scholarly journals Role of JAK/STAT3 Signaling in the Regulation of Metastasis, the Transition of Cancer Stem Cells, and Chemoresistance of Cancer by Epithelial–Mesenchymal Transition

Cells ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 217 ◽  
Author(s):  
Wook Jin

The JAK/STAT3 signaling pathway plays an essential role in various types of cancers. Activation of this pathway leads to increased tumorigenic and metastatic ability, the transition of cancer stem cells (CSCs), and chemoresistance in cancer via enhancing the epithelial–mesenchymal transition (EMT). EMT acts as a critical regulator in the progression of cancer and is involved in regulating invasion, spread, and survival. Furthermore, accumulating evidence indicates the failure of conventional therapies due to the acquisition of CSC properties. In this review, we summarize the effects of JAK/STAT3 activation on EMT and the generation of CSCs. Moreover, we discuss cutting-edge data on the link between EMT and CSCs in the tumor microenvironment that involves a previously unknown function of miRNAs, and also discuss new regulators of the JAK/STAT3 signaling pathway.

2019 ◽  
Vol 39 (2) ◽  
pp. 224-234 ◽  
Author(s):  
Y Qin ◽  
P Zhao ◽  
Y Chen ◽  
X Liu ◽  
H Dong ◽  
...  

Epithelial–mesenchymal transition (EMT) plays a key role in the process of pulmonary fibrosis (PF). Increasing evidences have shown that exaggerated EMT in recurrent pulmonary injury mediates the early pathogenesis of PF. This study aimed to evaluate EMT of human alveolar epithelial cells (A549) when cocultured with human macrophages Tohoku hospital pediatrics-1 (THP-1) induced by lipopolysaccharide (LPS) and investigate the role of Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) signaling pathway. Firstly, we detected the inflammatory and EMT biomarkers in A549 cells monoculture and A549/THP-1 cells coculture in the presence or absence of LPS. Then, the activation of JAK2/STAT3 signaling pathway was determined in coculture. Interestingly, inflammatory markers, such as interleukin (IL)-6, matrix metalloproteinase (MMP)-9, transforming growth factor (TGF)- β, and collagen type 1 (COL-1), were enhanced in LPS treated coculture. Besides, the expression of E-cadherin decreased but α-smooth muscle actin expression increased, indicating the presence of EMT in A549 cells when cocultured with THP-1 macrophages. However, these phenotypes could not be observed in LPS-treated A549 cells monoculture. Meanwhile, JAK2/STAT3 signaling pathway was activated, and the STAT3 DNA-binding and inflammatory markers were inhibited by Stattic. Together, these findings demonstrate the key role of JAK2/STAT3 signaling pathway in LPS promoted EMT of A549 in the presence of THP-1 macrophages as an in vitro PF model.


Cancers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 434 ◽  
Author(s):  
Wenjuan Mei ◽  
Xiaozeng Lin ◽  
Anil Kapoor ◽  
Yan Gu ◽  
Kuncheng Zhao ◽  
...  

Research in the last decade has clearly revealed a critical role of prostate cancer stem cells (PCSCs) in prostate cancer (PC). Prostate stem cells (PSCs) reside in both basal and luminal layers, and are the target cells of oncogenic transformation, suggesting a role of PCSCs in PC initiation. Mutations in PTEN, TP53, and RB1 commonly occur in PC, particularly in metastasis and castration-resistant PC. The loss of PTEN together with Ras activation induces partial epithelial–mesenchymal transition (EMT), which is a major mechanism that confers plasticity to cancer stem cells (CSCs) and PCSCs, which contributes to metastasis. While PTEN inactivation leads to PC, it is not sufficient for metastasis, the loss of PTEN concurrently with the inactivation of both TP53 and RB1 empower lineage plasticity in PC cells, which substantially promotes PC metastasis and the conversion to PC adenocarcinoma to neuroendocrine PC (NEPC), demonstrating the essential function of TP53 and RB1 in the suppression of PCSCs. TP53 and RB1 suppress lineage plasticity through the inhibition of SOX2 expression. In this review, we will discuss the current evidence supporting a major role of PCSCs in PC initiation and metastasis, as well as the underlying mechanisms regulating PCSCs. These discussions will be developed along with the cancer stem cell (CSC) knowledge in other cancer types.


Author(s):  
Cord Naujokat ◽  
Dwight L. McKee

: Cancer stem cells (CSCs) constitute a subpopulation of tumor cells that possess self-renewal and tumor initiation capacity, and the ability to give rise to the heterogeneous lineages of cancer cells that comprise the tumor. CSCs exhibit intrinsic mechanisms of resistance to virtually all conventional cancer therapeutics, allowing them to survive current cancer therapies and to initiate tumor recurrence and metastasis. Different pathways and mechanisms that confer resistance and survival of CSCs, including activation of the Wnt/β-catenin, Sonic Hedgehog, Notch, PI3K/Akt/mTOR and STAT3 signaling pathways, expression of aldehyde dehydrogenase 1 (ALDH1) and oncogenic microRNAs, and acquisition of epithelial-mesenchymal transition (EMT), have been identified recently. Certain phytochemicals, in particular curcumin, epigallocatechin-3-gallate (EGCG), sulforaphane, resveratrol and genistein have been shown to interfere with these intrinsic CSC pathways in vitro and in human xenograft mice, leading to elimination of CSCs. Moreover, recent clinical trials have demonstrated therapeutic efficacy of the five phytochemicals, alone or in combination with modern cancer therapeutics, and in various types of cancer. Since current cancer therapies fail to eradicate CSCs, leading to cancer recurrence and progression, targeting of CSCs with phytotochemicals such as curcumin, EGCG, sulforaphane, resveratrol and genistein, combined with each other and/or in combination with conventional cytotoxic drugs and novel cancer therapeutics, may offer a novel therapeutic strategy against cancer.


2021 ◽  
Vol 11 ◽  
Author(s):  
Xiaobo Zheng ◽  
Fuzhen Dai ◽  
Lei Feng ◽  
Hong Zou ◽  
Li Feng ◽  
...  

The epithelial–mesenchymal transition (EMT) is closely associated with the acquisition of aggressive traits by carcinoma cells and is considered responsible for metastasis, relapse, and chemoresistance. Molecular links between the EMT and cancer stem cells (CSCs) have indicated that EMT processes play important roles in the expression of CSC-like properties. It is generally thought that EMT-related transcription factors (EMT-TFs) need to be downregulated to confer an epithelial phenotype to mesenchymal cells and increase cell proliferation, thereby promoting metastasis formation. However, the genetic and epigenetic mechanisms that regulate EMT and CSC activation are contradictory. Emerging evidence suggests that EMT need not be a binary model and instead a hybrid epithelial/mesenchymal state. This dynamic process correlates with epithelial–mesenchymal plasticity, which indicates a contradictory role of EMT during cancer progression. Recent studies have linked the epithelial–mesenchymal plasticity and stem cell-like traits, providing new insights into the conflicting relationship between EMT and CSCs. In this review, we examine the current knowledge about the interplay between epithelial–mesenchymal plasticity and CSCs in cancer biology and evaluate the controversies and future perspectives. Understanding the biology of epithelial–mesenchymal plasticity and CSCs and their implications in therapeutic treatment may provide new opportunities for targeted intervention.


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