Exosomes from metastatic colon cancer cells drive the proliferation and migration of primary colon cancer through increased expression of cancer stem cell markers CD133 and DCLK1.

The exchange of biological material between the neighbouring cells is essential for homeostasis. In pathological conditions, such as cancer, the major challenge in cancer treatment is the abnormal expression of crucial proteins and miRNA exchanged between the cancer cells through extracellular vesicles called exosomes. Clinically, it has been noticed that the primary tumour and the distal metastases are interconnected and co-dependent. The exosomes are key factors responsible for preparing the pre-metastatic niche and communicating between the tumour and the distal metastatic site. Cancer stem cells (CSCs) are a subpopulation of cancer cells with self-renewal characteristics and are shown to be responsible for metastasis. This study aims to understand the effect of metastatic cell line-derived exosomes and their regulation of CSC marker expressions on primary colon cancer cell lines. We have identified that treatment of primary colon cancer cell lines with metastatic colon cancer cell-derived exosomes has significantly increased the proliferation, colony formation, cell migration, and invasion. In addition, there was a significant increase in the number and size of spheroids following the exosomes treatment. We found that this metastatic phenotype is due to the increased expression of CD133 and DCLK1 in primary colon cancer cells.

MiR-155 modulates the inflammatory phenotype of intestinal myofibroblasts by targeting SOCS1 in ulcerative colitis

Abnormal levels of microRNA (miR)-155, which regulate inflammation and immune responses, have been demonstrated in the colonic mucosa of patients with inflammatory bowel diseases (IBD), although its role in disease pathophysiology is unknown. We investigated the role of miR-155 in the acquisition and maintenance of an activated phenotype by intestinal myofibroblasts (IMF), a key cell population contributing to mucosal damage in IBD. IMF were isolated from colonic biopsies of healthy controls, ulcerative colitis (UC) and Crohn's disease (CD) patients. MiR-155 in IMF was quantified by quantitative reverse transcription-PCR in basal condition and following exposure to TNF-alpha, interleukin (IL)-1beta, lipopolysaccharide (LPS) or TGF-beta1. The effects of miR-155 mimic or inhibitor transfection on cytokine release and suppressor of cytokine signaling 1 (SOCS1) expression were assessed by enzyme-linked immunosorbent assay and western blot, respectively. Regulation of the target gene SOCS1 expression by miR-155 was assessed using luciferase reporter construct. We found that miR-155 was significantly upregulated in UC as compared with control- and CD-derived IMF. Moreover, TNF-alpha and LPS, but not TGF-beta1 and IL-1beta, significantly increased miR-155 expression in IMF. Ectopic expression of miR-155 in control IMF augmented cytokines release, whereas it downregulated SOCS1 expression. MiR-155 knockdown in UC-IMF reduced cytokine production and enhanced SOCS1 expression. Luciferase reporter assay demonstrated that miR-155 directly targets SOCS1. Moreover, silencing of SOCS1 in control IMF significantly increased IL-6 and IL-8 release. In all, our data suggest that inflammatory mediators induce miR-155 expression in IMF of patients with UC. By downregulating the expression of SOCS1, miR-155 wires IMF inflammatory phenotype.

MiR-155 modulates the inflammatory phenotype of intestinal myofibroblasts by targeting SOCS1 in ulcerative colitis

Abnormal levels of microRNA (miR)-155, which regulate inflammation and immune responses, have been demonstrated in the colonic mucosa of patients with inflammatory bowel diseases (IBD), although its role in disease pathophysiology is unknown. We investigated the role of miR-155 in the acquisition and maintenance of an activated phenotype by intestinal myofibroblasts (IMF), a key cell population contributing to mucosal damage in IBD. IMF were isolated from colonic biopsies of healthy controls, ulcerative colitis (UC) and Crohn's disease (CD) patients. MiR-155 in IMF was quantified by quantitative reverse transcription-PCR in basal condition and following exposure to TNF-alpha, interleukin (IL)-1beta, lipopolysaccharide (LPS) or TGF-beta1. The effects of miR-155 mimic or inhibitor transfection on cytokine release and suppressor of cytokine signaling 1 (SOCS1) expression were assessed by enzyme-linked immunosorbent assay and western blot, respectively. Regulation of the target gene SOCS1 expression by miR-155 was assessed using luciferase reporter construct. We found that miR-155 was significantly upregulated in UC as compared with control- and CD-derived IMF. Moreover, TNF-alpha and LPS, but not TGF-beta1 and IL-1beta, significantly increased miR-155 expression in IMF. Ectopic expression of miR-155 in control IMF augmented cytokines release, whereas it downregulated SOCS1 expression. MiR-155 knockdown in UC-IMF reduced cytokine production and enhanced SOCS1 expression. Luciferase reporter assay demonstrated that miR-155 directly targets SOCS1. Moreover, silencing of SOCS1 in control IMF significantly increased IL-6 and IL-8 release. In all, our data suggest that inflammatory mediators induce miR-155 expression in IMF of patients with UC. By downregulating the expression of SOCS1, miR-155 wires IMF inflammatory phenotype.

Peroxisome proliferator-activated receptor-γ mediates the anti-inflammatory effect of 3-hydroxy-4-pyridinecarboxylic acid derivatives: synthesis and biological evaluation.

Seven 3-hydroxy-4-pyridinecarboxylic acid derivatives (HPs), aza-analogues of salicylic acid and structurally close to other potent inflammatory pyridine compounds such as aminopyridinylmethanols and aminopyridinamines, were synthesized, and their anti-inflammatory activity was evaluated. The synthesis was performed by adopting a general procedure involving an intramolecular Diels-Alder cycloaddition of oxazoles with acrylic acid to form various substituted pyridinic acids. The newly synthesized HPs did not exhibit cytotoxic activity on human monocytes-derived macrophages at concentrations up to 10(2) µM. Anti-inflammatory activity of the compounds was screened in vitro by evaluating the capability to inhibit cytokines release from lipopolysaccharide (LPS) stimulated human macrophages. 3-Hydroxy-1-methyl-4-pyridinecarboxylic acid (24) was found to be the most active HP. At 10 µM concentration, HP 24 reduced LPS-induced and nuclear factor-κB activation and cyclooxygenase-2 expression, while increased intracellular reactive oxygen species generation and peroxisome proliferator-activated receptor (PPAR-γ) mRNA transcript level. Indeed, pre-treatment of LPS-exposed human macrophages with PPAR-γ specific antagonist completely prevented HP 24-induced TNF-α and IL8 down regulation, demonstrating that the PPARγ pathway is mandatory for the HP 24 anti-inflammatory effect. Finally, daily treatment with HP 24 ameliorated the outcome of DSS-induced colitis in mice, significantly reducing colonic MPO activity and IL-1ß tissue levels.