scholarly journals Phosphorylation of ERα at serine 118 in primary breast cancer and in tamoxifen-resistant tumours is indicative of a complex role for ERα phosphorylation in breast cancer progression

2006 ◽  
Vol 13 (3) ◽  
pp. 851-861 ◽  
Author(s):  
N Sarwar ◽  
J-S Kim ◽  
J Jiang ◽  
D Peston ◽  
H D Sinnett ◽  
...  

Oestrogen receptor-α (ERα) is an important prognostic marker in breast cancer and endocrine therapies are designed to inhibit or prevent ERα activity. In vitro studies have indicated that phosphorylation of ERα, in particular on serine 118 (S118), can result in activation in a ligand-independent manner, thereby potentially contributing to resistance to endocrine agents, such as tamoxifen and aromatase inhibitors. Here we report the immunohistochemistry (IHC) of S118 phosphorylation in 301 primary breast tumour biopsies. Surprisingly, this analysis shows that S118 phosphorylation is higher in more differentiated tumours, suggesting that phosphorylation at this site is associated with a good prognosis in patients not previously treated with endocrine agents. However, we also report that S118 phosphorylation was elevated in tumour biopsies taken from patients who had relapsed following tamoxifen treatment, when compared to pre-treatment biopsies. Taken together, these data are consistent with the view that S118 phosphorylation is a feature of normal ERα function and that increases in levels of phosphorylation at this site may play a key role in the emergence of endocrine resistance in breast cancer.

2018 ◽  
Author(s):  
Hoa Quynh Tran ◽  
Phuc Loi Luu ◽  
Van Thai Than ◽  
Declan Clarke ◽  
Hanh Ngoc Lam ◽  
...  

AbstractASMT is a key determinant of the levels of released melatonin. Though melatonin has been shown to exhibit anti-cancer activity and prevents endocrine resistance in breast cancer, the role of ASMT in breast cancer progression remains unclear. In this retrospective study, we analyzed gene expression profiles from thousands of patients and found thatASMTexpression was significantly lower in breast cancer tumors relative to healthy tissue. Among cancer patients, those with greater expression had better relapse-free survival outcomes and longer metastasis-free survival times, and they also experienced longer periods before relapse or distance recurrence following tamoxifen treatment. Administration of melatonin, in combination with tamoxifen, further promoted cancer cell death by promoting apoptosis. Motivated by these results, we devised an ASMT gene signature that identifies low-risk cases with great accuracy. This signature was validated using both mRNA array and RNAseq datasets. Intriguingly, patients who are classified as high-risk benefit from adjuvant chemotherapy, and those with grade II tumors who are classified as low-risk exhibit improved overall survival and distance relapse-free outcomes following endocrine therapy. Our findings more clearly elucidate the roles ofASMT,provide strategies for improving the efficacy of tamoxifen treatment, and help to identify those patients who may maximally benefit from adjuvant or endocrine therapies.


2017 ◽  
Vol 24 (10) ◽  
pp. R349-R366 ◽  
Author(s):  
Catherine Zabkiewicz ◽  
Jeyna Resaul ◽  
Rachel Hargest ◽  
Wen Guo Jiang ◽  
Lin Ye

Bone morphogenetic proteins (BMPs) belong to the TGF-β super family, and are essential for the regulation of foetal development, tissue differentiation and homeostasis and a multitude of cellular functions. Naturally, this has led to the exploration of aberrance in this highly regulated system as a key factor in tumourigenesis. Originally identified for their role in osteogenesis and bone turnover, attention has been turned to the potential role of BMPs in tumour metastases to, and progression within, the bone niche. This is particularly pertinent to breast cancer, which commonly metastasises to bone, and in which studies have revealed aberrations of both BMP expression and signalling, which correlate clinically with breast cancer progression. Ultimately a BMP profile could provide new prognostic disease markers. As the evidence suggests a role for BMPs in regulating breast tumour cellular function, in particular interactions with tumour stroma and the bone metastatic microenvironment, there may be novel therapeutic potential in targeting BMP signalling in breast cancer. This review provides an update on the current knowledge of BMP abnormalities and their implication in the development and progression of breast cancer, particularly in the disease-specific bone metastasis.


Author(s):  
Jun-Xian Du ◽  
Yi-Hong Luo ◽  
Si-Jia Zhang ◽  
Biao Wang ◽  
Cong Chen ◽  
...  

Abstract Background Intensive evidence has highlighted the effect of aberrant alternative splicing (AS) events on cancer progression when triggered by dysregulation of the SR protein family. Nonetheless, the underlying mechanism in breast cancer (BRCA) remains elusive. Here we sought to explore the molecular function of SRSF1 and identify the key AS events regulated by SRSF1 in BRCA. Methods We conducted a comprehensive analysis of the expression and clinical correlation of SRSF1 in BRCA based on the TCGA dataset, Metabric database and clinical tissue samples. Functional analysis of SRSF1 in BRCA was conducted in vitro and in vivo. SRSF1-mediated AS events and their binding motifs were identified by RNA-seq, RNA immunoprecipitation-PCR (RIP-PCR) and in vivo crosslinking followed by immunoprecipitation (CLIP), which was further validated by the minigene reporter assay. PTPMT1 exon 3 (E3) AS was identified to partially mediate the oncogenic role of SRSF1 by the P-AKT/C-MYC axis. Finally, the expression and clinical significance of these AS events were validated in clinical samples and using the TCGA database. Results SRSF1 expression was consistently upregulated in BRCA samples, positively associated with tumor grade and the Ki-67 index, and correlated with poor prognosis in a hormone receptor-positive (HR+) cohort, which facilitated proliferation, cell migration and inhibited apoptosis in vitro and in vivo. We identified SRSF1-mediated AS events and discovered the SRSF1 binding motif in the regulation of splice switching of PTPMT1. Furthermore, PTPMT1 splice switching was regulated by SRSF1 by binding directly to its motif in E3 which partially mediated the oncogenic role of SRSF1 by the AKT/C-MYC axis. Additionally, PTPMT1 splice switching was validated in tissue samples of BRCA patients and using the TCGA database. The high-risk group, identified by AS of PTPMT1 and expression of SRSF1, possessed poorer prognosis in the stage I/II TCGA BRCA cohort. Conclusions SRSF1 exerts oncogenic roles in BRCA partially by regulating the AS of PTPMT1, which could be a therapeutic target candidate in BRCA and a prognostic factor in HR+ BRCA patient.


2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Hongzhen Li ◽  
Chunyan Peng ◽  
Chenhui Zhu ◽  
Shuang Nie ◽  
Xuetian Qian ◽  
...  

Abstract Background Hypoxia is a characteristic of the tumor microenvironments within pancreatic cancer (PC), which has been linked to its malignancy. Recently, hypoxia has been reported to regulate the activity of important carcinogenic pathways by changing the status of histone modification. NOX4, a member of NADPH oxidase (NOX), has been found to be activated by hypoxia and promote cancer progression in several cancers. But whether it is involved in the epigenetic changes of tumor cells induced by hypoxia is still unclear, and its biological roles in PC also need to be explored. Methods A hypoxic-related gene signature and its associated pathways in PC were identified by analyzing the pancreatic cancer gene expression data from GEO and TCGA database. Candidate downstream gene (NOX4), responding to hypoxia, was validated by RT-PCR and western blot. Then, we evaluated the relationship between NOX4 expression and clinicopathologic parameters in 56 PC patients from our center. In vitro and in vivo assays were preformed to explore the phenotype of NOX4 in PC. Immunofluorescence, western blot and chromatin immunoprecipitation assays were further applied to search for a detailed mechanism. Results We quantified hypoxia and developed a hypoxia signature, which was associated with worse prognosis and elevated malignant potential in PC. Furthermore, we found that NADPH oxidase 4 (NOX4), which was induced by hypoxia and upregulated in PC in a HIF1A-independent manner, caused inactivation of lysine demethylase 5A (KDM5A), increased the methylation modification of histone H3 and regulated the transcription of EMT-associated gene_ snail family transcriptional repressor 1 (SNAIL1). This served to promote the invasion and metastasis of PC. NOX4 deficiency repressed hypoxia-induced EMT, reduced expression of H3K4ME3 and impaired the invasion and metastasis of PC cells; however, knockdown of KDM5A reversed the poor expression of H3KEME3 induced by NOX4 deficiency, thereby promoting EMT. Conclusions This study highlights the prognostic role of hypoxia-related genes in PC and strong correlation with EMT pathway. Our results also creatively discovered that NOX4 was an essential mediator for hypoxia-induced histone methylation modification and EMT in PC cells.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Maria De Luca ◽  
Roberta Romano ◽  
Cecilia Bucci

AbstractV-ATPase is a large multi-subunit complex that regulates acidity of intracellular compartments and of extracellular environment. V-ATPase consists of several subunits that drive specific regulatory mechanisms. The V1G1 subunit, a component of the peripheral stalk of the pump, controls localization and activation of the pump on late endosomes and lysosomes by interacting with RILP and RAB7. Deregulation of some subunits of the pump has been related to tumor invasion and metastasis formation in breast cancer. We observed a decrease of V1G1 and RAB7 in highly invasive breast cancer cells, suggesting a key role of these proteins in controlling cancer progression. Moreover, in MDA-MB-231 cells, modulation of V1G1 affected cell migration and matrix metalloproteinase activation in vitro, processes important for tumor formation and dissemination. In these cells, characterized by high expression of EGFR, we demonstrated that V1G1 modulates EGFR stability and the EGFR downstream signaling pathways that control several factors required for cell motility, among which RAC1 and cofilin. In addition, we showed a key role of V1G1 in the biogenesis of endosomes and lysosomes. Altogether, our data describe a new molecular mechanism, controlled by V1G1, required for cell motility and that promotes breast cancer tumorigenesis.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Chen Hang ◽  
Shanojie Zhao ◽  
Tiejun Wang ◽  
Yan Zhang

Abstract Background Breast cancer (BrCa) is the most common female malignancy worldwide and has the highest morbidity among all cancers in females. Unfortunately, the mechanisms of BrCa growth and metastasis, which lead to a poor prognosis in BrCa patients, have not been well characterized. Methods Immunohistochemistry (IHC) was performed on a BrCa tissue microarray (TMA) containing 80 samples to evaluate ubiquitin protein ligase E3C (UBE3C) expression. In addition, a series of cellular experiments were conducted to reveal the role of UBE3C in BrCa. Results In this research, we identified UBE3C as an oncogenic factor in BrCa growth and metastasis for the first time. UBE3C expression was upregulated in BrCa tissues compared with adjacent breast tissues. BrCa patients with high nuclear UBE3C expression in tumors showed remarkably worse overall survival (OS) than those with low nuclear expression. Knockdown of UBE3C expression in MCF-7 and MDA-MB-453 BrCa cells inhibited cell proliferation, migration and invasion in vitro, while overexpression of UBE3C in these cells exerted the opposite effects. Moreover, UBE3C promoted β-catenin nuclear accumulation, leading to the activation of the Wnt/β-catenin signaling pathway in BrCa cells. Conclusion Collectively, these results imply that UBE3C plays crucial roles in BrCa development and progression and that UBE3C may be a novel target for the prevention and treatment of BrCa.


2021 ◽  
Vol 63 ◽  
pp. 102144
Author(s):  
Sumadi Lukman Anwar ◽  
Roby Cahyono ◽  
Widya Surya Avanti ◽  
Heru Yudhanto Budiman ◽  
Wirsma Arif Harahap ◽  
...  

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Ya Fan ◽  
Jia Wang ◽  
Wen Jin ◽  
Yifei Sun ◽  
Yuemei Xu ◽  
...  

Abstract Background E3 ubiquitin ligase HRD1 (HMG-CoA reductase degradation protein 1, alias synoviolin with SYVN1 as the official gene symbol) was found downregulated and acting as a tumor suppressor in breast cancer, while the exact expression profile of HRD1 in different breast cancer subtypes remains unknown. Recent studies characterized circular RNAs (circRNAs) playing an regulatory role as miRNA sponge in tumor progression, presenting a new viewpoint for the post-transcriptional regulation of cancer-related genes. Methods Examination of the expression of HRD1 protein and mRNA was implemented using public microarray/RNA-sequencing datasets and breast cancer tissues/cell lines. Based on public RNA-sequencing results, online databases and enrichment/clustering analyses were used to predict the specific combinations of circRNA/miRNA that potentially govern HRD1 expression. Gain-of-function and rescue experiments in vitro and in vivo were executed to evaluate the suppressive effects of circNR3C2 on breast cancer progression through HRD1-mediated proteasomal degradation of Vimentin, which was identified using immunoblotting, immunoprecipitation, and in vitro ubiquitination assays. Results HRD1 is significantly underexpressed in triple-negative breast cancer (TNBC) against other subtypes and has an inverse correlation with Vimentin, inhibiting the proliferation, migration, invasion and EMT (epithelial-mesenchymal transition) process of breast cancer cells via inducing polyubiquitination-mediated proteasomal degradation of Vimentin. CircNR3C2 (hsa_circ_0071127) is also remarkably downregulated in TNBC, negatively correlated with the distant metastasis and lethality of invasive breast carcinoma. Overexpressing circNR3C2 in vitro and in vivo leads to a crucial enhancement of the tumor-suppressive effects of HRD1 through sponging miR-513a-3p. Conclusions Collectively, we elucidated a bona fide circNR3C2/miR-513a-3p/HRD1/Vimentin axis that negatively regulates the metastasis of TNBC, suggesting that circNR3C2 and HRD1 can act as potential prognostic biomarkers. Our study may facilitate the development of therapeutic agents targeting circNR3C2 and HRD1 for patients with aggressive breast cancer.


Cells ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 248 ◽  
Author(s):  
Aurore Claude-Taupin ◽  
Leïla Fonderflick ◽  
Thierry Gauthier ◽  
Laura Mansi ◽  
Jean-René Pallandre ◽  
...  

Early detection and targeted treatments have led to a significant decrease in mortality linked to breast cancer (BC), however, important issues need to be addressed in the future. One of them will be to find new triple negative breast cancer (TNBC) therapeutic strategies, since none are currently efficiently targeting this subtype of BC. Since numerous studies have reported the possibility of targeting the autophagy pathway to treat or limit cancer progression, we analyzed the expression of six autophagy genes (ATG9A, ATG9B, BECLIN1, LC3B, NIX and P62/SQSTM1) in breast cancer tissue, and compared their expression with healthy adjacent tissue. In our study, we observed an increase in ATG9A mRNA expression in TNBC samples from our breast cancer cohort. We also showed that this increase of the transcript was confirmed at the protein level on paraffin-embedded tissues. To corroborate these in vivo data, we designed shRNA- and CRISPR/Cas9-driven inhibition of ATG9A expression in the triple negative breast cancer cell line MDA-MB-436, in order to determine its role in the regulation of cancer phenotypes. We found that ATG9A inhibition led to an inhibition of in vitro cancer features, suggesting that ATG9A can be considered as a new marker of TNBC and might be considered in the future as a target to develop new specific TNBC therapies.


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.


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