Gene expression data from an adenocarcinoma derived cell line.

Gene expression data from an adenocarcinoma derived cell line following reactivation of p53 expression by tamoxifen treatment.

Gene expression data from microdissected p53 restored adenomas.

Gene expression data from microdissected p53 restored adenocarcinomas.

Gene expression data from microdissected p53 restored adenocarcinomas.

Metal / dielectric nanostructures, such as metal nanoparticles of different shape (spheres, rods, stars) capped with organic adsorbates, have a strong potential for the development of new materials for nanotechnology. Among these structures, those including monolayer protected clusters of noble metal nanoparticles modified with organic fluorophores are of great interest for the fabrication of new fluorescent bio- and chemical sensors, and for optical devices as well. The nature of the interactions between metals and organic fluorophores is still not totally understood. These interactions, which depend on various factors, including the geometry of the systems, the physicochemical properties of the interacting materials and their environment, often result in an enhancement or a quenching of the emission. The performed investigations comprise design, preparation, characterization and photophysical study of monolayer protected clusters of noble metal nanoparticles modified with newly synthesized organic fluorophore.

Tumorigenesis is a multistep process that results from the sequential accumulation of mutations in key oncogene and tumor-suppressor pathways. The quest to personalize cancer medicine based on targeting these underlying genetic abnormalities presupposes that sustained inactivation of tumor suppressors and activation of oncogenes are required for tumor maintenance. Mutations in the p53 tumor-suppressor pathway are a hallmark of cancer and significant efforts toward pharmaceutical reactivation of mutant p53 pathways are underway1-3. Here we show that restoration of p53 in established murine lung tumors leads to significant but incomplete tumor cell loss specifically in malignant adenocarcinomas but not in adenomas. Also, we define amplification of MAPK signaling as a critical determinant of malignant progression. The differential response to p53 restoration depends on activation of the Arf tumor suppressor downstream of hyperactive MAPK signaling. We propose that p53 naturally limits malignant progression by responding to increased oncogenic signaling, but is unresponsive to low levels of oncogene activity that are sufficient for early stages of lung tumor development. These data suggest that restoration of pathways important in tumor progression, as opposed to initiation, may lead to incomplete tumor regression due to the stage-heterogeneity of tumor cell populations. 3 cell lines each treated with Tamoxifen or EtOH vehicle. Tamoxifen treatment results in reactivation of p53 expression

Tumorigenesis is a multistep process that results from the sequential accumulation of mutations in key oncogene and tumor-suppressor pathways. The quest to personalize cancer medicine based on targeting these underlying genetic abnormalities presupposes that sustained inactivation of tumor suppressors and activation of oncogenes are required for tumor maintenance. Mutations in the p53 tumor-suppressor pathway are a hallmark of cancer and significant efforts toward pharmaceutical reactivation of mutant p53 pathways are underway1-3. Here we show that restoration of p53 in established murine lung tumors leads to significant but incomplete tumor cell loss specifically in malignant adenocarcinomas but not in adenomas. Also, we define amplification of MAPK signaling as a critical determinant of malignant progression. The differential response to p53 restoration depends on activation of the Arf tumor suppressor downstream of hyperactive MAPK signaling. We propose that p53 naturally limits malignant progression by responding to increased oncogenic signaling, but is unresponsive to low levels of oncogene activity that are sufficient for early stages of lung tumor development. These data suggest that restoration of pathways important in tumor progression, as opposed to initiation, may lead to incomplete tumor regression due to the stage-heterogeneity of tumor cell populations. 18 tumors of different grade and treatment status. 6 treated grade 3, 4 treated grade2, 4 untreated grade3, 4 untreated grade2

Tumorigenesis is a multistep process that results from the sequential accumulation of mutations in key oncogene and tumour suppressor pathways. Personalized cancer therapy that is based on targeting these underlying genetic abnormalities presupposes that sustained inactivation of tumour suppressors and activation of oncogenes is essential in advanced cancers. Mutations in the p53 tumour-suppressor pathway are common in human cancer and significant efforts towards pharmaceutical reactivation of defective p53 pathways are underway(1-3). Here we show that restoration of p53 in established murine lung tumours leads to significant but incomplete tumour cell loss specifically in malignant adenocarcinomas, but not in adenomas. We define amplification of MAPK signalling as a critical determinant of malignant progression and also a stimulator of Arf tumour-suppressor expression. The response to p53 restoration in this context is critically dependent on the expression of Arf. We propose that p53 not only limits malignant progression by suppressing the acquisition of alterations that lead to tumour progression, but also, in the context of p53 restoration, responds to increased oncogenic signalling to mediate tumour regression. Our observations also underscore that the p53 pathway is not engaged by low levels of oncogene activity that are sufficient for early stages of lung tumour development. These data suggest that restoration of pathways important in tumour progression, as opposed to initiation, may lead to incomplete tumour regression due to the stage-heterogeneity of tumour cell populations.