The miR-21/PTEN/Akt signaling pathway is involved in the anti-tumoral effects of zoledronic acid in human breast cancer cell lines.

Preclinical data indicate a direct anti-tumor effect of zoledronic acid (ZA) outside the skeleton, but its molecular mechanism is still not completely clarified. The aim of this study was to investigate the anti-cancer effects of ZA in human breast cancer cell lines, suggesting that they may in part be mediated via the miR-21/PTEN/Akt signaling pathway. The effect of ZA on cell viability was measured by MTT assay, and cell death induction was analyzed using either a double AO/EtBr staining and M30 ELISA assay. A Proteome Profiler Human Apoptosis Array was executed to evaluate the molecular basis of ZA-induced apoptosis. Cell cycle analysis was executed by flow cytometry. The effect of ZA on miR-21 expression was quantified by qRT-PCR, and the amount of PTEN protein and its targets were analyzed by Western blot. ZA inhibited cell growth in a concentration- and time-dependent manner, through the activation of cell death pathways and arrest of cell cycle progression. ZA downregulated the expression of miR-21, resulting in dephosphorilation of Akt and Bad and in a significant increase of p21 and p27 proteins expression. These results were observed also in MDA-MB-231 cells, commonly used as an experimental model of bone metastasis of breast cancer. This study revealed, for the first time, an involvement of the miR-21/PTEN/Akt signaling pathway in the mechanism of ZA anti-cancer actions in breast cancer cells. We would like to underline that this pathway is present both in the hormone responsive BC cell line (MCF-7) as well as in a triple negative cell line (MDA-MB-231). Taken together these results reinforce the use of ZA in clinical practice, suggesting the role of miR-21 as a possible mediator of its therapeutic efficacy.

Gene expression profile of prostate cancer cell lines: effect of nerve growth factor treatment.

A dysregulation of the nerve growth factor (NGF)-mediated control of prostate cell growth is associated with the malignant progression of prostate epithelial cells. Exogenous NGF induced in prostate cancer (PCa) cell lines DU145 and PC3 the expression of p75(NGFR), accompanied by a reduction of the cell malignancy. The aim of this study was to analyze the profile of NGF-regulated genes the PCa cell line DU145 by using the cDNA microarray technique. NGF treatment of DU145 cells decreased the expression of 52 known genes, while the expression of 40 known genes was increased. NGF treatment of the DU145 cell line modified the expression profile of clusters of genes involved in invasion and metastasis, in cell proliferation and apoptosis, inflammation, cell metabolism and transcriptional activity. Interestingly, NGF induced the same pattern of gene modifications in both PCa cell lines. Data presented here may help to identify gene/proteins that dispose to PCa progression and to assess future markers that could allow the development of new clinic diagnostic and therapeutical approaches.

[Alpha1 adrenoceptors in human urinary tract:expression, distribution and clinical implications].

Adrenergic receptors (ARs) are a class of proteins belonging to the G proteincoupled receptor family. Pharmacological and molecular studies allowed dividing ARs into three different categories: α1, α2 and ß. In this review, we focused on α1 ARs and α1 AR antagonists, since α1 ARs play an important role in the pathophysiology of a number of urinary tract (UT) dysfunctions. α1 ARs are widely expressed in human UT; in particular, the three ureter areas (distal, medial and proximal) show different patterns of receptor expression (i.e. distal > medial = proximal), giving the molecular basis for the use of α1 ARs antagonist in the expulsive therapy of distal ureter calculi. Bladder areas are characterized by important differences among trigone, detrusor and neck, the first showing a different pattern of expression compared to the other parts. Further, there are evidences of both density and subtype gender-dependent expressions. α1 ARs expression in prostate and detrusor is a widely investigated area of research, mainly due to the clinical impact of benign prostatic hyperplasia (BPH). Urethra has not been well studied in human, although it plays a role in the control of continence. Studies carried out on α1 AR subtype expression in the UT indicate that, although the presence of each subtype is observed, α1A firstly and then α1D ARs seem to be more expressed than α1B ARs. Thus, drugs that demonstrate high α1A/D AR selectivity have drawn the researchers' attention. As it relates specifically to the α1 AR antagonists used in the treatment of lower UT symptoms, the concept of uroselectivity has been operationally defined; indeed, in a number of recent publications uroselectivity has been defined as the degree to which a given compound inhibits norepinephrine-induced increase in urinary muscle contractions and/or its propensity to generate unwanted cardiovascular effects, such as decreases in blood pressure.