The potential role of miRNAs in the pathogenesis of salivary gland cancer - A Focus on signaling pathways interplay.

Salivary gland cancer (SGC) is immensely heterogeneous, both in terms of its physical manifestation and its aggressiveness. Developing a novel diagnostic and prognostic detection method based on the noninvasive profiling of microribonucleic acids (miRs) could be a goal for the clinical management of these specific malignancies, sparing the patients' valuable time. miRs are promising candidates as prognostic biomarkers and therapeutic targets or factors that can advance the therapy of SGC due to their ability to posttranscriptionally regulate the expression of various genes involved in cell proliferation, differentiation, cell cycle, apoptosis, invasion, and angiogenesis. Depending on their biological function, many miRs may contribute to the development of SGC. Therefore, this article serves as an accelerated study guide for SGC and the biogenesis of miRs. Here, we shall list the miRs whose function in SGC pathogenesis has recently been determined with an emphasis on their potential applications as therapeutic targets. We will also offer a synopsis of the current state of knowledge about oncogenic and tumor suppressor miRs in relation to SGC.

Acute and chronic metabolic effects of carvedilol in high-fructose, high-fat diet-fed mice: implication of ß-arrestin2 pathway.

We aimed to investigate the acute and chronic effects of carvedilol on insulin resistance in high-fructose, high-fat diet (HFrHFD) - fed mice and the implication of the ß-arrestin2 pathway. The acute effect of carvedilol (10 mg/kg, i.p.) on glucose tolerance and hepatic lipid signaling in normal and insulin resistant mice was investigated. Then, the chronic effect of carvedilol on insulin resistance and dyslipidemia in HFrHFD-fed mice was examined. Changes in ß-arrestin2 and its downstream signals in liver, skeletal muscle, and adipose tissue were measured. This involved measuring phosphatidylinositol 4,5-bisphosphate (PIP2) and diacylglycerol (DAG) levels and protein kinase B (AKT) activity. Carvedilol acutely reduced fasting blood glucose levels in both normal and insulin resistant mice without significantly affecting the glucose tolerance. These acute effects were associated with increased hepatic PIP2 but decreased hepatic DAG levels. Chronic administration of carvedilol significantly ameliorated insulin resistance and dyslipidemia in HFrHFD-fed mice. These chronic effects were associated with increased ß-arrestin2, PIP2, and AKT activity levels but decreased DAG levels in the classical insulin target tissues. In conclusion, carvedilol acutely maintains glucose homeostasis and chronically ameliorates insulin resistance and dyslipidemia in HFrHFD-fed mice. The insulin sensitizing effects of carvedilol are highly correlated with the upregulation of ß-arrestin2 pathway.

Propranolol and low-dose isoproterenol ameliorate insulin resistance, enhance ß-arrestin2 signaling, and reduce cardiac remodeling in high-fructose, high-fat diet-fed mice: Comparative study with metformin.

AIMS: ß-Arrestin2 signaling has emerged as a promising therapeutic target for the management of insulin resistance and related complications. Moreover, recent studies have shown that certain G protein-coupled receptor (GPCR) ligands can modulate ß-arrestin2 signaling. The current study examined the effects of the ß-blocker propranolol and a low dose of the agonist isoproterenol (L-D-ISOPROT) on ß-arrestin2 signaling, insulin resistance, and cardiac remodeling in high-fructose, high-fat diet (HFrHFD)-fed mice. In addition, the effects of these agents were compared to those of the clinical antidiabetic agent, metformin. MATERIALS AND METHODS: Insulin resistance was induced by HFrHFD feeding for 16 weeks. Mice were then randomly allocated to groups receiving propranolol, L-D-ISOPROT, metformin, or vehicle (control) for 4 weeks starting on week 13 of HFrHFD feeding. Survival rate, body weight, visceral fat weight, blood glucose, serum insulin, insulin resistance index, hepatic ß-arrestin2 signaling, heart weight, left and right ventricular thicknesses, cardiac fibrosis severity, serum endothelin-1, cardiac cardiotrophin-1, and cardiac ß-arrestin2 signaling were then compared among groups. KEY FINDINGS: HFrHFD for 16 weeks significantly increased insulin resistance index, cardiac fibrosis area, and serum endothelin-1, and reduced hepatic ß-arrestin2 signaling, cardiac cardiotrophin-1, and cardiac ß-arrestin2 signaling without significant changes in survival rate, body weight, visceral fat weight, heart weight, or left and right ventricular thicknesses. All three drugs reduced insulin resistance and cardiac remodeling parameters and enhanced ß-arrestin2 signaling with variable efficacies. SIGNIFICANCE: Propranolol and L-D-ISOPROT, like metformin, can reduce insulin-resistance and cardiac remodeling in HFrHFD-fed mice, possibly by upregulating ß-arrestin2 signaling activity. Therefore, ß-arrestin2-signaling modulation might be a promising strategy for insulin-resistance treatment.

Carvedilol Diminishes Cardiac Remodeling Induced by High-Fructose/High-Fat Diet in Mice via Enhancing Cardiac ß-Arrestin2 Signaling.

BACKGROUND: Insulin resistance (IR) is a well-known risk factor for cardiovascular complications. This study aimed to investigate the effect of a dietary model of IR in mice on cardiac remodeling, cardiac ß-arrestin2 signaling, and the protective effects of carvedilol as a ß-arrestin-biased agonist. METHODS AND RESULTS: Insulin resistance was induced by feeding mice high-fructose/high-fat diet (HFrHFD) for 16 weeks. Carvedilol was adiministered for 4 weeks starting at week 13. At the end of the experiment, body weight, heart weight, left and right ventricular thickness, visceral fat weight, fasting blood glucose (FBG), serum insulin, IR index, and serum endothelin-1 were measured. In addition, cardiac tissue samples were histopathologically examined. Also, cardiac levels of cardiotrophin-1, ß-arrestin2, phosphatidylinositol 4,5 bisphosphate (PIP2), diacylglycerol (DAG), and phosphoserine 473 Akt (pS473 Akt) were measured. Results showed significant increases in the FBG, serum insulin, IR index, serum endothelin-1, cardiac DAG, cardiac fibrosis, and degenerated cardiac myofibrils in HFrHFD-fed mice associated with a significant reduction in cardiac levels of cardiotrophin-1, ß-arrestin2, PIP2, and pS473 Akt. On the other hand, carvedilol significantly reduced the heart weight, FBG, serum insulin, IR index, serum endothelin-1, cardiac DAG, left ventricular thickness, right ventricular fibrosis, and degeneration of cardiac myofibrils. In addition, carvedilol significantly increased cardiac levels of cardiotrophin-1, ß-arrestin2, PIP2, and pS473 Akt. CONCLUSION: Carvedilol enhances cardiac ß-arrestin2 signaling and reduces cardiac remodeling in HFrHFD-fed mice.

Comparison of stromal CD10 expression in benign, borderline, and malignant phyllodes tumors among Egyptian female patients.

BACKGROUND: Phyllodes tumors are group of biphasic fibroepithelial tumors of the breast of varying malignant potential, ranging from benign tumors to fully malignant sarcomas. According to the Egyptian National Cancer Institute, female malignant cases showed appreciable increase in the recent time period for breast cancer with the malignant phyllodes tumors representing 0.41% of cases in the year 2003-2004. AIMS: This is an immunohistochemical study to compare CD10 expression in benign, borderline, and malignant phyllodes tumors, in order to highlight its diagnostic and prognostic values. MATERIALS AND METHODS: This study conducted 34 Egyptian female cases of phyllodes tumors of different grades to be studied histologically and immunohistochemically using antibodies against CD10. STATISTICAL ANALYSIS: The Chi-square test was used to determine differences in CD10 expression between benign, borderline, and malignant tumors. One-way ANOVA test was used to determine whether the difference was significant. Significance was established at P<0.05. RESULTS: In the 24 cases of benign phyllodes tumors, only four cases (16.7%) showed positive CD10 reactivity. Three cases (60%) out of five borderline phyllodes tumors showed positive CD10 reactivity, while four (80%) out of five cases of malignant phyllodes tumors showed positive CD10 staining. CONCLUSION: From these highly significant results, we believe that there is a strong correlation between CD10 expression and tumor grade, which could be an important observation that may have both diagnostic and prognostic implications as well as promising potential target for development of novel therapies.