New anti-cancer role for PDK1 inhibitors: preventing resistance to tamoxifen

2008 ◽  
Vol 417 (1) ◽  
pp. e5-e7 ◽  
Author(s):  
Christian Peifer ◽  
Dario R. Alessi
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Acquired Resistance ◽  
Mammalian Target Of Rapamycin ◽  
Signal Transduction Pathway ◽  
Cancer Treatments ◽  
Biochemical Journal ◽  
Anti Cancer ◽  
Phosphoinositide 3 Kinase

Tamoxifen is one of the most prescribed anti-breast-cancer drugs, but tumours becoming resistant hinder its efficacy in the clinic. There is therefore great interest in developing strategies to reduce resistance and sensitize breast cancer cells to tamoxifen. A groundbreaking study by Iorns et al. published in this issue of the Biochemical Journal suggests that a signal transduction pathway controlled by PDK1 (phosphoinositide-dependent kinase 1) plays a crucial role in regulating the sensitivity of breast cancer cells to tamoxifen. The implications of this study are that PDK1 or PI3K (phosphoinositide 3-kinase), Akt (also known as protein kinase B), S6K (S6 kinase) and mTOR (mammalian target of rapamycin) inhibitors, already being developed for cancer therapy, are likely to have additional utility in sensitizing breast tumours to tamoxifen. In this commentary we also discuss the possibility that inhibiting the PDK1 pathway may help overcome acquired resistance to other anti-cancer treatments.

scholarly journals Elevated SGK1 predicts resistance of breast cancer cells to Akt inhibitors

2013 ◽  
Vol 452 (3) ◽  
pp. 499-508 ◽  
Author(s):  
Eeva M. Sommer ◽  
Hannah Dry ◽  
Darren Cross ◽  
Sylvie Guichard ◽  
Barry R. Davies ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Clinical Trials ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Therapeutic Potential ◽  
Mammalian Target Of Rapamycin ◽  
Akt Inhibitor ◽  
Resistant Lines ◽  
Phosphoinositide 3 Kinase ◽  
Resistant Cells

The majority of human cancers harbour mutations promoting activation of the Akt protein kinase, and Akt inhibitors are being evaluated in clinical trials. An important question concerns the understanding of the innate mechanisms that confer resistance of tumour cells to Akt inhibitors. SGK (serum- and glucocorticoid-regulated kinase) is closely related to Akt and controlled by identical upstream regulators {PI3K (phosphoinositide 3-kinase), PDK1 (phosphoinositide-dependent kinase 1) and mTORC2 [mTOR (mammalian target of rapamycin) complex 2]}. Mutations that trigger activation of Akt would also stimulate SGK. Moreover, Akt and SGK possess analogous substrate specificities and are likely to phosphorylate overlapping substrates to promote proliferation. To investigate whether cancers possessing high SGK activity could possess innate resistance to Akt-specific inhibitors (that do not target SGK), we analysed SGK levels and sensitivity of a panel of breast cancer cells towards two distinct Akt inhibitors currently in clinical trials (AZD5363 and MK-2206). This revealed a number of Akt-inhibitor-resistant lines displaying markedly elevated SGK1 that also exhibited significant phosphorylation of the SGK1 substrate NDRG1 [N-Myc (neuroblastoma-derived Myc) downstream-regulated gene 1]. In contrast, most Akt-inhibitor-sensitive cell lines displayed low/undetectable levels of SGK1. Intriguingly, despite low SGK1 levels, several Akt-inhibitor-sensitive cells showed marked NDRG1 phosphorylation that was, unlike in the resistant cells, suppressed by Akt inhibitors. SGK1 knockdown markedly reduced proliferation of Akt-inhibitor-resistant, but not -sensitive, cells. Furthermore, treatment of Akt-inhibitor-resistant cells with an mTOR inhibitor suppressed proliferation and led to inhibition of SGK1. The results of the present study suggest that monitoring SGK1 levels as well as responses of NDRG1 phosphorylation to Akt inhibitor administration could have a use in predicting the sensitivity of tumours to compounds that target Akt. Our findings highlight the therapeutic potential that SGK inhibitors or dual Akt/SGK inhibitors might have for treatment of cancers displaying elevated SGK activity.

Recent Advances on Therapeutic Peptides for Breast Cancer Treatment

2020 ◽  
Vol 21 ◽  
Author(s):  
Samad Beheshtirouy ◽  
Farhad Mirzaei ◽  
Shirin Eyvazi ◽  
Vahideh Tarhriz
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Tumor Cells ◽  
Breast Cancer Cells ◽  
Specific Binding ◽  
High Specificity ◽  
The Novel ◽  
Anti Cancer ◽  
Therapeutic Peptides ◽  
Low Toxicity

: Breast cancer is a heterogeneous malignancy which is the second cause of mortality among women in the world. Increasing the resistance to anti-cancer drugs in breast cancer cells persuades researchers to search the novel therapies approaches for the treatment of the malignancy. Among the novel methods, therapeutic peptides which target and disrupt tumor cells have been of great interest. Therapeutic peptides are short amino acids monomer chains with high specificity to bind and modulate a protein interaction of interest. Several advantages of peptides such as specific binding on tumor cells surface, low molecular weight and low toxicity on normal cells make the peptides as an appealing therapeutic agents against solid tumors, particularly breast cancer. Also, National Institutes of Health (NIH) describes therapeutic peptides as suitable candidate for the treatment of drug-resistant breast cancer. In this review, we attempt to review the different therapeutic peptides against breast cancer cells which can be used in treatment and diagnosis of the malignancy. Meanwhile, we presented an overview of peptide vaccines which have been developed for the treatment of breast cancer.

Lobetyolin inhibits the proliferation of breast cancer cells via ASCT2 down-regulation-induced apoptosis

2021 ◽  
pp. 096032712110214
Author(s):  
Yansong Chen ◽  
Ye Tian ◽  
Gongsheng Jin ◽  
Zhen Cui ◽  
Wei Guo ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Mrna Expression ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Glutamine Metabolism ◽  
Down Regulation ◽  
Anti Cancer ◽  
Induced Apoptosis ◽  
Glutamine Uptake

This study aimed to investigate the anti-cancer effect of lobetyolin on breast cancer cells. Lobetyolin was incubated with MDA-MB-231 and MDA-MB-468 breast cancer cells for 24 h. Glucose uptake and the mRNA expression of GLUT4 ( SLC2A4), HK2 and PKM2 were detected to assess the effect of lobetyolin on glucose metabolism. Glutamine uptake and the mRNA expression of ASCT2 ( SLC1A5), GLS1, GDH and GLUL were measured to assess the effect of lobetyolin on glutamine metabolism. Annexin V/PI double staining and Hoechst 33342 staining were used to investigate the effect of lobetyolin on cell apoptosis. Immunoblot was employed to estimate the effect of lobetyolin on the expression of proliferation-related markers and apoptosis-related markers. SLC1A5 knockdown with specific siRNA was performed to study the role of ASCT2 played in the anti-cancer effect of lobetyolin on MDA-MB-231 and MDA-MB-468 breast cancer cells. C-MYC knockdown with specific siRNA was performed to study the role of c-Myc played in lobetyolin-induced ASCT2 down-regulation. Myr-AKT overexpression was performed to investigate the role of AKT/GSK3β signaling played in lobetyolin-induced down-regulation of c-Myc and ASCT2. The results showed that lobetyolin inhibited the proliferation of both MDA-MB-231 and MDA-MB-468 breast cancer cells. Lobetyolin disrupted glutamine uptake via down-regulating ASCT2. SLC1A5 knockdown attenuated the anti-cancer effect of lobetyolin. C-MYC knockdown attenuated lobetyolin-caused down-regulation of ASCT2 and Myr-AKT overexpression reversed lobetyolin-caused down-regulation of both c-Myc and ASCT2. In conclusion, the present work suggested that lobetyolin exerted anti-cancer effect via ASCT2 down-regulation-induced apoptosis in breast cancer cells.

Novel 3-fluoro-4-morpholinoaniline derivatives: Synthesis and assessment of anti-cancer activity in breast cancer cells

2021 ◽  
pp. 132127
Author(s):  
Namita A. More ◽  
Nitin L. Jadhao ◽  
Rohan J. Meshram ◽  
Prajkta Tambe ◽  
Rajesh A. Salve ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Anti Cancer ◽  
Cancer Activity

The palladacycle, AJ-5, exhibits anti-tumour and anti-cancer stem cell activity in breast cancer cells

2015 ◽  
Vol 357 (1) ◽  
pp. 206-218 ◽  
Author(s):  
Saeb Aliwaini ◽  
Jade Peres ◽  
Wendy L. Kröger ◽  
Angelique Blanckenberg ◽  
Jo de la Mare ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Stem Cell ◽  
Cancer Stem Cell ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Cell Activity ◽  
Anti Cancer ◽  
Stem Cell Activity
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