Investigation Of The Tumor Specific Biomarkers And Evaluation Of Biotargeted Drug Nanoparticles

The de velopment and p rogression of c ancer a re c ommonly t hought t o be amultistep cell-biological process that involves multi-gene disorder and coordination ofmulti c ellular pa thways, thus, the s tudy of a s ingle gene of ten cannot reflect t heentire process of cancer pr ogression. W ith t he a dvancement of pr oteomics, hi ghthroughput techniques have been developed to make it possible to study the complexcellular activities, and to uncover the molecular mechanism of tumorigenesis and gainnew m echanistic i nsights i nto c ancer. In a ddition, i dentification of ke y proteinscontributed t o c ancer p rogression i n t he pr otein-protein i nteraction ne tworks w illprovide novel diagnostic and prognostic biomarkers and potential therapeutic targetsfor cancer, even facilitating the development of personalized, molecularly targetedtherapy.In the present study, we employ a2D-PAGE and MS based high throughputcomparative proteomics approach t o s creen a nd i dentify pr oteins responsible f ormetastasis and drug resistance of breast cancer. We have successfully established andoptimized two-dimensional ge l e lectrophoresis method f or t he s eparation of t otalcellular protein and identify11di fferentially expressed proteins by using MALDI-TOF/MS followed by a database search. S everal reports showed that these proteinsare involved in tumor metastasis, energy metabolism, and cell proliferation. Withinthese proteins, Anxa2was significantly up-regulated and was further confirmed usingwestern blotting assay. S mall int erference R NA-mediated gene dow n r egulationdemonstrated that Anxa2was responsible for enhanced cell proliferation, migrationand invasion of the MDA-MB-231cells. Further analysis also found that Anxa2alsoplays an important role in the regulation of the expression of proliferation associatedgenes (c-myc and cyclin D1) and metastasis associated genes (MMP-2and MMP-9)through interaction with STAT3. Take together, our results showed that Anxa2maybe a pot ential biomarker f or cancer and m ay b e de veloped i nto a n e ffective drugtargets to inhibit tumor growth and metastasis.Meanwhile, we also produced a nanocarrier with folic acid modifed lipid-shelland pol ymer-core na noparticles (FLPNPs) by c ombining poly(D,L-lactide-co-glycolide)(PLGA) microspheres w ith l iposome technology. T he na nocarrier w ascomposed of a P LGA core s urrounded b y a s hell m ade of PEGylated octadecyl-quaternized lysine modifed chitosan (PEG-OQLCS), and targeted to folate receptor, which was highly expressed on t he tumor cell membrane. Our data showed that thetrend of burst release was more apparent for P LGANPs than that of LPNPs andFLPNP. The lipid and FAmodfied lipid outside the PLGA NPs retarded the PTXrelease f rom t he P LGAN Ps. The i nternalization fecfiency of FLPNPs weredemonstrated i n FR-positive H ela can cer cell a nd FR-negative A549c ell b yfowcytometry and confocal microscopy. In vitro and in vivo studies demonstrated thatPTX l oaded F LPNPs not onl y e xhibits a hi gher a ntitumor a ctivity but a lsosignifcantly reduces the toxicity and improves the bioavailability as compared to thatof the commercial PTX formulation (Taxol). Our data indicate that PTX loadedFLPNPs are a promising nano-sized drug formulation for cancer therapy.