scholarly journals The Harsh Microenvironment in Early Breast Cancer Selects for a Warburg Phenotype

2020 ◽  
Author(s):  
Mehdi Damaghi ◽  
Jeffrey West ◽  
Mark Robertson-Tessi ◽  
Liping Xu ◽  
Meghan C. Ferrall-Fairbanks ◽  
...  

AbstractThe harsh microenvironment of ductal carcinoma in situ (DCIS) exerts strong evolutionary selection pressures on cancer cells. We hypothesize that the poor metabolic conditions near the ductal center foment the emergence of a Warburg Effect (WE) phenotype, wherein cells rapidly ferment glucose to lactic acid, even in normoxia. To test this hypothesis, we subjected pre-malignant breast cancer cells to different microenvironmental selection pressures using combinations of hypoxia, acidosis, low glucose, and starvation for many months, and isolated single clones for metabolic and transcriptomic profiling. The two harshest conditions selected for constitutively expressed WE phenotypes. RNA-seq analysis of WE clones identified the transcription factors NFкB and KLF4 as potential inducers of the WE phenotype. NFкB was highly phosphorylated in the glycolytic clones. In stained DCIS samples, KLF4 expression was enriched in the area with the harshest microenvironmental conditions. We simulated in vivo DCIS phenotypic evolution using a mathematical model calibrated from the in vitro results. The WE phenotype emerged in the poor metabolic conditions near the necrotic core. We propose that harsh microenvironments within DCIS select for a Warburg phenotype through constitutive transcriptional reprogramming, thus conferring a survival advantage and facilitating further growth and invasion.

2021 ◽  
Vol 118 (3) ◽  
pp. e2011342118 ◽  
Author(s):  
Mehdi Damaghi ◽  
Jeffrey West ◽  
Mark Robertson-Tessi ◽  
Liping Xu ◽  
Meghan C. Ferrall-Fairbanks ◽  
...  

The harsh microenvironment of ductal carcinoma in situ (DCIS) exerts strong evolutionary selection pressures on cancer cells. We hypothesize that the poor metabolic conditions near the ductal center foment the emergence of a Warburg Effect (WE) phenotype, wherein cells rapidly ferment glucose to lactic acid, even in normoxia. To test this hypothesis, we subjected low-glycolytic breast cancer cells to different microenvironmental selection pressures using combinations of hypoxia, acidosis, low glucose, and starvation for many months and isolated single clones for metabolic and transcriptomic profiling. The two harshest conditions selected for constitutively expressed WE phenotypes. RNA sequencing analysis of WE clones identified the transcription factor KLF4 as potential inducer of the WE phenotype. In stained DCIS samples, KLF4 expression was enriched in the area with the harshest microenvironmental conditions. We simulated in vivo DCIS phenotypic evolution using a mathematical model calibrated from the in vitro results. The WE phenotype emerged in the poor metabolic conditions near the necrotic core. We propose that harsh microenvironments within DCIS select for a WE phenotype through constitutive transcriptional reprogramming, thus conferring a survival advantage and facilitating further growth and invasion.


2018 ◽  
Vol 18 (17) ◽  
pp. 1483-1493
Author(s):  
Ricardo Imbroisi Filho ◽  
Daniel T.G. Gonzaga ◽  
Thainá M. Demaria ◽  
João G.B. Leandro ◽  
Dora C.S. Costa ◽  
...  

Background: Cancer is a major cause of death worldwide, despite many different drugs available to treat the disease. This high mortality rate is largely due to the complexity of the disease, which results from several genetic and epigenetic changes. Therefore, researchers are constantly searching for novel drugs that can target different and multiple aspects of cancer. Experimental: After a screening, we selected one novel molecule, out of ninety-four triazole derivatives, that strongly affects the viability and proliferation of the human breast cancer cell line MCF-7, with minimal effects on non-cancer cells. The drug, named DAN94, induced a dose-dependent decrease in MCF-7 cells viability, with an IC50 of 3.2 ± 0.2 µM. Additionally, DAN94 interfered with mitochondria metabolism promoting reactive oxygen species production, triggering apoptosis and arresting the cancer cells on G1/G0 phase of cell cycle, inhibiting cell proliferation. These effects are not observed when the drug was tested in the non-cancer cell line MCF10A. Using a mouse model with xenograft tumor implants, the drug preventing tumor growth presented no toxicity for the animal and without altering biochemical markers of hepatic function. Results and Conclusion: The novel drug DAN94 is selective for cancer cells, targeting the mitochondrial metabolism, which culminates in the cancer cell death. In the end, DAN94 has been shown to be a promising drug for controlling breast cancer with minimal undesirable effects.


2021 ◽  
pp. 1-10
Author(s):  
Yu Wang ◽  
Han Zhao ◽  
Ping Zhao ◽  
Xingang Wang

BACKGROUND: Pyruvate kinase M2 (PKM2) was overexpressed in many cancers, and high PKM2 expression was related with poor prognosis and chemoresistance. OBJECTIVE: We investigated the expression of PKM2 in breast cancer and analyzed the relation of PKM2 expression with chemotherapy resistance to the neoadjuvant chemotherapy (NAC). We also investigated whether PKM2 could reverse chemoresistance in breast cancer cells in vitro and in vivo. METHODS: Immunohistochemistry (IHC) was performed in 130 surgical resected breast cancer tissues. 78 core needle biopsies were collected from breast cancer patients before neoadjuvant chemotherapy. The relation of PKM2 expression and multi-drug resistance to NAC was compared. The effect of PKM2 silencing or overexpression on Doxorubicin (DOX) sensitivity in the MCF-7 cells in vitro and in vivo was compared. RESULTS: PKM2 was intensively expressed in breast cancer tissues compared to adjacent normal tissues. In addition, high expression of PKM2 was associated with poor prognosis in breast cancer patients. The NAC patients with high PKM2 expression had short survival. PKM2 was an independent prognostic predictor for surgical resected breast cancer and NAC patients. High PKM2 expression was correlated with neoadjuvant treatment resistance. High PKM2 expression significantly distinguished chemoresistant patients from chemosensitive patients. In vitro and in vivo knockdown of PKM2 expression decreases the resistance to DOX in breast cancer cells in vitro and tumors in vivo. CONCLUSION: PKM2 expression was associated with chemoresistance of breast cancers, and could be used to predict the chemosensitivity. Furthermore, targeting PKM2 could reverse chemoresistance, which provides an effective treatment methods for patients with breast cancer.


2021 ◽  
Vol 20 ◽  
pp. 153303382110278
Author(s):  
Yayan Yang ◽  
Qian Feng ◽  
Chuanfeng Ding ◽  
Wei Kang ◽  
Xiufeng Xiao ◽  
...  

Although Epirubicin (EPI) is a commonly used anthracycline for the treatment of breast cancer in clinic, the serious side effects limit its long-term administration including myelosuppression and cardiomyopathy. Nanomedicines have been widely utilized as drug delivery vehicles to achieve precise targeting of breast cancer cells. Herein, we prepared a DSPE-PEG nanocarrier conjugated a peptide, which targeted the breast cancer overexpression protein Na+/K+ ATPase α1 (NKA-α1). The nanocarrier encapsulated the EPI and grafted with the NKA-α1 targeting peptide through the click reaction between maleimide and thiol groups. The EPI was slowly released from the nanocarrier after entering the breast cancer cells with the guidance of the targeting NKA-α1 peptide. The precise and controllable delivery and release of the EPI into the breast cancer cells dramatically inhibited the cells proliferation and migration in vitro and suppressed the tumor volume in vivo. These results demonstrate significant prospects for this nanocarrier as a promising platform for numerous chemotherapy drugs.


Cancers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 480
Author(s):  
Rakshitha Pandulal Miskin ◽  
Janine S. A. Warren ◽  
Abibatou Ndoye ◽  
Lei Wu ◽  
John M. Lamar ◽  
...  

In the current study, we demonstrate that integrin α3β1 promotes invasive and metastatic traits of triple-negative breast cancer (TNBC) cells through induction of the transcription factor, Brain-2 (Brn-2). We show that RNAi-mediated suppression of α3β1 in MDA-MB-231 cells caused reduced expression of Brn-2 mRNA and protein and reduced activity of the BRN2 gene promoter. In addition, RNAi-targeting of Brn-2 in MDA-MB-231 cells decreased invasion in vitro and lung colonization in vivo, and exogenous Brn-2 expression partially restored invasion to cells in which α3β1 was suppressed. α3β1 promoted phosphorylation of Akt in MDA-MB-231 cells, and treatment of these cells with a pharmacological Akt inhibitor (MK-2206) reduced both Brn-2 expression and cell invasion, indicating that α3β1-Akt signaling contributes to Brn-2 induction. Analysis of RNAseq data from patients with invasive breast carcinoma revealed that high BRN2 expression correlates with poor survival. Moreover, high BRN2 expression positively correlates with high ITGA3 expression in basal-like breast cancer, which is consistent with our experimental findings that α3β1 induces Brn-2 in TNBC cells. Together, our study demonstrates a pro-invasive/pro-metastatic role for Brn-2 in breast cancer cells and identifies a role for integrin α3β1 in regulating Brn-2 expression, thereby revealing a novel mechanism of integrin-dependent breast cancer cell invasion.


2021 ◽  
pp. 096032712199945
Author(s):  
AT Aliyev ◽  
S Ozcan-Sezer ◽  
A Akdemir ◽  
H Gurer-Orhan

Apigenin, a flavonoid, is reported to act as an estrogen receptor (ER) agonist and inhibit aromatase enzyme. However, amentoflavone, a biflavonoid bearing two apigenin molecules, has not been evaluated for its endocrine modulatory effects. Besides, it is highly consumed by young people to build muscles, enhance mood and lose weight. In the present study, apigenin was used as a reference molecule and ER mediated as well as ER-independent estrogenic/antiestrogenic activity of amentoflavone was investigated. Antitumor activity of amentoflavone was also investigated in both ER positive (MCF-7 BUS) and triple-negative (MDA-MB-231) breast cancer cells and its cytotoxicity was evaluated in human breast epithelial cells (MCF-10A). Our data confirmed ER agonist, aromatase inhibitory and cytotoxic effects of apigenin in breast cancer cells, where no ER mediated estrogenic effect and physiologically irrelevant, slight, aromatase inhibition was found for amentoflavone. Although selective cytotoxicity of amentoflavone was found in MCF-7 BUS cells, it does not seem to be an alternative to the present cytotoxic drugs. Therefore, neither an adverse effect, mediated by an estrogenic/antiestrogenic effect of amentoflavone nor a therapeutical benefit would be expected from amentoflavone. Further studies could be performed to investigate its in vivo effects.


Cancers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1366
Author(s):  
Russell Hughes ◽  
Xinyue Chen ◽  
Natasha Cowley ◽  
Penelope D. Ottewell ◽  
Rhoda J. Hawkins ◽  
...  

Metastatic breast cancer in bone is incurable and there is an urgent need to develop new therapeutic approaches to improve survival. Key to this is understanding the mechanisms governing cancer cell survival and growth in bone, which involves interplay between malignant and accessory cell types. Here, we performed a cellular and molecular comparison of the bone microenvironment in mouse models representing either metastatic indolence or growth, to identify mechanisms regulating cancer cell survival and fate. In vivo, we show that regardless of their fate, breast cancer cells in bone occupy niches rich in osteoblastic cells. As the number of osteoblasts in bone declines, so does the ability to sustain large numbers of breast cancer cells and support metastatic outgrowth. In vitro, osteoblasts protected breast cancer cells from death induced by cell stress and signaling via gap junctions was found to provide important juxtacrine protective mechanisms between osteoblasts and both MDA-MB-231 (TNBC) and MCF7 (ER+) breast cancer cells. Combined with mathematical modelling, these findings indicate that the fate of DTCs is not controlled through the association with specific vessel subtypes. Instead, numbers of osteoblasts dictate availability of protective niches which breast cancer cells can colonize prior to stimulation of metastatic outgrowth.


2016 ◽  
Vol 38 (3) ◽  
pp. 1003-1014 ◽  
Author(s):  
Aiyu Zhu ◽  
Yan Li ◽  
Wei Song ◽  
Yumei Xu ◽  
Fang Yang ◽  
...  

Background/Aims: Androgen receptor (AR), a steroid hormone receptor, has recently emerged as prognostic and treatment-predictive marker in breast cancer. Previous studies have shown that AR is widely expressed in up to one-third of triple-negative breast cancer (TNBC). However, the role of AR in TNBC is still not fully understood, especially in mesenchymal stem-like (MSL) TNBC cells. Methods: MSL TNBC MDA-MB-231 and Hs578T breast cancer cells were exposed to various concentration of agonist 5-α-dihydrotestosterone (DHT) or nonsteroidal antagonist bicalutamide or untreated. The effects of AR on cell viability and apoptosis were determined by MTT assay, cell counting, flow cytometry analysis and protein expression of p53, p73, p21 and Cyclin D1 were analyzed by western blotting. The bindings of AR to p73 and p21 promoter were detected by ChIP assay. MDA-MB-231 cells were transplanted into nude mice and the tumor growth curves were determined and expression of AR, p73 and p21 were detected by Immunohistochemistry (IHC) staining after treatment of DHT or bicalutamide. Results: We demonstrate that AR agonist DHT induces MSL TNBC breast cancer cells proliferation and inhibits apoptosis in vitro. Similarly, activated AR significantly increases viability of MDA-MB-231 xenografts in vivo. On the contrary, AR antagonist, bicalutamide, causes apoptosis and exerts inhibitory effects on the growth of breast cancer. Moreover, DHT-dependent activation of AR involves regulation in the cell cycle related genes, including p73, p21 and Cyclin D1. Further investigations indicate the modulation of AR on p73 and p21 mediated by direct binding of AR to their promoters, and DHT could make these binding more effectively. Conclusions: Our study demonstrates the tumorigenesis role of AR and the inhibitory effect of bicalutamide in AR-positive MSL TNBC both in vitro and in vivo, suggesting that AR inhibition could be a potential therapeutic approach for AR-positive TNBC patients.


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