Wnt/β-catenin signaling and p68 conjointly regulate CHIP in colorectal cancer

The differential expression pattern of Carboxy terminus of Hsc70 Interacting Protein (CHIP, alias STIP1 Homology and U box Containing Protein 1 or STUB1) in cancers is associated with ubiquitination mediated degradation of its client proteins. Emerging evidences suggest its abundant expression of CHIP in colorectal cancer compared to normal tissues, but the mechanistic detail of this augmented expression pattern is unclear. The signature driver of canonical Wnt pathway, β catenin, and its co-activator RNA helicase p68, are also overexpressed in colorectal cancer. In this study, we describe a novel mechanism of Wnt/ β catenin and p68 mediated transcriptional activation of CHIP gene leading to enhanced proliferation of colorectal cancer cells. Wnt3A treatment and pharmacological activation of canonical Wnt signaling pathway resulted in increased nuclear translocation of β catenin and elevated expression of CHIP. Likewise, overexpression and knockdown of β catenin and p68 upregulated and downregulated CHIP expression, respectively, at both mRNA and protein levels. After cloning CHIP promoter, the increased and decreased promoter activities of CHIP induced by overexpression and knockdown of either β catenin or p68 further confirmed transcriptional regulation of CHIP gene by Wnt/ β catenin signaling cascade. p68 along with β catenin were found to occupy Transcription Factor 4 (TCF4) binding sites on endogenous CHIP promoter and regulate its transcription. Finally, enhanced cellular propagation and migration of colorectal cancer cells induced by Wnt/ β catenin p68 CHIP axis established the significance of this pathway in oncogenesis. To the best of our knowledge, this is the first report elucidating the mechanistic details of transcriptional regulation of CHIP (STUB1) gene expression.

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An autoregulatory feedback loop of miR-21/VMP1 is responsible for the abnormal expression of miR-21 in colorectal cancer cells

Cell Death and Disease ◽

10.1038/s41419-020-03265-4 ◽

2020 ◽

Vol 11 (12) ◽

Author(s):

Caixia Wang ◽

Rui Peng ◽

Min Zeng ◽

Zhenhua Zhang ◽

Shengpeng Liu ◽

...

Keyword(s):

Colorectal Cancer ◽

Cancer Cells ◽

Transcriptional Activation ◽

Feedback Loop ◽

Nuclear Translocation ◽

New Approach ◽

Akt Phosphorylation ◽

Colorectal Cancer Cells ◽

Transcription Factor Eb ◽

Regulatory Loop

AbstractMircoRNA-21 (miR-21) was found to be highly expressed in various solid tumors, and its oncogenic properties have been extensively studied in recent years. However, the reason why miR-21 is highly expressed in various tumors remains elusive. Here, we found that the expression of miR-21 was negatively correlated with the expression of vacuole membrane protein-1 (VMP1) in colorectal cancer. Transcription of VMP1 activated either by small activating RNA (saRNA) or transcriptional activator GLI3 inhibited miR-21 expression through reducing its transcripts of VMP1-miR-21 and pri-miR-21, while no significant change in miR-21 expression after exogenous overexpression VMP1 in colorectal cancer cell HCT116. Considering the overlapping location of VMP1 and miR-21 gene in genome, the result suggested that the transcription of miR-21 was inhibited by the endogenous transcriptional activation of VMP1. Furthermore, we identified that miR-21 inhibited the activation and nuclear translocation of transcription factor EB (TFEB) through reducing the inhibitory of PTEN on AKT phosphorylation, which can directly activate the transcription of VMP1. Loss of miR-21 significantly increased VMP1 expression, which could be blocked by PTEN inhibitor (VO-Ohpic) or TFEB siRNA. These results showed that miR-21 negatively regulated VMP1 transcription through the PTEN/AKT/TFEB pathway, and TFEB-induced transcriptional activation of VMP1 could inhibit miR-21 expression, thus forming a feedback regulatory loop of miR-21/VMP1. We further found that disrupting the miR-21/VMP1 feedback loop will decrease the expression of miR-21, reduce the malignancy, and increase their sensitivity to 5-fluorouracil in colorectal cancer cells. Taken together, our results revealed a novel regulatory mechanism of miR-21 expression, and targeting the miR-21/VMP1 feedback loop may provide a new approach to inhibit miR-21 expression in colorectal cancer cells.

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Acetylshikonin Induces Apoptosis in Human Colorectal Cancer HCT-15 and LoVo Cells via Nuclear Translocation of FOXO3 and ROS Level Elevation

Oxidative Medicine and Cellular Longevity ◽

10.1155/2021/6647107 ◽

2021 ◽

Vol 2021 ◽

pp. 1-19

Author(s):

Heui Min Lim ◽

Jongsung Lee ◽

Myeong Jin Nam ◽

See-Hyoung Park

Keyword(s):

Colorectal Cancer ◽

Cancer Cells ◽

Nuclear Translocation ◽

Ros Generation ◽

Dependent Manner ◽

Oxygen Species ◽

Human Colorectal Cancer ◽

Antiproliferative Effects ◽

Lovo Cells ◽

Colorectal Cancer Cells

Acetylshikonin, a naphthoquinone, is a pigment compound derived from Arnebia sp., which is known for its anti-inflammatory potential. However, its anticarcinogenic effect has not been well investigated. Thus, in this study, we focused on investigating its apoptotic effects against HCT-15 and LoVo cells, which are human colorectal cancer cells. MTT assay, cell counting assay, and colony formation assay have shown acetylshikonin treatment induced cytotoxic and antiproliferative effects against colorectal cancer cells in a dose- and time-dependent manner. DNA fragmentation was observed via terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. Also, the increase of subG1 phase in cell cycle arrest assay and early/late apoptotic rates in annexin V/propidium iodide (PI) double staining assay was observed, which indicates an apoptotic potential of acetylshikonin against colorectal cancer cells. 2 ′ ,7 ′ -Dichlorofluorescin diacetate (DCF-DA) staining was used to evaluate reactive oxygen species (ROS) generation in acetylshikonin-treated colorectal cancer cells. Fluorescence-activated cell sorting (FACS) analysis showed that acetylshikonin induced an increase in reactive oxygen species (ROS) levels and apoptotic rate in a dose- and time-dependent manner in HCT-15 and LoVo cells. In contrast, cotreatment with N-acetyl cysteine (NAC) has reduced ROS generation and antiproliferative effects in colorectal cancer cells. Western blotting analysis showed that acetylshikonin treatment induced increase of cleaved PARP, γH2AX, FOXO3, Bax, Bim, Bad, p21, p27, and active forms of caspase-3, caspase-7, caspase-9, caspase-6, and caspase-8 protein levels, while those of inactive forms were decreased. Also, the expressions of pAkt, Bcl-2, Bcl-xL, peroxiredoxin, and thioredoxin 1 were decreased. Furthermore, western blotting analysis of cytoplasmic and nuclear fractionated proteins showed that acetylshikonin treatment induced the nuclear translocation of FOXO3, which might result from DNA damage by the increased intracellular ROS level. This study represents apoptotic potential of acetylshikonin against colorectal cancer cells via translocation of FOXO3 to the nucleus and upregulation of ROS generation.

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SOX4 induces drug resistance of colorectal cancer cells by downregulating CYLD through transcriptional activation of microRNA‐17

Journal of Biochemical and Molecular Toxicology ◽

10.1002/jbt.22910 ◽

2021 ◽

Author(s):

Shuang Pan ◽

Dongyan Bao ◽

Yao Li ◽

Dahua Liu ◽

Shuai Quan ◽

...

Keyword(s):

Colorectal Cancer ◽

Drug Resistance ◽

Cancer Cells ◽

Transcriptional Activation ◽

Colorectal Cancer Cells

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Abstract 1588: Canonical Wnt signaling mediates resistance of colorectal cancer cells to radiation therapy.

10.1158/1538-7445.am2013-1588 ◽

2013 ◽

Author(s):

Georg Emons ◽

Janneke Möller ◽

Melanie Spitzner ◽

Emil Kendziorra ◽

Jochen Gaedcke ◽

...

Keyword(s):

Colorectal Cancer ◽

Radiation Therapy ◽

Wnt Signaling ◽

Cancer Cells ◽

Canonical Wnt Signaling ◽

Colorectal Cancer Cells ◽

Canonical Wnt

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Activation of Tumor-Specific Splice Variant Rac1b by Dishevelled Promotes Canonical Wnt Signaling and Decreased Adhesion of Colorectal Cancer Cells

Cancer Research ◽

10.1158/0008-5472.can-06-2843 ◽

2007 ◽

Vol 67 (6) ◽

pp. 2469-2479 ◽

Cited By ~ 45

Author(s):

Susmita Esufali ◽

George S. Charames ◽

Vaijayanti V. Pethe ◽

Pinella Buongiorno ◽

Bharati Bapat

Keyword(s):

Colorectal Cancer ◽

Wnt Signaling ◽

Cancer Cells ◽

Splice Variant ◽

Canonical Wnt Signaling ◽

Colorectal Cancer Cells ◽

Canonical Wnt

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Calebin A Potentiates the Effect of 5-FU and TNF-β (Lymphotoxin α) against Human Colorectal Cancer Cells: Potential Role of NF-κB

International Journal of Molecular Sciences ◽

10.3390/ijms21072393 ◽

2020 ◽

Vol 21 (7) ◽

pp. 2393 ◽

Cited By ~ 8

Author(s):

Constanze Buhrmann ◽

Ajaikumar Kunnumakkara ◽

Bastian Popper ◽

Muhammed Majeed ◽

Bharat Aggarwal ◽

...

Keyword(s):

Colorectal Cancer ◽

Cancer Cells ◽

Nuclear Translocation ◽

Chemotherapeutic Agents ◽

Colorectal Cancer Cells ◽

Tumor Environment ◽

Proliferation And Metastasis ◽

Dtt Dithiothreitol ◽

Apoptotic Effects ◽

Lymphotoxin Α

Objective: The majority of chemotherapeutic agents stimulate NF-κB signaling that mediates cell survival, proliferation and metastasis. The natural turmeric non-curcuminoid derivate Calebin A has been shown to suppress cell growth, invasion and colony formation in colorectal cancer cells (CRC) by suppression of NF-κB signaling. Therefore, we hypothesized here that Calebin A might chemosensitize the TNF-β-treated tumor cells and potentiates the effect of 5-Fluorouracil (5-FU) in advanced CRC. Materials and Methods: CRC cells (HCT116) and their clonogenic 5-FU chemoresistant counterparts (HCT116R) were cultured in monolayer or alginate-based 3D tumor environment culture and were treated with/without Calebin A, TNF-β, 5-FU, BMS-345541 and DTT (dithiothreitol). Results: The results showed that TNF-β increased proliferation, invasion and resistance to apoptosis in chemoresistant CRC cells. Pretreatment with Calebin A significantly chemosensitized HCT116R to 5-FU and inhibited the TNF-β-induced enhanced efforts for survival, invasion and anti-apoptotic effects. We found further that Calebin A significantly suppressed TNF-β-induced phosphorylation and nuclear translocation of p65-NF-κB, similar to BMS-345541 (specific IKK inhibitor) and NF-κB-induced tumor-promoting biomarkers (NF-κB, β1-Integrin, MMP-9, CXCR4, Ki67). This was associated with increased apoptosis in HCT116 and HCT116R cells. Furthermore, blocking of p65-NF-κB stimulation by Calebin A was imparted through the downmodulation of p65-NF-κB binding to the DNA and this suppression was turned by DTT. Conclusion: Our findings indicate, for the first time, that Calebin A chemosensitizes human CRC cells to chemotherapy by targeting of the p65-NF-κB signaling pathway.

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Ursolic Acid Induces Apoptosis in Colorectal Cancer Cells Partially via Upregulation of MicroRNA-4500 and Inhibition of JAK2/STAT3 Phosphorylation

International Journal of Molecular Sciences ◽

10.3390/ijms20010114 ◽

2018 ◽

Vol 20 (1) ◽

pp. 114 ◽

Cited By ~ 16

Author(s):

Karam Kim ◽

Eun Shin ◽

Ji Jung ◽

Ji Park ◽

Dong Kim ◽

...

Keyword(s):

Colorectal Cancer ◽

Cancer Cells ◽

Ursolic Acid ◽

Nuclear Translocation ◽

Janus Kinase ◽

Terminal Deoxynucleotidyl Transferase ◽

Parp Cleavage ◽

Stat3 Phosphorylation ◽

Anti Cancer ◽

Colorectal Cancer Cells

Though ursolic acid (UA) isolated from Oldenlandia diffusa was known to exhibit anti-cancer, anti-inflammatory, and anti-obesity effects, the underlying antitumor mechanism of ursolic acid was not fully understood to date. Thus, in the present study, the apoptotic mechanism of ursolic acid was elucidated in HCT116 and HT29 colorectal cancer cells in association with STAT3 and microRNA-4500 (miR-4500) by MTT assay, Terminal deoxynucleotidyl transferase-dT-mediated dUTP nick end labelling (TUNEL) assay, cell cycle analysis, immunofluorescence, and Western blotting. Ursolic acid significantly exerted cytotoxicity, increased TUNEL positive cells and sub-G1 apoptotic portion, induced cleavage of poly (adenosine diphosphate-ribose) polymerase (PARP) and caspase 3 in HCT116 and HT29 cells. Of note, ursolic acid attenuated the expression of anti-apoptotic proteins such as Janus kinase 2 (JAK2) and signal transducer and activator of transcription 3 (STAT3) and also blocked nuclear translocation of STAT3 in colorectal cancer cells. Notably, ursolic acid increased the expression level of miR-4500 in HCT116 cells by qRT-PCR analysis and conversely miR-4500 inhibitor reversed cytotoxic, anti-proliferative, and apoptotic effects by increasing TUNEL positive cells, PARP cleavage and inhibiting p-STAT3 in ursolic acid treated colorectal cancer cells. Overall, our findings provide evidence that usolic acid induces apoptosis in colorectal cancer cells partially via upregulation of miR-4500 and inhibition of STAT3 phosphorylation as a potent anti-cancer agent for colorectal cancer therapy.

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