| 1. |
- Al-Haidari, Amr A., et al.
(författare)
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MiR-155-5p positively regulates CCL17-induced colon cancer cell migration by targeting RhoA
- 2017
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Ingår i: Oncotarget. - : Impact Journals, LLC. - 1949-2553. ; 8:9, s. 14887-14896
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Tidskriftsartikel (refereegranskat)abstract
- Colorectal cancer is the second most common cause of cancer-related death, which is due to migration of tumor cells to distant sites of metastasis. Accumulating data indicate that mciroRNAs play an important role in several aspects of colon cancer cell biology. Herein, we examined the role of miR-155-5p in colon cancer cell migration induced by the CCL17-CCR4 axis in HT-29 colon cancer cells. We found that miR-155-5p knockdown in serum starved colon cancer cells decreased CCL17-induced cell chemotaxis. Moreover, knocking down miR-155-5p markedly decreased CCL17-provoked activation of RhoA in colon cancer cells. Bioinformatics analysis predicted two putative binding sites in the AU-rich element at the 3'-UTR of RhoA mRNA. MiR-155-5p binding to RhoA mRNA was verified using a target site blocker and functionally validated by RNA immunoprecipitation assays, showing that miR-155-5p-dependent regulation of RhoA mRNA is mediated by AU-rich elements present in the 3'-UTR region. Taken together, these results show that miR-155-5p positively regulates RhoA mRNA levels and translation as well as cell migration in serum starved colon cancer cells and indicate that targeting miR-155-5p might be a useful strategy to antagonize colon cancer metastasis.
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| 2. |
- Al-Haidari, Amr, et al.
(författare)
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MiR-155-5p controls colon cancer cell migration via post-transcriptional regulation of Human Antigen R (HuR)
- 2018
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Ingår i: Cancer Letters. - : Elsevier BV. - 0304-3835. ; 421, s. 145-151
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Tidskriftsartikel (refereegranskat)abstract
- Colorectal cancer (CRC) is the third most common cancer and a significant cause of cancer-related deaths worldwide. Metastasis is the worst prognostic factor for patients with CRC. HuR (ELAVL1) is overexpressed in CRC and has been reported to promote colon cancer growth by targeting RNA in the cell cytoplasm. Herein, the role of miR-155-5p in regulating HuR expression and cell migration was examined in colon cancer cells. MiR-155-5p knockdown in serum-starved colon cancer cells decreased both colon cancer cell chemotaxis and cytoplasmic expression of HuR. Bioinformatics analysis predicted two putative binding sites in the AU-rich elements (AREs) at the 3′-UTR of HuR mRNA. MiR-155-5p binding to HuR was verified using specific target site blockers and functionally validated by use of RNA immunoprecipitation assays, showing that miR-155-5p-dependent regulation of HuR expression is mediated by AREs. Targeting AREs with a specific blocker inhibited colon cancer cell migration. Taken together, these novel findings demonstrate that AREs mediate miR-155-5p positive regulation of HuR mRNA levels and translation as well as migration in colon cancer cells, suggesting that targeting miR-155-5p and/or Hur might be useful therapeutic strategies against colon cancer metastasis.
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| 3. |
- Al-Haidari, Amr, et al.
(författare)
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Neutrophil extracellular traps promote surgery-induced peritoneal carcinosis of metastatic colorectal cancer via modulation of CXCR2 and αv integrin
- 2017. - Suppl 3
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Ingår i: Annals of Oncology. - : Elsevier BV. - 0923-7534. ; 28, s. 87-88
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Konferensbidrag (refereegranskat)abstract
- Introduction: Peritoneal carcinosis (PC) is the third common site of metastatic colorectal cancer which characterized by a very low survival rate. Surgical trauma has been identified as an important factor in the progression of PC, postulated to be caused by the inflammatory response to tissue injury. The mechanism behind tumor metastasis remains poorly understood. However, existing evidence indicates that neutrophils, via Neutrophil Extracellular Traps (NETs), are implicated in the development of metastatic disease and recently identified as one of the most significant key players in promoting tumor progression. In this study, we highlight the mechanism by which NETs promote surgery-induced colon cancer cell peritoneal metastasis through regulation of key receptors, CXCR2 and αvβ3 integrin.Methods: We developed a murine model of surgical stress-induced PC by post-surgery inoculation of CT-26 murine colon cancer cell line. Surface expression of CXCR2 and αvβ3 on CT-26 cells were evaluated by flow cytometry live staining. Gene expression of extracellular matrix (ECM) proteins from wound incision wall was quantified using qRT-PCR. Function of CXCR2 and αvβ3 in tumor cell migration, proliferation, and adhesion were assessed by blocking assays using CXCR2 antagonist SB225002 and anti-CD51 in vitro and in vivo. Role of neutrophils in promoting cancer cell migration and adhesion was demonstrated using in vitro co-cultured migration and adhesion assays. NET formation was measured using modified ELISA technique of Histone-DNA complex. Depletion of NETs were achieved by daily intraperitoneal administration of 2mg/kg DNase I to mice for 10 days and tumor growth was evaluated by counting macroscopic nodules number on the peritoneum.Results: Blocking CXCR2 and Targeting αv integrin reduced tumor nodules number in vivo by 70% and 65% respectively and decreased cancer cell migration, proliferation, and adhesion in vitro. Incision wound tissue displayed pronounced reduction in ECM proteins mRNAs in treated mice with both CXCR2 antagonist and αv antibody. Mice treatment with DNase I significantly reduced tumor nodules number more than 90% compared to tumor control. Anti-CD51 decreased NET-induced CT-26 cell adhesion. Neutrophils stimulation with MIP-2 exhibits dose-dependent increase of NETosis. Co-culture of neutrophils and cancer cells provoked NETs formation and increased capacity of colon cancer cell migration while DNase I treatment abolished neutrophils NETs-induced tumor cell migration in vitroConclusion: Our novel findings implicate NETs in the development of PC due to surgical stress, suggesting that blocking NET formation might be an interesting potential therapeutic approach.
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| 4. |
- Hawez, Avin, et al.
(författare)
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MiR-155 Regulates PAD4-Dependent Formation of Neutrophil Extracellular Traps
- 2019
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Ingår i: Frontiers in Immunology. - : Frontiers Media SA. - 1664-3224. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Accumulating data suggest that neutrophil extracellular traps (NETs) exert a key function in several diseases. Peptidylarginine deiminase 4 (PAD4) regulates NET formation via citrullination of histones. The aim of this study was to examine the role of miR-155 in controlling PAD4-dependent generation of NETs. Bone marrow neutrophils were stimulated with PMA and MIP-2. Pre-incubation of neutrophils with translational inhibitors (cycloheximide or puromycin) markedly decreased NET formation induced by PMA or MIP-2. Neutrophil transfection with a mimic miR-155 increased PMA-induced PAD4 mRNA expression and NET formation. In contrast, transfection with an antagomiR-155 decreased induction of PAD4 mRNA and NETs in response to PMA challenge. Bioinformatical examination of PAD4 revealed a potential binding site in AU-rich elements at the 3′-UTR region. MiR-155 binding to PAD4 was examined by use of target site blockers and RNA immunoprecipitation, revealing that miR-155 regulation of PAD4 mRNA is mediated via AU-rich elements in the 3′-UTR region. In conclusion, our findings demonstrate that miR-155 positively regulates neutrophil expression of PAD4 and expulsion of extracellular traps. Thus, our novel results indicate that targeting miR-155 might be useful to inhibit exaggerated NET generation in inflammatory diseases.
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