Expression and role of nuclear receptor coregulators in colorectal cancer

Nuclear receptor coregulators are proteins that modulate the transcriptional activity of steroid receptors and may explain cell-specific effects of glucocorticoid receptor action. Based on the uneven distribution of a number of coregulators in CRH-expressing cells in the hypothalamus of the rat brain, we tested the hypothesis that these proteins are involved as mediators in the glucocorticoid-induced repression of the CRH promoter. Therefore, we assessed the role of coregulator proteins on both induction and repression of CRH in the AtT-20 cell line, a model system for CRH repression by glucocorticoids. The steroid receptor coactivator 1a (SRC1a), SRC-1e, nuclear corepressor (N-CoR), and silencing mediator of the retinoid and thyroid hormone receptor (SMRT) were studied in this system. We show that the concentration of glucocorticoid receptor and the type of ligand, i.e. corticosterone or dexamethasone, determines the repression. Furthermore, overexpression of SRC1a, but not SRC1e, increased both efficacy and potency of the glucocorticoid receptor-mediated repression of the forskolin-induced CRH promoter. Unexpectedly, cotransfection of the corepressors N-CoR and SMRT did not affect the corticosterone-dependent repression but resulted in a marked decrease of the forskolin stimulation of the CRH gene. Altogether, our data demonstrate that 1) the concentration of the receptor, 2) the type of ligand, and 3) the coregulator recruited all determine the expression and the repression of the CRH gene. We conclude that modulation of coregulator activity may play a role in the control of the hypothalamus-pituitary-adrenal axis.

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Nuclear Receptor Interacting Protein-2 Mediates the Stabilization and Activation of β-Catenin During Podocyte Injury

Frontiers in Cell and Developmental Biology ◽

10.3389/fcell.2021.781792 ◽

2021 ◽

Vol 9 ◽

Author(s):

Qing Hou ◽

Weibo Le ◽

Shuyan Kan ◽

Jinsong Shi ◽

Yue Lang ◽

...

Keyword(s):

Colorectal Cancer ◽

Nuclear Receptor ◽

Protein Interactions ◽

Wnt Pathway ◽

Expression Data ◽

Podocyte Injury ◽

Interacting Protein ◽

Chemical Treatments ◽

Geo Dataset

Objective: Activation of β-catenin causes podocyte injury and proteinuria, but how β-catenin signalling is regulated during podocyte injury remains elusive. Nuclear receptor interacting protein 2 (NRIP2) modulates the Wnt pathway in colorectal cancer-initiating cells, but the role of NRIP2 in podocyte injury has not yet been investigated. We aimed to examine the interaction between NRIP2 and β-catenin signalling.Materials and Methods: Knockdown or overexpression of NRIP2 and β-catenin and chemical treatments were performed in cultured human podocytes. Immunoprecipitation, immunoblotting and immunofluorescence assays were used to assess protein interactions and expression. Data from the GEO dataset and kidney tissues from patients with focal segmental glomerulosclerosis (FSGS) and surgical nephrectomy were examined. An adriamycin (ADR) nephropathy model was established in NRIP2 knockout mice.Results: NRIP2 knockdown accelerated β-catenin degradation, which was reversed by MG132; specifically, NRIP2 bound β-catenin and stabilized it to prevent its degradation through the ubiquitin proteasomal pathway. Overexpression of NRIP2 led to β-catenin activation and Snail1 induction, and these effects were attenuated by β-catenin knockdown. NRIP2 knockdown blocked ADR-stimulated β-catenin activation. In ADR mice, genetic knockout of Nrip2 ameliorated podocyte injury and loss, glomerulosclerosis, and proteinuria by inhibiting β-catenin activation. Moreover, NRIP2 was significantly upregulated in podocytes of FSGS patients and colocalized with nuclear β-catenin.Conclusion: These results established NRIP2 as a stabilizer of β-catenin activation through the ubiquitin proteasomal pathway in podocyte injury.

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The Contemporary Role of Resection and Ablation in Colorectal Cancer Liver Metastases

Digestive Disease Interventions ◽

10.1055/s-0040-1715816 ◽

2020 ◽

Vol 04 (03) ◽

pp. 291-302

Author(s):

Mariam F. Eskander ◽

Christopher T. Aquina ◽

Aslam Ejaz ◽

Timothy M. Pawlik

Keyword(s):

Colorectal Cancer ◽

Portal Vein ◽

Surgical Oncology ◽

Portal Vein Ligation ◽

Safe Alternative ◽

Colorectal Cancer Liver Metastases ◽

Liver Remnant ◽

New Era ◽

Ablation Therapy

AbstractAdvances in the field of surgical oncology have turned metastatic colorectal cancer of the liver from a lethal disease to a chronic disease and have ushered in a new era of multimodal therapy for this challenging illness. A better understanding of tumor behavior and more effective systemic therapy have led to the increased use of neoadjuvant therapy. Surgical resection remains the gold standard for treatment but without the size, distribution, and margin restrictions of the past. Lesions are considered resectable if they can safely be removed with tumor-free margins and a sufficient liver remnant. Minimally invasive liver resections are a safe alternative to open surgery and may offer some advantages. Techniques such as portal vein embolization, association of liver partition with portal vein ligation for staged hepatectomy, and radioembolization can be used to grow the liver remnant and allow for resection. If resection is not possible, nonresectional ablation therapy, including radiofrequency and microwave ablation, can be performed alone or in conjunction with resection. This article presents the most up-to-date literature on resection and ablation, with a discussion of current controversies and future directions.

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