scholarly journals Knockdown of AKT3 Activates HER2 and DDR Kinases in Bone-Seeking Breast Cancer Cells, Promotes Metastasis In Vivo and Attenuates the TGFβ/CTGF Axis

Cells ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 430
Author(s):  
Nico Hinz ◽  
Anke Baranowsky ◽  
Michael Horn ◽  
Malte Kriegs ◽  
Freya Sibbertsen ◽  
...  

Bone metastases frequently occur in breast cancer patients and lack appropriate treatment options. Hence, understanding the molecular mechanisms involved in the multistep process of breast cancer bone metastasis and tumor-induced osteolysis is of paramount interest. The serine/threonine kinase AKT plays a crucial role in breast cancer bone metastasis but the effect of individual AKT isoforms remains unclear. Therefore, AKT isoform-specific knockdowns were generated on the bone-seeking MDA-MB-231 BO subline and the effect on proliferation, migration, invasion, and chemotaxis was analyzed by live-cell imaging. Kinome profiling and Western blot analysis of the TGFβ/CTGF axis were conducted and metastasis was evaluated by intracardiac inoculation of tumor cells into NOD scid gamma (NSG) mice. MDA-MB-231 BO cells exhibited an elevated AKT3 kinase activity in vitro and responded to combined treatment with AKT- and mTOR-inhibitors. Knockdown of AKT3 significantly increased migration, invasion, and chemotaxis in vitro and metastasis to bone but did not significantly enhance osteolysis. Furthermore, knockdown of AKT3 increased the activity and phosphorylation of pro-metastatic HER2 and DDR1/2 but lowered protein levels of CTGF after TGFβ-stimulation, an axis involved in tumor-induced osteolysis. We demonstrated that AKT3 plays a crucial role in bone-seeking breast cancer cells by promoting metastatic potential without facilitating tumor-induced osteolysis.

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.


2020 ◽  
Vol 11 (7) ◽  
Author(s):  
Yifan Wang ◽  
Ruocen Liao ◽  
Xingyu Chen ◽  
Xuhua Ying ◽  
Guanping Chen ◽  
...  

Abstract Breast cancer is considered to be the most prevalent cancer in women worldwide, and metastasis is the primary cause of death. Protease-activated receptor 1 (PAR1) is a GPCR family member involved in the invasive and metastatic processes of cancer cells. However, the functions and underlying mechanisms of PAR1 in breast cancer remain unclear. In this study, we found that PAR1 is highly expressed in high invasive breast cancer cells, and predicts poor prognosis in ER-negative and high-grade breast cancer patients. Mechanistically, Twist transcriptionally induces PAR1 expression, leading to inhibition of Hippo pathway and activation of YAP/TAZ; Inhibition of PAR1 suppresses YAP/TAZ-induced epithelial-mesenchymal transition (EMT), invasion, migration, cancer stem cell (CSC)-like properties, tumor growth and metastasis of breast cancer cells in vitro and in vivo. These findings suggest that PAR1 acts as a direct transcriptionally target of Twist, can promote EMT, tumorigenicity and metastasis by controlling the Hippo pathway; this may lead to a potential therapeutic target for treating invasive breast cancer.


2021 ◽  
Vol 22 (20) ◽  
pp. 11273
Author(s):  
Natalia Magdalena Lisiak ◽  
Izabela Lewicka ◽  
Mariusz Kaczmarek ◽  
Jacek Kujawski ◽  
Barbara Bednarczyk-Cwynar ◽  
...  

Approximately 20–30% of the diagnosed breast cancers overexpress the human epidermal growth factor receptor 2 (HER2). This type of cancer is associated with a more aggressive phenotype; thus, there is a need for the discovery of new compounds that would improve the survival in HER2-positive breast cancer patients. It seems that one of the most promising therapeutic cancer strategies could be based on the biological activity of pentacyclic triterpenes’ derivatives and the best-known representative of this group, oleanolic acid (OA). The biological activity of oleanolic acid and its two semisynthetic derivatives, methyl 3-hydroxyimino-11-oxoolean-12-en-28-oate (HIMOXOL) and 12α-bromo-3-hydroxyimonoolean-28→13-olide (Br-HIMOLID), was assessed in SK-BR-3 breast cancer cells (HER2-positive). Viability tests, cell cycle assessment, evaluation of apoptosis, autophagy, and adhesion/migration processes were performed using MTT, clonogenic, cytofluorometry, Western blot, and qPCR. Both derivatives revealed higher cytotoxicity in studied breast cancer cells than the maternal compound, OA. They also decreased cell viability, induced autophagy, and (when applied in sub-cytotoxic concentrations) decreased the migration of SK-BR-3 cells.This study is the first to report the cytostatic, proautophagic (mTOR/LC3/SQSTM/BECN1 pathway), and anti-migratory (integrin β1/FAK/paxillin pathway) activities of HIMOXOL and Br-HIMOLID in HER2-positive breast cancer cells.


2021 ◽  
Vol 39 (15_suppl) ◽  
pp. e13002-e13002
Author(s):  
Yinghuan Cen ◽  
Chang Gong ◽  
Jun Li ◽  
Gehao Liang ◽  
Zihao Liu ◽  
...  

e13002 Background: We previously demonstrated that BRMS1L (breast cancer metastasis suppressor 1 like) suppresses breast cancer metastasis through HDAC1 recruitment and histone H3K9 deacetylation at the promoter of FZD10, a receptor for Wnt signaling. It is still unclear whether BRMS1L regulates organ-specific metastases, such as bone metastasis, the most prevalent metastatic site of breast cancer. Methods: Examination of the expression of BRMS1L in primary tumors, bone metastatic and other metastatic tissues from breast cancer patients was implemented using qRT-PCR and immunohistochemistry staining. To investigate the mechanism by which BRMS1L drives breast cancer bone metastasis, we tested the mRNA expression by qRT-PCR of a set of potential bone related genes (BRGs) based on PubMed database in MDA-MB-231 cells over expressing BRMS1L and MCF-7 cells knocking-down BRMS1L, and detected the expression of CXCR4 in these established cells by western blot. Transwell assays were performed to assess the migration abilities of breast cancer cells towards osteoblasts. ChIP (Chromatin Immuno-Precipitation) were employed to test the interaction between BRMS1L and CXCR4. Results: At both mRNA and protein levels, the expression of BRMS1L was significantly lower in bone metastatic sites than that in primary cancer tissues and other metastatic sites of breast cancer patients. CXCR4 was screened out in a set of BRGs and negatively correlated with the expression of BRMS1L in breast cancer cell lines. BRMS1L inhibited the migration of breast cancer cells towards osteoblasts through CXCL12/CXCR4 axis. In the presence of TSA treatment, breast cancer cell lines showed an increased expression of CXCR4 in a TSA concentration-dependent manner. In addition, ChIP assays verified that BRMS1L directly bound to the promoter region of CXCR4 and inhibited its transcription through promoter histone deacetylation. Conclusions: BRMS1L mediates the migration abilities of breast cancer cells to bone microenvironment via targeting CXCR4 and contributes to bone metastasis of breast cancer cells. Thus, BRMS1L may be a potential biomarker for predicting bone metastasis in breast cancer.


Bone Research ◽  
2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Haemin Kim ◽  
Bongjun Kim ◽  
Sang Il Kim ◽  
Hyung Joon Kim ◽  
Brian Y. Ryu ◽  
...  

Abstract Bone destruction induced by breast cancer metastasis causes severe complications, including death, in breast cancer patients. Communication between cancer cells and skeletal cells in metastatic bone microenvironments is a principal element that drives tumor progression and osteolysis. Tumor-derived factors play fundamental roles in this form of communication. To identify soluble factors released from cancer cells in bone metastasis, we established a highly bone-metastatic subline of MDA-MB-231 breast cancer cells. This subline (mtMDA) showed a markedly elevated ability to secrete S100A4 protein, which directly stimulated osteoclast formation via surface receptor RAGE. Recombinant S100A4 stimulated osteoclastogenesis in vitro and bone loss in vivo. Conditioned medium from mtMDA cells in which S100A4 was knocked down had a reduced ability to stimulate osteoclasts. Furthermore, the S100A4 knockdown cells elicited less bone destruction in mice than the control knockdown cells. In addition, administration of an anti-S100A4 monoclonal antibody (mAb) that we developed attenuated the stimulation of osteoclastogenesis and bone loss by mtMDA in mice. Taken together, our results suggest that S100A4 released from breast cancer cells is an important player in the osteolysis caused by breast cancer bone metastasis.


2009 ◽  
Vol 27 (15_suppl) ◽  
pp. e14565-e14565
Author(s):  
D. Sharma ◽  
B. B. Knight ◽  
R. Yacoub ◽  
T. Liu ◽  
L. Taliaferro-Smith ◽  
...  

e14565 Background: The outcome for patients with breast cancer has been significantly improved by the use of targeted agents. The prognosis of triple negative (TN) breast cancers, which do not express hormone receptors (ER, PR) or Her2, is poor, because of an aggressive clinical course and lack of targeted therapeutic agents. Epigenetic silencing of specific genes has been observed in breast cancer and some of these genes are more important due to available targeted therapies such as ER. Since all endocrine therapies are designed to block ER function in some way, the identification of new therapies or strategies that could sensitize TN breast cancers to existing endocrine therapy could provide a revolutionary means of treating this aggressive subtype of cancer Methods: We examined the efficacy of combined treatment of HDAC inhibitor LBH589 and DNMT inhibitor decitabine to regenerate ER and PR in TN breast cancer cells using RT-PCR and immunoblotting. Changes in growth and proliferation of TN breast cancer cells in response to LBH589 and decitabine treatment were determined by XTT, BrdU incorporation and colony formation assay. Changes in apoptotic proteins were determined by western blotting. Athymic nude mice were used to establish pre-clinical models for TN breast cancer cells and effectiveness of combined treatment of LBH589 and decitabine was determined. Tumors biopsies were analyzed for ER and PR re-expression by western blot analysis and immunohistochemistry at the end of the treatment. Results: Combined treatment of LBH589 and decitabine resulted in re-expression of ER and PR in TN breast cancers in vitro and in vivo. Although re-expression of ER and PR were noted following LBH589 treatment alone, re-expression was more robust with the combination. TN breast cancer cells showing re-expressed ER can be targeted with tamoxifen. Tamoxifen inhibits growth of TN breast cancer cells re- expressing ER by triggering apoptosis. Conclusions: The importance of epigenetic events such as DNA methylation and HDAC inhibition in tumor progression is becoming increasingly evident. A trial evaluating the ability of LBH589 and decitabine to re- express ER, which can then be targeted by tamoxifen, is planned in patients with metastatic TN breast cancer. No significant financial relationships to disclose.


2011 ◽  
Vol 29 (27_suppl) ◽  
pp. 220-220
Author(s):  
S. Nishiya ◽  
H. Jinno ◽  
T. Hayashida ◽  
M. Takahashi ◽  
Y. Kitagawa

220 Background: The B-cell translocation gene-2 (BTG2) belongs to a class of proteins known as the Tob and BTG antiproliferative protein family. It was shown that estrogen and progesterone suppress BTG2 expression for the development of mammary gland. We demonstrated that proliferation rate of low level BTG2 expression in MCF7 was strongly inhibited by the administration of tamoxifen. In postmenopausal breast cancer patients, androgens can be converted to mitogenic estrogens by aromatase in breast cancer cells. Based on these results, we hypothesized that BTG2 expression affects the sensitivity against aromatase inhibitior. Methods: We used tetracycline-inducible BTG2 expression model in MCF7 stably transfected with the human aromatase gene (MCF7/tet/aro) as in vitro models of aromatase-driven breast cancer. The effects of BTG2 expression and administration of anastrozole in breast cancer cells were assessed by proliferation assays. Results: Administration of androstendion increased 79.1% of cellular proliferation, suggested that introduced aromatase gene worked well. Elevated level of BTG2 mRNA expression by tetracycline treatment was confirmed by Quantitative-RTPCR. Anastrozole treatment (100nM) reduced 37.8% of cellular proliferation ability, whereas the concomitant administration of tetracycline and anastorozole reduced 59.0% of cellular proliferation. These results suggested that the inhibitory effect of anastrozol for cellular proliferation was enhanced under the condition of BTG2 expression. Conclusions: Our results suggested loss of BTG2 expression may be affects the sensitivity against aromatase inhibitor.


2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Maruša Bizjak ◽  
Petra Malavašič ◽  
Klemen Dolinar ◽  
Jelka Pohar ◽  
Sergej Pirkmajer ◽  
...  

2019 ◽  
Author(s):  
Daniela Hühn ◽  
Pablo Martí-Rodrigo ◽  
Silvana Mouron ◽  
Catherine S. Hansel ◽  
Kirsten Tschapalda ◽  
...  

ABSTRACTEstrogen receptor (ER)-positive breast tumors are routinely treated with estrogen-depriving therapies. Despite their effectiveness, patients often progress into a more aggressive form of the disease. Through a chemical screen oriented to identify chemicals capable of inducing the expression of the immune-checkpoint ligand PD-L1, we found antiestrogens as hits. Subsequent validations confirmed that estrogen deprivation or ERα depletion induces PD-L1 expression in ER-positive breast cancer cells, both in vitro and in vivo. Likewise, PD-L1 expression is increased in metastasis arising from breast cancer patients receiving adjuvant hormonal therapy for their local disease. Transcriptome analyses indicate that estrogen deprivation triggers a broad immunosuppressive program, not restricted to PD-L1. Accordingly, estrogen deprived MCF7 cells are resistant to T-cell mediated cell killing, in a manner that can be reverted by estradiol. Our study reveals that while antiestrogen therapies effectively limit tumor growth in ER-positive breast cancers, they also trigger a transcriptional program that favors immune evasion.


2021 ◽  
Vol 11 ◽  
Author(s):  
Duanyang Zhai ◽  
Tianfu Li ◽  
Runyi Ye ◽  
Jiong Bi ◽  
Xiaying Kuang ◽  
...  

BackgroundMetastasis is a major factor weakening the long-term survival of breast cancer patients. Increasing evidence revealed that long non-coding RNAs (lncRNAs) were involved in the occurrence and development of breast cancer. In this study, we aimed to investigate the role of LGALS8-AS1 in the metastatic progression of breast cancer cells and its potential mechanisms.ResultsThe lncRNA LGALS8-AS1 was highly expressed in breast cancer and associated with poor survival. LGALS8-AS1 functioned as an oncogenic lncRNA that promoted the metastasis of breast cancer both in vitro and in vivo. It upregulated SOX12 via competing as a competing endogenous RNA (ceRNA) for sponging miR-125b-5p and acted on the PI3K/AKT signaling pathway to promote the metastasis of breast cancer. Furthermore, SOX12, in turn, activated LGALS8-AS1 expression via direct recognition of its sequence binding enrichment motif on the LGALS8-AS1 promoter, thereby forming a positive feedback regulatory loop.ConclusionThis study manifested a novel mechanism of LGALS8-AS1 facilitating the metastasis of breast cancer. The LGALS8-AS1/miR-125b-5p/SOX12 reciprocal regulatory loop dyscrasia promoted the migration and invasion of breast cancer cells. This signaling axis could be applicable to the design of novel therapeutic strategies against this malignancy.


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