Trichostatin A downregulates bromodomain and extra-terminal proteins to suppress osimertinib resistant non-small cell lung carcinoma

Abstract Background The third-generation epithelial growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) have shown significant therapeutic effects on patients with non-small cell lung carcinoma (NSCLC) who carry active EGFR mutations, as well as those who have developed acquired resistance to the first-generation of EGFR-TKIs due to the T790M mutation. However, most patients develop drug resistance after 8–10 months of treatment. Currently, the mechanism has not been well clarified, and new therapeutic strategies are urgently needed. Methods Osimertinib resistant cell lines were established by culturing sensitive cells in chronically increasing doses of osimertinib. The anticancer effect of reagents was examined both in vitro and in vivo using the sulforhodamine B assay and a xenograft mouse model. The molecular signals were detected by western blotting. The combination effect was analyzed using CompuSyn software. Results We found that bromodomain and extra-terminal proteins (BETs) were upregulated in osimertinib resistant (H1975-OR) cells compared with those in the paired parental cells (H1975-P), and that knockdown of BETs significantly inhibited the growth of H1975-OR cells. The BET inhibitor JQ1 also exhibited stronger growth-inhibitory effects on H1975-OR cells and a greater expression of BETs and the downstream effector c-Myc than were observed in H1975-P cells. The histone deacetylase (HDAC) inhibitor trichostatin A (TSA) showed stronger growth suppression in H1975-OR cells than in H1975-P cells, but vorinostat, another HDAC inhibitor, showed equal inhibitory efficacy in both cell types. Consistently, downregulation of BET and c-Myc expression was greater with TSA than with vorinostat. TSA restrained the growth of H1975-OR and H1975-P xenograft tumors. The combination of TSA and JQ1 showed synergistic growth-inhibitory effects in parallel with decreased BET and c-Myc expression in both H1975-OR and H1975-P cells and in xenograft nude mouse models. BETs were not upregulated in osimertinib resistant HCC827 cells compared with parental cells, while TSA and vorinostat exhibited equal inhibitory effects on both cell types. Conclusion Upregulation of BETs contributed to the osimertinib resistance of H1975 cells. TSA downregulated BET expression and enhanced the growth inhibitory effect of JQ1 both in vitro and in vivo. Our findings provided new strategies for the treatment of osimertinib resistance.

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The N-Terminal Domain of p73 Interacts with the CH1 Domain of p300/CREB Binding Protein and Mediates Transcriptional Activation and Apoptosis

Molecular and Cellular Biology ◽

10.1128/mcb.20.4.1299-1310.2000 ◽

2000 ◽

Vol 20 (4) ◽

pp. 1299-1310 ◽

Cited By ~ 62

Author(s):

Xiaoya Zeng ◽

Xiaorong Li ◽

Ashley Miller ◽

Zhimin Yuan ◽

Wuchao Yuan ◽

...

Keyword(s):

Transcriptional Activation ◽

Binding Protein ◽

Small Cell Lung Carcinoma ◽

Creb Binding Protein ◽

Cell Lung Carcinoma ◽

Cell Extracts ◽

N Terminus ◽

Mcf 7

ABSTRACT The newly identified p53 homolog p73 mimics the transcriptional function of p53. We have investigated the regulation of p73's transcriptional activity by p300/CREB binding protein (CBP). p73-p300 complexes were identified in HeLa cell extracts by cofractionation and coimmunoprecipitation assays. The p73-p300 interaction was confirmed in vitro by glutathione S-transferase–protein association assays and in vivo by coimmunoprecipitating the overexpressed p300 and p73 in human p53-free small-cell lung carcinoma H1299 or osteosarcoma Saos-2 cells. The N terminus but not the N-terminal truncation of p73 bound to the CH1 domain (amino acids [aa] 350 to 450) of p300/CBP. Accordingly, this p73 N-terminal deletion was unable to activate transcription or to induce apoptosis. Overexpression of either p300 or CBP stimulated transcription mediated by p73 but not its N-terminally deleted mutant in vivo. The N-terminal fragment from aa 19 to 597, but not the truncated fragment from aa 242 to 1700 of p300, reduced p73-mediated transcription markedly. p73-dependent transcription or apoptosis was partially impaired in either p300- or CBP-deficient human breast carcinoma MCF-7 or H1299 cells, suggesting that both coactivators mediate transcription by p73 in cells. These results demonstrate that the N terminus of p73 directly interacts with the N-terminal CH1 domain of p300/CBP to activate transcription.

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Ophiobolin A, a sesterterpenoid fungal phytotoxin, displays higher in vitro growth-inhibitory effects in mammalian than in plant cells and displays in vivo antitumor activity

International Journal of Oncology ◽

10.3892/ijo.2013.1979 ◽

2013 ◽

Vol 43 (2) ◽

pp. 575-585 ◽

Cited By ~ 24

Author(s):

MARINA BURY ◽

ESTHER NOVO-UZAL ◽

ANNA ANDOLFI ◽

SARA CIMINI ◽

NATHALIE WAUTHOZ ◽

...

Keyword(s):

Antitumor Activity ◽

Plant Cells ◽

In Vitro Growth ◽

Inhibitory Effects ◽

Growth Inhibitory ◽

In Vivo Antitumor Activity

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In vitro and in vivo growth-inhibitory effects of cladribine on neoplastic mast cells exhibiting the imatinib-resistant KIT mutation D816V

Experimental Hematology ◽

10.1016/j.exphem.2010.05.006 ◽

2010 ◽

Vol 38 (9) ◽

pp. 744-755 ◽

Cited By ~ 29

Author(s):

Alexandra Böhm ◽

Karoline Sonneck ◽

Karoline V. Gleixner ◽

Karina Schuch ◽

Winfried F. Pickl ◽

...

Keyword(s):

Mast Cells ◽

Inhibitory Effects ◽

Kit Mutation ◽

Growth Inhibitory ◽

Imatinib Resistant ◽

In Vivo Growth

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Chemical Constituents and Anticancer Activity of Curcuma zedoaria Roscoe Essential Oil against Non-Small Cell Lung Carcinoma Cells in Vitro and in Vivo

Journal of Agricultural and Food Chemistry ◽

10.1021/jf4026184 ◽

2013 ◽

Vol 61 (47) ◽

pp. 11418-11427 ◽

Cited By ~ 30

Author(s):

Chien-chang Chen ◽

Yuhsin Chen ◽

Yi-Ting Hsi ◽

Chih-Sheng Chang ◽

Li-Fen Huang ◽

...

Keyword(s):

Chemical Constituents ◽

Small Cell Lung Carcinoma ◽

Small Cell ◽

Carcinoma Cells ◽

Curcuma Zedoaria ◽

Small Cell Lung ◽

Cell Lung Carcinoma ◽

Lung Carcinoma Cells

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Fusion of the N-terminal 119 amino acids with the RelA-CTD renders its growth inhibitory effects (p)ppGpp-dependent

10.1101/2021.03.21.436043 ◽

2021 ◽

Author(s):

Jayashree Pohnerkar ◽

Krishma Tailor ◽

Prarthi Sagar ◽

Keyur Dave

Keyword(s):

Amino Acids ◽

Feedback Regulation ◽

Inhibitory Effects ◽

E Coli ◽

Growth Inhibitory ◽

In The Wild ◽

Regulatory Aspect ◽

And Function

The guanosine nucleotide derivatives ppGpp and pppGpp are central to the remarkable capacity of bacteria to adapt to fluctuating environment and metabolic perturbations. These alarmones are synthesized by two proteins, RelA and SpoT in E. coli and the activities of each of the two enzymes are highly regulated for homeostatic control of (p)ppGpp levels in the cell. Although the domain structure and function of RelA are well defined, the findings of this study unfold the regulatory aspect of RelA that is possibly relevant in vivo. We uncover here the importance of the N-terminal 1-119 amino acids of the enzymatically compromised (p)ppGpp hydrolytic domain (HD) of monofunctional RelA for the (p)ppGpp mediated regulation of RelA-CTD function. We find that even moderate level expression of RelA appreciably reduces growth when the basal levels of (p)ppGpp in the cells are higher than in the wild type, an effect independent of its ability to synthesize (p)ppGpp. This is evidenced by the growth inhibitory effects of oversynthesis of the RelA-CTD in the relA+ strain but not in relA null mutant, suggesting the requirement of the functional RelA protein for basal level synthesis of (p)ppGpp, accordingly corroborated by the restoration of the growth inhibitory effects of the RelA-CTD expression in the relA1 spoT202 mutant. The N-terminal 119 amino acids of RelA fused in-frame with the RelA-CTD, both from 406-744 amino acids (including TGS) and from 454-744 amino acids (sans TGS) caused growth inhibition only in spoT1 and spoT202 relA1 mutants, uncovering the hitherto unrealized (p)ppGpp-dependent regulation of RelA-CTD function. An incremental rise in the (p)ppGpp levels is proposed to progressively modulate the interaction of RelA-CTD with the ribosomes, with possible implications in the feedback regulation of the N-terminal (p)ppGpp synthesis function, a proposal that best explains the nonlinear relationship between (p)ppGpp synthesis and increased ratio of RelA:ribosomes, both in vitro as well as in vivo.

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179. CHARACTERISATION OF THE IN VITRO FUNCTION OF ACTIVIN AC

Reproduction Fertility and Development ◽

10.1071/srb09abs179 ◽

2009 ◽

Vol 21 (9) ◽

pp. 97

Author(s):

E. Gold ◽

C. Harrison ◽

Y. Makanji ◽

G. Risbridger

Keyword(s):

Physiological Role ◽

Activin A ◽

Type I ◽

Lncap Cells ◽

Inhibitory Effects ◽

Signalling Molecules ◽

Growth Inhibitory ◽

Potent Growth

Activins are members of the TGF-β superfamily that signal via type II and type I receptor subunits and intracellular Smads1. Activin A stimulates FSH release from the pituitary and is also a potent growth and differentiation factor in many physiological systems2. Over-expression of the activin-βC subunit in vitro leads to a reduction in activin A and an increase in activin AC3. Transgenic mice over-expressing activin-βC show decreased circulating activin A, implying that activin AC may also be formed in vivo4. Recently recombinant activin AC has become available, therefore this study examines the in vitro function and mechanism of action of activin AC. Activin AC stimulates FSH release in LβT2 cells and is a negative growth regulator in LNCaP cells, however the potency of activin AC is 8-10 fold less than activin A. Incubation of LNCaP cells with activin receptor antibodies (ALK4, ActRIIA, ActRIIB) abolishes the growth inhibitory effects of activin AC. Activin AC binds to ActRIIB, however a 20-30 fold decrease in both the potency and affinity of activin AC is evident compared to activin A. In addition, activin AC increases Smad-2 phosphorylation. These results indicate activin AC utilises the same receptors and intracellular signalling molecules as activin A. The activin A antagonists, follistatin and activin C4, also antagonise the growth inhibitory effects of activin AC and reduce Smad-2 phosphorylation and Smad-4 expression. This study shows for the first time that the in vitro function of activin AC is similar to activin A, albeit at a lower potency and provides the impetus to determine the physiological role of activin AC in vivo.

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The Anticancer Effect of Sanguinarine: A Review

Current Pharmaceutical Design ◽

10.2174/1381612824666180829100601 ◽

2018 ◽

Vol 24 (24) ◽

pp. 2760-2764 ◽

Cited By ~ 7

Author(s):

Chenxing Fu ◽

Guiping Guan ◽

Hongbing Wang

Keyword(s):

Tumor Cell ◽

In Vivo Studies ◽

Inhibitory Effects ◽

Anticancer Effect ◽

Growth Inhibitory ◽

Cell Proliferation Inhibition ◽

Anti Cancer ◽

Induced Apoptosis

In vitro and in vivo studies have revealed that Sanguinarine has antioxidant, anti-inflammatory, proapoptotic, and growth inhibitory effects on tumor cells of a variety of cancers. Previous research showed that sanguinarine induced apoptosis (cell death) and/or antiproliferative while reducing tumor cell antiangiogenic and anti-invasive properties. This paper describes various sanguinarine anti-cancer mechanisms, including inhibition of erroneously-activated signal transduction pathways, apoptosis, and tumor cell proliferation inhibition.

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