as-1411 and Adenocarcinoma-of-Lung

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