Project description:Proteome of exosomes purified from H1299-p53R273H (mutant) and H1299-p53-/- cells, which found the levels of Podocalyxin altered in p53-mutant cells.
Project description:This research study is studying a drug as a possible treatment for p53 mutant metastatic colorectal cancer.
The drug involved in this study is:
-Lamivudine
Project description:Mutant p53 proteins, resulting form frequent TP53 tumor suppressor missense mutations, possess gain-of-function activities and are among the most widespread and robust oncoproteins in human tumors. They are potentially important but understudied therapeutic targets. No studies to date have distinguished common, therapeutically relevant mutant p53 gain-of-function effects, from effects specific to different mutant variants and cell backgrounds. Here we identify 26S proteasome machinery as the common downstream effector controlled by mutant p53s in Triple Negative Breast Cancer (TNBC - aggressive carcinomas with TP53 as the most frequently mutated locus) and conserved in other human cancers. We have identified this pathway using a combination of single-model, multi-method vertical analysis (whole cell proteome, RNA sequencing an ChIP sequencing) and multi-cell line, horizontal analysis of transcriptiomes. We found that different missense mutant p53s regardless of the cell background transcriptionaly activate whole 26S proteasome machinery. Proteasome activity is significantly increased in p53 mutant versus wild-type or knockdown/null status - in cellular and mouse models as well as in human breast tumors. Increased proteasome activity leads to inhibition of tumor suppressive pathways. The control of mutant p53 over proteasome transcription and activity results in the increased resistance to proteasome inhibitors. By combining the mutant p53 targeting agents and proteasome inhibitor we were able to overcome the “bounce-back” proteasome inhibitor resistance mechanism in mutant p53 bearing TNBC cells and xenografts in vivo.
Project description:p63, like its homologue, the tumor suppressor p53, is also able to induce apoptosis in several cancer cell types. p53 family proteins are composed of three characteristic domains which are: 1) an N-terminal transactivation domain (TAD); 2) a central DNA-binding domain (DBD); and 3) an oligomerization domain (OD). In this study, we constructed recombinant adenoviruses containing hybrid genes composed of fragments of p53 and TAp63γ genes by connecting coding sequences of their three functional domains. The potency of tumor growth suppression of these hybrid molecules was evaluated using in vitro and in vivo models. One of the p53-p63 hybrid molecules, p63-53O, was observed to be the most potent activator of human cancer cells to apoptosis when compared to the p53, TAp63γ or several alternative p53-p63 hybrid molecules. p63-53O hybrid is composed of TAD and DBD of TAp63γ and OD of p53. In an effort to identify specific targets regulated by pro-apoptotic hybrid p63-53O, we next performed Affymetrix Genechip analysis and compared expression patterns in a human osteosarcoma cell line Saos-2 transfected separately with Ad-p53, Ad-TAp63γ and Ad-p63-53O. Saos-2 osteosarcoma cells were either transduced with adenoviral vectors expressing p53, TAp63gamma, p53-p63 hybrid (p63-53O), or GFP. After 24 hours, mRNA was isolated and analyzed by hybridization to Affymetrix HG-U133 plus 2 arrays.
Project description:p63, like its homologue, the tumor suppressor p53, is also able to induce apoptosis in several cancer cell types. p53 family proteins are composed of three characteristic domains which are: 1) an N-terminal transactivation domain (TAD); 2) a central DNA-binding domain (DBD); and 3) an oligomerization domain (OD). In this study, we constructed recombinant adenoviruses containing hybrid genes composed of fragments of p53 and TAp63γ genes by connecting coding sequences of their three functional domains. The potency of tumor growth suppression of these hybrid molecules was evaluated using in vitro and in vivo models. One of the p53-p63 hybrid molecules, p63-53O, was observed to be the most potent activator of human cancer cells to apoptosis when compared to the p53, TAp63γ or several alternative p53-p63 hybrid molecules. p63-53O hybrid is composed of TAD and DBD of TAp63γ and OD of p53. In an effort to identify specific targets regulated by pro-apoptotic hybrid p63-53O, we next performed Affymetrix Genechip analysis and compared expression patterns in a human osteosarcoma cell line Saos-2 transfected separately with Ad-p53, Ad-TAp63γ and Ad-p63-53O.
Project description:Salivary tumors isolated from MMTV-ras transgenic mice expressing wild-type p53, no p53 or p53R172H gain-of-funcion mutant were subjected to genome-wide gene expression profiling to assess the effect of the different p53 status on tumor gene expression.