Drug repositioning based on gene expression data for human HER2-positive breast cancer.

Human epidermal growth factor receptor 2 (HER2)-positive breast cancer represents approximately 15-30% of all invasive breast cancers. Despite the recent advances in therapeutic practices of HER2 subtype, drug resistance and tumor recurrence still have remained as major problems. Drug discovery is a long and difficult process, so the aim of this study is to find potential new application for existing therapeutic agents. Gene expression data for breast invasive carcinoma were retrieved from The Cancer Genome Atlas (TCGA) database. The normal and tumor samples were analyzed using Linear Models for Microarray Data (LIMMA) R package in order to find the differentially expressed genes (DEGs). These genes were used as entry for the library of integrated network-based cellular signatures (LINCS) L1000CDS2 software and suggested 24 repurposed drugs. According to the obtained results, some of these drugs including vorinostat, mocetinostat, alvocidib, CGP-60474, BMS-387032, AT-7519, and curcumin have significant functional similarity and structural correlation with FDA-approved breast cancer drugs. Based on the drug-target network, which consisted of the repurposed drugs and their target genes, the aforementioned drugs had the highest degrees. Moreover, the experimental approach verified curcumin as an effective therapeutic agent for HER2 positive breast cancer. Hence, our work suggested that some repurposed drugs based on gene expression data can be noticed as potential drugs for the treatment of HER2-positive breast cancer.

An enzyme-mediated controlled release system for curcumin based on cyclodextrin/cyclodextrin degrading enzyme.

In this study, an enzyme-triggered system based on ß-cyclodextrin (ß-CD) has been developed to achieve controlled release of hydrophobic drugs in the presence of maltogenic amylase (MAase). The inclusion complex formation of curcumin (CUR), as a model anticancer compound, with ß-CD was characterized by fluorescence and Fourier transform infrared (FTIR) spectroscopy. CUR was loaded into ß-CD with an encapsulation efficiency of approximately 30 %. The in vitro profiles of CUR release from ß-CD showed that 100 % of the drug was released after one hour incubation in the presence of MAase with cyclodextrin degrading activity. Fluorescence microscopy images indicate a significantly greater cellular uptake of CUR using ß-CD-CUR/MAase system compared to ß-CD-CUR inclusion complex without MAase. The ß-CD-CUR/MAase system exhibited lower IC50 values and greater anti-proliferative effects in comparison with free CUR and ß-CD-CUR in MCF-7 and Huh-7 cancer cells. The results from fluorescence microscopy and flow cytometric assay using the acridine orange/ethidium bromide and Annexin V-PE/7-AAD staining suggest that the ß-CD-CUR/MAase system exhibited higher cytotoxic and apoptotic effects on cancer cells compared to other formulations. This triggered release of CUR in the presence of MAase is owing to the ß-CD degradation by MAase resulting ring opening and chain scission in ß-CD. We demonstrate that this enzyme-mediated controlled release system has a potential application for controlled release of poorly water-soluble drugs or hydrophobic compounds such as CUR.

Targeted anticancer prodrug therapy using dextran mediated enzyme-antibody conjugate and ß-cyclodextrin-curcumin inclusion complex.

A targeted and controlled drug delivery system based on ß-cyclodextrin (ß-CD) for encapsulation and controlled release of hydrophobic drugs in the presence of maltogenic amylase (MAase), as a cyclodextrin-hydrolyzing enzyme, and trastuzumab antibody has been developed. In this study, the inclusion complex of curcumin (CUR), as a model anticancer compound, with ß-CD was prepared and we constructed an antibody-enzyme bioconjugate (dextran mediated MAase-Trastuzumab bioconjugate) for controlled and targeted release of CUR at HER2 positive cancer cells (including SKBR3 and BT474). Immunocytochemistry analysis indicated that the MAase-Trastuzumab bioconjugate had significant binding affinities to HER2 positive cancer cells and demonstrated high enzyme activity to degrade ß-CD in order to rapid release of CUR on targeted cell surface. Fluorescence microscopy images and cytotoxicity studies represent significantly greater cellular uptake and anti-proliferative effects of CUR by ß-CD-CUR/MAase-Trastuzumab bioconjugate compared to free CUR and ß-CD-CUR in presence and absence of MAase in HER2 positive cells. The results from flow cytometric assay suggest that the ß-CD-CUR/MAase-Trastuzumab conjugate exhibited higher cytotoxic and apoptotic effects on cancer cells compared to other formulation. We demonstrate that this formulation has a potential application for targeted and controlled release of drugs in cancer therapy with increased therapeutic efficiency.