DNA damage-induced cell death through chemo-drugs is the most widely used strategy in cancer therapy. However, selectivity remains a great concern in cancer chemotherapy because DNA damaging drugs kill both cancer cells and the surrounding normal cells, which is an important cause of side effects during cancer chemotherapy, and severely limits current treatment regimes. Functional p53 deficiency is common in human tumors and contributes to an aggressive chemo- or radiotherapy-resistant phenotype, therefore providing a potential target for cancer therapy. Several attempts in recent years to restore wt- p53 activity have led to the identification of numerous p53 modulators. However, strategies mimicking p53 activated transcriptional responses in wt-p53 or p53-deficient tumors have yet to be explored. We carried out a high-throughput cell-based screen for small molecules that trigger a p53 target transcription in cancer cells. Among several candidates that elevate the amounts of p53 proteins, a naturally occurring novel p53 modulator, piperlongumine (PPLGM) is of most interest for this application because it selectively kills cancer cells in both p53-dependent and p53-independent ways, while leaving normal cells unaffected. This compound effectively increases basal levels of p53 protein and its proapoptotic targets. Furthermore, in vivo experiments demonstrate potent anti-tumor activities of this compound at low concentrations, which have no apparent adverse effects on normal organ and tissue function. We also identified significant elevation of reactive oxygen species (ROS) as a potential cancer cell specific mechanism of action for this compound. Therefore, targeting ROS could be a strategy to be developed to selectively kill cancer cells but not untransformed or normal cells by additional ROS production, because cancer cells possess a much higher basal level of ROS in comparison to normal cells. The main goal of this application is to understand the underlying mechanisms for the unusual selective effect of PPLGM in cancer cells in vitro and in vivo. A detailed understanding of the mechanism of action of this compound in both cancer cells and normal cells should provide novel insights into the target based selective therapeutic strategies against cancer, and may also warrant further testing in preclinical and clinical settings.

Public Health Relevance

In cancer chemotherapy, selectivity remains a great concern because DNA damaging drugs kill both cancer cells and the surrounding normal cells, which is an important cause of side effects during cancer chemotherapy. The goal of this application is to understand the underlying mechanisms for the unusual cancer specific selective effect of a newly identified p53 activator.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
1R01CA142805-01
Application #
7766562
Study Section
Basic Mechanisms of Cancer Therapeutics Study Section (BMCT)
Program Officer
Forry, Suzanne L
Project Start
2010-02-01
Project End
2015-01-31
Budget Start
2010-02-01
Budget End
2011-01-31
Support Year
1
Fiscal Year
2010
Total Cost
$358,877
Indirect Cost
Name
Massachusetts General Hospital
Department
Type
DUNS #
073130411
City
Boston
State
MA
Country
United States
Zip Code
02199
Byun, Sanguine; Shin, Seung Ho; Park, Jiman et al. (2016) Sulforaphene suppresses growth of colon cancer-derived tumors via induction of glutathione depletion and microtubule depolymerization. Mol Nutr Food Res 60:1068-78
Yoon, Kyoung Wan; Byun, Sanguine; Kwon, Eunjeong et al. (2015) Control of signaling-mediated clearance of apoptotic cells by the tumor suppressor p53. Science 349:1261669
Byun, Sanguine; Lim, Semi; Mun, Ji Young et al. (2015) Identification of a Dual Inhibitor of Janus Kinase 2 (JAK2) and p70 Ribosomal S6 Kinase1 (S6K1) Pathways. J Biol Chem 290:23553-62
Namba, Takushi; Chu, Kiki; Kodama, Rika et al. (2015) Loss of p53 enhances the function of the endoplasmic reticulum through activation of the IRE1?/XBP1 pathway. Oncotarget 6:19990-20001
Hiraki, Masatsugu; Hwang, So-Young; Cao, Shugeng et al. (2015) Small-Molecule Reactivation of Mutant p53 to Wild-Type-like p53 through the p53-Hsp40 Regulatory Axis. Chem Biol 22:1206-16
Namba, Takushi; Tian, Fang; Chu, Kiki et al. (2013) CDIP1-BAP31 complex transduces apoptotic signals from endoplasmic reticulum to mitochondria under endoplasmic reticulum stress. Cell Rep 5:331-9
Brown-Endres, Lauren; Schoenfeld, David; Tian, Fang et al. (2012) Expression of the p53 target CDIP correlates with sensitivity to TNFýý-induced apoptosis in cancer cells. Cancer Res 72:2373-82
Raj, Lakshmi; Ide, Takao; Gurkar, Aditi U et al. (2011) Selective killing of cancer cells by a small molecule targeting the stress response to ROS. Nature 475:231-4
Mandinova, Anna; Lee, Sam W (2011) The p53 pathway as a target in cancer therapeutics: obstacles and promise. Sci Transl Med 3:64rv1