scholarly journals Transposon mutagenesis identifies genes that cooperate with mutant Pten in breast cancer progression

2016 ◽  
Vol 113 (48) ◽  
pp. E7749-E7758 ◽  
Author(s):  
Roberto Rangel ◽  
Song-Choon Lee ◽  
Kenneth Hon-Kim Ban ◽  
Liliana Guzman-Rojas ◽  
Michael B. Mann ◽  
...  

Triple-negative breast cancer (TNBC) has the worst prognosis of any breast cancer subtype. To better understand the genetic forces driving TNBC, we performed a transposon mutagenesis screen in a phosphatase and tensin homolog (Pten) mutant mice and identified 12 candidate trunk drivers and a much larger number of progression genes. Validation studies identified eight TNBC tumor suppressor genes, including the GATA-like transcriptional repressorTRPS1. Down-regulation ofTRPS1in TNBC cells promoted epithelial-to-mesenchymal transition (EMT) by deregulating multiple EMT pathway genes, in addition to increasing the expression ofSERPINE1andSERPINB2and the subsequent migration, invasion, and metastasis of tumor cells. Transposon mutagenesis has thus provided a better understanding of the genetic forces driving TNBC and discovered genes with potential clinical importance in TNBC.

Tumor Biology ◽  
2017 ◽  
Vol 39 (3) ◽  
pp. 101042831769552 ◽  
Author(s):  
Ebubekir Dirican ◽  
Mustafa Akkiprik

Breast cancer is the most commonly diagnosed cancer among women in Turkey and worldwide. It is considered a heterogeneous disease and has different subtypes. Moreover, breast cancer has different molecular characteristics, behaviors, and responses to treatment. Advances in the understanding of the molecular mechanisms implicated in breast cancer progression have led to the identification of many potential therapeutic gene targets, such as Breast Cancer 1/2, phosphatidylinositol 3-kinase catalytic subunit alpha, and tumor protein 53. The aim of this review is to summarize the roles of phosphatidylinositol 3-kinase regulatory subunit 1 (alpha) (alias p85α) and phosphatase and tensin homolog in breast cancer progression and the molecular mechanisms involved. Phosphatase and tensin homolog is a tumor suppressor gene and protein. Phosphatase and tensin homolog antagonizes the phosphatidylinositol 3-kinase/AKT signaling pathway that plays a key role in cell growth, differentiation, and survival. Loss of phosphatase and tensin homolog expression, detected in about 20%–30% of cases, is known to be one of the most common tumor changes leading to phosphatidylinositol 3-kinase pathway activation in breast cancer. Instead, the regulatory subunit p85α is a significant component of the phosphatidylinositol 3-kinase pathway, and it has been proposed that a reduction in p85α protein would lead to decreased negative regulation of phosphatidylinositol 3-kinase and hyperactivation of the phosphatidylinositol 3-kinase pathway. Phosphatidylinositol 3-kinase regulatory subunit 1 protein has also been reported to be a positive regulator of phosphatase and tensin homolog via the stabilization of this protein. A functional genetic alteration of phosphatidylinositol 3-kinase regulatory subunit 1 that results in reduced p85α protein expression and increased insulin receptor substrate 1 binding would lead to enhanced phosphatidylinositol 3-kinase signaling and hence cancer development. Phosphatidylinositol 3-kinase regulatory subunit 1 underexpression was observed in 61.8% of breast cancer samples. Therefore, expression/alternations of phosphatidylinositol 3-kinase regulatory subunit 1 and phosphatase and tensin homolog genes have crucial roles for breast cancer progression. This review will summarize the biological roles of phosphatidylinositol 3-kinase regulatory subunit 1 and phosphatase and tensin homolog in breast cancer, with an emphasis on recent findings and the potential of phosphatidylinositol 3-kinase regulatory subunit 1 and phosphatase and tensin homolog as a therapeutic target for breast cancer therapy.


Cancers ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1205 ◽  
Author(s):  
Vanessa Barriga ◽  
Nyanbol Kuol ◽  
Kulmira Nurgali ◽  
Vasso Apostolopoulos

The progression of breast cancer and its association with clinical outcome and treatment remain largely unexplored. Accumulating data has highlighted the interaction between cells of the immune system and the tumor microenvironment in cancer progression, and although studies have identified multiple facets of cancer progression within the development of the tumor microenvironment (TME) and its constituents, there is lack of research into the associations between breast cancer subtype and staging. Current literature has provided insight into the cells and pathways associated with breast cancer progression through expression analysis. However, there is lack of co-expression studies between immune pathways and cells of the TME that form pro-tumorigenic relationships contributing to immune-evasion. We focus on the immune checkpoint and TME elements that influence cancer progression, particularly studies in molecular subtypes of breast cancer.


Cancers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 3053
Author(s):  
Iulia-Monica Groza ◽  
Cornelia Braicu ◽  
Ancuta Jurj ◽  
Oana Zanoaga ◽  
Raduly Lajos ◽  
...  

Breast cancer is one of the most common oncological diseases in women, as its incidence is rapidly growing, rendering it unpredictable and causing more harm than ever before on an annual basis. Alterations of coding and noncoding genes are related to tumorigenesis and breast cancer progression. In this study, several key genes associated with epithelial-to-mesenchymal transition (EMT) and cancer stem cell (CSC) features were identified. EMT and CSCs are two key mechanisms responsible for self-renewal, differentiation, and self-protection, thus contributing to drug resistance. Therefore, understanding of the relationship between these processes may identify a therapeutic vulnerability that can be further exploited in clinical practice, and evaluate its correlation with overall survival rate. To determine expression levels of altered coding and noncoding genes, The Cancer Omics Atlas (TCOA) are used, and these data are overlapped with a list of CSCs and EMT-specific genes downloaded from NCBI. As a result, it is observed that CSCs are reciprocally related to EMT, thus identifying common signatures that allow for predicting the overall survival for breast cancer genes (BRCA). In fact, common CSCs and EMT signatures, represented by ALDH1A1, SFRP1, miR-139, miR-21, and miR-200c, are deemed useful as prognostic biomarkers for BRCA. Therefore, by mapping changes in gene expression across CSCs and EMT, suggesting a cross-talk between these two processes, we have been able to identify either the most common or specific genes or miRNA markers associated with overall survival rate. Thus, a better understanding of these mechanisms will lead to more effective treatment options.


2021 ◽  
Vol 14 (11) ◽  
pp. 1122
Author(s):  
Michelle M. Williams ◽  
Sabrina A. Hafeez ◽  
Jessica L. Christenson ◽  
Kathleen I. O’Neill ◽  
Nia G. Hammond ◽  
...  

Approval of checkpoint inhibitors for treatment of metastatic triple negative breast cancer (mTNBC) has opened the door for the use of immunotherapies against this disease. However, not all patients with mTNBC respond to current immunotherapy approaches such as checkpoint inhibitors. Recent evidence demonstrates that TNBC metastases are more immune suppressed than primary tumors, suggesting that combination or additional immunotherapy strategies may be required to activate an anti-tumor immune attack at metastatic sites. To identify other immune suppressive mechanisms utilized by mTNBC, our group and others manipulated oncogenic epithelial-to-mesenchymal transition (EMT) programs in TNBC models to reveal differences between this breast cancer subtype and its more epithelial counterpart. This review will discuss how EMT modulation revealed several mechanisms, including tumor cell metabolism, cytokine milieu and secretion of additional immune modulators, by which mTNBC cells may suppress both the innate and adaptive anti-tumor immune responses. Many of these pathways/proteins are under preclinical or clinical investigation as therapeutic targets in mTNBC and other advanced cancers to enhance their response to chemotherapy and/or checkpoint inhibitors.


2019 ◽  
Author(s):  
Fatima Valdes-Mora ◽  
Robert Salomon ◽  
Brian Gloss ◽  
Andrew MK. Law ◽  
Lesley Castillo ◽  
...  

AbstractBoth luminal and basal breast cancer subtypes originate in the mammary luminal progenitor cell compartment. Basal breast cancer is associated with younger age, early relapse, and high mortality rate. Here we used unbiased droplet-based single-cell RNAseq to elucidate the cellular basis of tumour progression during the specification of the basal breast cancer subtype from the luminal progenitor population. Basal–like cancer cells resembled the alveolar lineage that is specified upon pregnancy and showed molecular features indicative of an interaction with the tumour microenvironment (TME) including epithelial-to-mesenchymal transition (EMT), hypoxia, lactation and involution. Involution signatures in luminal breast cancer tumours with alveolar lineage features were associated with worse prognosis and features of basal breast cancer. Our high-resolution molecular characterisation of the tumour ecosystem also revealed a highly interactive cell-cell network reminiscent of an involution process. This involution mimicry involves malignant education of cancer-associated fibroblasts and myeloid cell recruitment to support tissue remodelling and sustained inflammation. Our study shows how luminal breast cancer acquires an aberrant post-lactation developmental program that involves both cancer cells and cells from the TME, to shift molecular subtype and promote tumour progression, with potential to explain the increased risk and poor prognosis of breast cancer associated to childbirth.


Cancers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 139 ◽  
Author(s):  
Billy Hill ◽  
Annachiara Sarnella ◽  
Domenica Capasso ◽  
Daniela Comegna ◽  
Annarita Del Gatto ◽  
...  

The mesenchymal sub-type of triple negative breast cancer (MES-TNBC) has a highly aggressive behavior and worse prognosis, due to its invasive and stem-like features, that correlate with metastatic dissemination and resistance to therapies. Furthermore, MES-TNBC is characterized by the expression of molecular markers related to the epithelial-to-mesenchymal transition (EMT) program and cancer stem cells (CSCs). The altered expression of αvβ3 integrin has been well established as a driver of cancer progression, stemness, and metastasis. Here, we showed that the high levels of αvβ3 are associated with MES-TNBC and therefore exploited the possibility to target this integrin to reduce the aggressiveness of this carcinoma. To this aim, MES-TNBC cells were treated with a novel peptide, named ψRGDechi, that we recently developed and characterized for its ability to selectively bind and inhibit αvβ3 integrin. Notably, ψRGDechi was able to hamper adhesion, migration, and invasion of MES-TNBC cells, as well as the capability of these cells to form vascular-like structures and mammospheres. In addition, this peptide reversed EMT program inhibits mesenchymal markers. These findings show that targeting αvβ3 integrin by ψRGDechi, it is possible to inhibit some of the malignant properties of MES-TNBC phenotype.


Cancers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 726 ◽  
Author(s):  
Sudha Suriyamurthy ◽  
David Baker ◽  
Peter ten Dijke ◽  
Prasanna Vasudevan Iyengar

The Transforming Growth Factor-β (TGF-β) signaling pathway has a well-documented, context-dependent role in breast cancer development. In normal and premalignant cells, it acts as a tumor suppressor. By contrast, during the malignant phases of breast cancer progression, the TGF-β signaling pathway elicits tumor promoting effects particularly by driving the epithelial to mesenchymal transition (EMT), which enhances tumor cell migration, invasion and ultimately metastasis to distant organs. The molecular and cellular mechanisms that govern this dual capacity are being uncovered at multiple molecular levels. This review will focus on recent advances relating to how epigenetic changes such as acetylation and methylation control the outcome of TGF-β signaling and alter the fate of breast cancer cells. In addition, we will highlight how this knowledge can be further exploited to curb tumorigenesis by selective targeting of the TGF-β signaling pathway.


2020 ◽  
Vol 26 (3) ◽  
pp. 372-375 ◽  
Author(s):  
Daniele Vergara ◽  
Tiziano Verri ◽  
Marina Damato ◽  
Marco Trerotola ◽  
Pasquale Simeone ◽  
...  

Background: Molecular changes associated with the initiation of the epithelial to mesenchymal transition (EMT) program involve alterations of large proteome-based networks. The role of protein products mapping to non-coding genomic regions is still unexplored. Objective: The goal of this study was the identification of an alternative protein signature in breast cancer cellular models with a distinct expression of EMT markers. Methods: We profiled MCF-7 and MDA-MB-231 cells using liquid-chromatography mass/spectrometry (LCMS/ MS) and interrogated the OpenProt database to identify novel predicted isoforms and novel predicted proteins from alternative open reading frames (AltProts). Results: Our analysis revealed an AltProt and isoform protein signature capable of classifying the two breast cancer cell lines. Among the most highly expressed alternative proteins, we observed proteins potentially associated with inflammation, metabolism and EMT. Conclusion: Here, we present an AltProts signature associated with EMT. Further studies will be needed to define their role in cancer progression.


2019 ◽  
Vol 37 (15_suppl) ◽  
pp. e12548-e12548
Author(s):  
Lucas Wang ◽  
Brittany Harlow ◽  
Laura Bowers ◽  
Stephen Hursting ◽  
Linda A deGraffenried ◽  
...  

e12548 Background: Almost 40% of women with breast cancer are obese at diagnosis. Obesity is associated with a worse prognosis in triple negative breast cancer (TNBC). Preclinical studies have shown that leptin is an important factor associated with TNBC by promoting cancer stem cell (CSC) enrichment and/or epithelial-to-mesenchymal transition (EMT). Transcription factors SNAIL, TWIST and ZEB are critical components in enhancing EMT in cancer cells. The specific mechanism(s) by leptin regulates SNAIL, TWIST and ZEB expression remain unclear, limiting the development of effective interventions to improve outcomes in obese TNBC patients. Recent studies have demonstrated that miR200c, downstream of leptin receptor signaling, regulates the expression of SNAIL1, TWIST and ZEB. We will test the hypothesis that leptin contributes to obesity-induced EMT/CSC in TNBC through modulation of miR200c. Methods: Ob-R (leptin receptor) expression was suppressed in TNBC MDA-MB-231 and E-Wnt cells using shRNA (Ob-R null). Ob-R and Ob-R null cells were exposed to sera pooled from lean or obese women, as well as lean sera supplemented with leptin, after which expression of SNAIL, TWIST, ZEB and miR200c was measured by qPCR, while activation of the JAK-STAT pathway was assessed by Western blotting. Results: TNBC cells exposed to obese and high leptin conditions demonstrated increased expression of EMT markers compared to levels expressed under lean conditions. The Ob-R WT and null cells were used to determine the specific role of leptin signaling in regulating expression of SNAIL, TWIST and ZEB through miR200c. Conclusions: Both obese and high leptin conditions result in increased expression of EMT regulators, suggesting that effective targeting of this pathway may provide clinical benefit in the obese breast cancer patient. Elucidating the specific mediators of this pathway will guide development of novel and more potent medical therapies.


Cancers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1967 ◽  
Author(s):  
Nour Jalaleddine ◽  
Layal El-Hajjar ◽  
Hassan Dakik ◽  
Abdullah Shaito ◽  
Jessica Saliba ◽  
...  

Loss of connexin-mediated cell-cell communication is a hallmark of breast cancer progression. Pannexin1 (PANX1), a glycoprotein that shares structural and functional features with connexins and engages in cell communication with its environment, is highly expressed in breast cancer metastatic foci; however, PANX1 contribution to metastatic progression is still obscure. Here we report elevated expression of PANX1 in different breast cancer (BRCA) subtypes using RNA-seq data from The Cancer Genome Atlas (TCGA). The elevated PANX1 expression correlated with poorer outcomes in TCGA BRCA patients. In addition, gene set enrichment analysis (GSEA) revealed that epithelial-to-mesenchymal transition (EMT) pathway genes correlated positively with PANX1 expression. Pharmacological inhibition of PANX1, in MDA-MB-231 and MCF-7 breast cancer cells, or genetic ablation of PANX1, in MDA-MB-231 cells, reverted the EMT phenotype, as evidenced by decreased expression of EMT markers. In addition, PANX1 inhibition or genetic ablation decreased the invasiveness of MDA-MB-231 cells. Our results suggest PANX1 overexpression in breast cancer is associated with a shift towards an EMT phenotype, in silico and in vitro, attributing to it a tumor-promoting effect, with poorer clinical outcomes in breast cancer patients. This association offers a novel target for breast cancer therapy.


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