scholarly journals The downregulation of WWOX induces epithelial–mesenchymal transition and enhances stemness and chemoresistance in breast cancer

2018 ◽  
Vol 243 (13) ◽  
pp. 1066-1073 ◽  
Author(s):  
Juan Li ◽  
Jie Liu ◽  
Pingping Li ◽  
Can Zhou ◽  
Peijun Liu

WW domain-containing oxidoreductase (WWOX), an important tumor suppressor, is essential for regulating cell proliferation and apoptosis. Our study demonstrates that low level of WWOX is associated with the triple-negative subtype of breast cancer (TNBC), which has higher stem cell phenotype and chemoresistance. We evaluated the role of WWOX in regulation of breast cancer stem cells (BCSC) phenotype and chemoresistance. Our results showed that knockdown of WWOX increases the stemness of breast cancer cells. Meanwhile, downregulation of WWOX induces the epithelial–mesenchymal transition (EMT) and chemoresistance of breast cancer cell lines. Our findings revealed the role of the WWOX in the regulation of the BCSC population and chemotherapeutic sensitivity and may provide insights for the development of more effective therapies targeting cancer stem cells in breast cancer. Impact statement Overcoming resistance to chemotherapy is one of the fundamental issues of clinical treatment and CSCs are responsible for the poor therapeutic effects of chemotherapy. WW domain-containing oxidoreductase (WWOX), an important tumor suppressor, regulates cancer cells’ response to chemotherapy. The major finding of our study is the novel role of WWOX in the chemoresistance of breast cancer through the regulation of cell stemness and EMT. The plasticity may play a crucial role in tumor metastasis, treatment resistance and tumor recurrence. Our findings may shed new light on the alterations of BCSCs and pave the way for the discovery of novel and more effective therapies to treat breast cancer by targeting WWOX.

2020 ◽  
Author(s):  
Ninjit Dhanota ◽  
Amanjit Bal ◽  
Gurpreet Singh ◽  
Sunil K Arora

AbstractIn order to delineate the underlying molecular mechanisms responsible for intra tumoral enrichment of BCSCs in aggressive breast tumors, firstly we evaluated the frequency and characteristics of breast cancer stem cells (BCSCs) within the tumor mass as well as in pathologically normal adjacent tissues in primary breast carcinomas of various clinical and histological grades. Then, we evaluated the expression profiles of various genes in non-cancer stem cells from these tumors to delineate the role played by cellular niche in de novo origin and/or expansion of intra-tumoral cancer stem cells.The study included primary tumor and adjacent normal breast tissue specimens from chemotherapy-naïve breast carcinoma patients. The BCSCs, identified as Lin-CD44+CD24- and aldehyde dehydrogenase 1 A1 positive were enumerated. The frequency of intra-tumoral BCSCs was correlated with various clinicopathological parameters of breast cancer. The flow-cytometrically sorted stromal cells and cancer cells from treatment naïve primary breast tumors were processed for gene expression profiling using a custom designed PCR array of genes known to facilitate cancer cell proliferation and disease progression.The frequency of BCSCs within the tumor mass as well as in the adjacent normal tissue correlated significantly with histopathological and molecular grades of tumors indicating a direct relationship of BCSC with aggressive behavior of breast cancer. A significantly higher number of BCSCs was also detected in metastatic LN group as compared to non-metastatic LN. Further, a significantly increased expression of the genes associated with growth factors, cytokines & matricellular proteins in tumors with high BCSCs content (> 5%; Hi-BCSCs tumors) as compared to Lo-BCSC tumors (with <5% intratumoral BCSC content) suggested the possible contribution of stromal cells and cancer cells in intra-tumoral expansion of CSCs. Similarly, a significant up-regulation of genes associated with hypoxia and angiogenesis in Hi-BCSCs tumors further supported the role of hypoxic environment. The expression levels of genes associated with epithelial to mesenchymal transition also followed a similar pattern. On the other hand, downregulated SNAI1 gene (generally upregulated in onset of EMT) in stromal cells of Hi-BCSCs tumors suggests a post EMT environment in Hi-BCSCs tumors.The findings suggest that the molecular crosstalk between the non-BCSC niche cells and the cancer stem cells within the breast cancer microenvironment directly contribute to formation of biologically conducive conditions for expansion of cancer stem cells.


2019 ◽  
Vol 21 (1) ◽  
pp. 53 ◽  
Author(s):  
Saiprasad Gowrikumar ◽  
Amar B. Singh ◽  
Punita Dhawan

Claudins are cell–cell adhesion proteins, which are expressed in tight junctions (TJs), the most common apical cell-cell adhesion. Claudin proteins help to regulate defense and barrier functions, as well as differentiation and polarity in epithelial and endothelial cells. A series of studies have now reported dysregulation of claudin proteins in cancers. However, the precise mechanisms are still not well understood. Nonetheless, studies have clearly demonstrated a causal role of multiple claudins in the regulation of epithelial to mesenchymal transition (EMT), a key feature in the acquisition of a cancer stem cell phenotype in cancer cells. In addition, claudin proteins are known to modulate therapy resistance in cancer cells, a feature associated with cancer stem cells. In this review, we have focused primarily on highlighting the causal link between claudins, cancer stem cells, and therapy resistance. We have also contemplated the significance of claudins as novel targets in improving the efficacy of cancer therapy. Overall, this review provides a much-needed understanding of the emerging role of claudin proteins in cancer malignancy and therapeutic management.


Cancers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1833
Author(s):  
Tsai-Tsen Liao ◽  
Wei-Chung Cheng ◽  
Chih-Yung Yang ◽  
Yin-Quan Chen ◽  
Shu-Han Su ◽  
...  

Cell migration is critical for regional dissemination and distal metastasis of cancer cells, which remain the major causes of poor prognosis and death in patients with colorectal cancer (CRC). Although cytoskeletal dynamics and cellular deformability contribute to the migration of cancer cells and metastasis, the mechanisms governing the migratory ability of cancer stem cells (CSCs), a nongenetic source of tumor heterogeneity, are unclear. Here, we expanded colorectal CSCs (CRCSCs) as colonospheres and showed that CRCSCs exhibited higher cell motility in transwell migration assays and 3D invasion assays and greater deformability in particle tracking microrheology than did their parental CRC cells. Mechanistically, in CRCSCs, microRNA-210-3p (miR-210) targeted stathmin1 (STMN1), which is known for inducing microtubule destabilization, to decrease cell elasticity in order to facilitate cell motility without affecting the epithelial–mesenchymal transition (EMT) status. Clinically, the miR-210-STMN1 axis was activated in CRC patients with liver metastasis and correlated with a worse clinical outcome. This study elucidates a miRNA-oriented mechanism regulating the deformability of CRCSCs beyond the EMT process.


2014 ◽  
Vol 60 (3) ◽  
pp. 322-331 ◽  
Author(s):  
E.A. Avilova ◽  
O.E. Andreeva ◽  
V.A. Shatskaya ◽  
M.A. Krasilnikov

The main goal of this work was to study the intracellular signaling pathways responsible for the development of hormone resistance and maintaining the autonomous growth of breast cancer cells. In particular, the role of PAK1 (p21-activated kinase 1), the key mitogenic signaling protein, in the development of cell resistance to estrogens was analyzed. In vitro studies were performed on cultured breast cancer cell lines: estrogen-dependent estrogen receptor (ER)-positive MCF-7 cells and estrogen-resistant ER-negative HBL-100 cells. We found that the resistant HBL-100 cells were characterized by a higher level of PAK1 and demonstrated PAK1 involvement in the maintaining of estrogen-independent cell growth. We have also shown PAK1 ability to up-regulate Snail1, one of the epithelial-mesenchymal transition proteins, and obtained experimental evidence for Snail1 importance in the regulation of cell proliferation. In general, the results obtained in this study demonstrate involvement of PAK1 and Snail1 in the formation of estrogen-independent phenotype of breast cancer cells showing the potential role of both proteins as markers of hormone resistance of breast tumors.


2021 ◽  
Author(s):  
Ningwei Fu ◽  
Ning Fan ◽  
Wenchao Luo ◽  
Lijia Lv ◽  
Jing Li ◽  
...  

Abstract Purpose: TFEB is a key regulator of autophagy-lysosomal biogenesis pathways, while its dysregulation is highly prevalent in various human cancers, but the specific contribution to breast cancer remains poorly understood. The main purpose of this study is to explore the role of TFEB in breast cancer proliferation, metastasis and maintaining breast cancer stem cells (BCSCs) traits, thus uncovering its underlying mechanism.Methods: Bioinformatics, western blotting and immunohistochemical staining were applied to analyze the expression of TFEB in breast cancer. Stable down-regulation TFEB cells were established in MCF-7 and MDA-MB-231 breast cancer cell lines. MTT, clone formation, wound healing, transwell and 3D tumor invasion assays were used to evaluate the proliferation, migration and invasion ability of breast cancer cells. Mammosphere formation, immunocytochemical (ICC) staining were used to detect the effect of down-regulating TFEB on breast cancer stem cells. Results: we demonstrated that higher expression of TFEB was found in breast cancer. TFEB depletion had inhibitory effects on cellular proliferation, migration and invasion of breast cancer cells. Moreover, knockdown TFEB decreased mammosphere formation ability of BCSCs and expression of cancer stem cell markers. Autophagy-lysosomal related proteins were decreased by down regulation of TFEB. Conclusion: we uncovered a critical role of TFEB in breast cancer proliferation and metastasis, and BCSCs self-renewal and stemness. The underlying mechanisms involve in maintaining BCSCs traits, and dysregulating lysosome functions.


Cancers ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1058 ◽  
Author(s):  
Gener ◽  
Rafael ◽  
Seras-Franzoso ◽  
Perez ◽  
Pindado ◽  
...  

Therapeutic resistance seen in aggressive forms of breast cancer remains challenging for current treatments. More than half of the patients suffer from a disease relapse, most of them with distant metastases. Cancer maintenance, resistance to therapy, and metastatic disease seem to be sustained by the presence of cancer stem cells (CSC) within a tumor. The difficulty in targeting this subpopulation derives from their dynamic interconversion process, where CSC can differentiate to non-CSC, which in turn de-differentiate into cells with CSC properties. Using fluorescent CSC models driven by the expression of ALDH1A 1(aldehyde dehydrogenase 1A1), we confirmed this dynamic phenotypic change in MDA-MB-231 breast cancer cells and to identify Serine/Threonine Kinase 2 (AKT2) as an important player in the process. To confirm the central role of AKT2, we silenced AKT2 expression via small interfering RNA and using a chemical inhibitor (CCT128930), in both CSC and non-CSC from different cancer cell lines. Our results revealed that AKT2 inhibition effectively prevents non-CSC reversion through mesenchymal to epithelial transition, reducing invasion and colony formation ability of both, non-CSC and CSC. Further, AKT2 inhibition reduced CSC survival in low attachment conditions. Interestingly, in orthotopic tumor mouse models, high expression levels of AKT2 were detected in circulating tumor cells (CTC). These findings suggest AKT2 as a promising target for future anti-cancer therapies at three important levels: (i) Epithelial-to-mesenchymal transition (EMT) reversion and maintenance of CSC subpopulation in primary tumors, (ii) reduction of CTC and the likelihood of metastatic spread, and (iii) prevention of tumor recurrence through inhibition of CSC tumorigenic and metastatic potential.


Cancers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2482
Author(s):  
Samson Mathews Samuel ◽  
Elizabeth Varghese ◽  
Lenka Koklesová ◽  
Alena Líšková ◽  
Peter Kubatka ◽  
...  

Despite the leaps and bounds in achieving success in the management and treatment of breast cancers through surgery, chemotherapy, and radiotherapy, breast cancer remains the most frequently occurring cancer in women and the most common cause of cancer-related deaths among women. Systemic therapeutic approaches, such as chemotherapy, although beneficial in treating and curing breast cancer subjects with localized breast tumors, tend to fail in metastatic cases of the disease due to (a) an acquired resistance to the chemotherapeutic drug and (b) the development of intrinsic resistance to therapy. The existence of cancer stem cells (CSCs) plays a crucial role in both acquired and intrinsic chemoresistance. CSCs are less abundant than terminally differentiated cancer cells and confer chemoresistance through a unique altered metabolism and capability to evade the immune response system. Furthermore, CSCs possess active DNA repair systems, transporters that support multidrug resistance (MDR), advanced detoxification processes, and the ability to self-renew and differentiate into tumor progenitor cells, thereby supporting cancer invasion, metastasis, and recurrence/relapse. Hence, current research is focusing on targeting CSCs to overcome resistance and improve the efficacy of the treatment and management of breast cancer. Studies revealed that metformin (1, 1-dimethylbiguanide), a widely used anti-hyperglycemic agent, sensitizes tumor response to various chemotherapeutic drugs. Metformin selectively targets CSCs and improves the hypoxic microenvironment, suppresses the tumor metastasis and inflammation, as well as regulates the metabolic programming, induces apoptosis, and reverses epithelial–mesenchymal transition and MDR. Here, we discuss cancer (breast cancer) and chemoresistance, the molecular mechanisms of chemoresistance in breast cancers, and metformin as a chemo-sensitizing/re-sensitizing agent, with a particular focus on breast CSCs as a critical contributing factor to acquired and intrinsic chemoresistance. The review outlines the prospects and directions for a better understanding and re-purposing of metformin as an anti-cancer/chemo-sensitizing drug in the treatment of breast cancer. It intends to provide a rationale for the use of metformin as a combinatory therapy in a clinical setting.


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