Project description:Prolonged treatment of HER2+ breast cancer cells with lapatinib (LAP) causes cellular senescence and acquired drug resistance, which often associating with poor prognosis for patients. We aim to explore the correlation between cellular senescence and LAP resistance in HER2+ breast cancer, screening for molecular marker of reversible senescence, and construct targeted nanobubbles for ultrasound molecular imaging and dynamically evaluate LAP resistance. In this study, we established a new cellular model of reversible cellular senescence using LAP and HER2+ breast cancer cells and found that reversible senescence contributed to LAP resistance in HER2+ breast cancer. Then we identified ecto-5'-nucleotidase (NT5E) as a marker of reversible senescence in HER2+ breast cancer. Based on this, we constructed NT5E targeted nanobubbles (NT5E-FITC-NBs) as a new molecular imaging modality which could both target reversible senescent cells and be used for ultrasound imaging. NT5E-FITC-NBs showed excellent physical and imaging characteristics. As an ultrasound contrast agent, NT5E-FITC-NBs could accurately identify reversible senescent cells both in vitro and in vivo. Our data demonstrate that cellular senescence-based ultrasound targeted imaging can identify reversible senescence and evaluate LAP resistance effectively in HER2+ breast cancer, which has the potential to improve cancer outcomes by altering treatment strategies ahead of aggressive recurrences.
Project description:Echo-contrast agents enhance the echogenicity of ultrasound and have been clinically used for diagonosis in current medical fields. Here, the combined effects of Sonazoid, an echo-contrast agent, and ultrasound on the gene expression in human lymphoma U937 cells were investigated using an Affymetrix GeneChip system. The cells were treated with Sonazoid (0.05%; Sonazoid only), ultrasound (0.3 W/cm2 for 1 min; ultrasound only) and the combination of Sonazoid and ultrasound (0.05% Sonazoid plus ultrasound 0.3 W/cm2 for 1 min; Sonazoid + Ultrasound) and followed by incubation for 3 h at 37°C. The percentage of DNA fragmentation 6 h after treatment was 5.8 ± 1.0 (mean ± SD, n = 3), 6.0 ± 0.4, 13.5 ± 1.0, and 18.3 ± 2.3 in cells treated with control, Sonazoid only, ultrasound only and Sonazoid + Ultrasound, respectively. Of approximately 47,000 probe sets analyzed, probe sets that were differentially expressed by a factor 2.0 or greater were 40, 184 and 144 in cells treated with Sonazoid only, ultrasound only and Sonazoid + Ultrasound, respectively. Experiment Overall Design: U937 cells, a human lymphoma cell line, were treated with Sonazoid (0.05%), ultrasound (0.3 W/cm2 for 1 min) and the combination of Sonazoid and ultrasound (0.05% Sonazoid plus ultrasound 0.3 W/cm2 for 1 min) and followed by incubation for 3 h at 37°C. Non-treated cells were served as control. Total RNA samples were prepared from the cells. Gene expression was analyzed by an Affymetrix GeneChip® system with a Human Genome U133-plus 2.0 array for analysis of over 47,000 transcripts. Sample preparation for array hybridization was carried out as described in the manufacturerâ??s instructions.
Project description:Use DIA proteomics to analyze the changes in the proteome of cells from young to senescent states; employ SILAC to analyze the turnover of the proteome in senescent cells; utilize TPP to analyze the differences in protein thermostability between senescent and young cells.
Project description:Echo-contrast agents enhance the echogenicity of ultrasound and have been clinically used for diagonosis in current medical fields. Here, the combined effects of Sonazoid, an echo-contrast agent, and ultrasound on the gene expression in human lymphoma U937 cells were investigated using an Affymetrix GeneChip system. The cells were treated with Sonazoid (0.05%; Sonazoid only), ultrasound (0.3 W/cm2 for 1 min; ultrasound only) and the combination of Sonazoid and ultrasound (0.05% Sonazoid plus ultrasound 0.3 W/cm2 for 1 min; Sonazoid + Ultrasound) and followed by incubation for 3 h at 37°C. The percentage of DNA fragmentation 6 h after treatment was 5.8 ± 1.0 (mean ± SD, n = 3), 6.0 ± 0.4, 13.5 ± 1.0, and 18.3 ± 2.3 in cells treated with control, Sonazoid only, ultrasound only and Sonazoid + Ultrasound, respectively. Of approximately 47,000 probe sets analyzed, probe sets that were differentially expressed by a factor 2.0 or greater were 40, 184 and 144 in cells treated with Sonazoid only, ultrasound only and Sonazoid + Ultrasound, respectively.
Project description:The presence of senescent cells in the aging/degenerating human disc is now well-recognized. Senescent cells are viable, cannot divide, remain metabolically active and accumulate within the disc over time. Molecular analysis of senescent cells in tissue, however, offers a special challenge since there are no cell surface markers for senescence which would let one use fluorescence-activated cell sorting as a method for separating out senescent cells. Here we use a novel experimental design using laser capture microdissection to selectively separately harvest senescent and non-senescent annulus cells in paraffin-embedded tissue, and then compare their gene expression with microarray analysis. An initial in vitro study using cultured human annulus cells was first performed to test whether there was any difference in identification of senescent cells using the accepted histochemical methodology vs. the immunofluoresent identification of cells positive for senescence-associated-ß-galactosidase in control cells and cells induced into stress-induced premature senescence via hydrogen peroxide exposure. No statistically significant difference was found between the 2 methods. Laser capture microdissection was used to separately harvest senescent and non-senescent cells from 11 human annulus specimens, and microarray analysis was used to determine gene expression levels. Genes with established relationships to senescence were found to be significantly upregulated in senescent cells vs. non-senescent cells. Additional genes related to cytokines, cell proliferation, and other cell processes were also identified. Disc Tissue samples were obtained from surgical disc procedures performed on patients with herniated discs and degenerative disc disease. Tissue was fixed and paraffin embedded. Standard laser capture microdissection (LCM) techniques were used to collect senescent cells. Remaining non-senescent cells were scraped from the histology slide. Total RNA was isolated and analyzed via mircoarray. Gene expression from senescent cells was compared to non-senescent cells. Eight histological samples were used to obtain both senescent and non-senescent cells. From an additional 3 samples, only senescent cells were harvested.