scholarly journals Gab2 Ablation Reverses the Stemness of HER2-Overexpressing Breast Cancer Cells

2018 ◽  
Vol 50 (1) ◽  
pp. 52-65 ◽  
Author(s):  
Peng Zhang ◽  
Yiying Chen ◽  
Miaomiao Gong ◽  
Zhumei Zhuang ◽  
Yueyue Wang ◽  
...  

Background/Aims: HER2 has been implicated in mammary tumorigenesis as well as aggressive tumor growth and metastasis. Its overexpression is related to a poor prognosis and chemoresistance in breast cancer patients. Although Grb2-associated binding protein 2 (Gab2) is important in the development and progression of human cancer, its effects and mechanisms in HER2-overexpressing breast cancer are unclear. Methods: Clone formation and MTT assays were used to examine cell proliferation. To detect the effect of Gab2 on the stemness of breast cancer cells, we used flow cytometry, a sphere formation assay, real-time PCR, and western blot. An animal model was created to validate the effect of Gab2 on tumor growth in vivo. Tissue slides were analyzed by immunohistochemistry. Results: Knockdown of Gab2 suppressed PI3K/AKT and MAPK/ERK pathway activity. Gab2 ablation also reduced the stemness of HER2-overexpressing breast cancer cells. In vivo, knockdown of Gab2 inhibited tumor growth. Conclusion: This study unveils a potential function of Gab2 in HER2-overexpressing breast cancer cells. Gab2 might be a potential target in the clinical therapy of HER2-overexpressing breast carcinoma.

2019 ◽  
Author(s):  
Zhenhua Zhai ◽  
Ye Zhou ◽  
Xing Liu ◽  
Ying Wang ◽  
Yuyang Zhang ◽  
...  

Abstract Background Centromere proteins (CENPs) are primary components for chromosomal segregation in the mitotic stage. CENP-N is a member of CENPs, and is a key factor for recruitment of other CENPs and formation of a link between the centromere and micro-tubules, which facilitate cell division. Methods In order to clarify the role of CENP-N in breast cancer, RNA sequences data were downloaded from TCGA online database and the CENP-N expression was knocked down in breast cancer cells. Results The results show that the expression of CENP-N was higher in breast cancer comparing with the paracancerous tissues. In breast cancer, patients with high expression of CENP-N have a short-term overall survival compared with low expression of CENP-N. Both in vitro and in vivo, the growth of breast cancer cells was inhibited by down-regulation of CENP-N. In the gene-chip analysis, it reveals that down-regulation of CENP-N is primarily associated with functions of immune response and anti-tumor ef-fects. Of these changed canonical pathways, the activated interferon signaling was the most significant in CENP-N down-regulated breast cancer cells. In the western blot as-say, up-regulated expressions of molecules involved in interferon signaling were also confirmed. Conclusions Our results suggest that CENP-N can be a potential therapeutic target in the treatment of breast cancer, and the involved interferon signaling needs to be mainly fo-cused on. Keywords: CENP-N, Breast cancer, interferon signaling, Tumor growth


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Ziwei Jiang ◽  
Lixia Pei ◽  
Ying Xie ◽  
Qun Ye ◽  
Xiaoqiang Liang ◽  
...  

Abstract Background Metastasis is the leading cause of death among breast cancer patients. MicroRNA-134 has been reported to have a tumor-suppressive role in breast cancer. Ruyiping (RYP), a traditional Chinese formula, has been shown with the ability to reduce breast cancer metastasis in pre-clinical studies. This present study was designed to examine whether miR-134 was involved in RYP-inhibited breast cancer metastasis. Methods The expression of SLUG, E-Cadherin, N-Cadherin and miR-134 in MDA-MB-231 and 4 T1 cells treated with RYP or vehicle control were determined by quantitative realtime-PCR and western blot. Invasiveness determined by transwell assay as well as SLUG gene expression determined by qPCR were detected in cells transfected with chemically synthesized miR-134 mimics or inhibitors. BALB/c mice were injected with 4 T1 cells orthotopically and fed with RYP through gavage. Breast tumor growth, metastasis and tumor expression of EMT markers were detected. Results Compared with the control, Ruyiping formula significantly inhibited SLUG-regulated breast cancer cells invasion. MiR-134 was induced by RYP in vitro and in vivo and was able to suppress SLUG by targeting its 3’UTR. RYP suppressed SLUG expression and cell invasion through miR-134. In 4 T1 tumor-bearing mice, RYP significantly inhibited 4 T1 tumor growth and lung metastasis, increased the levels of miR-134 and epithelial marker while decreased the levels of SLUG and mesenchymal marker. Conclusion Our data uncovered that Ruyiping formula exerts an anti-metastatic activity against breast cancer cells by regulating SLUG through miR-134. MiR-134-SLUG axis might be a promising strategy in breast cancer therapy.


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 ◽  
Author(s):  
SANJAY MISHRA ◽  
Manish Charan ◽  
Rajni Kant Shukla ◽  
Pranay Agarwal ◽  
Swati Misri ◽  
...  

Abstract Background: Metastasis is the major cause of mortality in breast cancer; however, the molecular mechanisms remain elusive. In our previous study, we demonstrated that S100A7/RAGE mediates breast cancer growth and metastasis by recruitment of tumor-associated macrophages. However, the downstream S100A7-mediated inflammatory oncogenic signaling cascade that enhances breast tumor growth and metastasis by generating the immunosuppressive tumor microenvironment (iTME) has not been studied. In this present study, we aimed to investigate the S100A7 and cPLA2 cross-talk in enhancing tumor growth and metastasis through enhancing the iTME.Methods: Human breast cancer tissue and plasma samples were used to analyze the expression of S100A7, cPLA2, and PGE2 titer. S100A7-overexpressing or downregulated human metastatic breast cancer cells were used to evaluate the S100A7-mediated downstream signaling mechanisms. Bi-transgenic mS100a7a15 overexpression, TNBC C3(1)/Tag transgenic, and humanized patient-derived xenograft mouse models and cPLA2 inhibitor (AACOCF3) were used to investigate the role of S100A7/cPLA2/PGE2 signaling in tumor growth and metastasis. Additionally, CODEX, a highly advanced multiplexed imaging was employed to delineate the effect of S100A7/cPLA2 inhibition on the recruitment of various immune cells.Results: S100A7 and cPLA2 are highly expressed and positively correlated in malignant breast cancer patients. S100A7/RAGE upregulates cPLA2/PGE2 axis in aggressive breast cancer cells. Furthermore, S100A7 is positively correlated with PGE2 in breast cancer patients. Moreover, cPLA2 pharmacological inhibition suppressed S100A7-mediated tumor growth and metastasis in multiple pre-clinical models. Mechanistically, S100A7-mediated activation of cPLA2 enhances the recruitment of immunosuppressive myeloid cells by increasing PGE2 to fuel breast cancer growth and its secondary spread. We revealed that cPLA2 inhibitor mitigates S100A7-mediated breast tumorigenicity by suppressing the iTME. Furthermore, CODEX imaging data showed that cPLA2 inhibition increased the infiltration of CD4+/CD8+ T cells in the TME. Analysis of metastatic breast cancer samples revealed a positive correlation between S100A7/cPLA2 with CD163+ tumor-associated M2-macrophages.Conclusions: Our study shows that cross-talk between S100A7 and cPLA2 plays an important role in enhancing breast tumor growth and metastasis by generating an immunosuppressive tumor microenvironment and reducing infiltration of T cells. Furthermore, S100A7 could be used as a novel non-invasive prognostic marker and cPLA2 inhibitors as promising drugs against S100A7-overexpressing metastatic breast cancer.


2019 ◽  
Author(s):  
Xi Qiao ◽  
Ying Liu ◽  
Maria Llamazares Prada ◽  
Abhishekh Gupta ◽  
Alok Jaiswal ◽  
...  

AbstractMYC protein expression has to be tightly controlled to allow for maximal cell proliferation without inducing apoptosis. Here we discover UBR5 as a novel MYC ubiquitin ligase and demonstrate how it functions as a molecular rheostat to prevent excess accumulation of MYC protein. UBR5 effects on MYC protein stability are independent on N-terminal FBW7 degron of MYC. Endogenous UBR5 inhibition induces MYC protein expression and activates MYC target genes. Moreover, UBR5 governs MYC-dependent phenotypes in vivo in Drosophila. In cancer cells, UBR5-mediated MYC protein suppression diminishes cell killing activity of cancer therapeutics. Further, we demonstrate that UBR5 dominates MYC protein expression at the single-cell level in human basal-type breast cancer tissue. Myc and Ubr5 are co-amplified in MYC-driven human cancer types, and UBR5 controls MYC-mediated apoptotic threshold in co-amplified basal type breast cancer cells. In summary, UBR5 is a novel MYC ubiquitin ligase and an endogenous rheostat for MYC protein expression in vivo. Clinically, expression of UBR5 may be important for protection of breast cancer cells from drug-induced, and MYC-dependent, apoptosis.


2020 ◽  
Vol 29 (2) ◽  
pp. 277-290
Author(s):  
Xuan Liu ◽  
Weirong Yao ◽  
Haiwei Xiong ◽  
Qiang Li ◽  
Yingliang Li

BACKGROUND: Breast cancer is the most common malignant tumor and usually occurs in women. Studies have shown that lncRNA nuclear enriched abundant transcript 1 (NEAT1) contributes to breast cancer progression. This study intends to further investigate the molecular mechanism of NEAT1 in breast cancer. METHODS: The expression levels of NEAT1, miR-410-3p and Cyclin D1 (CCND1) were detected by quantitative real-time PCR (qRT-PCR) in breast cancer tissues and cells. Kaplan-Meier analysis and the log-rank test were performed to determine the relationship between NEAT1 and overall survival. Cell Counting Kit-8 (CCK-8) assay analyzed cell proliferation. Transwell assay was performed to examine cell migration and invasion. The protein levels of CCND1 and epithelial-mesenchymal transition (EMT)-related proteins (E-cadherin, N-cadherin and Vimentin) were measured by western blot. The target relationship was predicted by bioinformatics analysis, and confirmed by luciferase reporter assay and RNA Immunoprecipitation (RIP) assay. Xenograft analysis was used to evaluate the tumor growth in vivo. RESULTS: NEAT1 and CCND1 were upregulated, while miR-410-3p was down-regulated in breast cancer tissues and cells. Higher NEAT1 expression level was associated with lower survival rate of breast cancer patients. Knockdown of miR-410-3p restored silenced NEAT1-mediated the inhibition of on proliferation, migration, invasion and EMT of breast cancer cells. In addition, NEAT1 regulated CCND1 expression by sponging miR-410-3p in breast cancer cells. NEAT1 knockdown blocked the tumor growth in vivo. CONCLUSION: NEAT1 induced breast cancer progression by regulating the miR-410-3p/CCND1 axis, indicating that NEAT1 may be a potential therapeutic target in breast cancer.


Sign in / Sign up

Export Citation Format

Share Document