scholarly journals Kinome rewiring reveals AURKA is a molecular barrier to the efficacy of PI3K/mTOR-pathway inhibitors in breast cancer

2017 ◽  
Author(s):  
Hayley J Donnella ◽  
James T Webber ◽  
Rebecca S Levin ◽  
Roman Camarda ◽  
Olga Momcilovic ◽  
...  

ABSTRACTDysregulation of the PI3K-AKT-mTOR signaling network is a prominent feature of breast cancers. However, clinical responses to drugs targeting this pathway have been modest. We hypothesized that dynamic changes in signaling, including adaptation and feedback, limit drug efficacy. Using a quantitative chemoproteomics approach we mapped dynamic changes in the kinome in response to various agents and identified signaling changes that correlate with drug sensitivity. Measurement of dynamics across a panel of breast cancer cell lines identified that maintenance of CDK4 and AURKA activity was associated with drug resistance. We tested whether incomplete inhibition of CDK4 or AURKA was a source of therapy failure and found that inhibition of either was sufficient to sensitize most breast cancer cells to PI3K, AKT, and mTOR inhibitors. In particular, drug combinations including the AURKA inhibitor MLN8237 were highly synergistic and induced apoptosis through enhanced suppression of mTOR signaling to S6 and 4E-BP1 leading to tumor regressionin vivo.This signaling map identifies survival factors whose presence limits the efficacy of target therapy and indicates that Aurora kinase co-inhibition could unlock the full potential of PI3K-AKT-mTOR pathway inhibitors in breast cancer.


2019 ◽  
Vol 1 (Supplement_1) ◽  
pp. i7-i7
Author(s):  
Jiaojiao Deng ◽  
Sophia Chernikova ◽  
Wolf-Nicolas Fischer ◽  
Kerry Koller ◽  
Bernd Jandeleit ◽  
...  

Abstract Leptomeningeal metastasis (LM), a spread of cancer to the cerebrospinal fluid and meninges, is universally and rapidly fatal due to poor detection and no effective treatment. Breast cancers account for a majority of LMs from solid tumors, with triple-negative breast cancers (TNBCs) having the highest propensity to metastasize to LM. The treatment of LM is challenged by poor drug penetration into CNS and high neurotoxicity. Therefore, there is an urgent need for new modalities and targeted therapies able to overcome the limitations of current treatment options. Quadriga has discovered a novel, brain-permeant chemotherapeutic agent that is currently in development as a potential treatment for glioblastoma (GBM). The compound is active in suppressing the growth of GBM tumor cell lines implanted into the brain. Radiolabel distribution studies have shown significant tumor accumulation in intracranial brain tumors while sparing the adjacent normal brain tissue. Recently, we have demonstrated dose-dependent in vitro and in vivo anti-tumor activity with various breast cancer cell lines including the human TNBC cell line MDA-MB-231. To evaluate the in vivo antitumor activity of the compound on LM, we used the mouse model of LM based on the internal carotid injection of luciferase-expressing MDA-MB-231-BR3 cells. Once the bioluminescence signal intensity from the metastatic spread reached (0.2 - 0.5) x 106 photons/sec, mice were dosed i.p. twice a week with either 4 or 8 mg/kg for nine weeks. Tumor growth was monitored by bioluminescence. The compound was well tolerated and caused a significant delay in metastatic growth resulting in significant extension of survival. Tumors regressed completely in ~ 28 % of treated animals. Given that current treatments for LM are palliative with only few studies reporting a survival benefit, Quadriga’s new agent could be effective as a therapeutic for both primary and metastatic brain tumors such as LM. REF: https://onlinelibrary.wiley.com/doi/full/10.1002/pro6.43



Cells ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 942
Author(s):  
Mei Qi Kwa ◽  
Rafael Brandao ◽  
Trong H. Phung ◽  
Jianfeng Ge ◽  
Giuseppe Scieri ◽  
...  

MRCKα is a ubiquitously expressed serine/threonine kinase involved in cell contraction and F-actin turnover, which is highly amplified in human breast cancer and part of a gene expression signature for bad prognosis. Nothing is known about the in vivo function of MRCKα. To explore MRCKα function in development and in breast cancer, we generated mice lacking a functional MRCKα gene. Mice were born close to the Mendelian ratio and showed no obvious phenotype including a normal mammary gland formation. Assessing breast cancer development using the transgenic MMTV-PyMT mouse model, loss of MRCKα did not affect tumor onset, tumor growth and metastasis formation. Deleting MRCKα and its related family member MRCKβ in two triple-negative breast cancer cell lines resulted in reduced invasion of MDA-MB-231 cells, but did not affect migration of 4T1 cells. Further genomic analysis of human breast cancers revealed that MRCKα is frequently co-amplified with the oncogenes ARID4B and AKT3 which might contribute to the prognostic value of MRCKα expression. Collectively, these data suggest that MRCKα might be a prognostic marker for breast cancer, but probably of limited functional importance.



1997 ◽  
Vol 11 (13) ◽  
pp. 2004-2015 ◽  
Author(s):  
I. Erenburg ◽  
B. Schachter ◽  
R. Mira y Lopez ◽  
L. Ossowski

Abstract Comparison of mRNA ratios of a non-DNA-binding estrogen receptor (ERα) isoform, missing exon 3 (ERαΔ3), to the full-length ERα, in normal breast epithelium to that in primary breast cancers and breast cancer cell lines revealed a 30-fold reduction of this ratio in cancer cells (P < 0.0001). To test what functions may have been affected by the loss of ERαΔ3, stable clones of MCF-7 cells expressing ectopic ERαΔ3 protein, at the range of physiological ERα, were generated. In vector-transfected controls the ERαΔ3-mRNA and protein were less than 10% while in the ERαΔ3-expressing clones, ERαΔ3-mRNA and protein ranged from 36–76% of the total ERα. Estrogen (E2) stimulated the expression of pS2-mRNA in pMV7 vector control cells, but the stimulation was reduced by up to 93% in ERαΔ3-expressing clones. In addition, several properties associated with the transformed phenotype were also strongly affected when ERαΔ3 protein was reexpressed. Compared with vector-transfected control cells, the saturation density of the ERαΔ3-expressing clones was reduced by 50–68%, while their exponential growth rate was only slightly (14.5 ± 5%) lower. The in vivo invasiveness of the ERαΔ3-expressing cells was significantly reduced (P = 0.007) by up to 79%. E2 stimulated anchorage-independent growth of the pMV7 vector control cells, but reduced it to below baseline levels in ERαΔ3 clones. The reduction of the pS2 response to E2 in the ERαΔ3-expressing clones and the E2 block of anchorage-independent growth to below baseline were more pronounced than expected from the dominant negative function of ERαΔ3. These observations suggest that E2 may activate an additional ERαΔ3-dependent inhibitory pathway. The drastic reduction of ERαΔ3 to ERα ratio in breast cancer, and the fact that when present in breast cancer cells this isoform leads to a suppression, rather than enhancement, of the transformed phenotype by E2 suggests that the regulation of ERα-mRNA splicing may need to be altered for the breast carcinogenesis to proceed.



2020 ◽  
Vol 22 (1) ◽  
Author(s):  
Jessica Finlay-Schultz ◽  
Britta M. Jacobsen ◽  
Duncan Riley ◽  
Kiran V. Paul ◽  
Scott Turner ◽  
...  

Abstract Background Breast cancer is a highly heterogeneous disease characterized by multiple histologic and molecular subtypes. While a myriad of breast cancer cell lines have been developed over the past 60 years, estrogen receptor alpha (ER)+ disease and some mutations associated with this subtype remain underrepresented. Here we describe six breast cancer cell lines derived from patient-derived xenografts (PDX) and their general characteristics. Methods Established breast cancer PDX were processed into cell suspensions and placed into standard 2D cell culture; six emerged into long-term passageable cell lines. Cell lines were assessed for protein expression of common luminal, basal, and mesenchymal markers, growth assessed in response to estrogens and endocrine therapies, and RNA-seq and oncogenomics testing performed to compare relative transcript levels and identify putative oncogenic drivers. Results Three cell lines express ER and two are also progesterone receptor (PR) positive; PAM50 subtyping identified one line as luminal A. One of the ER+PR+ lines harbors a D538G mutation in the gene for ER (ESR1), providing a natural model that contains this endocrine-resistant genotype. The third ER+PR−/low cell line has mucinous features, a rare histologic type of breast cancer. The three other lines are ER− and represent two basal-like and a mixed ductal/lobular breast cancer. The cell lines show varied responses to tamoxifen and fulvestrant, and three were demonstrated to regrow tumors in vivo. RNA sequencing confirms all cell lines are human and epithelial. Targeted oncogenomics testing confirmed the noted ESR1 mutation in addition to other mutations (i.e., PIK3CA, BRCA2, CCND1, NF1, TP53, MYC) and amplifications (i.e., FGFR1, FGFR3) frequently found in breast cancers. Conclusions These new generation breast cancer cell lines add to the existing repository of breast cancer models, increase the number of ER+ lines, and provide a resource that can be genetically modified for studying several important clinical breast cancer features.



2011 ◽  
Vol 63 (2) ◽  
pp. 264-271 ◽  
Author(s):  
Gopal Singh ◽  
Argun Akcakanat ◽  
Chandeshwar Sharma ◽  
David Luyimbazi ◽  
Katherine Naff ◽  
...  


2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi70-vi70
Author(s):  
Jiaojiao Deng ◽  
Sophia Chernikova ◽  
Wolf-Nicolas Fischer ◽  
Kerry Koller ◽  
Bernd Jandeleit ◽  
...  

Abstract Leptomeningeal metastasis (LM), a spread of cancer to the cerebrospinal fluid and meninges, is universally and rapidly fatal due to poor detection and no effective treatment. Breast cancers account for a majority of LMs from solid tumors, with triple-negative breast cancers (TNBCs) having the highest propensity to metastasize to LM. The treatment of LM is challenged by poor drug penetration into CNS and high neurotoxicity. Therefore, there is an urgent need for new modalities and targeted therapies able to overcome the limitations of current treatment options. Quadriga has discovered a novel, brain-permeant chemotherapeutic agent that is currently in development as a potential treatment for glioblastoma (GBM). Recently, we have demonstrated dose-dependent in vitro and in vivo anti-tumor activity with various breast cancer cell lines including the human TNBC cell line MDA-MB-231. To evaluate the in vivo antitumor activity of the compound on LM, we used the mouse model of LM based on the internal carotid injection of luciferase-expressing MDA-MB-231-BR3 cells. Once the bioluminescence signal intensity from the metastatic spread reached (0.2 - 0.5) x 106photons/sec, mice were dosed i.v. (8 mg/kg once a week for nine weeks) or i.p. (4 or 8 mg/kg twice a week for nine weeks). Tumor growth was monitored by bioluminescence. The compound was well tolerated and caused a significant delay in metastatic growth resulting in significant extension of survival. Tumors regressed completely in ~ 28 % of treated animals in the i.p. group. Given that current treatments for LM are palliative with only few studies reporting a survival benefit, Quadriga’s new agent could be effective as a therapeutic for both primary and metastatic brain tumors such as LM. REF: https://onlinelibrary.wiley.com/doi/full/10.1002/pro6.43



2020 ◽  
Author(s):  
Chengheng Liao ◽  
Cherise Ryan Glodowski ◽  
Cheng Fan ◽  
Juan Liu ◽  
Kevin Raynard Mott ◽  
...  

Abstract Metabolic dysregulation is one of the distinctive features in breast cancer. However, examining the metabolic features in various subtypes of breast cancer in their relationship to gene expression features in a physiologically relevant setting remains understudied. By performing metabolic profiling on triple-negative breast cancer (TNBC) and ER+ breast cancers from patients, TNBC patient-derived xenografts (PDXs), and representative breast cancer cell lines grown as tumors in vivo, we identify two distinctive groups defined by metabolites; a “Nucleotide-Enriched” group that shows high levels of pyrimidine pathway metabolites and biosynthetic enzymes, and a “Arginine Biosynthesis-Enriched” group that shows high levels of arginine biosynthesis intermediates. We reveal different metabolic enrichment profiles between cell lines grown in vitro versus in vivo, where cell lines grown in vivo more faithfually recapitulate patient tumors metabolic profiles. In addition, with integrated metabolic and gene expression profiling we identify a subset of genes that strongly correlates with the Nucleotide-Enriched metabolic profile, and which strongly predicts patient prognosis. As a proof-of-principle, when we target Nucleotide-Enriched metabolic dysregulation with a pyrimidine biosynthesis inhibitor (Brequinar), and/or a glutaminase inhibitor (CB-839), we observe therapeutic efficacy and decreased tumor growth in representative TNBC cell lines and an in vivo PDX upon combinatorial drug treatment. Our study reveals new therapeutic opportunities in breast cancer guided by a genomic biomarker, which could prove highly impactful for rapidly proliferating breast cancers specifically.



2018 ◽  
Vol 2018 ◽  
pp. 1-9
Author(s):  
Hongbo Huang ◽  
Ke Li ◽  
Gaochao Lv ◽  
Guiqing Liu ◽  
Xueyu Zhao ◽  
...  

Positron emission tomography (PET) imaging is a useful method to evaluate in situ estrogen receptor (ER) status for the early diagnosis of breast cancer and optimization of the appropriate treatment strategy. The 18F-labeled estradiol derivative has been successfully used to clinically assess the ER level of breast cancer. In order to simplify the radiosynthesis process, one-step 18F-19F isotope exchange reaction was employed for the 18F-fluorination of the tracer of [18F]AmBF3-TEG-ES. The radiotracer was obtained with the radiochemical yield (RCY) of ~61% and the radiochemical purity (RCP) of >98% within 40 min. Cell uptake and blocking assays indicated that the tracer could selectively accumulate in the ER-positive human breast cancer cell lines MCF-7 and T47D. In vivo PET imaging on the MCF-7 tumor-bearing mice showed relatively high tumor uptake (1.4~2.3 %D/g) and tumor/muscle uptake ratio (4~6). These results indicated that the tracer is a promising PET imaging agent for ER-positive breast cancers.



2020 ◽  
Author(s):  
Xiao Tan ◽  
Zhongqiang Zhang ◽  
Ping Liu ◽  
Hongliang Yao ◽  
jingshan tong

Abstract Background: PIK3CA mutations are common genomic alterations in estrogen receptor (ER)-positive breast cancers, currently, the development of selective PI3Kα (phosphatidylinositol 3-kinase α) inhibitors is ongoing. The mechanisms contributing to the anticancer activity of alpelisib in PIK3CA-mutant breast cancer cells and the mechanism of acquired resistance to alpelisib remain elusive. Methods: Drug-sensitive cell lines were exposed to alpelisib to establish alpelisib-resistant cell lines. Western blotting was used to assess changes in protein expression. Apoptosis was evaluated by flow cytometry. In vivo with mouse xenograft models and in vitro colony formation and MTS and assay were carried out to determine the growth inhibitory effects of the tested drugs. Protein half-lives were examined and proteasome inhibitors were used to estimate protein degradation. Gene knockdown was carried out using shRNA or siRNA. Results: In the present study, we report the potent induction of apoptosis by alpelisib in PIK3CA-mutant breast cancer cell lines. AKT phosphorylation suppression, AKT/Foxo3a-dependent Bim induction, and AKT/GSK-3β-dependent Mcl-1 degradation were observed. Apoptosis induced by alpelisib was attenuated by Mcl-1 (4A) overexpression or Bim suppression. Furthermore, alpelisib could not modulate Mcl-1 or Bim levels in cell lines that were resistant to alpelisib. AKT inhibitor and alpelisib combination restored the sensitivity of alpelisib-resistant cells to growth inhibition and apoptosis in vitro and in vivo. Conclusions: Therefore, modulation of Mcl-1 degradation and AKT-dependent Bim induction are crucial for mediating the resistance and sensitivity of PIK3CA-mutant breast tumor cells to alpelisib, thus making it a productive strategy for overcoming acquired resistance to alpelisib.



Cells ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1986
Author(s):  
Virginia Solar Fernandez ◽  
Marco Fiocchetti ◽  
Manuela Cipolletti ◽  
Marco Segatto ◽  
Paolo Cercola ◽  
...  

The expression of the α-subtype of Estrogen Receptor (ERα) characterizes most breast cancers (more than 75%), for which endocrine therapy is the mainstay for their treatment. However, a high percentage of ERα+ breast cancers are de novo or acquired resistance to endocrine therapy, and the definition of new targets for improving therapeutic interventions and the prediction of treatment response is demanding. Our previous data identified the ERα/AKT/neuroglobin (NGB) pathway as a common pro-survival process activated in different ERα breast cancer cell lines. However, no in vivo association between the globin and the malignity of breast cancer has yet been done. Here, we evaluated the levels and localization of NGB in ERα+ breast ductal carcinoma tissue of different grades derived from pre-and post-menopausal patients. The results indicate a strong association between NGB accumulation, ERα, AKT activation, and the G3 grade, while no association with the menopausal state has been evidenced. Analyses of the data set (e.g., GOBO) strengthen the idea that NGB accumulation could be linked to tumor cell aggressiveness (high grade) and resistance to treatment. These data support the view that NGB accumulation, mainly related to ER expression and tumor grade, represents a compensatory process, which allows cancer cells to survive in an unfavorable environment.



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