scholarly journals Therapeutic Targeting of Epithelial Plasticity Programs: Focus on the Epithelial-Mesenchymal Transition

2017 ◽  
Vol 203 (2) ◽  
pp. 114-127 ◽  
Author(s):  
Reem Malek ◽  
Hailun Wang ◽  
Kekoa Taparra ◽  
Phuoc T. Tran

Mounting data points to epithelial plasticity programs such as the epithelial-mesenchymal transition (EMT) as clinically relevant therapeutic targets for the treatment of malignant tumors. In addition to the widely realized role of EMT in increasing cancer cell invasiveness during cancer metastasis, the EMT has also been implicated in allowing cancer cells to avoid tumor suppressor pathways during early tumorigenesis. In addition, data linking EMT to innate and acquired treatment resistance further points towards the desire to develop pharmacological therapies to target epithelial plasticity in cancer. In this review we organized our discussion on pathways and agents that can be used to target the EMT in cancer into 3 groups: (1) extracellular inducers of EMT, (2) the transcription factors that orchestrate the EMT transcriptome, and (3) the downstream effectors of EMT. We highlight only briefly specific canonical pathways known to be involved in EMT, such as the signal transduction pathways TGFβ, EFGR, and Axl-Gas6. We emphasize in more detail pathways that we believe are emerging novel pathways and therapeutic targets such as epigenetic therapies, glycosylation pathways, and immunotherapy. The heterogeneity of tumors and the dynamic nature of epithelial plasticity in cancer cells make it likely that targeting only 1 EMT-related process will be unsuccessful or only transiently successful. We suggest that with greater understanding of epithelial plasticity regulation, such as with the EMT, a more systematic targeting of multiple EMT regulatory networks will be the best path forward to improve cancer outcomes.

Author(s):  
Ozal Beylerli ◽  
Ilgiz F. Gareev ◽  
Aferin Beilerli

Cancer metastasis is a multistep process in which cancer cells leave the primary focus, survive in the bloodstream, and colonize in a distant organ. This is the main cause of cancer morbidity and mortality. It is mediated by a multistep process called the metastatic cascade. Initial steps include local invasion and migration, angiogenesis, epithelial-mesenchymal transition (EMF) and intravasation. Non-coding RNAs represent a large part of the transcriptome, with long non-coding RNAs (lncRNAs) constituting a large proportion. The perception of long non-coding RNAs as fragments of RNA and transcriptional noise has been constantly replaced by their role as confirmed targets for various physiological processes in the past few years. A large amount of evidence has revealed their role at all stages of carcinogenesis and in modulating metastasis through regulatory networks. In this review, we focus on the role of long non-coding RNAs as promoters or inhibitors in the main stages of the metastatic cascade, and in particular consider their role in the metastasis of malignant tumors to the brain.


Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 558
Author(s):  
Jin Kyung Seok ◽  
Eun-Hee Hong ◽  
Gabsik Yang ◽  
Hye Eun Lee ◽  
Sin-Eun Kim ◽  
...  

Oxidized phospholipids are well known to play physiological and pathological roles in regulating cellular homeostasis and disease progression. However, their role in cancer metastasis has not been entirely understood. In this study, effects of oxidized phosphatidylcholines such as 1-palmitoyl-2-(5-oxovaleroyl)-sn-glycero-3-phosphocholine (POVPC) on epithelial-mesenchymal transition (EMT) and autophagy were determined in cancer cells by immunoblotting and confocal analysis. Metastasis was analyzed by a scratch wound assay and a transwell migration/invasion assay. The concentrations of POVPC and 1-palmitoyl-2-glutaroyl-sn-glycero-phosphocholine (PGPC) in tumor tissues obtained from patients were measured by LC-MS/MS analysis. POVPC induced EMT, resulting in increase of migration and invasion of human hepatocellular carcinoma cells (HepG2) and human breast cancer cells (MCF7). POVPC induced autophagic flux through AMPK-mTOR pathway. Pharmacological inhibition or siRNA knockdown of autophagy decreased migration and invasion of POVPC-treated HepG2 and MCF7 cells. POVPC and PGPC levels were greatly increased at stage II of patient-derived intrahepatic cholangiocarcinoma tissues. PGPC levels were higher in malignant breast tumor tissues than in adjacent nontumor tissues. The results show that oxidized phosphatidylcholines increase metastatic potential of cancer cells by promoting EMT, mediated through autophagy. These suggest the positive regulatory role of oxidized phospholipids accumulated in tumor microenvironment in the regulation of tumorigenesis and metastasis.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Wen Yin ◽  
Hecheng Zhu ◽  
Jun Tan ◽  
Zhaoqi Xin ◽  
Quanwei Zhou ◽  
...  

Abstract Background Gliomas account for the majority of fatal primary brain tumors, and there is much room for research in the underlying pathogenesis, the multistep progression of glioma, and how to improve survival. In our study, we aimed to identify potential biomarkers or therapeutic targets of glioma and study the mechanism underlying the tumor progression. Methods We downloaded the microarray datasets (GSE43378 and GSE7696) from the Gene Expression Omnibus (GEO) database. Then, we used weighted gene co-expression network analysis (WGCNA) to screen potential biomarkers or therapeutic targets related to the tumor progression. ESTIMATE (Estimation of STromal and Immune cells in MAlignant Tumors using Expression data) algorithm and TIMER (Tumor Immune Estimation Resource) database were used to analyze the correlation between the selected genes and the tumor microenvironment. Real-time reverse transcription polymerase chain reaction was used to measure the selected gene. Transwell and wound healing assays were used to measure the cell migration and invasion capacity. Western blotting was used to test the expression of epithelial-mesenchymal transition (EMT) related markers. Results We identified specific module genes that were positively correlated with the WHO grade but negatively correlated with OS of glioma. Importantly, we identified that 6 collagen genes (COL1A1, COL1A2, COL3A1, COL4A1, COL4A2, and COL5A2) could regulate the immunosuppressive microenvironment of glioma. Moreover, we found that these collagen genes were significantly involved in the EMT process of glioma. Finally, taking COL3A1 as a further research object, the results showed that knockdown of COL3A1 significantly inhibited the migration, invasion, and EMT process of SHG44 and A172 cells. Conclusions In summary, our study demonstrated that collagen genes play an important role in regulating the immunosuppressive microenvironment and EMT process of glioma and could serve as potential therapeutic targets for glioma management.


2018 ◽  
Vol 19 (12) ◽  
pp. 3968 ◽  
Author(s):  
Enrico Spugnini ◽  
Mariantonia Logozzi ◽  
Rossella Di Raimo ◽  
Davide Mizzoni ◽  
Stefano Fais

Metastatic diffusion is thought to be a multi-step phenomenon involving the release of cells from the primary tumor and their diffusion through the body. Currently, several hypotheses have been put forward in order to explain the origin of cancer metastasis, including epithelial–mesenchymal transition, mutagenesis of stem cells, and a facilitating role of macrophages, involving, for example, transformation or fusion hybridization with neoplastic cells. In this paradigm, tumor-secreted extracellular vesicles (EVs), such as exosomes, play a pivotal role in cell communications, delivering a plethora of biomolecules including proteins, lipids, and nucleic acids. For their natural role in shuttling molecules, EVs have been newly considered a part of the metastatic cascade. They have a prominent role in preparing the so-called “tumor niches” in target organs. However, recent evidence has pointed out an even more interesting role of tumor EVs, consisting in their ability to induce malignant transformation in resident mesenchymal stem cells. All in all, in this review, we discuss the multiple involvements of EVs in the metastatic cascade, and how we can exploit and manipulate EVs in order to reduce the metastatic spread of malignant tumors.


Molecules ◽  
2021 ◽  
Vol 26 (19) ◽  
pp. 5792
Author(s):  
Tiantian Tan ◽  
Jie Li ◽  
Ruhua Luo ◽  
Rongrong Wang ◽  
Liyan Yin ◽  
...  

Malignant tumors are life-threatening, and chemotherapy is one of the common treatment methods. However, there are often many factors that contribute to the failure of chemotherapy. The multidrug resistance of cancer cells during chemotherapy has been reported, since tumor cells’ sensitivity decreases over time. To overcome these problems, extensive studies have been conducted to reverse drug resistance in tumor cells. Elemene, an extract of the natural drug Curcuma wenyujin, has been found to reverse drug resistance and sensitize cancer cells to chemotherapy. Mechanisms by which elemene reverses tumor resistance include inhibiting the efflux of ATP binding cassette subfamily B member 1(ABCB1) transporter, reducing the transmission of exosomes, inducing apoptosis and autophagy, regulating the expression of key genes and proteins in various signaling pathways, blocking the cell cycle, inhibiting stemness, epithelial–mesenchymal transition, and so on. In this paper, the mechanisms of elemene’s reversal of drug resistance are comprehensively reviewed.


2019 ◽  
Vol 17 (1) ◽  
Author(s):  
Min Deng ◽  
Xiaodong Cai ◽  
Ling Long ◽  
Linying Xie ◽  
Hongmei Ma ◽  
...  

Abstract Background Accumulating evidence indicates that CD36 initiates metastasis and correlates with an unfavorable prognosis in cancers. However, there are few reports regarding the roles of CD36 in initiation and metastasis of cervical cancer. Methods Using immunohistochemistry, we analyzed 133 cervical cancer samples for CD36 protein expression levels, and then investigated the correlation between changes in its expression and clinicopathologic parameters. The effect of CD36 expression on the epithelial–mesenchymal transition (EMT) in cervical cancer cells was evaluated by Western immunoblotting analysis. In vitro invasion and in vivo metastasis assays were also used to evaluate the role of CD36 in cervical cancer metastasis. Results In the present study, we confirmed that CD36 was highly expressed in cervical cancer samples relative to normal cervical tissues. Moreover, overexpression of CD36 promoted invasiveness and metastasis of cervical cancer cells in vitro and in vivo, while CD36 knockdown suppressed proliferation, migration, and invasiveness. We demonstrated that TGF-β treatment attenuated E-cadherin expression and enhanced the expression levels of CD36, vimentin, slug, snail, and twist in si-SiHa, si-HeLa, and C33a–CD36 cells, suggesting that TGF-β synergized with CD36 on EMT via active CD36 expression. We also observed that the expression levels of TGF-β in si-SiHa cells and si-HeLa cells were down-regulated, whereas the expression levels of TGF-β were up-regulated in C33a–CD36 cells. These results imply that CD36 and TGF-β interact with each other to promote the EMT in cervical cancer. Conclusions Our findings suggest that CD36 is likely to be an effective target for guiding individualized clinical therapy of cervical cancer.


2019 ◽  
Vol 11 (6) ◽  
pp. 251-263 ◽  
Author(s):  
Federico Bocci ◽  
Satyendra C Tripathi ◽  
Samuel A Vilchez Mercedes ◽  
Jason T George ◽  
Julian P Casabar ◽  
...  

Abstract The epithelial-mesenchymal transition (EMT) is a key process implicated in cancer metastasis and therapy resistance. Recent studies have emphasized that cells can undergo partial EMT to attain a hybrid epithelial/mesenchymal (E/M) phenotype – a cornerstone of tumour aggressiveness and poor prognosis. These cells can have enhanced tumour-initiation potential as compared to purely epithelial or mesenchymal ones and can integrate the properties of cell-cell adhesion and motility that facilitates collective cell migration leading to clusters of circulating tumour cells (CTCs) – the prevalent mode of metastasis. Thus, identifying the molecular players that can enable cells to maintain a hybrid E/M phenotype is crucial to curb the metastatic load. Using an integrated computational-experimental approach, we show that the transcription factor NRF2 can prevent a complete EMT and instead stabilize a hybrid E/M phenotype. Knockdown of NRF2 in hybrid E/M non-small cell lung cancer cells H1975 and bladder cancer cells RT4 destabilized a hybrid E/M phenotype and compromised the ability to collectively migrate to close a wound in vitro. Notably, while NRF2 knockout simultaneously downregulated E-cadherin and ZEB-1, overexpression of NRF2 enriched for a hybrid E/M phenotype by simultaneously upregulating both E-cadherin and ZEB-1 in individual RT4 cells. Further, we predict that NRF2 is maximally expressed in hybrid E/M phenotype(s) and demonstrate that this biphasic dynamic arises from the interconnections among NRF2 and the EMT regulatory circuit. Finally, clinical records from multiple datasets suggest a correlation between a hybrid E/M phenotype, high levels of NRF2 and its targets and poor survival, further strengthening the emerging notion that hybrid E/M phenotype(s) may occupy the ‘metastatic sweet spot’.


2019 ◽  
Vol 51 (8) ◽  
pp. 791-798 ◽  
Author(s):  
Lu Min ◽  
Chuanyang Liu ◽  
Jingyu Kuang ◽  
Xiaomin Wu ◽  
Lingyun Zhu

Abstract MicroRNAs (miRNAs) are a class of endogenous noncoding genes that regulate gene expression at the posttranscriptional level. In recent decades, miRNAs have been reported to play important roles in tumor growth and metastasis, while some reported functions of a specific miRNA in tumorigenesis are contradictory. In this study, we reevaluated the role of miR-214, which has been reported to serve as an oncogene or anti-oncogene in breast cancer metastasis. We found that miR-214 inhibited breast cancer via targeting RNF8, a newly identified regulator that could promote epithelial–mesenchymal transition (EMT). Specifically, the survival rate of breast cancer patients was positively correlated with miR-214 levels and negatively correlated with RNF8 expression. The overexpression of miR-214 inhibited cell proliferation and invasion of breast cancer, while suppression of miR-214 by chemically modified antagomir enhanced the proliferation and invasion of breast cancer cells. Furthermore, miR-214 could modulate the EMT process via downregulating RNF8. To our knowledge, this is the first report that reveals the role of the miR-214–RNF8 axis in EMT, and our results demonstrate a novel mechanism for miR-214 acting as a tumor suppressor through the regulation of EMT.


Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 1421-1421
Author(s):  
Min Soon Cho ◽  
Qianghua Hu ◽  
Rajesha Rupaimoole ◽  
Anil Sood ◽  
Vahid Afshar-Kharghan

Abstract We have shown that complement component 3 (C3) is expressed in malignant ovarian epithelial cells and enhances cell proliferation in vitro and tumor growth in vivo. C3 is secreted by cancer cells into the tumor microenvironment and promotes tumor growth through an autocrine loop. To understand the mechanism of upregulation of C3 expression in malignant epithelial cells, we studied the transcriptional regulation of C3, and found that TWIST1, a major regulator of EMT, binds to the C3 promoter and regulates C3 transcription. Knockdown of the TWIST1 gene reduced C3 mRNA, and TWIST1 overexpression increased C3 mRNA. TWIST1 promotes epithelial-mesenchymal transition (EMT) during normal development and in metastasis of malignant tumors. An important marker of EMT is a reduction in the surface expression of E-cadherin on cells facilitating migration and invasion of these cells. TWIST1 is a transcriptional repressor of E-cadherin; and because TWIST1 increases C3 expression, we investigated whether C3 is also a negative regulator of E-cadherin expression. We overexpressed C3 in ovarian cancer cells by stable transduction of lentivirus carrying C3 cDNA. Overexpression of C3 was associated with 32% reduction in the expression of E-cadherin resulting in enhanced migration ability of cells by 2.3 folds and invasiveness by 1.75 folds, as compared to control cells transduced with control lentivirus. To investigate whether TWIST1-induced reduction in E-cadherin is C3-mediated or not, we studied the effect of TWIST1 overexpression simultaneous with C3 knockdown in ovarian cancer cells. Overexpression of TWIST1 alone resulted in 70% reduction in E-cadherin mRNA and this was completely reversed after simultaneous C3 knockdown in these cells. To investigate the correlation between C3 and TWIST1 in vivo, we studied the co-expression of these two proteins in mouse embryos (physiologic EMT) and in malignant tumors (pathologic EMT). Given the role of EMT in embryogenesis we immunostained mouse embryos at different stages of development, using antibodies against TWIST1 or C3. Transverse section of 9.5-day post-coitum (9.5dpc) mouse embryos showed co-expression of TWIST1 and C3 in otocyst (ot) and hindbrain (hb) of neural crest. In the whole-mounted 11.5dpc mouse embryos, C3 and TWIST1 were co-expressed in limb buds. Given the role of EMT in malignancy, tumors induced in mice after intraperitoneal injection of murine ovarian cancer cells were resected and immunostained for C3 and TWIST1 proteins. TWIST1 and C3 co-localized at tumor edges, where EMT and tumor cells migration occur. Taken together, these data provide evidence that TWIST1 regulates C3 expression, and C3 promotes EMT through E-cadherin. Disclosures No relevant conflicts of interest to declare.


2016 ◽  
Vol 1 (1) ◽  
pp. 48
Author(s):  
Khemraj Singh Baghel ◽  
Smrati Bhadauria

Metastatic breast cancer is a stage of breast cancer wherever the disease has spread to distant parts of the body. Onset of metastasis is one of the biggest obstacles to the successful treatment of cancer. The potential of a tumor cell to metastasize profoundly depends on its microenvironment, or “niche” interactions with local components. Macrophages provide tropic support to tumors. Resident macrophages contribute a set of common functions, including their capability to defend against microbial infections, to maintain normal cell turnover and tissue remodelling, and to help repair sites of injury. Macrophages are recruited into the tumor microenvironment where they differentiate to become Tumor-associated-macrophages (TAMs). TAMs are the most abundant subpopulation of tumor-stroma and actively drive cancer cell invasion and metastasis. Cancer metastasis is not solely regulated by the deregulation of metastasis promoting or suppressing genes in cancer cells. Recently the interaction between the stromal cells and cancer cells has been demonstrated to promote cancer metastasis. TAMs can advocate epithelial-mesenchymal transition of cancer cells. Loss of e-cadherin, a major phenomenon of epithelial to mesenchymal transition (EMT), reduces adhesiveness and releases cancer cells to distant (secondary) sites. A positive correlation between tumor progression and the expression of matrix metallo proteinases (MMPs) in tumor tissues has been demonstrated in numerous human and animal studies. The dynamic interactions of cancer-cells with TAMs actively promote invasion-metastasis cascade through intercellular-signalling-networks that need better elucidation.


Sign in / Sign up

Export Citation Format

Share Document