[show abstract][hide abstract] ABSTRACT: Cancer cell adopts peculiar metabolic strategies aimed to sustain the continuous proliferation in an environment characterized by relevant fluctuations in oxygen and nutrient levels. Monocarboxylate transporters MCT1 and MCT4 can drive such adaptation permitting the transport across plasma membrane of different monocarboxylic acids involved in energy metabolism.
Role of MCTs in tumor-stroma metabolic relationship was investigated in vitro and in vivo using transformed prostate epithelial cells, carcinoma cell lines and normal fibroblasts. Moreover prostate tissues from carcinoma and benign hypertrophy cases were analyzed for individuating clinical-pathological implications of MCT1 and MCT4 expression.
Transformed prostate epithelial (TPE) and prostate cancer (PCa) cells express both MCT1 and MCT4 and demonstrated variable dependence on aerobic glycolysis for maintaining their proliferative rate. In glucose-restriction the presence of L-lactate determined, after 24 h of treatment, in PCa cells the up-regulation of MCT1 and of cytochrome c oxidase subunit I (COX1), and reduced the activation of AMP-activated protein kinase respect to untreated cells. The blockade of MCT1 function, performed by si RNA silencing, determined an appreciable antiproliferative effect when L-lactate was utilized as energetic fuel. Accordingly L-lactate released by high glycolytic human diploid fibroblasts WI-38 sustained survival and growth of TPE and PCa cells in low glucose culture medium. In parallel, the treatment with conditioned medium from PCa cells was sufficient to induce glycolytic metabolism in WI-38 cells, with upregulation of HIF-1a and MCT4. Co-injection of PCa cells with high glycolytic WI-38 fibroblasts determined an impressive increase in tumor growth rate in a xenograft model that was abrogated by MCT1 silencing in PCa cells. The possible interplay based on L-lactate shuttle between tumor and stroma was confirmed also in human PCa tissue where we observed a positive correlation between stromal MCT4 and tumor MCT1 expression.
Our data demonstrated that PCa progression may benefit of MCT1 expression in tumor cells and of MCT4 in tumor-associated stromal cells. Therefore, MCTs may result promising therapeutic targets in different phases of neoplastic transformation according to a strategy aimed to contrast the energy metabolic adaptation of PCa cells to stressful environments.
BMC Cancer 03/2014; 14(1):154. · 3.33 Impact Factor
[show abstract][hide abstract] ABSTRACT: Starting from our in-house library of pyrazolo[3,4-d]pyrimidines, cross-docking simulation was conducted on Bcr-Abl T315I mutant to select new derivatives for biological investigations. Among the selected compounds (2a-e), derivative 2b showed a high activity against the Bcr-Abl T315I mutant (Ki = 36 nM). Binding free energy calculation (MM-GBSA), molecular interaction field (MIF) analysis and free energy perturbation (FEP) studies highlighted the importance of a bromine atom of the para position of the N1 side chain phenyl ring for the interaction with the hydrophobic region I in the T315I mutant. A series of 4-bromo derivatives was thus synthesized and biologically evaluated in cell-free assays (c-Src, Abl wt, Abl T315I mutant) and in the murine myeloid 32D cell lines expressing the human wild type p210-Bcr-Abl or the Bcr-Abl T315I mutant. Compound 2j was identified as the most promising derivative showing a good balance of different ADME properties, high activity in cell-free assays and an interesting sub-micromolar potency against T315I Bcr-Abl expressing cells. In addition, liposome encapsulated 2j was tested on 32D-p210 and 32D-T315I cell lines at concentrations of 0.1 and 1 μM in comparison with the DMSO dissolved 2j. Liposomal formulation increases the solubility of pyrazolo[3,4-d]pyrimidines preserving a good activity on leukemic T315I cells and avoiding the use of DMSO as solubilizing agent. In vivo studies on mice inoculated with 32D-T315I cells and treated for 17 days with 2j showed a more than 50% reduction in tumor volumes when compared to placebo treated mice.
Journal of Medicinal Chemistry 06/2013; · 5.61 Impact Factor
[show abstract][hide abstract] ABSTRACT: Design and synthesis of prodrugs of promising drug candidates represents a valid strategy to overcome the lack of favorable ADME properties, in particular aqueous solubility and bioavailability. We report herein the successful application of this strategy with two representative pyrazolo[3,4-d]pyrimidine derivatives (1 and 2), which led to the development of the corresponding and highly water-soluble antitumor prodrugs (7 and 8). In vitro studies confirmed a significant improvement of aqueous solubility and, for compound 8, good plasma stability, suggesting superior in vivo bioavailability. As expected, the uncleaved water-soluble prodrugs 7 and 8 showed no activity toward the enzymatic targets (c-Src and c-Abl) but revealed promising antiproliferative activity in myeloid cell lines, as a consequence of the in vitro hydrolysis of the selected solubilizing moiety, followed by the release of the active compounds (1 and 2).
[show abstract][hide abstract] ABSTRACT: Pim-1 is a serine/threonine kinase critically involved in the initiation and progression of various types of cancer, especially leukemia, lymphomas and solid tumors such as prostate, pancreas and colon, and is considered a potential drug target against these malignancies. In an effort to discover new potent Pim-1 inhibitors, a previously identified ATP-competitive indolyl-pyrrolone scaffold was expanded to derive structure-activity relationship data. A virtual screening campaign was also performed, which led to the discovery of additional ATP-competitive inhibitors as well as a series of 2-aminothiazole derivatives, which are noncompetitive with respect to both ATP and peptide substrate. This mechanism of action, which resembles allosteric inhibition, has not previously been characterized for Pim-1. Notably, further evaluation of the 2-aminothiazoles indicated a synergistic inhibitory effect in enzymatic assays when tested in combination with ATP-competitive inhibitors. A synergistic effect in the inhibition of cell proliferation by ATP-competitive and ATP-noncompetitive compounds was also observed in prostate cancer cell lines (PC3), where all Pim-1 inhibitors tested in showed synergism with the known anticancer agent, paclitaxel. These results further establish Pim-1 as a target in cancer therapy, and highlight the potential of these agents for use as adjuvant agents in the treatment of cancer diseases in which Pim-1 is associated with chemotherapeutic resistance.
[show abstract][hide abstract] ABSTRACT: The formation of new blood vessels is an essential therapeutic target in many diseases such as cancer, ischemic diseases, and chronic inflammation. In this regard, extremely low-frequency (ELF) electromagnetic fields (EMFs) seem able to inhibit vessel growth when used in a specific window of amplitude. To investigate the mechanism of anti-angiogenic action of ELF-EMFs we tested the effect of a sinusoidal magnetic field (MF) of 2 mT intensity and frequency of 50 Hz on endothelial cell models HUVEC and MS-1 measuring cell status and proliferation, motility and tubule formation ability. MS-1 cells when injected in mice determined a rapid tumor-like growth that was significantly reduced in mice inoculated with MF-exposed cells. In particular, histological analysis of tumors derived from mice inoculated with MF-exposed MS-1 cells indicated a reduction of hemangioma size, of blood-filled spaces, and in hemorrhage. In parallel, in vitro proliferation of MS-1 treated with MF was significantly inhibited. We also found that the MF-exposure down-regulated the process of proliferation, migration and formation of tubule-like structures in HUVECs. Using western blotting and immunofluorescence analysis, we collected data about the possible influence of MF on the signalling pathway activated by the vascular endothelial growth factor (VEGF). In particular, MF exposure significantly reduced the expression and activation levels of VEGFR2, suggesting a direct or indirect influence of MF on VEGF receptors placed on cellular membrane. In conclusion MF reduced, in vitro and in vivo, the ability of endothelial cells to form new vessels, most probably affecting VEGF signal transduction pathway that was less responsive to activation. These findings could not only explain the mechanism of anti-angiogenic action exerted by MFs, but also promote the possible development of new therapeutic applications for treatment of those diseases where excessive angiogenesis is involved.
PLoS ONE 01/2013; 8(11):e79309. · 3.73 Impact Factor
[show abstract][hide abstract] ABSTRACT: The prostate is the most frequent site of cancer in men aged 68 years and older. Although prostate cancer is frequently a slow-progressing cancer, the increase in lifespan is posing new challenges in order to avoid prostate cancer-associated mortality. epidemiological studies have clearly demonstrated that the westernised lifestyle and diet may fuel prostate cancer incidence and mortality, and the associated current pandemic of obesity is becoming one of the principal risk factors for age-related chronic diseases. obesity and ageing seem to contribute independently to deregulating adipose tissue homoeostasis and in turn systemic metabolism. nowadays, adipose tissue is recognised as an active and complex endocrine and immunological organ able to control the homoeostasis of different distant organs through the release of a variety of factors, collectively termed adipokines. These factors are master regulators of energy balance and immune response and may account for some of the most frequent obesity- and age-related health problems, including cancer. The dissection of mechanisms leading to altered metabolic control by adipose tissue will eventually indicate a new preventive strategy for prostate cancer.
[show abstract][hide abstract] ABSTRACT: Based on the growing deal of data concerning the biological activity of flavonoid-rich natural products, the aim of the present study was to explore in vitro the potential anti-tumoral activity of Citrus Bergamia (bergamot) juice (BJ), determining its molecular interaction with cancer cells. Here we show that BJ reduced growth rate of different cancer cell lines, with the maximal growth inhibition observed in neuroblastoma cells (SH-SY5Y) after 72 hs of exposure to 5% BJ. The SH-SY5Y antiproliferative effect elicited by BJ was not due to a cytotoxic action and it did not induce apoptosis. Instead, BJ stimulated the arrest in the G1 phase of cell cycle and determined a modification in cellular morphology, causing a marked increase of detached cells. The inhibition of adhesive capacity on different physiologic substrates and on endothelial cells monolayer were correlated with an impairment of actin filaments, a reduction in the expression of the active form of focal adhesion kinase (FAK) that in turn caused inhibition of cell migration. In parallel, BJ seemed to hinder the association between the neural cell adhesion molecule (NCAM) and FAK. Our data suggest a mechanisms through which BJ can inhibit important molecular pathways related to cancer-associated aggressive phenotype and offer new suggestions for further studies on the role of BJ in cancer treatment.
PLoS ONE 01/2013; 8(4):e61484. · 3.73 Impact Factor
[show abstract][hide abstract] ABSTRACT: The ability of a cell to modify the extracellular matrix is important in several pathophysiological alterations including
tumorigenesis. Cell transformation is accompanied by changes in the surrounding stroma as a result of the action of specific
proteases such as the urokinase plasminogen activator (uPA), which has been associated with invasive potential in many tumor
types. In this study, we analyzed the release of vesicle-associated uPA by the aggressive prostatic carcinoma cell line PC3
and the implications of this release for the invasive behaviour of prostatic tumor cells. Zymography and Western blot analysis
revealed the presence of vesicle-associated uPA in the high-molecular weight form. Vesicles adhered to and degraded both collagen
IV and reconstituted basal membrane (Matrigel), and plasminogen enhanced the degradation in a dose-dependent manner. Addition
of membrane vesicles shed by PC3 cells to cultures of the poorly invasive prostate cancer cell line LnCaP enhanced the adhesive
and invasive capabilities of the latter, suggesting a mechanism involving substrate recognition and degradation. Together,
these findings indicate that membrane vesicles can promote tumor invasion and point to the important role of vesicle-associated
uPA in the extracellular compartment.
Clinical and Experimental Metastasis 04/2012; 18(2):163-170. · 3.46 Impact Factor
[show abstract][hide abstract] ABSTRACT: Neuroblastoma (NB) represents the most common extracranial paediatric solid tumor for which no specific FDA-approved treatment is currently available. The tyrosine kinase c-Src has been reported to play an important role in the differentiation, cell-adhesion and survival of NB cells. Starting from dual Src/Abl inhibitors previously found active in NB cell lines (1-3), small modification of the original structures almost abolished the Abl activity with a contemporary improvement of affinity and specificity for c-Src. Among the synthesized compounds, the most potent c-Src inhibitor (10a) showed a very interesting antiproliferative activity in SH-SY5Y cells with an IC(50) of 80 nM and a favourable ADME profile. A 3D SAR analysis was also attempted and may guide the design of more potent c-Src inhibitors as potential agents for NB treatment.
[show abstract][hide abstract] ABSTRACT: Metalloproteinases (MMPs) are a cluster of at least 23 enzymes belonging to the more wide family of endopeptidases called Metzincins, whose structure is characterized by the presence of a zinc ion at the catalytic site. Although the general view of MMPs as physiologic scissors involved in extracellular matrix (ECM) degradation and tissue remodeling is still valid, additional functions have recently emerged, including the ability to cleave non ECM molecules such as growth factors, cytokines and chemokines from their membrane-anchored proforms. These functions are utilized by tumor cells and are fundamental in the determination of tumor progression and invasion. The effect of MMPs activity in cancer progression has been traditionally associated with the acquisition by tumor cells of an invasive phenotype, an indispensable requisite for the metastatic spreading of cancer cells. In addition to the traditional view, a new role for MMPs in creating a favourable microenvironment has been proposed, so that MMPs are not only involved in cell invasion, but also in signaling pathways that control cell growth, inflammation, or angiogenesis. Finally, recent evidence suggest a role of MMPs in the so called "pre-metastatic niche" that is the hypothesis of an early distant modification of the premetastatic site by primary cancer cells. This new hypothesis is changing our traditional view about MMPs and provides important insights into the effective time window for the therapeutic use of MMP inhibitors. In this review we provide the main available data about the ability of MMPs in creating a suitable microenvironment for tumor growth in metastatic sites and we indicate the implication of these data on the potential use of MMP inhibitors in the metastatic therapy.
Current Molecular Medicine 06/2011; 11(8):609-22. · 4.20 Impact Factor
[show abstract][hide abstract] ABSTRACT: Tyrosine kinase inhibitors are currently one of the most important classes of cancer drugs, essentially because many kinases and regulators are molecules related to frequently mutated oncogenes and tumor suppressors. Many experiments and clinical data in different tumors show that better cancer therapy can be obtained by blocking several tumor cell biochemical pathways at once, accurately selecting critical targets and adjusting drug dosages for the best results. Through our direct experience in experimental models of prostate cancer (PCa), we discuss in this review the issues of tyrosine kinase inhibition in neoplastic cells and illustrate the opportunities to extend cancer proliferation control to other key biological targets of clinical interest, aiming at the realization of better polypharmacology applications in cancer chemotherapy. Briefly, in this review the main experimental evidences on the efficacy of tyrosine kinase inhibitors (TKIs) on PCa are described, together with a reasoned analysis of biological data which may be useful for a general extension to other clinical areas of cancer multitargeted and possibly individualized polychemotherapy.
Current Medicinal Chemistry 06/2011; 18(19):2827-35. · 4.07 Impact Factor
[show abstract][hide abstract] ABSTRACT: EphA2 kinase regulates cell shape, adhesion, and motility and is frequently overexpressed in several cancers, including melanoma, prostate, breast, and colon cancers and lung carcinoma. Although a function in both tumor onset and metastasis has been proposed, the role played by EphA2 in tumor progression is still debated. In melanoma, EphA2 has been reported to affect cell migration and invasiveness allowing cells to move by a proteolysis-independent strategy, commonly referred as amoeboid motility. With the aim to understand the role of EphA2 in prostate cancer metastatic spreading, we stably silenced EphA2 expression in a model of aggressive metastatic prostate carcinoma. Our results show that EphA2 drives the metastatic program of prostate carcinoma, although its involvement greatly differs among metastatic steps. Indeed, EphA2 expression (i) greatly affects prostate carcinoma cell motility style, guiding an amoeboid movement based on Rho-mediated cell rounding and independent from metalloprotases, (ii) is ineffective on transendothelial migration, adhesion onto extracellular matrix proteins, and on resistance to anoikis, (iii) regulates clonogenic potential of prostate carcinoma, thereby increasing anchorage-independent growth and self-renewal, prostasphere formation, tumor onset, dissemination to bone, and growth of metastatic colonies. Our finding indicate that EphA2-overexpressing prostate carcinoma cells gain an invasive benefit from their amoeboid motility style to escape from primary tumors and then, enhancing their clonogenic potential successfully target bone and grow metastases, thereby acknowledging EphA2 as a target for antimetastatic therapy of aggressive prostate cancers.
Molecular Cancer Research 02/2011; 9(2):149-60. · 4.35 Impact Factor