as-1411 and Adenocarcinoma

Doxorubicin (Dox) inhibits DNA replication and causes DNA damage resulting in cell death. It is a common drug for treatment of many cancers. Treatment efficacy and side effects of Dox are critical issues in using it because the drug lacks of specificity. The objective of this study was to improve the specificity of Dox by the incorporation of this drug with AS1411 aptamer (ASA).. Dox was intercalated into the duplex sites of ASA, a recognition molecule for a number of cancer cells, and formed Dox-loaded ASA. The recognition ability proceeded through specific binding between the aptamer and nucleolin overexpressed in the cancer cells. The tested cells were human colorectal adenocarcinoma cell line (SW480) and human normal colon cell CCD841 CoN (CCD841). Binding of ASA to the cells was tested using flow cytometer and fluorescence microscope. Intercalation of Dox into DNA duplex was confirmed by fluorescence spectrometry. Effect of ASA, Dox, and Dox-loaded ASA on cell viability was examined by cell proliferation assay. Caspase-3 activation was analyzed by western blotting.. ASA bound specifically to SW480 cells via interaction between the aptamer and nucleolin because the nucleolin was highly expressed in SW480 cells. ASA decreased the viability of SW480 cells in a dose-dependent manner. Dox was more toxic than ASA. Fluorescence quenching revealed that Dox was able to intercalate in base pairing sites of the aptamer. Dox-loaded ASA inhibited the proliferation of SW480 cells, because the aptamer facilitated the Dox uptake into these cells which caused the cell apoptosis, indicated by the significant decrease in procaspase-3, apoptosis marker protein.. This study succeeded to prepare Dox-loaded ASA by intercalation of the drug that inherited the binding function from the aptamer and anti-cancer activity from Dox. Dox-loaded ASA showed promise for effective cancer treatment with lower level of side effects.

Topics: Adenocarcinoma; Aptamers, Nucleotide; Cell Line, Tumor; Cell Proliferation; Cell Survival; Colorectal Neoplasms; Doxorubicin; Drug Delivery Systems; Humans; Oligodeoxyribonucleotides

In the current study camptothecin-loaded pegylated PAMAM dendrimer were synthesized and were functionalized with AS1411 anti-nucleolin aptamers for site-specific targeting against colorectal cancer cells which over expresses nucleolin receptors. The morphological properties and size dispersity of the prepared nanoparticles were evaluated using transmission electron microscope (TEM) and DLS. The drug-loading content and encapsulation efficiency were obtained 8.1% and 93.67% respectively. The in vitro release of camptothecin from the formulation was provided the sustained release of encapsulated camptothecin during 4days. Comparative in vitro cytotoxicity experiments demonstrated that the targeted camptothecin loaded-pegylated dendrimers had higher antiproliferation activity, towards nucleolin-positive HT29 and C26 colorectal cancer cells than nucleolin-negative CHO cell line. Fluorscence microscopy and flow cytometry also confirmed the enhanced cellular uptake of AS1411 targeted pegylated-dendrimer. In vivo study in C26 tumor-bearing BALB/C mice revealed that the AS1411-functionalized camptothecin loaded pegylated dendrimers improved antitumor activity and survival rate of the encapsulated camptothecin. Conjugation of AS1411 aptamer to the camptothecin loaded-pegylated dendrimer surface provides site-specific delivery of camptothecin, inhibit C26 tumor growth in vivo and significantly decrease systemic toxicity. These results suggested that the new nucleolin-targeted pegylated PAMAM dendrimer as a delivery system for camptothecin have the potential for the treatment of nucleolin-overexpressed colorectal cancer.

Topics: Adenocarcinoma; Animals; Aptamers, Nucleotide; Camptothecin; Cell Line, Tumor; CHO Cells; Colon; Colonic Neoplasms; Cricetulus; Dendrimers; Drug Carriers; Drug Delivery Systems; HT29 Cells; Humans; Mice; Mice, Inbred BALB C; Nanoparticles; Nucleolin; Oligodeoxyribonucleotides; Phosphoproteins; RNA-Binding Proteins

Guanine (G)-rich oligonucleotides have attracted considerable interest as therapeutic agents. Two G-rich aptamers were selected against epidermal growth factor receptor (EGFR)-transfected A549 cells, and their G-rich domains (S13 and S50) were identified to account for the binding of parental aptamers. Circular dichroism (CD) spectra showed that S13 and S50 bound to their targets by forming parallel quadruplexes. Their binding, internalization, and antiproliferation activity in cancer and noncancer cells were investigated by flow cytometry and 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay, and compared with those of nucleolin-binding AS1411 and thrombin-binding aptamer. The two truncated aptamers (S13 and S50) have good binding and internalization in cancer cells and noncancer cells; however, only S50, similar to AS1411, shows potent antiproliferation against cancer cells. Our data suggest that tumor-selective antiproliferation of G-rich oligonucleotides does not directly depend on the binding of the G-rich aptamer to cells.

Topics: Adenocarcinoma; Adenocarcinoma of Lung; Antineoplastic Agents; Aptamers, Nucleotide; Base Sequence; Cell Line, Tumor; Cell Proliferation; ErbB Receptors; G-Quadruplexes; Humans; Lung; Lung Neoplasms; Molecular Sequence Data; Nucleolin; Oligodeoxyribonucleotides; Phosphoproteins; RNA-Binding Proteins

To explore the effects of AS1411 on the apoptosis of taxol-resistant lung adenocarinoma A549 cell (A549/T cell).. A549/T cells were treated with AS1411 at a concentration gradient of 0-20.0 µmol/L. The assays of methyl tolyl sulfide (MTS) and colony formation were used to detect the cellular vitality (absorbance value (A490 nm)) and proliferation. The apoptotic effects were detected by flow cytometer and the relevant apoptotic signaling proteins detected by Western blot.. A549/T cells exhibited some characteristics of epithelial mesenchymal transition (EMT) and a negative expression of epidermal growth factor receptor (EGFR). After a treatment of 5.0 µmol/L AS1411, compared to the control sequence, cell vitality was inhibited (A490 nm: 0.185 ± 0.009 vs 0.272 ± 0.006, P < 0.001) and the number of clone formation decreased (74 ± 13 vs 120 ± 12, P = 0.010). With rising AS1411 concentration, A549/T cells vitality decreased in a dose-dependent manner. After a 48-hour treatment of 20.0 µmol/L AS1411, the ratio of apoptosis ((19.9 ± 2.6)%) had significant difference (P = 0.002) with the control sequence group ((8.8 ± 1.3)%). Compared to the control sequence group, the expressions of protein kinase B (AKT), extracellular regulated protein kinases 1/2 (ERK1/2) and B-cell lymphoma 2 (Bcl-2) protein declined (0.353 ± 0.003, 0.432 ± 0.015, 0.294 ± 0.015 vs 0.688 ± 0.003, 0.911 ± 0.019, 0.422 ± 0.018, all P < 0.001).. AS1411 may induce the apoptosis of A549/T cells through inhibiting the AKT-ERK pathways.

Topics: Adenocarcinoma; Adenocarcinoma of Lung; Apoptosis; Aptamers, Nucleotide; Cell Line, Tumor; Extracellular Signal-Regulated MAP Kinases; Humans; Lung Neoplasms; Oligodeoxyribonucleotides; Paclitaxel; Proto-Oncogene Proteins c-akt; Proto-Oncogene Proteins c-bcl-2; Signal Transduction