Mir-135b induces osteosarcoma invasion by the modulation of foxo-1 and c-myc

Background: Osteosarcoma (OS) is the most common type of bone malignancy. Many studies have attempted to find the association between microRNAs and cancer-associated processes. Alterations in miRNA expression through genetic or epigenetic changes, impairment of transcription factors, and ectopic expression of miRNAs induce the development and progression of cancer. Al-though miR-135b has been thoroughly documented as an oncogene in the majority of studies, some controversies remain about the conflicting role of miR-135b as a tumor-suppressor. Objectives: The present study aimed at investigating the oncogenic and/or tumor-suppressing role of miR-135b in human OS. Methods: In this study, 21 OS tissue samples, along with 21 adjacent bone tissues (normal) as control specimens were collected to analyze the expression of miR-135b. The Saos2 cell-line was transiently transfected with the miR-135b mimic and inhibitor to assess its effect on two critical transcription factors, namely FOXO-1 and c-Myc. qRT-PCR was performed to quantify the expression of miR-135b in both OS tissues and the Saos2 cell-line. The MTT, cell migration, and cell invasion assays were used to characterize the miR-135b function. The western blot analysis was carried out to monitor the targets of miR-135b. Finally, the changes in cellular functions such as migration and invasion, following the transfection of miR-135b mimic and inhibitor, were verified. Results: The results showed that in comparison with the adjacent normal bone tissues, the expression of miR-135b was higher in OS tissue samples, which inversely correlated with the expression rate of FOXO-1, whereas the expression of c-Myc had a direct relationship to miR-135b expression. Functionally, the miR-135b mimic led to an increase in cell proliferation, invasion, and migration of OS cancer cells. Conclusions: MiR-135b induces the proliferation and invasion of OS cells by the degradation of FOXO-1 and upregulation of c-Myc. © 2020, Author(s)

Decreased serum levels of CTRP12/adipolin in patients with coronary artery disease in relation to inflammatory cytokines and insulin resistance

Coronary artery disease (CAD) is the leading cause of death worldwide. Atherosclerosis as the main underlying mechanism of CAD is associated with inflammation and adipose tissue dysfunction. C1q/TNF-related protein12 (CTRP12) is a newly discovered adipokine which is a paralog of adiponectin. CTRP12 has anti-inflammatory and insulin sensitizing effects. Circulating levels of this adipokine have been reported to be lower in patients with type 2 diabetes and women with polycystic ovarian syndrome. The present study was undertaken for the first time to evaluate serum levels of CTRP12 in CAD patients and its association with anthropometric and biochemical parameters. Serum levels of CTRP12 were measured using ELISA kit in 188 CAD patients (angiography confirmed) and 70 controls. The serum levels of adiponectin, TNF-α and IL-6 were measured using ELISA kits. Serum levels of CTRP12 were found to be lower in CAD patients (585.48 ± 201.67 pg/mL) than in the controls (814.86 ± 247.85 pg/mL; p < 0.001). CTRP12 also showed an independent association with the risk of CAD (OR CI = 0.998 0.996�0.999; p = 0.019). Moreover, it showed an inverse correlation with HOMA-IR (r = �0.298; p = 0.012) and TNF-α (r = �0.269; p = 0.023) and a positive correlation with adiponectin (r = 0.344; p = 0.003) in the controls. In CAD patients, CTRP12 was inversely correlated with BMI (r = �0.181, p = 0.013), HOMA-IR (r = -0.199; p = 0.006), TNF-α (r = -0.259; p < 0.001) and IL-6 (r = -320; p < 0.001) and a positive correlation with high density lipoprotein-cholesterol(r = 0.342; p < 0.001) and adiponectin (r = 0.398; p < 0.001). The present study showed for the first time that serum levels of CTRP12 are independently associated with CAD and that CTRP12 is associated with several CAD risk factors. The results suggest a possible link between CTRP12 and pathogenic mechanisms of atherosclerosis, such as inflammation and high density lipoprotein-cholesterol metabolism; however, more study is required in this regard. © 2018 Elsevier Lt

Hesperetin is a potent bioactivator that activates SIRT1-AMPK signaling pathway in HepG2 cells

Sirtuin 1 (SIRT1) is a deacetylase enzyme that plays crucial roles in controlling many cellular processes and its downregulation has been implicated in different metabolic disorders. Recently, several polyphenols have been considered as the effective therapeutic approaches that appear to influence SIRT1. The main goal of this study was to evaluate the effect of hesperetin, a citrus polyphenolic flavonoid, on SIRT1 and AMP-activated kinase (AMPK). HepG2 cells were treated with hesperetin in the presence or absence of EX-527, a SIRT1 specific inhibitor, for 24 h. Resveratrol was used as a positive control. SIRT1 gene expression, protein level, and activity were measured by RT-PCR, Western blotting, and fluorometric assay, respectively. AMPK phosphorylation was also determined by Western blotting. Our results indicated a significant increase in SIRT1 protein level and activity as well as an induction of AMPK phosphorylation by hesperetin. These effects of hesperetin were abolished by EX-527. Furthermore, hesperetin reversed the EX-527 inhibitory effects on SIRT1 protein expression and AMPK phosphorylation. These findings suggest that hesperetin can be a novel SIRT1 activator, even stronger than resveratrol. Therefore, the current study may introduce hesperetin as a new strategy aimed at upregulation SIRT1-AMPK pathway resulting in various cellular processes regulation. © 2019, University of Navarra