Anti-Tumor Study of H6, a 4-Substituted Coumarins Derivative, Loaded Biodegradable Self-Assembly Nano-Micelles In Vitro and In Vivo
JOURNAL OF BIOMEDICAL NANOTECHNOLOGY
Authors: Zhu, Zejiang; Su, Zhengying; Yang, Jianhong; Liu, Huili; Tang, Minghai; Hu, Qiaoqiao; Bai, Peng; Wen, Jiaolin; He, Jun; Niu, Ting; Chen, Lijuan
Abstract
In our previous study, we identified a class of 4-substituted coumarins as a powerful microtubule inhibitors binding to the colchicine site of beta-tubulin. H6 showed potent anti-proliferative ability with IC50 values from 7 to 47 nM, and remarkable ability to reduce tumor growth in several xenograft models including taxol resistant tumor models. However, the extremely hydrophobicity limited its clinical application. In this study, to improve the anticancer activity and reduce the toxicity of H6, we successfully prepared MPEG-PCL with different proportions and H6-loaded polymeric micelles (H6/MPEG2k-PCL2k micelles) by a simple thin-film hydration method. The prepared H6/MPEG-PCL micelles had a drug loading of 3.79 +/- 0.001%, an encapsulation efficiency of 98.00 +/- 0.41%, a mean particle size of 30.45 +/- 0.18nm and a polydispersity index (PDI) of 0.096 +/- 0.009. Computer simulation results revealed a good compatibility of H6 and MPEG(2k)-PCL2k copolymer. In in vitro release study and pharmacokinetic study showed H6 micelles can release H6 over an extended period. Furthermore, H6 micelles possessed comparative effect as free H6 in inhibiting cell growth, preventing cell migration, and inducing apoptosis. Mechanism study identified that H6 is a novel reversible microtubule inhibitor. In in vivo studies, H6 micelles exhibited tumor growth inhibition on two pulmonary metastatic tumor models (B16/F10 and 4T1). Importantly, H6 micelles significantly improved the solubility, reduced the toxicity, extended the half-life of drugs, and augmented the therapeutic window. All these results imply that H6 micelles have great potential for suppression of tumor metastasis.
Overcoming Intrinsic Doxorubicin Resistance in Melanoma by Anti-Angiogenic and Anti-Metastatic Effects of Liposomal Prednisolone Phosphate on Tumor Microenvironment
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
Authors: Licarete, Emilia; Rauca, Valentin Florian; Luput, Lavinia; Drotar, Denise; Stejerean, Ioana; Patras, Laura; Dume, Bogdan; Toma, Vlad Alexandru; Porfire, Alina; Gherman, Claudia; Sesarman, Alina; Banciu, Manuela
Abstract
Regardless of recent progress, melanoma is very difficult to treat, mainly due to the drug resistance modulated by tumor cells as well as by the tumor microenvironment (TME). Among the immune cells recruited at the tumor site, tumor associated macrophages (TAMs) are the most abundant, promoting important tumorigenic processes: angiogenesis, inflammation and invasiveness. Furthermore, it has been shown that TAMs are involved in mediating the drug resistance of melanoma cells. Thus, in the present study, we used liposomal formulation of prednisolone disodium phosphate (LCL-PLP) to inhibit the protumor function of TAMs with the aim to sensitize the melanoma cells to the cytotoxic drug doxorubicin (DOX) to which human melanoma has intrinsic resistance. Consequently, we evaluated the in vivo effects of the concomitant administration of LCL-PLP and liposomal formulation of DOX (LCL-DOX) on B16.F10 melanoma growth and on the production of key molecular markers for tumor development. Our results demonstrated that the concomitant administration of LCL-PLP and LCL-DOX induced a strong inhibition of tumor growth, primarily by inhibiting TAMs-mediated angiogenesis as well as the tumor production of MMP-2 and AP-1. Moreover, our data suggested that the combined therapy also affected TME as the number of infiltrated macrophages in melanoma microenvironment was reduced significantly.