Project description:Ewing Sarcoma is caused by a pathognomonic genomic translocation that places an N-terminal EWSR1 gene in approximation with one of several ETS genes (typically FLI1). This aberration, in turn, alters the transcriptional regulation of more than five hundred genes and perturbs a number of critical pathways that promote oncogenesis, cell growth, invasion, and metastasis. Among them, translocation-mediated up-regulation of the insulin-like growth factor receptor 1 (IGF-1R) and mammalian target of rapamycin (mTOR) are of particular importance since they work in concert to facilitate IGF-1R expression and ligand-induced activation, respectively, of proven importance in ES transformation. When used as a single agent in Ewing sarcoma therapy, IGF-1R or mTOR inhibition leads to rapid counter-regulatory effects that blunt the intended therapeutic purpose. Therefore, identify new mechanisms of resistance that are used by Ewing sarcoma to evade cell death to single-agent IGF-1R or mTOR inhibition might suggest a number of therapeutic combinations that could improve their clinical activity. Male non-obese diabetic (NOD)-SCID-IL-2Rgnull mice were used to generate EW5 explants (2 mm). Mice bearing subcutaneous tumors were randomized into treatment and control groups when their tumors reached a diameter of 6 mm and received MK-8669 (mTOR inhibitor, 5mg/kg per dose, once weekly), MK-0646 (IGF-1R inhibitor monoclonal antibody, 0.5mg IP twice weekly), or a placebo control (sterile buffer). Animals were treated either until their tumors reached 1500 mm3 in volume. Affymetrix Geneship profiling of EW5 xenografts treated in vivo either with MK-0646, MK-8669, and control and compared each other using extracted RNA and hybridized on Affymetrix microrrays ( Affymetrix Human Genome U133A 2.0 cartridge arrays).
Project description:Insulin-like growth factor receptor-1 (IGF-1R) inhibition could be a relevant therapeutic approach in small cell lung cancer (SCLC) given the importance of an IGF-1R autocrine loop and its role in DNA damage repair processes. We assessed IGF-1R and pAkt protein expression in 83 SCLC human specimens. The efficacy of R1507 (a monoclonal antibody directed against IGF-1R) alone or combined with cisplatin or ionizing radiation (IR) was evaluated in H69, H146 and H526 cells in vitro and in vivo. Innovative genomic and functional approaches were conducted to analyze the molecular behavior under the different treatment conditions. A total of 53% and 37% of human specimens expressed IGF-1R and pAkt, respectively. R1507 demonstrated single agent activity in H146 and H526 cells but not in H69 cells. R1507 exhibited synergistic effects with both Cisplatin and IR in vitro. The triple combination R1507-Cisplatin-IR led to a dramatic delay in tumor growth compared to Cisplatin-IR in H526 cells. Analyzing the apparent absence of antitumoral effect of R1507 alone in vivo, we observed a transient reduction of IGF-1R staining intensity in vivo, concomitant to the activation of multiple cell surface receptors and intracellular proteins involved in proliferation, angiogenesis and survival. Finally, we identified that the nucleotide excision repair pathway (NER) was mediated after exposure to R1507-CDDP and R1507-IR in vitro and in vivo. In conclusion, adding R1507 to the current standard Cisplatin-IR doublet reveals remarkable chemo- and radiosensitizing effects in selected SCLC models and warrants to be investigated in the clinical setting. We used microarrays to investigate the effect of IGF-1R targetting on the global gene expression. Gene expression data from H526 xenografts under various treatment and time conditions Total mRNA from 33 NCI-H526 SCLC (small-cell lung cancer) xenografts was hybridized to Affymetrix HGU133 Plus 2.0 expression arrays. Log2 gene expression values were calculated using RMA. (A) To identify the molecular mechanisms involved in the response to R1507 alone along the treatment time, we performed global gene expression profiling in H526 xenografts at the following time points: baseline (vehicle), R1507 day 1 and R1507 day 7. (B) To identify the molecular mechanisms involved in the response to CDDP- and IR-R1507 combinations, we performed global gene expression profiling on mice bearing H526 xenografts treated with the following treatment conditions: vehicle, R1507 CDDP, IR, CDDP-R1507 and IR-R1507.
Project description:Ewing Sarcoma is caused by a pathognomonic genomic translocation that places an N-terminal EWSR1 gene in approximation with one of several ETS genes (typically FLI1). This aberration, in turn, alters the transcriptional regulation of more than five hundred genes and perturbs a number of critical pathways that promote oncogenesis, cell growth, invasion, and metastasis. Among them, translocation-mediated up-regulation of the insulin-like growth factor receptor 1 (IGF-1R) and mammalian target of rapamycin (mTOR) are of particular importance since they work in concert to facilitate IGF-1R expression and ligand-induced activation, respectively, of proven importance in ES transformation. When used as a single agent in Ewing sarcoma therapy, IGF-1R or mTOR inhibition leads to rapid counter-regulatory effects that blunt the intended therapeutic purpose. Therefore, identify new mechanisms of resistance that are used by Ewing sarcoma to evade cell death to single-agent IGF-1R inhibition might suggest a number of therapeutic combinations that could improve its clinical activity.
Project description:Ewing Sarcoma is caused by a pathognomonic genomic translocation that places an N-terminal EWSR1 gene in approximation with one of several ETS genes (typically FLI1). This aberration, in turn, alters the transcriptional regulation of more than five hundred genes and perturbs a number of critical pathways that promote oncogenesis, cell growth, invasion, and metastasis. Among them, translocation-mediated up-regulation of the insulin-like growth factor receptor 1 (IGF-1R) and mammalian target of rapamycin (mTOR) are of particular importance since they work in concert to facilitate IGF-1R expression and ligand-induced activation, respectively, of proven importance in ES transformation. When used as a single agent in Ewing sarcoma therapy, IGF-1R or mTOR inhibition leads to rapid counter-regulatory effects that blunt the intended therapeutic purpose. Therefore, identify new mechanisms of resistance that are used by Ewing sarcoma to evade cell death to single-agent IGF-1R or mTOR inhibition might suggest a number of therapeutic combinations that could improve their clinical activity.
Project description:Ewing Sarcoma is caused by a pathognomonic genomic translocation that places an N-terminal EWSR1 gene in approximation with one of several ETS genes (typically FLI1). This aberration, in turn, alters the transcriptional regulation of more than five hundred genes and perturbs a number of critical pathways that promote oncogenesis, cell growth, invasion, and metastasis. Among them, translocation-mediated up-regulation of the insulin-like growth factor receptor 1 (IGF-1R) and mammalian target of rapamycin (mTOR) are of particular importance since they work in concert to facilitate IGF-1R expression and ligand-induced activation, respectively, of proven importance in ES transformation. When used as a single agent in Ewing sarcoma therapy, IGF-1R or mTOR inhibition leads to rapid counter-regulatory effects that blunt the intended therapeutic purpose. Therefore, identify new mechanisms of resistance that are used by Ewing sarcoma to evade cell death to single-agent IGF-1R or mTOR inhibition might suggest a number of therapeutic combinations that could improve their clinical activity.
Project description:Liposarcoma is a type of soft tissue sarcoma, exhibiting poor survival and a high recurrence rate. Treatment is generally limited to surgery and radiation, emphasizing the need to understand this disease. Because very few in vivo and in vitro models can reproducibly recapitulate the human disease, we generated several xenograft models from surgically resected human dedifferentiated liposarcoma. Our study demonstrates that all xenografts recapitulate morphologic and gene expression characteristics of the patient tumors after continuous in vivo passages. Importantly, xenograftability is directly correlated with disease specific survival of liposarcoma patients. When treated with the PI3K/AKT/mTOR pathway inhibitor rapamycin alone or in combination with the multi-kinase inhibitor sorafenib, all xenografts responded with increased lipid content and a more differentiated gene expression profile. One-color arrays: Vehicle vs combination (rapamycin & sorafenib) treatment for 2 separate dedifferentiated liposarcoma xenografts. Two-color arrays: Comparison of patient tumor, several passages of xenograft generated from that tumor, and cells cultured from xenografted tumors.
Project description:Ewing Sarcoma is caused by a pathognomonic genomic translocation that places an N-terminal EWSR1 gene in approximation with one of several ETS genes (typically FLI1). This aberration, in turn, alters the transcriptional regulation of more than five hundred genes and perturbs a number of critical pathways that promote oncogenesis, cell growth, invasion, and metastasis. Among them, translocation-mediated up-regulation of the insulin-like growth factor receptor 1 (IGF-1R) and mammalian target of rapamycin (mTOR) are of particular importance since they work in concert to facilitate IGF-1R expression and ligand-induced activation, respectively, of proven importance in ES transformation. When used as a single agent in Ewing sarcoma therapy, IGF-1R or mTOR inhibition leads to rapid counter-regulatory effects that blunt the intended therapeutic purpose. Therefore, identify new mechanisms of resistance that are used by Ewing sarcoma to evade cell death to single-agent mTOR inhibition might suggest a number of therapeutic combinations that could improve its clinical activity.