Matching Items (2)
Description
The p53 gene functions as a tumor suppressor that inhibits proliferation, regulates apoptosis, DNA repair, and normal cell cycle arrest. Mutation of the p53 gene is linked to be prevalent in 50% of all human cancers. In this paper, we are exploring triple negative breast cancer and the effects of simvastatin on tumor growth and survival. Simvastatin is a drug that is primarily used to treat high cholesterol and heart disease. Simvastatin is unique because it is able to inhibit protein prenylation through regulation of the mevalonate pathway. This makes it a potential targeted drug for therapy against p53 mutant cancer. The mechanism behind this is hypothesized to be correlated to aberrant activation of the Ras pathway. The Ras subfamily functions to transcriptionally regulate cell growth and survival, and will therefore allow for a tumor to thrive if the pathway is continually and abnormally activated. The Ras protein has to be prenylated in order for activation of this pathway to occur, making statin drug treatment a viable option as a cancer treatment. This is because it acts as a regulator of the mevalonate pathway which is upstream of protein prenylation. It is thus vital to understand these pathways at both the gene and protein level in different p53 mutants to further understand if simvastatin is indeed a drug with anti-cancer properties and can be used to target cancers with p53 mutation. The goal of this project is to study the biochemistry behind the mutation of p53's sensitivity to statin. With this information we can create a possible signature for those who could benefit from Simvastatin drug treatment as a possible targeted treatment for p53 mutant cancers.
ContributorsGrewal, Harneet (Co-author) / Loo, Yi Jia Valerie (Co-author) / Anderson, Karen (Thesis director) / Blattman, Joseph (Committee member) / Ferdosi, Shayesteh (Committee member) / Department of Psychology (Contributor) / School of Life Sciences (Contributor) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
Description
Glioblastoma (GBM) is the most aggressive adult brain tumor with a devastating median survival time of about fourteen months post-surgery and standard of care therapy with radiation and temozolomide. The low incidence of GBM, cost of developing novel therapeutics, and time cost of clinical trials are dis-incentives to develop novel therapies. To overcome that obstacle, we investigated the efficacy of repurposing four FDA approved drugs known to cross the blood brain barrier (BBB), minocycline, propranolol, chlorpromazine, and metformin, to inhibit signaling and metabolism in GBM cells.
Minocycline is a tetracycline class broad spectrum antibiotic commonly used to treat severe acne and other skin infections. Propranolol is a beta blocker type heart medication primarily used to treat high blood pressure and irregular heartbeat. Chlorpromazine is a phenothiazine antipsychotic usually used for schizophrenia. Metformin is the most widely used first-line oral treatment for type-2 diabetes. Based on a literature survey, minocycline is expected to prevent the phosphorylation of STAT3, a transcription factor downstream of EGFR; propranolol is expected to disrupt EGFR trafficking; chlorpromazine is expected to target the PI3K/mTOR/Akt signaling pathway; metformin is believed to exploit vulnerabilities in cancer cell metabolism, as well as upregulate AMPK against the PI3K/mTOR/Akt pathway.
Efficacy of minocycline in inhibiting EGFR-driven STAT3 activation was investigated using western blot analysis. Our results demonstrate that Minocycline effectively inhibits activation of EGFR-driven STAT3 in U373 glioma cells at 100μM. The ability of chlorpromazine to inhibit the PI3K/mTOR/Akt pathway was similarly tested via western blot, which showed inhibition of phosphorylated Akt and S6 at 10μM. Efficacy of propranolol in perturbing EGFR trafficking was evaluated using flow cytometry and immunofluorescence, which failed to depict altered membrane-associated EGFR abundance. Finally, concentration-dependent inhibition of colony formation was tested for all four drugs. Propranolol and minocycline showed potential biphasic stimulatory effects at 10μM, but all drugs inhibited cell growth at 50μM and higher. Efficacy of these drugs in the treatment of GBM is being further evaluated using in vitro neurosphere cultures from patients identified as having the cellular vulnerabilities potentially targeted by these drugs. Successful completion of this project will lead to in vivo efficacy testing of these four drugs in orthotopic GBM PDX models.
Minocycline is a tetracycline class broad spectrum antibiotic commonly used to treat severe acne and other skin infections. Propranolol is a beta blocker type heart medication primarily used to treat high blood pressure and irregular heartbeat. Chlorpromazine is a phenothiazine antipsychotic usually used for schizophrenia. Metformin is the most widely used first-line oral treatment for type-2 diabetes. Based on a literature survey, minocycline is expected to prevent the phosphorylation of STAT3, a transcription factor downstream of EGFR; propranolol is expected to disrupt EGFR trafficking; chlorpromazine is expected to target the PI3K/mTOR/Akt signaling pathway; metformin is believed to exploit vulnerabilities in cancer cell metabolism, as well as upregulate AMPK against the PI3K/mTOR/Akt pathway.
Efficacy of minocycline in inhibiting EGFR-driven STAT3 activation was investigated using western blot analysis. Our results demonstrate that Minocycline effectively inhibits activation of EGFR-driven STAT3 in U373 glioma cells at 100μM. The ability of chlorpromazine to inhibit the PI3K/mTOR/Akt pathway was similarly tested via western blot, which showed inhibition of phosphorylated Akt and S6 at 10μM. Efficacy of propranolol in perturbing EGFR trafficking was evaluated using flow cytometry and immunofluorescence, which failed to depict altered membrane-associated EGFR abundance. Finally, concentration-dependent inhibition of colony formation was tested for all four drugs. Propranolol and minocycline showed potential biphasic stimulatory effects at 10μM, but all drugs inhibited cell growth at 50μM and higher. Efficacy of these drugs in the treatment of GBM is being further evaluated using in vitro neurosphere cultures from patients identified as having the cellular vulnerabilities potentially targeted by these drugs. Successful completion of this project will lead to in vivo efficacy testing of these four drugs in orthotopic GBM PDX models.
ContributorsNeal, Tristan Thomas (Co-author) / Neal, Tristan (Co-author) / Byron, Sara (Co-author) / Dhruv, Harshil (Co-author, Committee member) / Berens, Michael (Co-author) / Wilson, Melissa (Thesis director) / Ferdosi, Shayesteh (Committee member) / School of Human Evolution & Social Change (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05