Publications by authors named "Antonio Filippini"

62 Publications

Flavonoids increase melanin production and reduce proliferation, migration and invasion of melanoma cells by blocking endolysosomal/melanosomal TPC2.

Sci Rep 2021 Apr 19;11(1):8515. Epub 2021 Apr 19.

Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-University, Munich, Germany.

Two-pore channel 2 (TPC2) resides in endolysosomal membranes but also in lysosome-related organelles such as the melanin producing melanosomes. Gain-of-function polymorphisms in hTPC2 are associated with decreased melanin production and blond hair color. Vice versa genetic ablation of TPC2 increases melanin production. We show here an inverse correlation between melanin production and melanoma proliferation, migration, and invasion due to the dual activity of TPC2 in endolysosomes and melanosomes. Our results are supported by both genetic ablation and pharmacological inhibition of TPC2. Mechanistically, our data show that loss/block of TPC2 results in reduced protein levels of MITF, a major regulator of melanoma progression, but an increased activity of the melanin-generating enzyme tyrosinase. TPC2 inhibition thus provides a twofold benefit in melanoma prevention and treatment by increasing, through interference with tyrosinase activity, the synthesis of UV blocking melanin in melanosomes and by decreasing MITF-driven melanoma progression by increased GSK3β-mediated MITF degradation.
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http://dx.doi.org/10.1038/s41598-021-88196-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8055690PMC
April 2021

Anti-tumor Effect of Oleic Acid in Hepatocellular Carcinoma Cell Lines Autophagy Reduction.

Front Cell Dev Biol 2021 5;9:629182. Epub 2021 Feb 5.

Department of Anatomical, Histological, Forensic Medicine, and Orthopedic Sciences, Sapienza University of Rome, Rome, Italy.

Oleic acid (OA) is a component of the olive oil. Beneficial health effects of olive oil are well-known, such as protection against liver steatosis and against some cancer types. In the present study, we focused on OA effects in hepatocellular carcinoma (HCC), investigating responses to OA treatment (50-300 μM) in HCC cell lines (Hep3B and Huh7.5) and in a healthy liver-derived human cell line (THLE-2). Upon OA administration higher lipid accumulation, perilipin-2 increase, and autophagy reduction were observed in HCC cells as compared to healthy cells. OA in the presence of 10% FBS significantly reduced viability of HCC cell lines at 300 μM through Alamar Blue staining evaluation, and reduced cyclin D1 expression in a dose-dependent manner while it was ineffective on healthy hepatocytes. Furthermore, OA increased cell death by about 30%, inducing apoptosis and necrosis in HCC cells but not in healthy hepatocytes at 300 μM dosage. Moreover, OA induced senescence in Hep3B, reduced P-ERK in both HCC cell lines and significantly inhibited the antiapoptotic proteins c-Flip and Bcl-2 in HCC cells but not in healthy hepatocytes. All these results led us to conclude that different cell death processes occur in these two HCC cell lines upon OA treatment. Furthermore, 300 μM OA significantly reduced the migration and invasion of both HCC cell lines, while it has no effects on healthy cells. Finally, we investigated autophagy role in OA-dependent effects by using the autophagy inducer torin-1. Combined OA/torin-1 treatment reduced lipid accumulation and cell death as compared to single OA treatment. We therefore concluded that OA effects in HCC cells lines are, at least, in part dependent on OA-induced autophagy reduction. In conclusion, we report for the first time an autophagy dependent relevant anti-cancer effect of OA in human hepatocellular carcinoma cell lines.
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http://dx.doi.org/10.3389/fcell.2021.629182DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7892977PMC
February 2021

TNF-α inhibits GDNF levels in Sertoli cells, through a NF-κB-dependent, HES1-dependent mechanism.

Andrology 2020 Dec 12. Epub 2020 Dec 12.

Department of Anatomy, Histology, Forensic Medicine and Orthopedic, Section of Histology, Sapienza University of Rome, Rome, Italy.

Background: Glial cell line-derived neurotrophic factor (GDNF) is a soluble molecule crucial for the regulation of the spermatogonial stem cells (SSC) of the testis. The effects of GDNF on target cells have been extensively described, but mechanisms underlying GDNF regulation are currently under investigation. In the nervous system, GDNF expression is regulated by pro-inflammatory cytokines including lipopolysaccharide (LPS), interleukin 1 beta (IL-1β), and tumor necrosis factor alpha (TNF-α) but the effect of these cytokines on GDNF expression in the testis is unclear.

Objectives: The aim of the present study was to investigate the impact of TNF-α on GDNF expression levels using primary murine Sertoli cells as experimental model.

Material And Methods: The expression of TNF-α-regulated genes including Gdnf in different culture conditions was determined by real-time PCR. GDNF protein levels were determined by ELISA. The activation of the NF-κb pathway and HES1 levels were assessed by Western Blot analysis and immunofluorescence. HES1 expression was downregulated by RNAi.

Results: In primary Sertoli cells, TNF-α downregulates GDNF levels through a nuclear factor-κB (NF-κB)-dependent mechanism. Mechanistically, TNF-α induces the transcriptional repressor HES1 by a NF-Κb-dependent mechanism, which in turn downregulates GDNF.

Discussion: Under physiological conditions, TNF-α is secreted by germ cells suggesting that this cytokine plays a role in the paracrine control of SSC niche by modulating GDNF levels. HES1, a well-known target of the Notch pathway, is implicated in the regulation of GDNF expression. In Sertoli cells, TNF-α and Notch signaling may converge at molecular level, to regulate the expression of HES1 and HES1- target genes, including GDNF.

Conclusions: Because of the importance of GDNF for spermatogonial stem cell self-renewal and proliferation, this data may give important insights on how cytokine signals in the testis modulate the expression of niche-derived factors.
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http://dx.doi.org/10.1111/andr.12959DOI Listing
December 2020

The PI3K/AKT Pathway Is Activated by HGF in NT2D1 Non-Seminoma Cells and Has a Role in the Modulation of Their Malignant Behavior.

Int J Mol Sci 2020 Nov 17;21(22). Epub 2020 Nov 17.

Section of Histology and Medical Embryology, Department of Anatomy, Histology, Forensic-Medicine and Orthopedics, "Sapienza" University of Rome, 00161 Rome, Italy.

Overactivation of the c-MET/HGF system is a feature of many cancers. We previously reported that type II testicular germ cell tumor (TGCT) cells express the c-MET receptor, forming non-seminomatous lesions that are more positive compared with seminomatous ones. Notably, we also demonstrated that NT2D1 non-seminomatous cells (derived from an embryonal carcinoma lesion) increase their proliferation, migration, and invasion in response to HGF. Herein, we report that HGF immunoreactivity is more evident in the microenvironment of embryonal carcinoma biopsies with respect to seminomatous ones, indicating a tumor-dependent modulation of the testicular niche. PI3K/AKT is one of the signaling pathways triggered by HGF through the c-MET activation cascade. Herein, we demonstrated that phospho-AKT increases in NT2D1 cells after HGF stimulation. Moreover, we found that this pathway is involved in HGF-dependent NT2D1 cell proliferation, migration, and invasion, since the co-administration of the PI3K inhibitor LY294002 together with HGF abrogates these responses. Notably, the inhibition of endogenous PI3K affects collective cell migration but does not influence proliferation or chemotactic activity. Surprisingly, LY294002 administered without the co-administration of HGF increases cell invasion at levels comparable to the HGF-administered samples. This paradoxical result highlights the role of the testicular microenvironment in the modulation of cellular responses and stimulates the study of the testicular secretome in cancer lesions.
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http://dx.doi.org/10.3390/ijms21228669DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7698414PMC
November 2020

Naringenin is a powerful inhibitor of SARS-CoV-2 infection in vitro.

Pharmacol Res 2021 01 20;163:105255. Epub 2020 Oct 20.

Unit of Histology and Medical Embryology, Department of Anatomy, Histology, Forensic Medicine and Orthopaedics, SAPIENZA University of Rome, 16 Via A. Scarpa, Rome, 00161 Italy.

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http://dx.doi.org/10.1016/j.phrs.2020.105255DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7574776PMC
January 2021

Mas Receptor Activation Contributes to the Improvement of Nitric Oxide Bioavailability and Vascular Remodeling During Chronic AT1R (Angiotensin Type-1 Receptor) Blockade in Experimental Hypertension.

Hypertension 2020 12 19;76(6):1753-1761. Epub 2020 Oct 19.

Division of Cardiology, Clinical and Molecular Medicine Department, Sant'Andrea Hospital (C.S., E.A., R.P., A.B., M.V.), Sapienza University of Rome, Italy.

Angiotensin (1-7) production increases during AT1R (angiotensin type-1 receptor) blockade. The contribution of Ang (1-7) (angiotensin [1-7]) and its receptor (MasR) to the favorable effect of angiotensin receptor blockers on remodeling and function of resistance arteries remains unclear. We sought to determine whether MasR contributes to the improvement of vascular structure and function during chronic AT1R blockade. Spontaneously hypertensive rats were treated with Ang (1-7) or olmesartan ± MasR antagonist A-779, or vehicle, for 14 days. Blood pressure was measured by tail cuff methodology. Mesenteric arteries were dissected and mounted on a pressurized micromyograph to evaluate media-to-lumen ratio (M/L) and endothelial function. Expression of MasR and eNOS (endothelial nitric oxide synthase) was evaluated by immunoblotting, plasma nitrate by colorimetric assay, and reactive oxygen species production by dihydroethidium staining. Independently of blood pressure, olmesartan significantly reduced M/L and improved NO bioavailability, A-779 prevented these effects. Likewise, Ang (1-7) significantly reduced M/L and NO bioavailability. MasR expression was significantly increased by Ang (1-7) as well as by olmesartan, and it was blunted in the presence of A-779. Both Ang (1-7) and olmesartan increased eNOS expression and plasma nitrite which were reduced by A-779. Superoxide generation was attenuated by olmesartan and Ang (1-7) and was blunted in the presence of A-779. These MasR-mediated actions were independent of AT2R activation since olmesartan and Ang (1-7) increased MasR expression and reduced M/L in Ang II (angiotensin II)-infused AT2R knockout mice, independently of blood pressure control. A-779 prevented these effects. Hence, MasR activation may contribute to the favorable effects of AT1R antagonism on NO bioavailability and microvascular remodeling, independently of AT2R activation and blood pressure control.
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http://dx.doi.org/10.1161/HYPERTENSIONAHA.120.15527DOI Listing
December 2020

The Role of Autophagy in Osteoclast Differentiation and Bone Resorption Function.

Biomolecules 2020 09 30;10(10). Epub 2020 Sep 30.

Department of Anatomy, Histology, Forensic Medicine and Orthopaedics, Unit of Histology and Medical Embryology, Sapienza University of Rome, 00161 Rome, Italy.

Autophagy is an evolutionary conserved and highly regulated recycling process of cellular wastes. Having a housekeeping role, autophagy through the digestion of domestic cytosolic organelles, proteins, macromolecules, and pathogens, eliminates unnecessary materials and provides nutrients and energy for cell survival and maintenance. The critical role of autophagy and autophagy-related proteins in osteoclast differentiation, bone resorption, and maintenance of bone homeostasis has previously been reported. Increasing evidence reveals that autophagy dysregulation leads to alteration of osteoclast function and enhanced bone loss, which is associated with the onset and progression of osteoporosis. In this review, we briefly consolidate the current state-of-the-art technology regarding the role of autophagy in osteoclast function in both physiologic and pathologic conditions to have a more general view on this issue.
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http://dx.doi.org/10.3390/biom10101398DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7601508PMC
September 2020

Toll-Iike Receptor-3 Activation Enhances Malignant Traits in Human Breast Cancer Cells Through Hypoxia-inducible Factor-1α.

Anticancer Res 2020 Oct;40(10):5379-5391

Department of Anatomy, Histology, Forensic Medicine and Orthopedics, Unit of Histology and Medical Embryology, Sapienza University of Rome, Rome, Italy.

Background/aim: Hypoxia-inducible factor 1 (HIF1) inhibitors have been proposed as therapeutic agents for several tumor types. HIF1α is induced by hypoxia and by pathogens in normoxia through toll-like receptors (TLRs). The TLR3 activator polyinosinic:polycytidylic acid [poly(I:C)] induces apoptosis in various types of cancer but not in the most aggressive breast cancer cell lines. We hypothesized that the failure of TLR3 stimulation to induce apoptosis in these cells might be due to an elevated HIF1α level and this link might be exploited.

Materials And Methods: Poly(I:C)-induced signaling pathway and expression of HIF1α and HIF1α targets were studied in MDA MB-231 and MCF-7 breast cancer cell lines by western blot. Flow cytometry was used for apoptotic responses and vasculogenic mimicry as bioassay.

Results: Poly(I:C) increased expression of HIF1α and its targets BCL2 apoptosis regulator and c-MYC. Moreover, using pharmacological or genetic HIF1 inhibition, reduction of poly(I:C)-induced expression of HIF1α was paralleled by lowering of c-MYC and increased sensitivity to poly(I:C)-induced apoptosis, demonstrating the crucial role of this factor. We provide the first evidence in breast cancer cells that TLR3 stimulation induces HIF1α-dependent vasculogenic mimicry. By using specific inhibitors, we identified a signaling cascade upstream of HIF1α induction.

Conclusion: Combined treatment with poly(I:C) and HIF1 inhibitors deserves consideration as an effective strategy in breast cancer therapy.
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http://dx.doi.org/10.21873/anticanres.14546DOI Listing
October 2020

Loss of Two-Pore Channel 2 (TPC2) Expression Increases the Metastatic Traits of Melanoma Cells by a Mechanism Involving the Hippo Signalling Pathway and Store-Operated Calcium Entry.

Cancers (Basel) 2020 Aug 24;12(9). Epub 2020 Aug 24.

Department of Anatomy, Histology, Forensic Medicine and Orthopaedics, Unit of Histology and Medical Embryology, SAPIENZA University of Rome, 16 Via A. Scarpa, 00161 Roma, Italy.

Melanoma is one of the most aggressive and treatment-resistant human cancers. The two-pore channel 2 (TPC2) is located on late endosomes, lysosomes and melanosomes. Here, we characterized how TPC2 knockout (KO) affected human melanoma cells derived from a metastatic site. TPC2 KO increased these cells' ability to invade the extracelullar matrix and was associated with the increased expression of mesenchymal markers ZEB-1, Vimentin and N-Cadherin, and the enhanced secretion of MMP9. TPC2 KO also activated genes regulated by YAP/TAZ, which are key regulators of tumourigenesis and metastasis. Expression levels of ORAI1, a component of store-operated Ca entry (SOCE), and PKC-βII, part of the HIPPO pathway that negatively regulates YAP/TAZ activity, were reduced by TPC2 KO and RNA interference knockdown. We propose a cellular mechanism mediated by ORAI1/Ca/PKC-βII to explain these findings. Highlighting their potential clinical significance, patients with metastatic tumours showed a reduction in TPC2 expression. Our research indicates a novel role of TPC2 in melanoma. While TPC2 loss may not activate YAP/TAZ target genes in primary melanoma, in metastatic melanoma it could activate such genes and increase cancer aggressiveness. These findings aid the understanding of tumourigenesis mechanisms and could provide new diagnostic and treatment strategies for skin cancer and other metastatic cancers.
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http://dx.doi.org/10.3390/cancers12092391DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7564716PMC
August 2020

Caveolae and Lipid Rafts in Endothelium: Valuable Organelles for Multiple Functions.

Biomolecules 2020 08 21;10(9). Epub 2020 Aug 21.

Dipartimento di Scienze della Vita e Sanità Pubblica, Sezione di Istologia ed Embriologia, Università Cattolica del Sacro Cuore, Fondazione Policlinico Universitario "Agostino Gemelli", IRCCS, 00168 Roma, Italia.

Caveolae are flask-shaped invaginations of the plasma membrane found in numerous cell types and are particularly abundant in endothelial cells and adipocytes. The lipid composition of caveolae largely matches that of lipid rafts microdomains that are particularly enriched in cholesterol, sphingomyelin, glycosphingolipids, and saturated fatty acids. Unlike lipid rafts, whose existence remains quite elusive in living cells, caveolae can be clearly distinguished by electron microscope. Despite their similar composition and the sharing of some functions, lipid rafts appear more heterogeneous in terms of size and are more dynamic than caveolae. Following the discovery of caveolin-1, the first molecular marker as well as the unique scaffolding protein of caveolae, we have witnessed a remarkable increase in studies aimed at investigating the role of these organelles in cell functions and human disease. The goal of this review is to discuss the most recent studies related to the role of caveolae and caveolins in endothelial cells. We first recapitulate the major embryological processes leading to the formation of the vascular tree. We next discuss the contribution of caveolins and cavins to membrane biogenesis and cell response to extracellular stimuli. We also address how caveolae and caveolins control endothelial cell metabolism, a central mechanism involved in migration proliferation and angiogenesis. Finally, as regards the emergency caused by COVID-19, we propose to study the caveolar platform as a potential target to block virus entry into endothelial cells.
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http://dx.doi.org/10.3390/biom10091218DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7563503PMC
August 2020

Effect of direct renin inhibition on vascular function after long-term treatment with aliskiren in hypertensive and diabetic patients.

J Hypertens 2021 Jan;39(1):169-180

Clinica Medica, Department of Clinical and Experimental Sciences, University of Brescia, Brescia.

Objective: We tested the hypothesis that chronic treatment with the direct renin inhibitor aliskiren improves vascular function in resistance and conduit arteries of type two diabetic and hypertensive patients.

Method: Sixteen patients with mild essential hypertension and with a previous diagnosis of noninsulin-dependent diabetes mellitus were included in the study. Patients were then randomized to aliskiren (150 mg once daily, n = 9), or ramipril (5 mg once daily, n = 7). Each patient underwent a biopsy of the subcutaneous tissue and small arteries were dissected and mounted on a pressurized micromyograph to evaluate endothelium dependent vasorelaxation in response to acetylcholine ± N omega-nitro-L-arginine methyl ester hydrochloride in vessels precontracted with norepinephrine. Endothelial function has been quantified also in large conduit arteries by flow-mediated dilation.

Results: A similar office blood pressure-lowering effect was observed with the two drugs, although changes in DBP were not statistically significant in the ramipril group. Aliskiren significantly improved endothelium-dependent relaxation in subcutaneous resistance arteries, as well as increased flow-mediated dilation in conduit arteries, whereas the effects induced by ramipril did not reach statistical significance. Only aliskiren significantly increased the expression of p1177-endothelial nitric oxide synthase in the endothelium. Both aliskiren and ramipril had a negligible effect on markers of oxidative stress.

Conclusion: Aliskiren restored endothelial function and induced a more prompt peripheral vasodilation in hypertensive and diabetic patients possibly through the increased production of nitric oxide via the enhanced expression and function of the active phosphorylated form of endothelial nitric oxide synthase.
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http://dx.doi.org/10.1097/HJH.0000000000002595DOI Listing
January 2021

Circular RNAs in Embryogenesis and Cell Differentiation With a Focus on Cancer Development.

Front Cell Dev Biol 2020 27;8:389. Epub 2020 May 27.

Department of Anatomical, Histological, Forensic & Orthopedic Sciences, Section of Histology & Medical Embryology, Sapienza University of Rome, Rome, Italy.

In the recent years thousands of non-coding RNAs have been identified, also thanks to highthroughput sequencing technologies. Among them, circular RNAs (circRNAs) are a well-represented class characterized by the high sequence conservation and cell type specific expression in eukaryotes. They are covalently closed loops formed through back-splicing. Recently, circRNAs were shown to regulate a variety of cellular processes functioning as miRNA sponges, RBP binding molecules, transcriptional regulators, scaffold for protein translation, as well as immune regulators. A growing number of studies are showing that deregulated expression of circRNAs plays important and decisive actions during the development of several human diseases, including cancer. The research on their biogenesis and on the various molecular mechanisms in which they are involved is going very fast, however, there are still few studies that address their involvement in embryogenesis and eukaryotic development. This review has the intent to describe the most recent progress in the study of the biogenesis and molecular activities of circRNAs providing insightful information in the field of embryogenesis and cell differentiation. In addition, we describe the latest research on circRNAs as novel promising biomarkers in diverse types of tumors.
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http://dx.doi.org/10.3389/fcell.2020.00389DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7266935PMC
May 2020

Altered Tregs Differentiation and Impaired Autophagy Correlate to Atherosclerotic Disease.

Front Immunol 2020 13;11:350. Epub 2020 Mar 13.

Unit of Histology and Medical Embryology, Department of Anatomy, Histology, Forensic Medicine and Orthopaedics, Sapienza University of Rome, Rome, Italy.

Atherosclerosis is a progressive vascular disease representing the primary cause of morbidity and mortality in developed countries. Formerly, atherosclerosis was considered as a mere passive accumulation of lipids in blood vessels. However, it is now clear that atherosclerosis is a complex and multifactorial disease, in which the involvement of immune cells and inflammation play a key role. A variety of studies have shown that autophagy-a cellular catalytic mechanism able to remove injured cytoplasmic components in response to cellular stress-may be proatherogenic. So far, in this context, its role has been investigated in smooth muscle cells, macrophages, and endothelial cells, while the function of this catabolic protective process in lymphocyte functionality has been overlooked. The few studies carried out so far, however, suggested that autophagy modulation in lymphocyte subsets may be functionally related to plaque formation and development. Therefore, in this research, we aimed at better clarifying the role of lymphocyte subsets, mainly regulatory T cells (Tregs), in human atherosclerotic plaques and in animal models of atherosclerosis investigating the contribution of autophagy on immune cell homeostasis. Here, we investigate basal autophagy in a mouse model of atherosclerosis, apolipoprotein E (ApoE)-knockout (KO) mice, and we analyze the role of autophagy in driving Tregs polarization. We observed defective maturation of Tregs from ApoE-KO mice in response to tumor growth factor-β (TGFβ). TGFβ is a well-known autophagy inducer, and Tregs maturation defects in ApoE-KO mice seem to be related to autophagy impairment. In this work, we propose that autophagy underlies Tregs maturation, advocating that the study of this process in atherosclerosis may open new therapeutic strategies.
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http://dx.doi.org/10.3389/fimmu.2020.00350DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7082762PMC
March 2021

Modulating the dose-rate differently affects the responsiveness of human epithelial prostate- and mesenchymal rhabdomyosarcoma-cancer cell line to radiation.

Int J Radiat Biol 2020 06 23;96(6):823-835. Epub 2020 Mar 23.

Department of Radiology, Radiotherapy, Oncology, Anatomopathology, "Sapienza" University of Rome, Rome, Italy.

Radiation therapy (RT), by using ionizing radiation (IR), destroys cancer cells inducing DNA damage. Despite several studies are continuously performed to identify the best curative dose of IR, the role of dose-rate, IR delivered per unit of time, on tumor control is still largely unknown. Rhabdomyosarcoma (RMS) and prostate cancer (PCa) cell lines were irradiated with 2 or 10 Gy delivered at dose-rates of 1.5, 2.5, 5.5 and 10.1 Gy/min. Cell-survival rate and cell cycle distribution were evaluated by clonogenic assays and flow cytometry, respectively. The production of reactive oxygen species (ROS) was detected by cytometry. Quantitative polymerase chain reaction assessed the expression of anti-oxidant-related factors including NRF2, SODs, CAT and GPx4 and miRNAs (miR-22, -126, -210, -375, -146a, -34a). Annexin V and caspase-8, -9 and -3 activity were assessed to characterize cell death. Senescence was determined by assessing β-galactosidase (SA-β-gal) activity. Immunoblotting was performed to assess the expression/activation of: i) phosphorylated H2AX (γ-H2AX), markers of DNA double strand breaks (DSBs); ii) p19, p21 and p27, senescence-related-markers; iii) p62, LC3-I and LC3-II, regulators of autophagy; iv) ATM, RAD51, DNA-PKcs, Ku70 and Ku80, mediators of DSBs repair. Low dose-rate (LDR) more efficiently induced apoptosis and senescence in RMS while high dose-rate (HDR) necrosis in PCa. This paralleled with a lower ability of LDR-RMS and HDR-PCa irradiated cells to activate DSBs repair. Modulating the dose rate did not differently affect the anti-oxidant ability of cancer cells. The present results indicate that a stronger cytotoxic effect was induced by modulating the dose-rate in a cancer cell-dependent manner, this suggesting that choose the dose-rate based on the individual patient's tumor characteristics could be strategic for effective RT exposures.
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http://dx.doi.org/10.1080/09553002.2020.1739774DOI Listing
June 2020

Calcium Mobilization in Endothelial Cell Functions.

Int J Mol Sci 2019 Sep 12;20(18). Epub 2019 Sep 12.

Istituto di Istologia ed Embriologia, Università Cattolica del Sacro Cuore, Fondazione Policlinico Universitario "Agostino Gemelli", IRCCS, 00168 Rome, Italy.

Endothelial cells (ECs) constitute the innermost layer that lines all blood vessels from the larger arteries and veins to the smallest capillaries, including the lymphatic vessels. Despite the histological classification of endothelium of a simple epithelium and its homogeneous morphological appearance throughout the vascular system, ECs, instead, are extremely heterogeneous both structurally and functionally. The different arrangement of cell junctions between ECs and the local organization of the basal membrane generate different type of endothelium with different permeability features and functions. Continuous, fenestrated and discontinuous endothelia are distributed based on the specific function carried out by the organs. It is thought that a large number ECs functions and their responses to extracellular cues depend on changes in intracellular concentrations of calcium ion ([Ca]). The extremely complex calcium machinery includes plasma membrane bound channels as well as intracellular receptors distributed in distinct cytosolic compartments that act jointly to maintain a physiological [Ca], which is crucial for triggering many cellular mechanisms. Here, we first survey the overall notions related to intracellular Ca mobilization and later highlight the involvement of this second messenger in crucial ECs functions with the aim at stimulating further investigation that link Ca mobilization to ECs in health and disease.
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http://dx.doi.org/10.3390/ijms20184525DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6769945PMC
September 2019

Stem-like and highly invasive prostate cancer cells expressing CD44v8-10 marker originate from CD44-negative cells.

Oncotarget 2018 Jul 20;9(56):30905-30918. Epub 2018 Jul 20.

Department of Anatomy, Histology, Forensic Medicine and Orthopaedics, Section of Histology and Medical Embryology, Sapienza University, Rome, Italy.

In human prostate cancer (PCa), the neuroendocrine cells, expressing the prostate cancer stem cell (CSC) marker CD44, may be resistant to androgen ablation and promote tumor recurrence. During the study of heterogeneity of the highly aggressive neuroendocrine PCa cell lines PC3 and DU-145, we isolated and expanded a minor subpopulation of very small cells lacking CD44 (CD44). Unexpectedly, these sorted CD44 cells rapidly and spontaneously converted to a stable CD44 phenotype specifically expressing the CD44v8-10 isoform which the sorted CD44 subpopulation failed to express. Surprisingly and potentially interesting, in these cells expression of CD44v8-10 was found to be induced in stem cell medium. CD44 variant isoforms are known to be more expressed in CSC and metastatic cells than CD44 standard isoform. In agreement, functional analysis of the two sorted and cultured subpopulations has shown that the CD44v8-10 PC3 cells, resulting from the conversion of the CD44 subpopulation, were more invasive and had a higher clonogenic potential than the sorted CD44 cells, in that they produced mainly holoclones, known to be enriched in stem-like cells. Of interest, the CD44v8-10 is more expressed in human PCa biopsies than in normal gland. The discovery of CD44v8-10 cells with stem-like and invasive features, derived from a minoritarian CD44 cell population in PCa, alerts on the high plasticity of stem-like markers and urges for prudency on the approaches to targeting the putative CSC.
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http://dx.doi.org/10.18632/oncotarget.25773DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6089404PMC
July 2018

The caveolar membrane system in endothelium: From cell signaling to vascular pathology.

J Cell Biochem 2018 07 10;119(7):5060-5071. Epub 2018 Apr 10.

Istituto di Istologia ed Embriologia, Università Cattolica del Sacro Cuore, Rome, Italy.

Caveolae are 50- to 100-nm cholesterol and glycosphingolipid-rich flask-shaped invaginations commonly observed in many terminally differentiated cells. These organelles have been described in many cell types and are particularly abundant in endothelial cells, where they have been involved in the regulation of certain signaling pathways. Specific scaffolding proteins termed caveolins, along with the more recently discovered members of the cavin family, represent the major protein components during caveolae biogenesis. In addition, multiple studies aimed to investigate the expression and the regulation of these proteins significantly contributed to elucidate the role of caveolae and caveolins in endothelial cell physiology and disease. The aim of this review is to survey recent evidence of the involvement of the caveolar network in endothelial cell biology and endothelial cell dysfunction.
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http://dx.doi.org/10.1002/jcb.26793DOI Listing
July 2018

Multifaceted Roles of GSK-3 in Cancer and Autophagy-Related Diseases.

Oxid Med Cell Longev 2017 12;2017:4629495. Epub 2017 Dec 12.

Department of Anatomical, Histological, Forensic Medicine and Orthopedic Sciences, Sapienza University of Rome, Rome, Italy.

GSK-3 is a ubiquitously expressed serine/threonine kinase existing as GSK-3 and GSK-3 isoforms, both active under basal conditions and inactivated upon phosphorylation by different upstream kinases. Initially discovered as a regulator of glycogen synthesis, GSK-3 is also involved in several signaling pathways controlling many different key functions. Here, we discuss recent advances regarding (i) GSK-3 structure, function, regulation, and involvement in several cancers, including hepatocarcinoma, cholangiocarcinoma, breast cancer, prostate cancer, leukemia, and melanoma (active GSK-3 has been shown to induce apoptosis in some cases or inhibit apoptosis in other cases and to induce cancer progression or inhibit tumor cell proliferation, suggesting that different GSK-3 modulators may address different specific targets); (ii) GSK-3 involvement in autophagy modulation, reviewing signaling pathways involved in neurodegenerative and liver diseases; (iii) GSK-3 role in oxidative stress and autophagic cell death, focusing on liver injury; (iv) GSK-3 as a possible therapeutic target of natural substances and synthetic inhibitors in many diseases; and (v) GSK-3 role as modulator of mammalian aging, related to metabolic alterations characterizing senescent cells and age-related diseases. Studies summarized here underline the GSK-3 multifaceted role and indicate such kinase as a molecular target in different pathologies, including diseases associated with autophagy dysregulation.
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http://dx.doi.org/10.1155/2017/4629495DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5742885PMC
August 2018

Ned-19 inhibition of parasite growth and multiplication suggests a role for NAADP mediated signalling in the asexual development of Plasmodium falciparum.

Malar J 2017 09 12;16(1):366. Epub 2017 Sep 12.

Department of Anatomy, Histology, Forensic Medicine and Orthopedics, Section of Histology and Medical Embryology, Sapienza University of Rome, Rome, Italy.

Background: Although malaria is a preventable and curable human disease, millions of people risk to be infected by the Plasmodium parasites and to develop this illness. Therefore, there is an urgent need to identify new anti-malarial drugs. Ca signalling regulates different processes in the life cycle of Plasmodium falciparum, representing a suitable target for the development of new drugs.

Results: This study investigated for the first time the effect of a highly specific inhibitor of nicotinic acid adenine dinucleotide phosphate (NAADP)-induced Ca release (Ned-19) on P. falciparum, revealing the inhibitory effect of this compound on the blood stage development of this parasite. Ned-19 inhibits both the transition of the parasite from the early to the late trophozoite stage and the ability of the late trophozoite to develop to the multinucleated schizont stage. In addition, Ned-19 affects spontaneous intracellular Ca oscillations in ring and trophozoite stage parasites, suggesting that the observed inhibitory effects may be associated to regulation of intracellular Ca levels.

Conclusions: This study highlights the inhibitory effect of Ned-19 on progression of the asexual life cycle of P. falciparum. The observation that Ned-19 inhibits spontaneous Ca oscillations suggests a potential role of NAADP in regulating Ca signalling of P. falciparum.
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http://dx.doi.org/10.1186/s12936-017-2013-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5596470PMC
September 2017

Naringenin Impairs Two-Pore Channel 2 Activity And Inhibits VEGF-Induced Angiogenesis.

Sci Rep 2017 07 11;7(1):5121. Epub 2017 Jul 11.

Institute of Biophysics - CNR, Via De Marini 6, 16149, Genoa, Italy.

Our research introduces the natural flavonoid naringenin as a novel inhibitor of an emerging class of intracellular channels, Two-Pore Channel 2 (TPC2), as shown by electrophysiological evidence in a heterologous system, i.e. Arabidopsis vacuoles lacking endogenous TPCs. In view of the control exerted by TPC2 on intracellular calcium signaling, we demonstrated that naringenin dampens intracellular calcium responses of human endothelial cells stimulated with VEGF, histamine or NAADP-AM, but not with ATP or Angiopoietin-1 (negative controls). The ability of naringenin to impair TPC2-dependent biological activities was further explored in an established in vivo model, in which VEGF-containing matrigel plugs implanted in mice failed to be vascularized in the presence of naringenin. Overall, the present data suggest that naringenin inhibition of TPC2 activity and the observed inhibition of angiogenic response to VEGF are linked by impaired intracellular calcium signaling. TPC2 inhibition is emerging as a key therapeutic step in a range of important pathological conditions including the progression and metastatic potential of melanoma, Parkinson's disease, and Ebola virus infection. The identification of naringenin as an inhibitor of TPC2-mediated signaling provides a novel and potentially relevant tool for the advancement of this field of research.
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http://dx.doi.org/10.1038/s41598-017-04974-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5505983PMC
July 2017

Lipid Storage and Autophagy in Melanoma Cancer Cells.

Int J Mol Sci 2017 Jun 15;18(6). Epub 2017 Jun 15.

Department of Anatomy, Histology, Forensic Medicine and Orthopedics, Sapienza University of Rome, Rome 00161, Italy.

Cancer stem cells (CSC) represent a key cellular subpopulation controlling biological features such as cancer progression in all cancer types. By using melanospheres established from human melanoma patients, we compared less differentiated melanosphere-derived CSC to differentiating melanosphere-derived cells. Increased lipid uptake was found in melanosphere-derived CSC vs. differentiating melanosphere-derived cells, paralleled by strong expression of lipogenic factors Sterol Regulatory Element-Binding Protein-1 (SREBP-1) and Peroxisome Proliferator-Activated Receptor-γ (PPAR-γ). An inverse relation between lipid-storing phenotype and autophagy was also found, since microtubule-associated protein 1A/1B-Light Chain 3 (LC3) lipidation is reduced in melanosphere-derived CSC. To investigate upstream autophagy regulators, Phospho-AMP activated Protein Kinase (P-AMPK) and Phospho-mammalian Target of Rapamycin (P-mTOR) were analyzed; lower P-AMPK and higher P-mTOR expression in melanosphere-derived CSC were found, thus explaining, at least in part, their lower autophagic activity. In addition, co-localization of LC3-stained autophagosome spots and perilipin-stained lipid droplets was demonstrated mainly in differentiating melanosphere-derived cells, further supporting the role of autophagy in lipid droplets clearance. The present manuscript demonstrates an inverse relationship between lipid-storing phenotype and melanoma stem cells differentiation, providing novel indications involving autophagy in melanoma stem cells biology.
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http://dx.doi.org/10.3390/ijms18061271DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5486093PMC
June 2017

Microvascular Alterations in Hypertension and Vascular Aging.

Curr Hypertens Rev 2017 ;13(1):16-23

Department of Anatomical Sciences, Histological, Legal Medical and Locomotor Sapienza University of Rome, Rome, Italy.

Hypertension and aging are characterized by vascular remodelling and stiffness as well as endothelial dysfunction. Endothelial function declines with age, since aging is associated with senescence of the endothelium due to increased rate of apoptosis and reduced regenerative capacity of the endothelium. Different phenotypes of hypertension have been described in younger and adult subjects with hypertension. In younger patients, functional and structural alterations of resistance arteries occur as the earliest vascular alterations which have prognostic significance and may contribute to stiffness of large arteries through wave reflection. In individuals above age of 50 years as well as in subjects with long-lasting elevated blood pressure, vascular changes occur predominantly in conduit arteries which become stiffer. Activation of renin-angiotensin-aldosterone and endothelin systems plays a key role in endothelial dysfunction, vascular remodelling, and aging by inducing reactive oxygen species production, and promoting inflammation and cell growth.
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http://dx.doi.org/10.2174/1573402113666170505115010DOI Listing
December 2017

A novel role of c-FLIP protein in regulation of ER stress response.

Cell Signal 2016 09 3;28(9):1262-9. Epub 2016 Jun 3.

Department of Anatomy, Histology, Forensic Medicine and Orthopedics, Sapienza University of Rome, 00161 Rome, Italy. Electronic address:

Cellular-Flice-like inhibitory protein (c-FLIP) is an apoptosis modulator known to inhibit the extrinsic apoptotic pathway thus blocking Caspase-8 processing in the Death Inducing Signalling Complex (DISC). We previously demonstrated that c-FLIP localizes at the endoplasmic reticulum (ER) and that c-FLIP-deficient mouse embryonic fibroblasts (MEFs) display an enlarged ER morphology. In the present study, we have addressed the consequences of c-FLIP ablation in the ER stress response by investigating the effects of pharmacologically-induced ER stress in Wild Type (WT) and c-FLIP-/- MEFs. Surprisingly, c-FLIP-/- MEFs were found to be strikingly more resistant than WT MEFs to ER stress-mediated apoptosis. Analysis of Unfolded Protein Response (UPR) pathways revealed that Pancreatic ER Kinase (PERK) and Inositol-Requiring Enzyme 1 (IRE1) branch signalling is compromised in c-FLIP-/- cells when compared with WT cells. We found that c-FLIP modulates the PERK pathway by interfering with the activity of the serine threonine kinase AKT. Indeed, c-FLIP-/- MEFs display higher levels of active AKT than WT MEFs upon ER stress, while treatment with a specific AKT inhibitor of c-FLIP-/- MEFs subjected to ER stress restores the PERK but not the IRE1 pathway. Importantly, the AKT inhibitor or dominant negative AKT transfection sensitizes c-FLIP-/- cells to ER stress-induced cell death while the expression of a constitutively active AKT reduces WT cells sensitivity to ER stress-induced death. Thus, our results demonstrate that c-FLIP modulation of AKT activity is crucial in controlling PERK signalling and sensitivity to ER stress, and highlight c-FLIP as a novel molecular player in PERK and IRE1-mediated ER stress response.
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http://dx.doi.org/10.1016/j.cellsig.2016.06.003DOI Listing
September 2016

NAADP-Dependent Ca(2+) Signaling Controls Melanoma Progression, Metastatic Dissemination and Neoangiogenesis.

Sci Rep 2016 Jan 6;6:18925. Epub 2016 Jan 6.

Department of Anatomy, Histology, Forensic Medicine and Orthopaedics, Unit of Histology and Medical Embryology,SAPIENZA University of Rome, 16 Via A. Scarpa, 00161 Rome, Italy.

A novel transduction pathway for the powerful angiogenic factor VEGF has been recently shown in endothelial cells to operate through NAADP-controlled intracellular release of Ca(2+). In the present report the possible involvement of NAADP-controlled Ca(2+) signaling in tumor vascularization, growth and metastatic dissemination was investigated in a murine model of VEGF-secreting melanoma. Mice implanted with B16 melanoma cells were treated with NAADP inhibitor Ned-19 every second day for 4 weeks and tumor growth, vascularization and metastatization were evaluated. Control specimens developed well vascularized tumors and lung metastases, whereas in Ned-19-treated mice tumor growth and vascularization as well as lung metastases were strongly inhibited. In vitro experiments showed that Ned-19 treatment controls the growth of B16 cells in vitro, their migratory ability, adhesive properties and VEGFR2 expression, indicating NAADP involvement in intercellular autocrine signaling. To this regard, Ca(2+) imaging experiments showed that the response of B16 cells to VEGF stimulation is NAADP-dependent. The whole of these observations indicate that NAADP-controlled Ca(2+) signaling can be relevant not only for neoangiogenesis but also for direct control of tumor cells.
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http://dx.doi.org/10.1038/srep18925DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4702115PMC
January 2016

Cancer Microenvironment and Endoplasmic Reticulum Stress Response.

Mediators Inflamm 2015 27;2015:417281. Epub 2015 Sep 27.

Istituto Pasteur-Fondazione Cenci Bolognetti, Department of Anatomy, Histology, Forensic Medicine and Orthopedics, Section of Histology and Medical Embryology, Sapienza University of Rome, 00161 Rome, Italy.

Different stressful conditions such as hypoxia, nutrient deprivation, pH changes, or reduced vascularization, potentially able to act as growth-limiting factors for tumor cells, activate the unfolded protein response (UPR). UPR is therefore involved in tumor growth and adaptation to severe environments and is generally cytoprotective in cancer. The present review describes the molecular mechanisms underlying UPR and able to promote survival and proliferation in cancer. The critical role of UPR activation in tumor growth promotion is discussed in detail for a few paradigmatic tumors such as prostate cancer and melanoma.
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http://dx.doi.org/10.1155/2015/417281DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4600498PMC
June 2016

Regulation of Angiogenic Functions by Angiopoietins through Calcium-Dependent Signaling Pathways.

Biomed Res Int 2015 4;2015:965271. Epub 2015 Jun 4.

Department of Anatomy, Histology, Forensic Medicine and Orthopaedics, Unit of Histology and Medical Embryology, Sapienza University of Rome, 00161 Rome, Italy.

Angiopoietins are vascular factors essential for blood vessel assembly and correct organization and maturation. This study describes a novel calcium-dependent machinery activated through Angiopoietin-1/2-Tie receptor system in HUVECs monolayer. Both cytokines were found to elicit intracellular calcium mobilization. Targeting intracellular Ca(2+) signaling, antagonizing IP3 with 2-APB or cADPR with 8Br-cADPR, was found to modulate in vitro angiogenic responses to Angiopoietins in a specific way. 2-APB and 8Br-cADPR impaired the phosphorylation of AKT and FAK induced by Ang-1 and Ang-2. On the other hand, phosphorylation of ERK1/2 and p38, as well as cell proliferation, was not affected by either inhibitor. The ability of ECs to migrate following Angs stimulation, evaluated by "scratch assay," was reduced by either 2-APB or 8Br-cADPR following Ang-2 stimulation and only slightly affected by 2-APB in cells stimulated with Ang-1. These results identify a novel calcium-dependent machinery involved in the complex interplay regulating angiogenic processes showing that IP3- and cADPR-induced Ca(2+) release specifically regulates distinct Angs-mediated angiogenic steps.
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http://dx.doi.org/10.1155/2015/965271DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4471310PMC
March 2016

c-Flip KO fibroblasts display lipid accumulation associated with endoplasmic reticulum stress.

Biochim Biophys Acta 2015 Jul 5;1851(7):929-36. Epub 2015 Mar 5.

Istituto Pasteur-Fondazione Cenci Bolognetti, Department of Anatomy, Histology, Forensic Medicine and Orthopedics, Section of Histology and Medical Embryology, Sapienza University of Rome, Rome, Italy.

c-Flip proteins are well-known apoptosis modulators. They generally contribute to tissue homeostasis maintenance by inhibiting death-receptor-mediated cell death. In the present manuscript, we show that c-Flip knock-out (KO) mouse embryonic fibroblasts (MEFs) kept in culture under starvation conditions gradually modify their phenotype and accumulate vacuoles, becoming progressively larger according to the duration of starvation. Large vacuoles are present in KO MEFs though not in WT MEFs, and are Oil Red-O positive, which indicates that they represent lipid droplets. Western blot experiments reveal that, unlike WT MEFs, KO MEFs express high levels of the lipogenic transcription factor PPAR-γ. Lipid droplet accumulation was found to be associated with endoplasmic reticulum (ER) stress activation and autophagic modulation valuated by means of BIP increase, LC3 lipidation and AMP-activated protein kinase (AMPK) phosphorylation, and p62 accumulation. Interestingly, XBP-1, an ER stress-induced lipogenic transcription factor, was found to preferentially localize in the nucleus rather than in the cytoplasm of KO MEFs. These data demonstrate that, upon starvation, c-Flip affects lipid accumulation, ER stress and autophagy, thereby pointing to an important role of c-Flip in the adaptive response and ER stress response programs under both normal and pathological conditions.
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http://dx.doi.org/10.1016/j.bbalip.2015.02.018DOI Listing
July 2015

Transfected poly(I:C) activates different dsRNA receptors, leading to apoptosis or immunoadjuvant response in androgen-independent prostate cancer cells.

J Biol Chem 2015 Feb 7;290(9):5470-83. Epub 2015 Jan 7.

From the Istituto Pasteur-Fondazione Cenci Bolognetti, Department of Anatomy, Histology, Forensic Medicine, and Orthopedics, Section of Histology and Medical Embryology, "Sapienza" University of Rome, Rome, Italy and

Despite the effectiveness of surgery or radiation therapy for the treatment of early-stage prostate cancer (PCa), there is currently no effective strategy for late-stage disease. New therapeutic targets are emerging; in particular, dsRNA receptors Toll-like receptor 3 (TLR3) and cytosolic helicases expressed by cancer cells, once activated, exert a pro-apoptotic effect in different tumors. We previously demonstrated that the synthetic analog of dsRNA poly(I:C) induces apoptosis in the androgen-dependent PCa cell line LNCaP in a TLR3-dependent fashion, whereas only a weak apoptotic effect is observed in the more aggressive and androgen-independent PCa cells PC3 and DU145. In this paper, we characterize the receptors and the signaling pathways involved in the remarkable apoptosis induced by poly(I:C) transfected by Lipofectamine (in-poly(I:C)) compared with the 12-fold higher free poly(I:C) concentration in PC3 and DU145 cells. By using genetic inhibition of different poly(I:C) receptors, we demonstrate the crucial role of TLR3 and Src in in-poly(I:C)-induced apoptosis. Therefore, we show that the increased in-poly(I:C) apoptotic efficacy is due to a higher binding of endosomal TLR3. On the other hand, we show that in-poly(I:C) binding to cytosolic receptors MDA5 and RIG-I triggers IRF3-mediated signaling, leading uniquely to the up-regulation of IFN-β, which likely in turn induces increased TLR3, MDA5, and RIG-I proteins. In summary, in-poly(I:C) activates two distinct antitumor pathways in PC3 and DU145 cells: one mediated by the TLR3/Src/STAT1 axis, leading to apoptosis, and the other one mediated by MDA5/RIG-I/IRF3, leading to immunoadjuvant IFN-β expression.
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http://dx.doi.org/10.1074/jbc.M114.601625DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4342463PMC
February 2015

TLR3 engagement induces IRF-3-dependent apoptosis in androgen-sensitive prostate cancer cells and inhibits tumour growth in vivo.

J Cell Mol Med 2015 Feb 2;19(2):327-39. Epub 2014 Dec 2.

Istituto Pasteur-Fondazione Cenci Bolognetti, Department of Anatomy, Histology, Forensic Medicine and Orthopedics, Section of Histology and Medical Embryology, Sapienza University of Rome, Rome, Italy.

Toll-like receptors (TLRs) are a family of highly conserved transmembrane proteins expressed in epithelial and immune cells that recognize pathogen associated molecular patterns. Besides their role in immune response against infections, numerous studies have shown an important role of different TLRs in cancer, indicating these receptors as potential targets for cancer therapy. We previously demonstrated that the activation of TLR3 by the synthetic double-stranded RNA analogue poly I:C induces apoptosis of androgen-sensitive prostate cancer (PCa) LNCaP cells and, much less efficiently, of the more aggressive PC3 cell line. Therefore, in this study we selected LNCaP cells to investigate the mechanism of TLR3-mediated apoptosis and the in vivo efficacy of poly I:C-based therapy. We show that interferon regulatory factor-3 (IRF-3) signalling plays an essential role in TLR3-mediated apoptosis in LNCaP cells through the activation of the intrinsic and extrinsic apoptotic pathways. Interestingly, hardly any apoptosis was induced by poly I:C in normal prostate epithelial cells RWPE-1. We also demonstrate for the first time the direct anticancer effect of poly I:C as a single therapeutic agent in a well-established human androgen-sensitive PCa xenograft model, by showing that tumour growth is highly impaired in poly I:C-treated immunodeficient mice. Immunohistochemical analysis of PCa xenografts highlights the antitumour role of poly I:C in vivo both on cancer cells and, indirectly, on endothelial cells. Notably, we show the presence of TLR3 and IRF-3 in both human normal and PCa clinical samples, potentially envisaging poly I:C-based therapy for PCa.
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http://dx.doi.org/10.1111/jcmm.12379DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4407608PMC
February 2015