scholarly journals CSN8 is a key regulator in hypoxia-induced epithelial–mesenchymal transition and dormancy of colorectal cancer cells

2020 ◽  
Vol 19 (1) ◽  
Author(s):  
Songwen Ju ◽  
Feng Wang ◽  
Yirong Wang ◽  
Songguang Ju

AbstractHypoxic stress plays a pivotal role in cancer progression; however, how hypoxia drives tumors to become more aggressive or metastatic and adaptive to adverse environmental stress is still poorly understood. In this study, we revealed that CSN8 might be a key regulatory switch controlling hypoxia-induced malignant tumor progression. We demonstrated that the expression of CSN8 increased significantly in colorectal cancerous tissues, which was correlated with lymph node metastasis and predicted poor patient survival. CSN8 overexpression induces the epithelial-mesenchymal transition (EMT) process in colorectal cancer cells, increasing migration and invasion. CSN8 overexpression arrested cell proliferation, upregulated key dormancy marker (NR2F1, DEC2, p27) and hypoxia response genes (HIF-1α, GLUT1), and dramatically enhanced survival under hypoxia, serum deprivation, or chemo-drug 5-fluorouracil treatment conditions. In particular, silenced CSN8 blocks the EMT and dormancy processes induced by the hypoxia of 1% O2 in vitro and undermines the adaptive capacity of colorectal cancer cells in vivo. The further study showed that CSN8 regulated EMT and dormancy partly by activating the HIF-1α signaling pathway, which increased HIF-1α mRNA expression by activating NF-κB and stabilized the HIF-1α protein via HIF-1α de-ubiquitination. Taken together, CSN8 endows primary colorectal cancer cells with highly aggressive/metastatic and adaptive capacities through regulating both EMT and dormancy induced by hypoxia. CSN8 could serve as a novel prognostic biomarker for colorectal cancer and would be an ideal target of disseminated dormant cell elimination and tumor metastasis, recurrence, and chemoresistance prevention.

Cancers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 172
Author(s):  
Izabela Papiewska-Pająk ◽  
Patrycja Przygodzka ◽  
Damian Krzyżanowski ◽  
Kamila Soboska ◽  
Izabela Szulc-Kiełbik ◽  
...  

During metastasis, cancer cells undergo phenotype changes in the epithelial-mesenchymal transition (EMT) process. Extracellular vesicles (EVs) released by cancer cells are the mediators of intercellular communication and play a role in metastatic process. Knowledge of factors that influence the modifications of the pre-metastatic niche for the migrating carcinoma cells is important for prevention of metastasis. We focus here on how cancer progression is affected by EVs released from either epithelial-like HT29-cells or from cells that are in early EMT stage triggered by Snail transcription factor (HT29-Snail). We found that EVs released from HT29-Snail, as compared to HT29-pcDNA cells, have a different microRNA profile. We observed the presence of interstitial pneumonias in the lungs of mice injected with HT29-Snail cells and the percent of mice with lung inflammation was higher after injection of HT29-Snail-EVs. Incorporation of EVs released from HT29-pcDNA, but not released from HT29-Snail, leads to the increased secretion of IL-8 from macrophages. We conclude that Snail modifications of CRC cells towards more invasive phenotype also alter the microRNA cargo of released EVs. The content of cell-released EVs may serve as a biomarker that denotes the stage of CRC and EVs-specific microRNAs may be a target to prevent cancer progression.


Cancers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 735 ◽  
Author(s):  
Kwang Seock Kim ◽  
Dongjun Jeong ◽  
Ita Novita Sari ◽  
Yoseph Toni Wijaya ◽  
Nayoung Jun ◽  
...  

Our current understanding of the role of microRNA 551b (miR551b) in the progression of colorectal cancer (CRC) remains limited. Here, studies using both ectopic expression of miR551b and miR551b mimics revealed that miR551b exerts a tumor suppressive effect in CRC cells. Specifically, miR551b was significantly downregulated in both patient-derived CRC tissues and CRC cell lines compared to normal tissues and non-cancer cell lines. Also, miR551b significantly inhibited the motility of CRC cells in vitro, including migration, invasion, and wound healing rates, but did not affect cell proliferation. Mechanistically, miR551b targets and inhibits the expression of ZEB1 (Zinc finger E-box-binding homeobox 1), resulting in the dysregulation of EMT (epithelial-mesenchymal transition) signatures. More importantly, miR551b overexpression was found to reduce the tumor size in a xenograft model of CRC cells in vivo. Furthermore, bioinformatic analyses showed that miR551b expression levels were markedly downregulated in the advanced-stage CRC tissues compared to normal tissues, and ZEB1 was associated with the disease progression in CRC patients. Our findings indicated that miR551b could serve as a potential diagnostic biomarker and could be utilized to improve the therapeutic outcomes of CRC patients.


2020 ◽  
Author(s):  
Sisi Wei ◽  
Shiping Sun ◽  
Xinliang Zhou ◽  
Cong Zhang ◽  
Xiaoya Li ◽  
...  

Abstract A substantial fraction of transcripts are known as long noncoding RNAs (lncRNAs), and these transcripts play pivotal roles in the development of cancer. However, little information has been published regarding the functions of lncRNAs in oesophageal squamous cell carcinoma (ESCC) and the underlying mechanisms. In our previous studies, we demonstrated that small nucleolar RNA host gene 5 (SNHG5), a known lncRNA, is dysregulated in gastric cancer (GC). In this study, we explored the expression and function of SNHG5 in development of ESCC. SNHG5 was found to be downregulated in human ESCC tissues and cell lines, and this downregulation was associated with cancer progression, clinical outcomes and survival rates of ESCC patients. Furthermore, we also found that overexpression of SNHG5 significantly inhibited the proliferation, migration and invasion of ESCC cells in vivo and in vitro. Notably, we found that metastasis-associated protein 2 (MTA2) was pulled down by SNHG5 in ESCC cells using RNA pulldown assay. We also found that SNHG5 reversed the epithelial–mesenchymal transition by interacting with MTA2. In addition, overexpression of SNHG5 downregulated the transcription of MTA2 and caused its ubiquitin-mediated degradation. Thus, overexpression of MTA2 partially abrogated the effect of SNHG5 in ESCC cell lines. Furthermore, we found that MTA2 mRNA expression was significantly elevated in ESCC specimens, and a negative correlation between SNHG5 and MTA2 expression was detected. Overall, this study demonstrated, for the first time, that SNHG5-regulated MTA2 functions as an important player in the progression of ESCC and provide a new potential therapeutic strategy for ESCC.


2019 ◽  
Vol 37 (15_suppl) ◽  
pp. e15107-e15107
Author(s):  
Wan He ◽  
Han Wu ◽  
Dongcheng Liu ◽  
Wenwen Li ◽  
Ruilian Xu ◽  
...  

e15107 Background: Our previous studies revealed the increased expression of Jagged 2 (JAG2) in most intestinal cancer tissues. In colon cancer cell lines, JAG2 involved in the regulation of migration and invasion without affecting cell proliferation. This study further explored the mechanisms of how JAG2 promotes migration and invasion of colorectal cancer cells. Methods: We analyzed the expression of JAG2 mRNA and protein in normal human colon tissue cells and colorectal cancer cells. The promotive role of JAG2 in migration and invasion was tested by JAG2 siRNA and JAG2 overexpression in various colon cancer cell lines. To understand the mechanisms, we first treated HT29 cells with LY2157299, a TGF-β signaling pathway inhibitor, and Slug siRNA, to identify the cross-talk between JAG2 and EMT pathway. In addition, co-expression status of JAG2 and TGF-β-induced epithelial-mesenchymal transition (EMT) markers was analyzed. Finally, by using siRNA and proteomics technology, co-expressed proteins of JAG2 in colorectal cancer cells were identified. Results: JAG2 was abnormally expressed in colorectal cancer tissues and directly related with clinical stages. Similar to the findings in human tissues, the expression of both JAG2 mRNA and protein was significantly increased in the colorectal cancer cell lines compared with that of normal colorectal cell line CCD18-Co. Interestingly, the promotion of JAG2 in migration and invasion was independent of EMT pathway. Furthermore, we found that the expression of JAG2 was correlated with PRAF2 (PRA1 Domain Family Member 2), a protein involved in the formation of exosome-like vesicles. In the presence of PRAF2, JAG2-rich exosome promoted migration and invasion. JAG2 might regulate the migration and invasion of colon cell through PRAF2. Conclusions: This is the evidence supporting the biological function of JAG2 in migration and invasion through non-EMT-dependent pathways and also the first exploration of the role of PRAF2 in colorectal cancer cells. These findings provide the theoretical basis for potential targeted therapy against JAG2/PRAF2.


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