A novel pyrido-thieno-pyrimidine derivative activates p53 through induction of phosphorylation and acetylation in colorectal cancer cells

Abstract

The tumor suppressor p53 plays a key role in regulation of the cell cycle, apoptosis and senescence in response to various stresses. We screened a library of 7920 chemical compounds for the p53 activator and identified N-[2-(dimethylamino)ethyl]-2,3-dimethyl-4-oxo-4H-pyrido[1,2-a]thieno[2,3-d]pyrimidine-9-carboxamide (PTP), which significantly increased p53-mediated reporter activity in colorectal cancer cells. PTP was found to induce p53 protein and activated transcription of downstream genes, such as p21 and PUMA, in HCT116 cells, leading to growth delay, G1-phase cell cycle arrest, cell senescence and cell death. Proximity ligation assay revealed that PTP weakened the interaction between p53 and murine double minute 2 (MDM2) in situ, thereby inhibiting MDM2-mediated p53 degradation. Although DNA damage has been known to promote phosphorylation of p53 and MDM2, thereby preventing their interaction and stabilizing p53, PTP did not cause DNA damage or activate any DNA damage response signaling. Instead, phosphorylation of p53 was mediated by Erk1/2 MAP kinase. In addition, PTP induced acetylation of p53 at Lys382 in a p300-dependent manner, but sirtuin (SIRT)1 and histone deacetylase (HDAC)1, a well-known p53-regulating deacetylase, were not involved. In the present study, the novel anticancer agent PTP was shown to cause the accumulation of p53 by inducing multiple post-translational modifications, as well as cell cycle arrest, senescence and cell death.

SIRT2 mediates multidrug resistance in acute myelogenous leukemia cells via ERK1/2 signaling pathway

“…In our previous study we demonstrated that the MAPKs signaling pathways participate in mediation of the imatinib resistance in CML (21). In the present study, we detected the expression level of ERK1/2, an upstream regulator of p53 as well as BCL-2, an anti-apoptotic protein expressed in most cases of AML and may contribute to drug resistance in AML (22,23). It has been observed that downregulation of both SIRT1 and SIRT2 can enhance the sensitivity of chemotherapy in mammalian cells via p53-independent mechanism (24), thus, we also evaluated p53.…”

Interleukin-1α associates with the tumor suppressor p53 following DNA damage

“…In theory, the PLA can detect proteins separated by a maximal distance of 30-40 nm 39 . This experimental approach was previously used to study the interaction partners of both p53 [40][41][42][43][44][45] and IL-1α 46 . The advantage of the PLA is that it can be used to detect interactions between low-abundance endogenous proteins and allows visualization of the sites of these interactions.…”

Radiosensitizing Effect of Novel Phenylpyrimidine Derivatives on Human Lung Cancer Cells via Cell Cycle Perturbation

“…2003; Levine and Oren, 2009). The PPA moiety was identified by performing cell-based high-throughput screening to identify novel small molecules that increase radiosensitivity via p53 modulation (Kang et al, 2015). Among the 17 derivatives of PPA investigated, six were selected based on their ability to inhibit cell viability and induce G 2 /M arrest.…”

“…In our attempts to identify novel radiosensitizers, we performed cell-based screening using a luciferase-reporter assay system targeting tumor protein 53 (p53; TP53), nuclear factor (erythroid-derived 2)-like 2 (Nrf2; NFE2L2), and transforming growth factor b (Lee et al, 2012;Lim et al, 2012;Jung et al, 2015;Kang et al, 2015). A chemical library of 14,600 compounds was screened, and we identified a hit compound containing an aniline-pyrimidine scaffold, as shown in Table 1.…”