The effect of fenofibrate, a PPARα activator on toll-like receptor-4 signal transduction in melanoma both in vitro and in vivo.

BACKGROUND: The anti-cancer effect of peroxisome proliferator-activated receptor (PPAR) α ligands on growth and metastatic potential of melanoma cells has been shown previously. However, the mechanism underlying these effects remains to be elucidated. Here, we investigated the effects of fenofibrate (PPAR ligand) on Toll-like receptor-4 (TLR-4) signaling in mice melanoma. METHODS: Mice melanoma cells (B16F10) were treated with fenofibrate or LPS or LPS + fenofibrate or pre-treated with CLI-095 (a TLR4 inhibitor), followed by fenofibrate. In in vivo model, C57BL/6 mice were subcutaneously injected with B16F10 cells (with/without LPS pre-treatment), and fenofibrate was administrated after development of palpable tumors. Cell proliferation, the expression level of Tlr4, Myd88, Nf-κb1 genes, TLR-4 protein expression, TNF-α levels, and tumor volume were measured. RESULT: Our results indicated that fenofibrate significantly inhibited the Tlr-4, Myd-88, and Nf-kb1 mRNA expression and TNF-α concentration in B16F10 LPS-stimulated cells. In addition, blocking TLR-4 signaling increased the anti-inflammatory potential of fenofibrate. Also fenofibrate can reduce LPS-induced tumor volume, Tlr-4, Myd-88, Nf-kb1 mRNA, and TLR-4 protein expression in tumor tissue and also TNF-α level in tumor tissue lysate. CONCLUSION: Our data indicate that fenofibrate may exert its anti-melanoma effects via interaction with TLR4-dependent signaling pathway (TLR-4/MyD-88/ NF-kB).

Effect of Plasma-Derived Exosomes of Refractory/Relapsed or Responsive Patients with Diffuse Large B-Cell Lymphoma on Natural Killer Cells Functions.

OBJECTIVE: The purpose of this study was to investigate effect of plasma-derived exosomes of refractory/relapsed or responsive diffuse large B-cell lymphoma (DLBCL) patients on natural killer (NK) cell functions. MATERIALS AND METHODS: In this cross-sectional and experimental study, NK cells were purified from responsive patients (n=10) or refractory/relapsed patients (n=12) and healthy donors (n=12). NK cells were treated with plasma-derived exosomes of responsive or refractory/relapsed patients. We examined the expression levels of hsa-miR-155-5p, hsalet- 7g-5p, INPP5D(SHIP-1) and SOCS-1 in NK cells quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Percentages of NK cells expressing CD69, NKG2D and CD16, NK cell cytotoxicity and NK cell proliferation (using flow-cytometry) as well as interferon-gamma (IFN-γ) level in the supernatant of NK cells using ELISA were also investigated. RESULTS: We observed an increased level of hsa-miR-155-5p and a decreased level of SOCS-1 in NK cells treated with exosomes compared to untreated NK cell in healthy donors and DLBCL patients. An increase in hsa-miR-155-5p level was associated with an increased level of IFN-γ in healthy donors. The decreased levels of hsa-let-7g-5p were observed in NK cells treated with exosomes in comparison with untreated NK cells in DLBCL patients (P<0.05). There was no significant difference in the percentage of CD69+ NK cells and NKG2D+ NK cells in the absence or presence of exosomes of DLBCL patients in each group. Furthermore, we observed significant reduction of NK cell proliferation in DLBCL patients and healthy donors in the presence of exosomes of refractory/relapsed patients (P<0.05). A significant decrease was observed in cytotoxicity of NK cell in patients with DLBCL treated with exosomes of responsive patients. CONCLUSION: Our findings demonstrated adverse effect of plasma-derived exosomes of DLBCL patients on some functions of NK cell. It was also determined that low NK cell count might be associated with impaired response to R-CHOP and an increased recurrence risk of cancer.

Influence of morphine on TLR4/ NF-kB signaling pathway of MCF-7 cells.

Morphine affects the risk of metastasis in cancer. The TLR4 gene promotes migration in adenocarcinoma cells. We investigated the effect of morphine on TLR4, MyD88 and NF-κ B-expression and migration. Migration of estrogen receptor-positive MCF7 breast cancer cells was studied after 24 and 48 hours incubation with morphine, with boyden chamber method. Morphine effect on TLR4, MyD88 and NF-κB mRNA expression was determined by quantitative Real-Time polymerase chain reaction. Migration was reduced at the doses of 0.5 and 5 µM (p < 0.05). However, TLR4, MyD88 and NF-κBmRNA expression was decreased at the doses of 0.5, 5 and 500 µM. Morphine at the dose of 50 µM increased the expression of mentioned genes. MCF-7 cell line after 48 hours incubation with the dose of 0.5 µM morphine decreased the migration and at the dose of 0.5 µM down-regulated the mRNA expression of TLR4, MyD88 and NF-κB, however, the higher doses increased the expression of TLR4, MyD88 and NF-κB. Morphine affects TLR4expression in breast cancer cell, which depends on time and concentration (Tab. 1, Fig. 5, Ref. 24).