover novel therapeutic approaches targeting glycolytic metabolism in OS.

Click Pt(IV)-Carbohydrates Pro-Drugs for Treatment of Osteosarcoma

The selectivity vs. cancer cells has always been a major challenge for chemotherapeutic agents and in particular for cisplatin, one of the most important anticancer drugs for the treatment of several types of tumors. One strategy to overtake this challenge is to modify the coordination sphere of the metallic center with specific vectors whose receptors are overexpressed in the tumoral cell membrane, such as monosaccharides. In this paper, we report the synthesis of four novel glyco-modified Pt(IV) pro-drugs, based on cisplatin scaffold, and their biological activity against osteosarcoma (OS), a malignant tumor affecting in particular adolescents and young adults. The sugar moiety and the Pt scaffold are linked exploiting the Copper Azide Alkyne Cycloaddition (CUAAC) reaction, which has become the flagship of click chemistry due to its versatility and mild conditions. Cytotoxicity and drug uptake on three different OS cell lines as well as CSCs (Cancer Stem Cell) are described.

Quantification of 2-NBDG, a probe for glucose uptake, in GLUT1 overexpression in HEK293T cells by LC-MS/MS

The growth and proliferation of most cancer cells involve the excessive uptake of glucose mediated by glucose transporters. An effective strategy for cancer therapy has been to inhibit the GLUTs that are usually overexpressed in a variety of tumor cells. 2-NBDG is a GLUT1 substrate that can be used as a probe for GLUT1 inhibitors. An accurate and simple assay for 2-NBDG in a HEK293T cell model overexpressing GLUT1 was developed using liquid chromatography-tandem mass spectrometry. Chromatographic separation was achieved using a Xbridge® Amide column (3.5 μm, 2.1 mm × 150 mm, Waters) with acetonitrile-water containing 2 μM ammonium acetate (80:20, v/v) at a flow rate of 0.25 mL/min. Mass detection was conducted in the parallel reaction monitoring (PRM) mode. The calibration curve for 2-NBDG showed good linearity in the concentration range of 5-500 ng/mL with satisfactory precision, a relative standard deviation ranging from 2.92 to 9.59% and accuracy with a relative error ranging from -13.14 to 7.34%. This method was successfully applied to quantify the uptake of GLUT1-mediated 2-NBDG, and the results clearly indicated inhibition of GLUT1 by WZB117 and quercetin (two potent glucose transporter inhibitors) in the GLUT1-HEK293T cell model. This study provides a convenient and accurate method for high-throughput screening of selective and promising GLUT1 inhibitors.