scholarly journals LncRNA EGFR-AS1 Regulates Breast Cancer Cells Function and Sensitivity to Docetaxel Via the miR-149-5p/ELP5 Axis

Author(s):  
Shiping Li ◽  
Xiaoyi Mi ◽  
Mingfang Sun ◽  
Jie Zhang ◽  
Miaomiao Hao ◽  
...  

Abstract Background: Recently, an increasing number of studies have focused on investigating long non-coding RNAs (lncRNAs) and their role in regulating the progression of various cancer types. However, the biological effects and underlying mechanisms of EGFR-AS1, a typical lncRNA, remain largely unclear in breast cancer.Methods: Differential expression of EGFR-AS1 in breast cancer tissue was analyzed using an integrative database and verified in breast cancer tissue samples and cells via real-time PCR analysis and western blotting analysis. The tumor promoter role of EGFR-AS1 in breast cancer cells was determined through MTT, EDU analysis, colony formation and transwell assays,and the effect of EGFR-AS1 on docetaxel drug sensitivity was examined. We then performed bioinformatic analysis and the dual-luciferase reporter assay to identify the binding sites of EGFR-AS1/miR-149-5p and miR-149-5p/ELP5. Results from western blotting and biological function studies provided insights into whether the EGFR-AS1/miR-149-5p/ELP5 axis regulates breast cancer development in vitro and in vivo. Results: EGFR-AS1 is upregulated in breast cancer tissues and cells and promotes the progression of breast cancer cells both in vitro and in vivo. Moreover, miR-149-5p is downregulated in breast cancer tissues and cell lines. Mechanistically, EGFR-AS1 regulates ELP5 levels by sponging miR-149-5p, thereby affecting cell progression and promoting epithelial-to-mesenchymal transition. Hence, the EGFR-AS1/miR-149-5p/ELP5 axis is involved in breast cancer proliferation, migration, invasion, and resistance to the chemotherapeutic drug, docetaxel, in breast cancer cells. Conclusions: EGFR-AS1 sponges miR-149-5p to affect the expression level of ELP5 ultimately acting as a new tumor promotor in breast cancer. This study provides novel insights into diagnostic and docetaxel-related chemotherapy targets for breast cancer.

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.


Nanomaterials ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 804 ◽  
Author(s):  
Ying-Jie Hu ◽  
Jing-Ying Zhang ◽  
Qian Luo ◽  
Jia-Rui Xu ◽  
Yan Yan ◽  
...  

The heterogeneity of breast cancer and the development of drug resistance are the relapse reasons of disease after chemotherapy. To address this issue, a combined therapeutic strategy was developed by building the nanostructured dihydroartemisinin plus epirubicin liposomes. Investigations were performed on human breast cancer cells in vitro and xenografts in nude mice. The results indicated that dihydroartemisinin could significantly enhance the efficacy of epirubicin in killing different breast cancer cells in vitro and in vivo. We found that the combined use of dihydroartemisinin with epirubicin could efficiently inhibit the activity of Bcl-2, facilitate release of Beclin 1, and further activate Bax. Besides, Bax activated apoptosis which led to the type I programmed death of breast cancer cells while Beclin 1 initiated the excessive autophagy that resulted in the type II programmed death of breast cancer cells. In addition, the nanostructured dihydroartemisinin plus epirubicin liposomes prolonged circulation of drugs, and were beneficial for simultaneously delivering drugs into breast cancer tissues. Hence, the nanostructured dihydroartemisinin plus epirubicin liposomes could provide a new therapeutic strategy for treatment of breast cancer.


Life ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 93
Author(s):  
Ho Tsoi ◽  
Ling Shi ◽  
Man-Hong Leung ◽  
Ellen P. S. Man ◽  
Zi-Qing So ◽  
...  

NCOR2 is a co-repressor for estrogen receptor (ER) and androgen receptor (AR). Our group previously identified a novel splice variant of NCOR2, BQ323636.1 (BQ), that mediates tamoxifen resistance via interference of NCOR2 repression on ER. Luciferase reporter assay showed BQ overexpression could enhance the transcriptional activity of androgen response element (ARE). We proposed that BQ employs both AR and ER to confer tamoxifen resistance. Through in silico analysis, we identified interleukin-8 (IL-8) as the sole ERE and ARE containing gene responsiveness to ER and AR activation. We confirmed that BQ overexpression enhanced the expression of IL-8 in ER+ve breast cancer cells, and AR inhibition reduced IL-8 expression in the BQ overexpressing cell lines, suggesting that AR was involved in the modulation of IL-8 expression by BQ. Moreover, we demonstrated that IL-8 could activate both AKT and ERK1/2 via CXCR1 to confer tamoxifen resistance. Targeting CXCR1/2 by a small inhibitor repertaxin reversed tamoxifen resistance of BQ overexpressing breast cancer cells in vitro and in vivo. In conclusion, BQ overexpression in ER+ve breast cancer can enhance IL-8 mediated signaling to modulate tamoxifen resistance. Targeting IL-8 signaling is a promising approach to overcome tamoxifen resistance in ER+ve breast cancer.


2020 ◽  
Vol 11 ◽  
Author(s):  
Imran Hussain ◽  
Paromita Deb ◽  
Avisankar Chini ◽  
Monira Obaid ◽  
Arunoday Bhan ◽  
...  

HOXA5 is a homeobox-containing gene associated with the development of the lung, gastrointestinal tract, and vertebrae. Here, we investigate potential roles and the gene regulatory mechanism in HOXA5 in breast cancer cells. Our studies demonstrate that HOXA5 expression is elevated in breast cancer tissues and in estrogen receptor (ER)-positive breast cancer cells. HOXA5 expression is critical for breast cancer cell viability. Biochemical studies show that estradiol (E2) regulates HOXA5 gene expression in cultured breast cancer cells in vitro. HOXA5 expression is also upregulated in vivo in the mammary tissues of ovariectomized female rats. E2-induced HOXA5 expression is coordinated by ERs. Knockdown of either ERα or ERβ downregulated E2-induced HOXA5 expression. Additionally, ER co-regulators, including CBP/p300 (histone acetylases) and MLL-histone methylases (MLL2, MLL3), histone acetylation-, and H3K4 trimethylation levels are enriched at the HOXA5 promoter in present E2. In summary, our studies demonstrate that HOXA5 is overexpressed in breast cancer and is transcriptionally regulated via estradiol in breast cancer cells.


2021 ◽  
Author(s):  
xingang wang ◽  
YAN ZHENG ◽  
YU WANG

Abstract Background and AimsPseudopodium-enriched atypical kinase 1 (PEAK1) has reported to be upregulated in human malignancies and related with poor prognosis. Enhanced PEAK1 expression facilitates tumor cell survival, invasion, metastasis and chemoresistance. However, the role of PEAK1 in breast cancer is not clear. Here, we investigated the PEAK1 expression in breast cancer and analyzed its relation with clinicopathological status and chemotherapy resistance to the neoadjuvant chemotherapy (NAC). We also investigated the role of PEAK1 on breast cancer cells in vitro and in vivo. MethodsImmunohistochemistry (IHC) was performed in 112 surgical resected breast cancer tissues. The associations between clinicopathological status, multi-drug resistance and PEAK1 expression were determined. Effect of PEAK1 overexpression or down-expression on proliferation, colony formation, invasion, migration, metastasis and Doxorubicin sensitivity in the MCF-7 cells in vitro and in vivo was detected. ResultsPEAK1 was overexpressed in breast cancer tissues and NAC -resistant breast cancer tissues. High PEAK1 expression was related with tumor size, high tumor grade, T stage, LN metastasis, recurrence, Ki-67 expression, Her-2 expression and multi-drug resistance. Targeting PEAK1 inhibited cell growth, invasion, metastasis and reversed chemoresistance to Doxorubicin in breast cancer cells in vitro and in vivo. ConclusionHigh PEAK1 expression was associated with invasion, metastasis and chemoresistance of breast cancers. Furthermore, targeting PEAK1 could inhibit cell growth and metastasis, and reverse chemoresistance in breast cancer cells, which provides an effective treatment strategies for breast cancer.


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.


2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Therina Du Toit ◽  
Amanda C Swart

Abstract The metabolism of 11β-hydroxyandrostenedione (11OHA4), a major adrenal C19 steroid, was first characterised in our in vitro prostate models showing that 11OHA4, catalysed by 11βHSDs, 17βHSDs and 5α-reductases, yields potent androgens, 11keto-testosterone (11KT) and 11keto-dihydrotestosterone (11KDHT) in the 11OHA4-pathway [1]. Findings have since led to the analysis of C11-oxy steroids in PCOS, CAH and 21OHD. However, the only circulating C11-oxy steroids included to date have been 11OHA4, 11keto-androstenedione (11KA4), 11β-hydroxytestosterone (11OHT) and 11KT, with 11KT reported as the only potent androgen produced from 11OHA4. We have identified higher levels of 11KDHT compared to 11KT in prostate cancer tissue and benign prostatic hyperplasia tissue and serum, with data suggesting impeded glucuronidation of the C11-oxy androgens [2,3]. The assessment of 11KDHT and the inactivation/conjugation of the C11-oxy steroids in clinical conditions is therefore crucial. We investigated the metabolism of testosterone, 11KT, 11OHT, dihydrotestosterone, 11KDHT and 11OHDHT in JEG-3 placenta choriocarcinoma, MCF-7 BUS and T-47D breast cancer cells, focusing on glucuronidation and sulfation. Steroids were assayed at 1 µM and metabolites were quantified using UPC2-MS/MS. Conjugated steroids were not detected in JEG-3 cells with DHT (0.6 µM remaining) metabolised to 5α-androstane-3α,17β-diol and androsterone (AST), and 11KDHT (0.9 µM remaining) to 11OHAST and 11KAST. 11OHA4 was converted to 11KA4 (12%) and 11KT (2.5%); and 11KT to 11KDHT (14%). In MCF-7 BUS cells, DHT was significantly glucuronidated, whereas 11KDHT was not. 11KAST was the only steroid in the MCF-7 BUS and T-47D cells that was significantly sulfated (p<0.05). In parallel we investigated sulfation in the LNCaP prostate model. Comparing sulfated to glucuronidated levels, only DHT was sulfated, 26%. Analysis showed that C19 steroids were significantly conjugated (glucuronidated + sulfated) compared to the C11-oxy C19 steroids. As there exists an intricate interplay between steroid production and inactivation, impacting pre- and post-receptor activation, efficient conjugation would limit adverse downstream effects. Our data demonstrates the production and impeded conjugation of active C11-oxy C19 steroids, allowing the prolonged presence of androgenic steroids in the cellular microenvironment. Identified for the first time is the 11OHA4-pathway in placenta and breast cancer cells, and the sulfation of 11KAST. Characterising steroidogenic pathways in in vitro models paves the direction for in vivo studies associated with characterising clinical disorders and disease, which the C11-oxy C19 steroids and their intermediates, including inactivated and conjugated end-products, have highlighted. [1] Bloem, et al. JSBMB 2015, 153; [2] Du Toit & Swart. MCE 2018, 461; [3] Du Toit & Swart, JSBMB 2020, 105497.


2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Chong Lu ◽  
Yu Zhao ◽  
Jing Wang ◽  
Wei Shi ◽  
Fang Dong ◽  
...  

Abstract Background Extracellular vesicles (EVs) derived from tumor cells are implicated in the progression of malignancies through the transfer of molecular cargo microRNAs (miRNAs or miRs). We aimed to explore the role of EVs derived from breast cancer cells carrying miR-182-5p in the occurrence and development of breast cancer. Methods Differentially expressed miRNAs and their downstream target genes related to breast cancer were screened through GEO and TCGA databases. miR-182-5p expression was examined in cancer tissues and adjacent normal tissues from patients with breast cancer. EVs were isolated from breast cancer cell line MDA-MB-231 cells and identified. The gain- and loss-of function approaches of miR-182-5p and CKLF-like MARVEL transmembrane domain-containing 7 (CMTM7) were performed in MDA-MB-231 cells and the isolated EVs. Human umbilical vein endothelial cells (HUVECs) were subjected to co-culture with MDA-MB-231 cell-derived EVs and biological behaviors were detected by CCK-8 assay, flow cytometry, immunohistochemical staining, Transwell assay and vessel-like tube formation in vitro. A xenograft mouse model in nude mice was established to observe the tumorigenesis and metastasis of breast cancer cells in vivo. Results miR-182-5p was highly expressed in breast cancer tissues and cells, and this high expression was associated with poor prognosis of breast cancer patients. miR-182-5p overexpression was shown to promote tumor angiogenesis in breast cancer. Moreover, our data indicated that miR-182-5p was highly enriched in EVs from MDA-MD-231 cells and then ultimately enhanced the proliferation, migration, and angiogenesis of HUVECs in vitro and in vivo. Moreover, we found that CMTM7 is a target of miR-182-5p. EVs-miR-182-5p promotes tumorigenesis and metastasis of breast cancer cells by regulating the CMTM7/EGFR/AKT signaling axis. Conclusions Taken altogether, our findings demonstrates that EVs secreted by breast cancer cells could carry miR-182-5p to aggravate breast cancer through downregulating CMTM7 expression and activating the EGFR/AKT signaling pathway.


2020 ◽  
Author(s):  
Cheng-Fei Jiang ◽  
Yun-Xia Xie ◽  
Ying-Chen Qian ◽  
Min Wang ◽  
Ling-Zhi Liu ◽  
...  

Abstract BackgroundChemoresistance is a critical risk problem for breast cancer treatment. However, mechanisms by which chemoresistance arises remains to be elucidated. The expression of T-box transcription factor 15 (TBX-15) was found downregulated in some cancer tissues. However, role and mechanism of TBX15 in breast cancer chemoresistance is unknown. Here we aimed to identify the effects and mechanisms of TBX15 in doxorubicin resistance in breast cancer.MethodsAs measures of Drug sensitivity analysis, MTT and IC50 assays were used in DOX-resistant breast cancer cells. ECAR and OCR assays were used to analyze the glycolysis level, while Immunoblotting and Immunofluorescence assays were used to analyze the autophagy levels in vitro. By using online prediction software, luciferase reporter assays, co-Immunoprecipitation, Western blotting analysis and experimental animals models, we further elucidated the mechanisms.ResultsWe found TBX15 expression levels were decreased in Doxorubicin (DOX)-resistant breast cancer cells. Overexpression of TBX15 reversed the DOX resistance by inducing microRNA-152 (miR-152) expression. We found that KIF2C levels were highly expressed in DOX-resistant breast cancer tissues and cells, and KIF2C was a potential target of miR-152. TBX15 and miR-152 overexpression suppressed autophagy and glycolysis in breast cancer cells, while KIF2C overexpression reversed the process. Overexpression of KIF2C increased DOX resistance in cancer cells. Furthermore, KIF2C directly binds with PKM2 for inducing the DOX resistance. KIF2C can prevent the ubiquitination of PKM2 and increase its protein stability. In addition, we further identified that Domain-2 of KIF2C played a major role in the binding with PKM2 and preventing PKM2 ubiquitination, which enhanced DOX resistance by promoting autophagy and glycolysis. ConclusionsOur data identify a new mechanism by which TBX15 abolishes DOX chemoresistance in breast cancer, and suggest that TBX15/miR-152/KIF2C axis is a novel signaling pathway for mediating DOX resistance in breast cancer through regulating PKM2 ubiquitination and the enhancement of PKM2 stability. This finding suggests new therapeutic target and/or novel strategy development for cancer treatment to overcome drug resistance in the future.


Author(s):  
Xingang Wang ◽  
Yan Zheng ◽  
Yu Wang

AbstractPseudopodium-enriched atypical kinase 1 (PEAK1) has been reported to be upregulated in human malignancies and is correlated with a poor prognosis. Enhanced PEAK1 expression facilitates tumor cell survival, invasion, metastasis and chemoresistance. However, the role of PEAK1 in breast cancer is unclear. We investigated PEAK1 expression in breast cancer and analyzed the relationship with clinicopathological status and chemotherapy resistance. We also investigated the role of PEAK1 in breast cancer cells in vitro and in vivo. Immunohistochemistry for PEAK1 was performed in 112 surgically resected breast cancer tissues. The association between clinicopathological status, chemotherapy resistance and PEAK1 expression was determined. The effect of PEAK1 overexpression or downregulation on proliferation, colony formation, invasion, migration, metastasis and doxorubicin sensitivity in MCF-7 cells in vitro and in vivo was studied. PEAK1 was overexpressed in breast cancer tissues. High PEAK1 expression was correlated with tumor size, high tumor grade, tumor stage, lymph node metastasis, recurrence, Ki-67 expression, Her-2 expression and chemotherapy resistance. Inhibiting PEAK1 decreased cell growth, invasion, metastasis and reversed chemoresistance to doxorubicin in breast cancer cells both in vitro and in vivo. High PEAK1 expression was associated with the invasion, metastasis and chemoresistance of breast cancers. Furthermore, targeting PEAK1 inhibited cell growth and metastasis and reversed chemoresistance in breast cancer cells. Targeting PEAK1 could be an effective treatment strategy for breast cancer.


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