Downregulation of Potential Tumor Suppressor miR-203a by Promoter Methylation Contributes to the Invasiveness of Gastric Cardia Adenocarcinoma

<p>Like many tumor suppressor genes, some miRNA genes harboring CpG islands undergo methylation-mediated silencing. In the study, we found significant downregulation and proximal promoter methylation of miR-203a and miR-203b in gastric cardia adenocarcinoma (GCA) tissues. The methylation status of miR-203a and miR-203b in tumor tissues was negatively correlated with their expression level. GCA patients in stage III and IV with reduced expression or hypermethylation of miR-203a demonstrated poor patient survival. In all, miR-203a and miR-203b may function as tumor suppressive miRNAs, and reactivation of miR-203a may have therapeutic potential and may be used as prognostic marker for GCA patients.</p

Nanopore Single-Molecule Analysis of DNA–Doxorubicin Interactions

Anticancer activity and toxicity of doxorubicin (Dox) are associated with its DNA intercalation. To understand the role in gene regulation and the drug mechanism, it is a challenge to detect the DNA–Dox interaction at the single-molecule level without the use of laborious, time-consuming labeling assays and an error-prone amplification method. Here, we utilized the simplest and cheapest, yet highly sensitive, single-molecule nanopore technology to investigate the DNA–Dox interaction and explore in situ the intercalative reaction kinetics. Distinctive electronic signal patterns between DNA and the DNA–Dox complex allow protein nanopore to readily detect the changes in structure and function of DNA. After Dox insertion, nanopore unzipping time of DNA was elevated 10-fold while the blocking current decreased, demonstrating the higher affinity of the DNA–Dox complex (formation constant <i>K</i>_f = 3.09 × 10⁵ M^–1). Continuous rapid nanopore detection in real time displayed that Dox intercalation in DNA is a two-state dynamic process: fast binding and slow conformational adaption. The nanopore platform provides a powerful tool for studying small molecule–biomacromolecule interactions and paves the way for novel applications aimed at drug screening and functional analysis

Anti-tumor effect of ultrasound-induced Nordy-loaded microbubbles destruction

<p><b>Background:</b> Synthesized dl-Nordihydroguaiaretic acid (dl-NGDA or “Nordy”) can inhibit the growth of malignant human tumors, especially the tumor angiogenesis. However, its liposoluble nature limits its <i>in vivo</i> efficacy in the hydrosoluble circulation of human.</p> <p><b>Purpose:</b> We tried to use the ultrasonic microbubble as the carrier and the ultrasound-induced destruction for the targeted release of Nordy and evaluate its <i>in vitro</i> and <i>in vivo</i> anti-tumor effect.</p> <p><b>Methods:</b> Nordy-loaded lipid microbubbles were prepared by mechanical vibration. Effects of ultrasound-induced Nordy-loaded microbubbles destruction on proliferation of human umbilical vein endothelial cells (HUVECs), tumor derived endothelial cells (Td-ECs), and rabbit transplanted VX2 tumor models were evaluated.</p> <p><b>Results:</b> The ultrasound-induced Nordy-loaded microbubbles destruction inhibited the proliferations of HUVECs and Td-ECs <i>in vitro</i>, and inhibited the tumor growth and the microvasculature <i>in vivo</i>. Its efficacy was higher than those of Nordy used only and Nordy with ultrasound exposure.</p> <p><b>Conclusion:</b> Ultrasonic microbubbles can be used as the carrier of Nordy and achieve its targeted release with improved anti-tumor efficacy in the condition of ultrasound-induced microbubbles destruction.</p

MOESM1 of Construction of ultrasonic nanobubbles carrying CAIX polypeptides to target carcinoma cells derived from various organs

Additional file 1. Mass spectrogram of polypeptides. a Mass spectrogram of the unmodified polypeptides. b Mass spectrogram of the FITC-modified polypeptides

Cell growth curves of C4-2 cells (A) and LNCaP cells (B) after transfection.

<p>Significant inhibition of cell growth was observed in Groups 3, 5, and 6 for both cell lines. The data are presented as the means ± SD (n = 10). Groups 1–6 represent bare AR siRNA + blank nanobubbles, nanobubbles carrying AR siRNA, bare AR siRNA + ultrasonic irradiation, blank nanobubbles + ultrasonic irradiation, bare AR siRNA + blank nanobubbles + ultrasonic irradiation, and nanobubbles carrying AR siRNA + ultrasonic irradiation, respectively.</p

qRT-PCR quantification of AR expression in the animals in Groups 1–7.

<p>The lowest relative expression of AR mRNA was observed in Group 6 (siRNA-NB+US). The data in the histograms represent the means ± SEM of 8 animals (each sample was assayed in triplicate). # P<0.05, ## P<0.01, and ### P<0.001 compared with Group 1 (independent-samples t-test).</p

Electrophoresis results for RT-PCR products.

<p>Lanes 1–6 represent Groups 1–6, respectively (Group1: siRNA+NB, Group2: siRNA-NB, Group3: siRNA+US, Group4: NB+US, Group5: siRNA+NB+US, Group6: siRNA-NB+US). The sizes of the markers (the M lane, from bottom to top) are 50, 100, 150, 200, 250, 300, 350, 400, and 450 bp. GAPDH served as an internal reference. The highest suppression of AR mRNA expression was observed in Group 6. (A) and (B): Bands of RT-PCR products and the results of image quantification; the data in the histograms represent the means ± SD of five independent experiments. (* P<0.05 and ** P<0.01 vs. Group 1 C4-2 cells; # P<0.05 and ## P<0.01 vs. Group 1 LNCaP cells).</p

Western blot results of AR protein expression in C4-2 and LNCaP cells.

<p>Lanes 1–6 represent Groups 1–6, respectively (Group1: siRNA+NB, Group2: siRNA-NB, Group3: siRNA+US, Group4: NB+US, Group5: siRNA+NB+US, Group6: siRNA-NB+US). GAPDH protein served as an internal reference. The highest suppression was observed in Group 6. (A) and (B): Immuno-bands and the results of image quantification; the data in the histograms represent the means ± SD of five independent experiments. (* P<0.05 and ** P<0.01 vs. Group 1 C4-2 cells; # P<0.05 and ## P<0.01 vs. Group 1 LNCaP cells).</p

Cell growth inhibition in three prostate cancer cell lines on the sixth day after transfection.

<p>The data are presented as the means ± SD (n = 10). An asterisk (*) indicates that the growth inhibition of C4-2 and LNCAP cells in Group 6 was significantly different from that in Groups 1, 2, and 4 (P<0.05). A triangle (Δ) indicates that the growth inhibition of C4-2 and LNCaP cells in Group 6 was significantly different from that of the PC-3 cells in the same group (P<0.05).</p

Nanobubbles with Cy3-labeled AR siRNA observed under fluorescence microscopy.

<p>(A) PLL nanobubbles under bright-field microscopy. (B) Obvious fluorescence was observed in the PLL nanobubbles. (C) Blank nanobubbles under bright-field microscopy. (D) No fluorescence was observed in the blank nanobubbles. The red arrows in the images indicate nanobubbles (1,000×).</p