Search

The current study aimed to investigate the antitumor and antiangiogenesis effects of apatinib in triple-negative breast cancer in vitro and also whether the combination of docosahexaenoic acid (DHA) and apatinib is more effective than apatinib monotherapy. The cell counting kit-8 assay was used to measure cell proliferation. Flow cytometry was utilized to determine the cell apoptosis rate. A wound healing assay was utilized to assess cell migration. Western blot analysis was carried out to determine the effects of apatinib and DHA on Bcl-2, BAX, cleaved caspase-3, caspase-3, phosphorylated protein kinase B (p-Akt), and Akt expression. DHA in combination with apatinib showed enhanced inhibitory effects on cell proliferation and migration compared with apatinib or DHA monotherapy. Meanwhile, DHA combined with apatinib strongly increased the cell apoptosis percentage. DHA was observed to enhance the antitumor and antiangiogenesis effects of apatinib via further downregulation of p-Akt expression. Abbreviations : FITC: fluorescein isothiocyanate; PI: propidium iodide.

Preclinical investigation and clinical experience have provided evidence on the potential anticancer effect of artemisinin and its derivatives (ARTs) in the recent two decades. The major mechanisms of action of ARTs may be due to toxic-free radicals generated by an endoperoxide moiety, cell cycle arrest, induction of apoptosis, and inhibition of tumor angiogenesis. It is very promising that ARTs are expected to be a new class of antitumor drugs of wide spectrum due to their detailed information regarding efficacy and safety. For developing repurposed drugs, many other characteristics of ARTs should be studied, including through further investigations on possible new pathways of anticancer effects, exploration on efficient and specific drug delivery systems-especially crossing biological barriers, and obtaining sufficient data in clinical trials. The aim of this review is to highlight these achievements and propose the potential strategies to develop ARTs as a new class of cancer therapeutic agents.

Polymeric micelles are effective drug-loading sites and often used to formulate poorly water-soluble agents. In the present study, the amphiphilic copolymer methoxy-capped poly(ethyleneglycol)-block-poly(Ɛ-caprolactone) (mPEG-b-PCL) was successfully developed for the delivery of 20(R)-dammarane-3β,12β,20,25-tetrol (25-OH-PPD), a natural anticancer product from Panax notoginseng. The 25-OH-PPD-loaded micelles were characterized by morphological observation and thermodynamic stability testing. The concentrations of 25-OH-PPD was determined by HPLC-MS/MS. The optimum MRM transition of 25-OH-PPD was selected at m/z 479.4.0→461.4. The chromatographic separation was achieved on a SB-C18 column (1.8μm, 2.1×50mm) with an optimized gradient mobile phase system. The extraction recoveries of plasma and various tissue homogenates were within the range of 81.1%-110.4% and the matrix effects ranged from 81.9% to 106.7%. The intra- and inter- day precision values (RSD%) were less than 12.0%, with accuracies ranging from 85.2% to 114.2%. In addition, 25-OH-PPD was found to be stable in different biological matrix after three freeze-thaw cycles, at room temperature and at -70°C for 4 weeks. The pharmacokinetics of 25-OH-PPD-loaded micelles was evaluated in rats. The micelles appeared as transparent liquid, stable and uniform spheres with an average particle size of 35.4±4.2nm. The maximum concentration of 25-OH-PPD in micelles was much lower than in free drug preparation. However, the drug in the micelles was released steadily, with a t1/2 of 9.1±4.0h, significantly longer than in free drug (3.3±1.4h). However, the drug concentrations in tissues after the micelle administration were lower than the levels after administration of the free drugs. In summary, the micelles were characterized by long circulation and sustained release, with an ability to avoid uptake by the reticuloendothelial system, providing a promising approach to deliver intravenous 25-OH-PPD for therapy., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Natural products with biodiversity and chemical variations present a rich source for the discovery and development of new therapeutic and preventive drugs. Bioactive components derived from natural medicines including traditional Chinese medicine have been widely used for the screening of effective and safe anticancer drugs. Meanwhile, the investigation on mechanism of action (MOA) of natural bioactive components has a critical role in identifying and validating new molecular targets of those anticancer agents. Considering the high complexity of pharmacodynamic (PD) and pharmacokinetic (PK) characteristics of natural product anticancer agents, there are several major challenges in understanding mechanisms of action in vitro and in vivo for these agents. The recent rapid progress made in molecular and cell biology, genetics and genomics, and translational medicine, preclinical investigations provides an impetus for a better understanding of mechanisms of action and structure-activity relationships (SAR) of natural products. In addition, the simultaneous evaluation of PD-PK characterizations would allow a full assessment of the safety, efficacy, and indication of natural product anticancer drugs in various regimens and in various clinical settings. In this review, we provide a brief summary for recent advances in translational pharmacology, focusing on target validation and PK-PD, MOA, and SAR. Several examples for clinically used agents, and cancer preventive agents and therapeutic agents under preclinical and clinical development are used to illustrate the importance of such translational research and challenges we are facing.

Apatinib has been proved effective in the treatment of advanced gastric cancer. Traditional Chinese medicine is often considered as adjuvants which could increase the effects and counteract the side effects of chemotherapy. The present study aims to explore the antitumor effects of Astragalus polysaccharide (AsPs) in combination with Apatinib in gastric cancer AGS cells. Our results demonstrated that the expression of VEGFR-2 was observed in human gastric cancer line AGS. Both Apatinib and AsPs could significantly inhibit the proliferation of AGS cells in a dose-dependent manner and Apatinib in combination with AsPs showed enhanced inhibitory effects on cell proliferation, migration and invasion compared with Apatinib monotherapy. Moreover, there was a remarkable increase in apoptosis following Apatinib treatment which could be enhanced by the addition of AsPs. Western blotting showed that the combination of Apatinib and AsPs could inhibit the expression of phosphorylated AKT (p-AKT) and MMP-9 expression. In addition, both Apatinib alone and Apatinib in combination with AsPs induced celluar autophagy which could be attenuated by the autophagy inhibitor 3-MA. The suppression of autophagy leaded to further apoptosis induction and cell proliferation suppression. In conclusion, the current study showed AsPs enhanced antitumor effects of Apatinib on AGS cells by the mechanism which includes inhibition of AKT signaling pathway. Apatinib-induced autophagy could be attenuated by 3-MA, which subsequently increased the apoptosis rate. On the basis of our study, the combination of Apatinib and AsPs could be considered as a potential candidate in the gastric cancer treatment. [ABSTRACT FROM AUTHOR]