scholarly journals RB1 deficiency in triple-negative breast cancer induces mitochondrial protein translation

2016 ◽  
Vol 126 (10) ◽  
pp. 3739-3757 ◽  
Author(s):  
Robert A. Jones ◽  
Tyler J. Robinson ◽  
Jeff C. Liu ◽  
Mariusz Shrestha ◽  
Veronique Voisin ◽  
...  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
YoungJun Ju ◽  
Yaacov Ben-David ◽  
Daniela Rotin ◽  
Eldad Zacksenhaus

AbstractThe eukaryotic elongation factor-2 kinase, eEF2K, which restricts protein translation elongation, has been identified as a potential therapeutic target for diverse types of malignancies including triple negative breast cancer (TNBC). However, the contexts in which eEF2K inhibition is essential in TNBC and its consequences on the proteome are largely unknown. Here we show that genetic or pharmacological inhibition of eEF2K cooperated with glutamine (Gln) starvation, and synergized with glutaminase (GLS1) inhibitors to suppress growth of diverse TNBC cell lines. eEF2K inhibition also synergized with depletion of eukaryotic translation initiation factor 4E-binding protein 1 (eIF4EBP1; 4EBP1), a suppressor of eukaryotic protein translation initiation factor 4E (eIF4E), to induce c-MYC and Cyclin D1 expression, yet attenuate growth of TNBC cells. Proteomic analysis revealed that whereas eEF2K depletion alone uniquely induced Cyclin Dependent Kinase 1 (CDK1) and 6 (CDK6), combined depletion of eEF2K and 4EBP1 resulted in overlapping effects on the proteome, with the highest impact on the ‘Collagen containing extracellular matrix’ pathway (e.g. COL1A1), as well as the amino-acid transporter, SLC7A5/LAT1, suggesting a regulatory loop via mTORC1. In addition, combined depletion of eEF2K and 4EBP1 indirectly reduced the levels of IFN-dependent innate immune response-related factors. Thus, eEF2K inhibition triggers cell cycle arrest/death under unfavourable metabolic conditions such as Gln-starvation/GLS1 inhibition or 4EBP1 depletion, uncovering new therapeutic avenues for TNBC and underscoring a pressing need for clinically relevant eEF2K inhibitors.


2020 ◽  
Vol 11 (11) ◽  
Author(s):  
Ayse Ertay ◽  
Huiquan Liu ◽  
Dian Liu ◽  
Ping Peng ◽  
Charlotte Hill ◽  
...  

AbstractTriple-negative breast cancer (TNBC) is the most aggressive type of breast cancer that lacks the oestrogen receptor, progesterone receptor and human epidermal growth factor receptor 2, making it difficult to target therapeutically. Targeting synthetic lethality is an alternative approach for cancer treatment. TNBC shows frequent loss of phosphatase and tensin homologue (PTEN) expression, which is associated with poor prognosis and treatment response. To identify PTEN synthetic lethal interactions, TCGA analysis coupled with a whole-genome siRNA screen in isogenic PTEN-negative and -positive cells were performed. Among the candidate genes essential for the survival of PTEN-inactive TNBC cells, WDHD1 (WD repeat and high-mobility group box DNA-binding protein 1) expression was increased in the low vs. high PTEN TNBC samples. It was also the top hit in the siRNA screen and its knockdown significantly inhibited cell viability in PTEN-negative cells, which was further validated in 2D and 3D cultures. Mechanistically, WDHD1 is important to mediate a high demand of protein translation in PTEN-inactive TNBC. Finally, the importance of WDHD1 in TNBC was confirmed in patient samples obtained from the TCGA and tissue microarrays with clinic-pathological information. Taken together, as an essential gene for the survival of PTEN-inactive TNBC cells, WDHD1 could be a potential biomarker or a therapeutic target for TNBC.


Planta Medica ◽  
2015 ◽  
Vol 81 (11) ◽  
Author(s):  
AJ Robles ◽  
L Du ◽  
S Cai ◽  
RH Cichewicz ◽  
SL Mooberry

2020 ◽  
pp. 75-80
Author(s):  
S.A. Lyalkin ◽  
◽  
L.A. Syvak ◽  
N.O. Verevkina ◽  
◽  
...  

The objective: was to evaluate the efficacy of the first line chemotherapy in patients with metastatic triple negative breast cancer (TNBC). Materials and methods. Open randomized study was performed including 122 patients with metastatic TNBC. The efficacy and safety of the first line chemotherapy of regimens АТ (n=59) – group 1, patients received doxorubicine 60 мг/м2 and paclitaxel 175 мг/м2 and ТР (n=63) – group 2, patients received paclitaxel 175 мг/м2 and carboplatin AUC 5 were evaluated. Results. The median duration of response was 9.5 months (4.5–13.25 months) in patients received AT regimen and 8.5 months (4.7–12.25 months), in TP regimen; no statistically significant differences were observed, р=0.836. The median progression free survival was 7 months (95% CI 5–26 months) in group 1 and 7.5 months (95% CI 6–35 months) in group 2, p=0.85. Both chemotherapy regimens (AT and TP) had mild or moderate toxicity profiles (grade 1 or 2 in most patients). No significant difference in gastrointestinal toxicity was observed. The incidence of grade 3–4 neutropenia was higher in patients of group 2 (TP regimen): 42.8% versus 27% (р<0.05). Conclusions. Both regimens of chemotherapy (AT and TP) are appropriate to use in the first line setting in patients with metastatic TNBC. Key words: metastatic triple negative breast cancer, chemotherapy, progression free survival, chemotherapy toxicity.


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