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:Tamoxifen is the most widely administered adjuvant first-line hormone therapy for Estrogen receptor α (ERα) positive breast cancer patients. However, one from three patients will develop resistance, while the underlying molecular mechanisms are currently unclear. Recent studies reported that abnormal expression of miRNAs played a role in cancer progress. To study the potential function of miRNAs in tamoxifen resistance, Affymetrix GeneChip® miRNA 3.0 microarray was employed to identify differentially expressed miRNAs between tamoxifen sensitive MCF7 parent (MCF7-Pa) cells and induced resistant (MCF7-Re) 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:Tamoxifen, an antagonist to estrogen receptor (ER), is a first line drug used in breast cancer treatment. However, this therapy is complicated by the fact that a substantial number of patients exhibit either de novo or acquired resistance. To characterize the signaling mechanisms underlying the resistance to tamoxifen, we established a tamoxifen-resistant cell line by treating the MCF7 breast cancer cell line with tamoxifen for over 6 months. We showed that this cell line exhibited resistance to tamoxifen both in vitro and in vivo. In order to quantify the phosphorylation alterations associated with tamoxifen resistance, we performed SILAC-based quantitative phosphoproteomic profiling on the resistant and vehicle-treated sensitive cell lines where we identified >5,600 unique phosphopeptides. We found phosphorylation levels of 1,529 peptides were increased (>2 fold) and 409 peptides were decreased (<0.5-fold) in tamoxifen resistant cells compared to tamoxifen sensitive cells. Gene set enrichment analysis revealed that focal adhesion pathway was the top enriched signaling pathway activated in tamoxifen resistant cells. We observed hyperphosphorylation of the focal adhesion kinases FAK1 and FAK2 in the tamoxifen resistant cells. Of note, FAK2 was not only hyperphosphorylated but also transcriptionally upregulated in tamoxifen resistant cells. Suppression of FAK2 by specific siRNA knockdown could sensitize the resistant cells to the treatment of tamoxifen. We further showed that inhibiting FAK activity using the small molecule inhibitor PF562271 repressed cellular proliferation in vitro and tumor formation in vivo. More importantly, our survival analysis revealed that high expression of FAK2 significantly associated with short metastasis-free survival of ER-positive breast cancer patients treated with tamoxifen-based hormone therapy. Our studies suggest that FAK2 is a great potential target for the development of therapy for the treatment of hormone refractory breast cancers.
Project description:The primary objective is, first, the comparison of tamoxifen and anastrozole and, second, the comparison of zoledronate added to standard adjuvant therapy with controls according to disease-free survival (DFS) in premenopausal patients with non-metastatic breast cancer treated with tamoxifen or anastrozole. To assess whether zoledronate added to standard adjuvant therapy can decrease or even prevent bone loss in patients treated with hormonal blockade combined with an antiestrogen or aromatase inhibitor.
Project description:Resistance to tamoxifen is a major challenge in the treatment of estrogen receptor positive breast cancer. Acquired resistance to drug involves multilayered genetic and epigenetic regulation . The oncogene EZH2 plays significant role in the development of resistance against tamoxifen, widely used in the treatment of breast cancer. Inhibition of EZH2 has proven to reverse the tamoxifen resistance breast cancer cells back to the sensitive state. The molecular mechanism through which EZH2 inhibition triggers its effects are not known.This study was conducted to understand the global change in proteome profile of tamoxifen resistant MCF-7 breast cancer cells as a result of effect of EZH2 knockdown. Label Free Quantitative proteomics revealed a large number of proteins altered in acquired tamoxifen resistant cells compared to the sensitive cells. A total of 286 proteins were identified with normalized RT for each m/z out of which 86 proteins were upregulated by more than 1.3 fold and 98 proteins were down regulated by more than 1.3 fold in MCF-7 tamoxifen resistant breast cancer cells in comparison to the sensitive breast cancer cells. Upon EZH2 knockdown in tamoxifen resistant cells, a total of 115 proteins were found to be altered with 20 proteins upregulated by more than 1.3 fold and 49 proteins down regulated by more than 1.3 fold. Among the top upregulated proteins were L-lactate dehydrogenase A chain, Alpha and Gamma-enolase, Calreticulin, heat shock protein HSP-90-beta, Alpha-actinin-4, Elongation factor 1-alpha, Vimentin, Protein S100A6, Putative protein FAM10A5, Heterogeneous nuclear ribonucleoprotein A1 and Keratin 1. In addition, 15 proteins were found to be down regulated in EZH2si transfected tamoxifen sensitive cells which otherwise were highlyup regulated in resistant cells in the presence of normal level of EZH2. This indicates a possible regulation of these molecules by EZH2 leading to loss of resistance. Our data unveils important molecular players downstream to EZH2 knockdown leading to regain of sensitivity to tamoxifen in acquired tamoxifen resistance.Thus, EZH2 seems to exert its effects through regulation of metabolism, epithelial to mesenchymal transition and protein synthesis & folding. Hence, targeting EZH2 or the molecules down the cascade might be helpful in reacquiring sensitivity to tamoxifen intamoxifen-resistant cells.
Project description:Low-intensity pulsed ultrasound (LIPUS) has been applied as a therapeutic adjunct to promote fracture healing. However, the detailed molecular mechanisms by which LIPUS promotes bone fracture healing have not yet been fully elucidated. In the present study, the early response genes elicited by low-intensity pulsed ultrasound (LIPUS) in bone marrow stromal cells (BMSCs) were investigated using GeneChip® oligonucleotide microarrays.
Project description:Torpor is an energy-conserving state in which animals dramatically decrease their metabolic rate and body temperature to survive harsh environmental conditions. Here, we report the noninvasive, precise, and safe induction of a torpor-like hypothermic and hypometabolic state in rodents by remote transcranial ultrasound stimulation at the hypothalamus preoptic area (POA). We achieve a long-lasting (> 24 hours) torpor-like state in mice via closed-loop feedback control of ultrasound stimulation with automated detection of body temperature. Ultrasound-induced hypothermia and hypometabolism (UIH) is triggered by activation of POA neurons, involves the dorsomedial hypothalamus as a downstream brain region and subsequent inhibition of thermogenic brown adipose tissue. Single-nucleus RNA-sequencing of POA neurons reveals TRPM2 as an ultrasound-sensitive ion channel, the knockdown of which suppresses UIH. We also demonstrate that UIH is feasible in a non-torpid animal, the rat. Our findings establish UIH as a promising technology for the noninvasive and safe induction of a torpor-like state. To investigate the mechanism of ultrasound-induced neuronal activation, we applied ultrasound stimulation in hypothalamic preoptic area region and performed single-nuclei RNA sequencing in the ultrasound stimulated neurons (US+) and neurons without ultrasound stimulation (US-). In our sn-RNAseq analysis, we examined the association between the expression of neuronal activation markers (or IEGs) and ion channels, as well as neuron types.
Project description:Tamoxifen is the most widely used antiestrogen in patients with estrogen receptor (ER) positive breast cancer . However, less than half of patients benefit from tamoxifen treatment and 30-50% acquire resistance and the disease progresses. Resistance to tamoxifen is a serious problem in breast cancer therapy and major efforts are underway to find out underlying mechanisms. To find out the differential expression levels of mRNAs in tamoxifen-sensitive T47D versus tamoxifen-resistant T47D (T47DR) human breast cancer cells, T47DR (tamoxifen-resistant) cell line was established from T47D cells after the following continuous exposure to 1 μmol/L 4-Hydroxytamoxifen (H7904, Sigma, USA) for more than 6 months.Thousands of significantly different mRNA expression levels were found and analysed. Our study provides a reference data for the study of tamoxifen resistance .