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Chronic myeloid leukemia (CML) is a myeloproliferative disorder characterized by accumulation of immature cells in bone marrow and peripheral blood. Although successful results were obtained with tyrosine kinase inhibitors, several patients showed resistance. For this reason, the identification of new strategies and therapeutic biomarkers represents an attractive goal. The role of transient receptor potential (TRP) ion channels as possible drug targets has been elucidated in different types of cancer. Among natural compounds known to activate TRPs, cannabidiol (CBD) displays anticancer properties. By using FACS analysis, confocal microscopy, gene silencing, and cell growth assay, we demonstrated that CBD, through TRPV2, inhibits cell proliferation and cell cycle in CML cells. It promoted mitochondria dysfunction and mitophagy as shown by mitochondrial mass reduction and up-regulation of several mitophagy markers. These effects were associated with changes in the expression of octamer-binding transcription factor 4 and PU.1 markers regulated during cellular differentiation. Interestingly, a synergistic effect by combining CBD with the standard drug imatinib was found and imatinib-resistant cells remain susceptible to CBD effects. Therefore, the targeting of TRPV2 by using CBD, through the activation of mitophagy and the reduction in stemness, could be a promising strategy to enhance conventional therapy and improve the prognosis of CML patients.

Introduction: Calcium flux is the master second messenger that influences the proliferation–apoptosis balance. The ability of calcium flux alterations to reduce cell growth makes ion channels interesting targets for therapy. Among all, we focused on transient receptor potential vanilloid 1, a ligand-gated cation channel with selectivity for calcium. Its involvement in hematological malignancies is poorly investigated, especially in the field of chronic myeloid leukemia, a malignancy characterized by the accumulation of immature cells.Methods: FACS analysis, Western blot analysis, gene silencing, and cell viability assay were performed to investigate the activation of transient receptor potential vanilloid 1, by N-oleoyl-dopamine, in chronic myeloid leukemia cell lines.Results: We demonstrated that the triggering of transient receptor potential vanilloid 1 inhibits cell growth and promotes apoptosis of chronic myeloid leukemia cells. Its activation induced calcium influx, oxidative stress, ER stress, mitochondria dysfunction, and caspase activation. Interestingly, a synergistic effect exerted by N-oleoyl-dopamine and the standard drug imatinib was found.Conclusion: Overall, our results support that transient receptor potential vanilloid 1 activation could be a promising strategy to enhance conventional therapy and improve the management of chronic myeloid leukemia.

Glioblastoma is the most aggressive malignant tumor overall and remains an incurable neoplasm with a median survival of 15 months. Since 2005, the gold standard treatment for glioblastoma has remained unchanged, and it is a common goal of the scientific community to work towards a better prognosis and improved survival for glioblastoma patients. Herein, we report a case of glioblastoma multiforme in a patient with a poor prognosis who, following partial removal of the neoplasm, refused conventional therapy consisting of a combination of radiotherapy and temozolomide-based chemotherapy due to personal serious side effects. The patient started an unconventional therapeutic path by alternating periods of oxygen–ozone therapy with concomitant administration of legal medical cannabis products (Bedrocan and Bedrolite) and melatonin. This approach resulted in a complete and durable remission of the disease and long survival. Indeed, the patient is still alive. The exceptional result obtained here encourages us to share and carefully investigate this unconventional treatment as a possible future direction in the management of glioblastoma.

Evening Primrose oil (EPO), obtained from the seeds of Evening Primrose (Oenothera L.), is largely used as a dietary supplement, especially after cancer diagnosis. Human pancreatic ductal adenocarcinoma (PDAC) is an aggressive disease correlated with poor clinical prognosis and a very low response rate to common chemotherapy. The aim of this work was to study the potential ability of EPO to improve the effects of chemotherapeutic drugs in PANC-1 and MIAPaCa-2 cell lines. Cytotoxicity, cell death, reactive oxygen species (ROS) production and EPO anticancer activity associated with the main chemotherapeutic drugs commonly used in therapy were investigated. Results showed that EPO reduced PDAC cell viability and increased paclitaxel efficacy. This evidence suggests that EPO may be used as a potential supplement to increase chemotherapeutic efficacy in PDAC therapy.

This Special Issue in Biomolecules explores the roles of Transient Receptor Potential channels (TRPs) in cancer [...]

Among cancers that affect the central nervous system, glioblastoma is the most common. Given the negative prognostic significance of transient receptor potential mucolipin 1 (TRPML1) channel reduction in patients with glioblastoma, as discussed in previous publications, the aim of the current study was to investigate the biological advantage of TRPML1 loss for glioma cells. Human glioblastoma primary cancer cells (FSL and FCL) and glioblastoma cell lines (T98 and U251) were used for that purpose. TRPML1 silencing in T98 cells induces defective autophagy, nitric oxide (NO) production, and cathepsin B-dependent apoptosis in the first 48 h and then apoptotic-resistant cells proliferate with a high growth rate with respect to control cells. In U251 cells, knock-down of TRPML1 stimulates NO generation and protein oxidation, arrests cell cycle at G2/M phase, and induces autophagy leading to cathepsin B-dependent senescence. Finally, in both cell lines, the long-term effects of TRPML1 silencing promote survival and invasion capacity with respect to control cells. Silencing of TRPML1 also affects the phenotype of glioblastoma primary cells. FSL cells show increased proliferation ability, while FCL cells enter into senescence associated with an increased invasion ability. In conclusion, although the molecular heterogeneity among different glioblastoma cell lines mirrors the intercellular heterogeneity in cancer cells, our data support TRPML1 downregulation as a negative prognostic factor in glioblastoma.

Glioblastoma (GBM) is the most malignant glioma with an extremely poor prognosis. It is characterized by high vascularization and its growth depends on the formation of new blood vessels. We have previously demonstrated that TRPML2 mucolipin channel expression increases with the glioma pathological grade. Herein by ddPCR and Western blot we found that the silencing of TRPML2 inhibits expression of the VEGFA/Notch2 angiogenic pathway. Moreover, the VEGFA/Notch2 expression increased in T98 and U251 cells stimulated with the TRPML2 agonist, ML2-SA1, or by enforced-TRPML2 levels. In addition, changes in TRPML2 expression or ML2-SA1-induced stimulation, affected Notch2 activation and VEGFA release. An increased invasion capability, associated with a reduced VEGF/VEGFR2 expression and increased vimentin and CD44 epithelial-mesenchymal transition markers in siTRPML2, but not in enforced-TRPML2 or ML2-SA1-stimulated glioma cells, was demonstrated. Furthermore, an increased sensitivity to Doxorubicin cytotoxicity was demonstrated in siTRPML2, whereas ML2-SA1-treated GBM cells were more resistant. The role of proteasome in Cathepsin B-dependent and -independent pRB degradation in siTRPML2 compared with siGLO cells was studied. Finally, through Kaplan-Meier analysis, we found that high TRPML2 mRNA expression strongly correlates with short survival in GBM patients, supporting TRPML2 as a negative prognostic factor in GBM patients.

Aniseed (Pimpinella anisum L., Apiaceae) is a medicinal and aromatic plant widely cultivated in the Mediterranean area and used in foodstuffs, as ingredient of famous liqueurs, confectionery and bakery products. Its essential oil is one of the most selled on the market and used on an industrial level. In addition, aniseed is exploited as an herbal remedy to threat respiratory disorders. However, little information is available about its effect on respiratory tissues during inflammation. In the present work, we evaluated the anti-inflammatory activity and the effect on mucin secretion of aniseed essential oil in primary airway bronchial and tracheal epithelial cells (HBEpC and HTEpC, respectively) in a model of lung inflammation induced by lypopolysaccharide (LPS). The aniseed essential oil was obtained by hydrodistillation of the fruits from plants cultivated in central Italy, and analysed by gas chromatography-mass spectrometry (GC–MS). HBEpC and HTEpC lines were treated with LPS and then incubated with 0.3% of aniseed essential oil. Levels of pro-inflammatory cytokines, IL-8 and IL-1 beta were assessed by RT/PCR and Western Blot analysis. Muc5ac protein release was determined in culture medium of HBEpC- and HTEpC- LPS-treated lines by Western Blot analysis. Aniseed essential oil showed a very high level of (E)-anethole (97.9%). At non-toxic doses, it significantly decreased the expression levels of IL-1 and IL-8 and increased the Muc5ac secretion in LPS-treated HBEpC and HTEpC lines. These results provide new evidence supporting the ethnobotanical use of aniseed in the treatment of respiratory diseases. In particular, aniseed essential oil showed a significant anti-inflammatory effect on both HBEpC and HTEpC cells together with mucus hypersecretion.

In the present article the 1,4-dioxane derivative 1, a potent noncompetitive NMDA receptor antagonist, showed cytotoxic activity in the MCF7 breast cancer cell line significantly higher than those of the functionally related compounds (S)-(+)-ketamine and MK-801. Encouraged by this result and considering that copper complexes have been highlighted to be promising anticancer agents, the NMDA receptor ligand 1 was linked to the bifunctionalizable species 2 and 3, affording the conjugated derivatives 4 and 5 that were used for the preparation of the stable Cu(II) complexes 6 and 7. All the compounds were evaluated against a panel of human cancer cell lines derived from solid tumors. Complex 7 showed the best antitumor activity in all the studied cell lines. This result suggests that 7 might act through synergistic mechanisms of action due to the presence of the NMDA ligand 1 and copper(II) in the same chemical entity. Furthermore, the cellular mechanisms affected by complex 7 were assessed through cytofluorimetric and western blot analyses. Data suggested the induction of cell death through paraptosis mediated by endoplasmic reticulum (ER) stress.

Transient receptor potential (TRP) cation channel superfamily plays important roles in a variety of cellular processes such polymodal cellular sensing, adhesion, polarity, proliferation, differentiation and apoptosis. The expression of TRP channels is strictly regulated and their de-regulation can stimulate cancer development and progression.In human cancers, specific miRNAs are expressed in different tissues, and changes in the regulation of gene expression mediated by specific miRNAs have been associated with carcinogenesis. Several miRNAs/TRP channel pairs have been reported to play an important role in tumor biology. Thus, the TRPM1 gene regulates melanocyte/melanoma behaviour via TRPM1 and microRNA-211 transcripts. Both miR-211 and TRPM1 proteins are regulated through microphthalmia-associated transcription factor (MIFT) and the expression of miR-211 is decreased during melanoma progression. Melanocyte phenotype and melanoma behaviour strictly depend on dual TRPM1 activity, with loss of TRPM1 protein promoting melanoma aggressiveness and miR-211 expression supporting tumour suppressor. TRPM3 plays a major role in the development and progression of human clear cell renal cell carcinoma (ccRCC) with von Hippel-Lindau (VHL) loss. TRPM3, a direct target of miR-204, is enhanced in ccRCC with inactivated or deleted VHL. Loss of VHL inhibits miR-204 expression that lead to increased oncogenic autophagy. Therefore, the understanding of specific TRP channels/miRNAs molecular pathways in distinct tumors could provide a clinical rationale for target therapy in cancer.

Cancer cells acquire the ability to modify the calcium signaling network by altering the expression and functions of cation channels, pumps or transporters. Calcium signaling pathways are involved in proliferation, angiogenesis, invasion, immune evasion, disruption of cell death pathways, ECM remodelling, epithelial-mesenchymal transition (EMT) and drug resistance. Among cation channels, a pivotal role is played by the Transient Receptor Potential non-selective cation-permeable receptors localized in plasma membrane, endoplasmic reticulum, mitochondria and lysosomes. Several findings indicate that the dysregulation in calcium signaling induced by TRP channels is responsible for cancer growth, metastasis and chemoresistance. Drug resistance represents a major limitation in the application of current therapeutic regimens and several efforts are spent to overcome it. Here we describe the ability of Transient Receptor Potential Channels to modify, by altering the intracellular calcium influx, the cancer cell sensitivity to chemotherapeutic drugs.

Transient receptor potential (TRP) cation channel superfamily plays important roles in a variety of cellular processes such polymodal cellular sensing, adhesion, polarity, proliferation, differentiation and apoptosis. The expression of TRP channels is strictly regulated and their de-regulation can stimulate cancer development and progression.In human cancers, specific miRNAs are expressed in different tissues, and changes in the regulation of gene expression mediated by specific miRNAs have been associated with carcinogenesis. Several miRNAs/TRP channel pairs have been reported to play an important role in tumor biology. Thus, the TRPM1 gene regulates melanocyte/melanoma behaviour via TRPM1 and microRNA-211 transcripts. Both miR-211 and TRPM1 proteins are regulated through microphthalmia-associated transcription factor (MIFT) and the expression of miR-211 is decreased during melanoma progression. Melanocyte phenotype and melanoma behaviour strictly depend on dual TRPM1 activity, with loss of TRPM1 protein promoting melanoma aggressiveness and miR-211 expression supporting tumour suppressor. TRPM3 plays a major role in the development and progression of human clear cell renal cell carcinoma (ccRCC) with von Hippel-Lindau (VHL) loss. TRPM3, a direct target of miR-204, is enhanced in ccRCC with inactivated or deleted VHL. Loss of VHL inhibits miR-204 expression that lead to increased oncogenic autophagy. Therefore, the understanding of specific TRP channels/miRNAs molecular pathways in distinct tumors could provide a clinical rationale for target therapy in cancer.

Changes in transient receptor potential (TRP) Ca2+ permeable channels are associated with development and progression of different types of cancer. Herein, we report data relative to the expression and function of TRP vanilloid 2 (TRPV2) channels in cancer. Overexpression of TRPV2 is observed in high-grade urothelial cancers and treatment with the TRPV2 agonist cannabidiol induces apoptosis. In prostate cancer, TRPV2 promotes migration and invasion, and TRPV2 overexpression characterizes the castration-resistant phenotype. In breast cancer cells, inhibition of TRPV2 by tranilast reduces the insulin-like growth factor-1 stimulated proliferation. TRPV2 overexpression in triple-negative breast cancer cells is associated with high recurrence-free survival. Increased TRPV2 overexpression is present in patients with esophageal squamous cell carcinoma associated with advanced disease, lymph node metastasis, and poor prognosis. Increased TRPV2 transcripts have been found both in benign hepatoma and in hepatocarcinomas, where TRPV2 expression is associated with portal vein invasion and reduction of cancer stem cell expression. TRPV2 expression and function has been also evaluated in gliomagenesis. This receptor negatively controls survival, proliferation, and resistance to CD95- or BCNU-induced apoptosis. In glioblastoma stem cells, TRPV2 activation promotes differentiation and inhibits the proliferation in vitro and in vivo. In glioblastoma, the TRPV2 is part of an interactome-based signature complex, which is negatively associated with survival, and it is expressed in high risk of recurrence and temozolomide-resistant patients. Finally, also in hematological malignancies, such as myeloma or acute myeloid leukemia, TRPV2 might represent a target for novel therapeutic approaches. Overall, these findings demonstrate that TRPV2 exhibits an oncogenic activity in different types of cancers, controlling survival, proliferation, migration, angiogenesis, and invasion signaling pathways. Thus, it prompts the pharmacological use of TRPV2 targeting in the control of cancer progression.

The interest in liquid biopsy is growing because it could represent a non-invasive prognostic or predictive tool for clinical outcome in patients with pancreatic ductal adenocarcinoma (PDAC), an aggressive and lethal disease. In this pilot study, circulating tumor cells (CTCs), CD16 positive atypical CTCs, and CTC clusters were captured and characterized in the blood of patients with PDAC before and after palliative first line chemotherapy by ScreenCell device, immunohistochemistry, and confocal microscopy analysis. Gene profiles were performed by digital droplet PCR in isolated CTCs, five primary PDAC tissues, and three different batches of RNA from normal human pancreatic tissue. Welsh's t-test, Kaplan-Meier survival, and Univariate Cox regression analyses have been performed. Statistical analysis revealed that the presence of high CTC number in blood is a prognostic factor for poor overall survival and progression free survival in advanced PDAC patients, before and after first line chemotherapy. Furthermore, untreated PDAC patients with CTCs, characterized by high ALCAM, POU5F1B, and SMO mRNAs expression, have shorter progression free survival and overall survival compared with patients expressing the same biomarkers at low levels. Finally, high SHH mRNA levels are negatively associated to progression free survival, whereas high vimentin mRNA levels are correlated with the most favorable prognosis. By hierarchical clustering and correlation index analysis, two cluster gene signatures were identified in CTCs: the first, with high expression of VEGFA, NOTCH1, EPCAM, IHH, is the signature of PDAC patients before chemotherapy, whereas the second, with an enrichment in the expression of CD44, ALCAM, and POU5F1B stemness and pluripotency genes, is reported after palliative chemotherapy. Overall our data support the clinic value of the identification of CTC's specific biomarkers to improve the prognosis and the therapy in advanced PDAC patients.

A series of derivatives obtained by moving the aromatic moiety on the 1,4-dioxane ring of compounds 1-3 from position 6 to position 2 or 3 was prepared and evaluated for the affinity for 5-HT

// Massimo Nabissi 1, * , Maria Beatrice Morelli 2, * , Massimo Offidani 3 , Consuelo Amantini 4 , Silvia Gentili 3 , Alessandra Soriani 2 , Claudio Cardinali 2 , Pietro Leoni 3 , Giorgio Santoni 1 1 School of Pharmacy, Experimental Medicine Section, University of Camerino, Camerino, Italy 2 Department of Molecular Medicine, Sapienza University, Rome, Italy 3 Clinica di Ematologia, Azienda Ospedaliero Universitaria Ospedali Riuniti di Ancona, Ancona, Italy 4 School of Biosciences and Veterinary Medicine, University of Camerino, Camerino, Italy * These authors have contributed equally to this work Correspondence to: Massimo Nabissi, email: massimo.nabissi@unicam.it Keywords: carfilzomib, THC, CBD, multiple myeloma, immuno-proteasome, combination therapy Received: September 01, 2016 Accepted: October 05, 2016 Published: October 18, 2016 ABSTRACT Several studies showed a potential anti-tumor role for cannabinoids, by modulating cell signaling pathways involved in cancer cell proliferation, chemo-resistance and migration. Cannabidiol (CBD) was previously noted in multiple myeloma (MM), both alone and in synergy with the proteasome inhibitor bortezomib, to induce cell death. In other type of human cancers, the combination of CBD with Δ 9 -tetrahydrocannabinol (THC) was found to act synergistically with other chemotherapeutic drugs suggesting their use in combination therapy. In the current study, we evaluated the effects of THC alone and in combination with CBD in MM cell lines. We found that CBD and THC, mainly in combination, were able to reduce cell viability by inducing autophagic-dependent necrosis. Moreover, we showed that the CBD-THC combination was able to reduce MM cells migration by down-regulating expression of the chemokine receptor CXCR4 and of the CD147 plasma membrane glycoprotein. Furthermore, since the immuno-proteasome is considered a new target in MM and also since carfilzomib (CFZ) is a new promising immuno-proteasome inhibitor that creates irreversible adducts with the β5i subunit of immuno-proteasome, we evaluated the effect of CBD and THC in regulating the expression of the β5i subunit and their effect in combination with CFZ. Herein, we also found that the CBD and THC combination is able to reduce expression of the β5i subunit as well as to act in synergy with CFZ to increase MM cell death and inhibits cell migration. In summary, these results proved that this combination exerts strong anti-myeloma activities.

Glioma stem-like cells (GSCs) correspond to a tumor cell subpopulation, involved in glioblastoma multiforme (GBM) tumor initiation and acquired chemoresistance. Currently, drug-induced differentiation is considered as a promising approach to eradicate this tumor-driving cell population. Recently, the effect of cannabinoids (CBs) in promoting glial differentiation and inhibiting gliomagenesis has been evidenced. Herein, we demonstrated that cannabidiol (CBD) by activating transient receptor potential vanilloid-2 (TRPV2) triggers GSCs differentiation activating the autophagic process and inhibits GSCs proliferation and clonogenic capability. Above all, CBD and carmustine (BCNU) in combination overcome the high resistance of GSCs to BCNU treatment, by inducing apoptotic cell death. Acute myeloid leukemia (Aml-1) transcription factors play a pivotal role in GBM proliferation and differentiation and it is known that Aml-1 control the expression of several nociceptive receptors. So, we evaluated the expression levels of Aml-1 spliced variants (Aml-1a, b and c) in GSCs and during their differentiation. We found that Aml-1a is upregulated during GSCs differentiation, and its downregulation restores a stem cell phenotype in differentiated GSCs. Since it was demonstrated that CBD induces also TRPV2 expression and that TRPV2 is involved in GSCs differentiation, we evaluated if Aml-1a interacted directly with TRPV2 promoters. Herein, we found that Aml-1a binds TRPV2 promoters and that Aml-1a expression is upregulated by CBD treatment, in a TRPV2 and PI3K/AKT dependent manner. Altogether, these results support a novel mechanism by which CBD inducing TRPV2-dependent autophagic process stimulates Aml-1a-dependent GSCs differentiation, abrogating the BCNU chemoresistance in GSCs.

Multiple myeloma (MM) is a plasma cell (PC) malignancy characterised by the accumulation of a monoclonal PC population in the bone marrow (BM). Cannabidiol (CBD) is a non-psychoactive cannabinoid with antitumoural activities, and the transient receptor potential vanilloid type-2 (TRPV2) channel has been reported as a potential CBD receptor. TRPV2 activation by CBD decreases proliferation and increases susceptibility to drug-induced cell death in human cancer cells. However, no functional role has been ascribed to CBD and TRPV2 in MM. In this study, we identified the presence of heterogeneous CD138+TRPV2+ and CD138+TRPV2- PC populations in MM patients, whereas only the CD138+ TRPV2- population was present in RPMI8226 and U266 MM cell lines. Because bortezomib (BORT) is commonly used in MM treatment, we investigated the effects of CBD and BORT in CD138+TRPV2- MM cells and in MM cell lines transfected with TRPV2 (CD138+TRPV2+). These results showed that CBD by itself or in synergy with BORT strongly inhibited growth, arrested cell cycle progression and induced MM cells death by regulating the ERK, AKT and NF-κB pathways with major effects in TRPV2+ cells. These data provide a rationale for using CBD to increase the activity of proteasome inhibitors in MM.

More than 30 different Transient Receptor Potential channels (TRP) have been identified in mammals and are grouped in 6 families. Members of these subunit families, specifically of the vanilloid TRP (TRPV), melastatin TRP (TRPM), ankyrin TRP (TRPA), polycystin TRP (TRPP) and canonical or classical TRP (TRPC) family, are considered relevant in central nervous system neurodegenerative diseases. In fact, TRP channels have received increased attention in recent years, since they are involved in a broad array of pathways and respond to different environmental stimuli. Preclinical research has identified TRPs involved in hereditary neuropathies as well as in a heterogeneous group of neuronal disorders. Moreover, changes in TRP channel expression and functionality have been associated to diabetic thermal hyperalgesia, painful neuropathies and headache. At the molecular level, TRPs are involved in a wide range of mechanisms regulating osmosis, thermal, stretch, chemical and sensory signaling, highlighting TRPs as potential targets for pharmacological intervention. The area of small molecule TRP agonists/antagonists drug development is moving rapidly. This review will evaluate current evidence that supports particular TRP channels as targets for novel drugs, summarizing the current perspectives for the therapeutic potential of TRP agonists and antagonists in the treatment of a wide range of neuropathies, along with potential adverse effects that may limit drug development.

Transient Receptor Potential (TRP) channels affect several inflammatory and neoplastic conditions. About thirty TRPs have been identified to date and divided into seven families: TRPC (Canonical), TRPV (Vanilloid), TRPM (Melastatin), TRPML (Mucolipin), TRPP (Polycystin), and TRPA (Ankyrin transmembrane protein) and TRPN (NomPClike). Among these, the TRPC, TRPM, and TRPV families have been mainly correlated with malignant growth and progression. The aim of this review is to summarize data reported so far on the expression and functional role of TRP channels in different types of cancers. TRP channels have been recently implicated in the triggering of enhanced proliferation, aberrant differentiation, and resistance to apoptotic cell death, leading to uncontrolled tumor growth and progression. Depending on cancer stage, up and down-regulation of TRP mRNAs and protein expression have been reported. These changes have been shown to exhibit cancer promoting (oncogenic) or inhibiting/delaying (tumor suppressor) effects. We are only at the beginning, and more detailed study on the physiopathologic role of TRP channels is required to understand how the deregulation of TRP channel expression and function contributes to tumor development and progression. It is hoped that greater knowledge about TRP biology will enable future development of new chemotherapeutic agents for specific TRP targets, and the use of TRP channels as evaluable markers in diagnostic and/or prognostic analysis.

// Maria Beatrice Morelli 1, 2 , Consuelo Amantini 3 , Massimo Nabissi 1 , Claudio Cardinali 1, 2 , Matteo Santoni 4 , Giovanni Bernardini 2, 5 , Angela Santoni 2, 5 , Giorgio Santoni 1 1 School of Pharmacy, University of Camerino, Camerino, Italy 2 Department of Molecular Medicine, Sapienza University, Rome, Italy 3 School of Biosciences and Veterinary Medicine, University of Camerino, Camerino, Italy 4 Department of Medical Oncology, Polytechnic University of Marche, Ancona, Italy 5 I.N.M. Neuromed, Pozzilli, Isernia, Italy Correspondence to: Giorgio Santoni, email: giorgio.santoni@unicam.it Keywords: axitinib, glioblastoma, bortezomib, p21, senescence Received: August 02, 2016 Accepted: November 18, 2016 Published: December 01, 2016 ABSTRACT Glioblastoma is associated with a poor overall survival despite new treatment advances. Antiangiogenic strategies targeting VEGF based on tyrosine kinase inhibitors (TKIs) are currently undergoing extensive research for the treatment of glioma. Herein we demonstrated that the TKI axitinib induces DNA damage response (DDR) characterized by γ-H2AX phosphorylation and Chk1 kinase activation leading to G2/M cell cycle arrest and mitotic catastrophe in U87, T98 and U251 glioma cell lines. Moreover, we found that p21(Waf1/Cip1) increased levels correlates with induction of ROS and senescence-associated cell death in U87 and T98 cell lines, which are reverted by N-acetyl cysteine pretreatment. Conversely, U251 cell line showed a resistant phenotype in response to axitinib treatment, as evidenced by cell cycle arrest but no sign of cell death. The combinatorial use of axitinib with other therapies, with the aim of inhibiting multiple signaling pathways involved in tumor growth, can increase the efficiency of this TKI. Thus, we addressed the combined effects of axitinib with no toxic doses of the proteasome inhibitor bortezomib on the growth of U87 and T98 axitinib-sensitive and axitinib-resistant U251 cell lines. Compared to single treatments, combined exposure was more effective in inhibiting cell viability of all glioma cell lines, although with different cell death modalities. The regulation of key DDR and cell cycle proteins, including Chk1, γ-H2AX and p21(Waf1/Cip1) was also studied in glioma cell lines. Collectively, these findings provide new perspectives for the use of axitinib in combination with Bortezomib to overcome the therapy resistance in gliomas.

To cite this article: Farfariello V, Amantini C, Nabissi M, Morelli MB, Aperio C, Caprodossi S, Carlucci A, Bianchi AM, Santoni G. IL-22 mRNA in peripheral blood mononuclear cells from allergic rhinitic and asthmatic pediatric patients. Pediatr Allergy Immunol 2011;: 419–423. Abstract T helper (TH)-17 lymphocytes are characterized by the expression of many regulatory cytokines, including IL-17A and IL-22, but at present no clinical data are available on the expression of these cytokines in peripheral blood mononuclear cells (PBMC) from allergic asthmatic and rhinitic (AR) children. The aim of this study was to investigate a possible relationship between IL-22 and IL-17A mRNAs and clinical parameters in seroatopic, AR, and asthmatic children. The study, conduced during the pollen season, included 18 healthy and 18 allergic (n = 9 asthmatic and n = 9 rhinitic) children. Serum total and specific IgE, eosinophil count, and skin prick test were performed; in addition, IL-22 and IL-17A mRNA levels were detected in PBMC from healthy and allergic subjects by quantitative real-time PCR. Despite the absence of the mRNA for the IL-17A cytokine, IL-22 expression was found in PBMC from asthmatic patients, with increased IL-22 mRNA levels in patients with chronic severe respect to those with moderate asthma. A positive correlation between IL-22 mRNA and serum total IgE levels was found in asthmatic children. In addition, higher IL-22 and IL-17A mRNA levels were detected in both AR and asymptomatic seroatopic children, compared to healthy individuals, and a correlation between IL-22 and IL17A mRNA and serum total IgE levels was demonstrated. Moreover, the mRNA level of retinoic acid-related orphan receptor C, the TH17 transcription factor, was found to be increased in AR but not in asthmatic patients. This study provides the first evidence that IL-22 mRNA might be expressed in chronic severe asthmatic and AR children. The expression of IL-22 and IL-17A mRNAs in asymptomatic monosensitized seroatopic children suggests a role of these cytokines in the early events involved in the development of these allergic diseases.

Kalogris C, Caprodossi S, Amantini C, Lambertucci F, Nabissi M, Morelli M B, Farfariello V, Filosa A, Emiliozzi M C, Mammana G & Santoni G (2010) Histopathology 57, 744–752 Expression of transient receptor potential vanilloid-1 (TRPV1) in urothelial cancers of human bladder: relation to clinicopathological and molecular parameters Aims: To evaluate the expression of transient receptor potential vanilloid type-1 channel protein (TRPV1) in normal and neoplastic urothelial tissues and to correlate TRPV1 expression with clinicopathological parameters and disease-specific survival. Methods and results: TRPV1 expression was analysed in normal and neoplastic urothelial samples at both mRNA and protein levels by quantitative real time polymerase chain reaction (qPCR) and immunohistochemistry, respectively. TRPV1 downregulation was found in urothelial cancer (UC) specimens, which correlated with tumour progression. Moreover, TRPV1 mRNA levels were associated with clinicopathological parameters to assess the role of TRPV1 downregulation as a negative prognostic factor for survival. Kaplan–Meier survival analysis demonstrated a significantly shorter survival in patients showing TRPV1 mRNA downregulation. Multivariate Cox regression analysis indicated further that TRPV1 mRNA expression retained its significance as an independent risk factor. Conclusions: The progression of UC of human bladder is associated with a marked decrease in TRPV1 expression, with a progressive loss in high-grade muscle invasive UC. Downregulation of TRPV1 mRNA expression may represent an independent negative prognostic factor for bladder cancer patients.

Tyrosine kinase inhibitors (TKIs) including axitinib have been introduced in the treatment of renal cell carcinoma (RCC) because of their anti-angiogenic properties. However, no evidence are presently available on a direct cytotoxic anti-tumor activity of axitinib in RCC. Herein we reported by western blot analysis that axitinib treatment induces a DNA damage response (DDR) initially characterized by γ-H2AX phosphorylation and Chk1 kinase activation and at later time points by p21 overexpression in A-498 and Caki-2 RCC cells although with a different potency. Analysis by immunocytochemistry for the presence of 8-oxo-7,8-dihydro-2′-deoxyguanosine in cellular DNA and flow cytometry using the redox-sensitive fluorescent dye DCFDA, demonstrated that DDR response is accompanied by the presence of oxidative DNA damage and reactive oxygen species (ROS) generation. This response leads to G2/M cell cycle arrest and induces a senescent-like phenotype accompanied by enlargement of cells and increased senescence-associated β-galactosidase activity, which are abrogated by N-acetyl cysteine (NAC) pre-treatment. In addition, axitinib-treated cells undergo to cell death through mitotic catastrophe characterized by micronucleation and abnormal microtubule assembly as assessed by fluorescence microscopy. On the other hand, axitinib, through the DDR induction, is also able to increase the surface NKG2D ligand expression. Accordingly, drug treatment promotes NK cell recognition and degranulation in A-498 RCC cells in a ROS-dependent manner. Collectively, our results indicate that both cytotoxic and immunomodulatory effects on RCC cells can contribute to axitinib anti-tumor activity.

Calcium (Ca2+) increases the proliferation of human advanced prostate cancer (PCa) cells but the ion channels involved are unknown. Santoni and Quaglia groups investigated the correlation between alpha1D-adrenergic receptor (α1D-AR) and the transient receptor potential vanilloid type 1 (TRPV1) ion channel expression in PCa cells. The α1D-AR and TRPV1 mRNAs are increased in PCa compared to BPH. α1D-AR and TRPV1 are co-expressed in PCa cells. Norepinephrine (NE) induced α1D-AR- and TRPV1-dependent protons release, Ca2+ flux in PC3 cells and activation of PLC, PKC and ERK path-ways that stimulated PC3 cell proliferation. Similarly, a role for TRPC6 or GPR55 in α1-AR-dependent proliferation of mesangial cells and PCa cells was reported. Overall, a crosstalk between α1-AR and TRPs in PCa cells, involved in the control of cell proliferation has been demonstrated. These data strongly promote a putative novel pharmacological approach in the treatment of PCa by targeting both α1-AR and TRP channels.

Transient receptor potential (TRP) channels are important candidates mediating Ca 2+ influx in excitable and nonexcitable cells such as normal and neoplastic hematopoietic tissues. They are non selective cation channels implicated in Ca 2+ signaling in hematologic tumor cells. Here, we review the growing experimental evidence indicating that TRP channels should be included among the genes whose expression is altered in hematologic malignancies such as leukemias (AML, ALL, CML and CLL), B- and T-lymphomas and multiple myelomas (MM). These effects depend on the widespread roles played by the TRP channels in the modulation of the proliferation, differentiation and apoptosis of the hematopoietic cells. The analysis of the expression of the different TRP channels belonging to the TRPMs, TRPVs, TRPCs, TRPPs channel families expressed in different hematological malignacies, evidenced a widespread expression of TRPV2 channel in the myeloid and lymphoid leukemias, and a very peculiar expression of this channel in different types of B cell lymphomas and multiple myeloma, that is parallel to the restricted expression of TRPV2 in normal immune cells with respect to its presence in other human tissues. In vivo studies in children AML and ALL patients also evidenced the presence of a genetic polymorphism of the TRPM5 gene, that reduced the risk to develop leukemia in the children. Finally, the coexpression of TRPV5 and TRPV6 channels in lymphocytes, and their involvement in the radioresistance of K562 erythroleukemia cells to ionizing radiation exposure is of more interest. Thus in conclusion, the TRP channels represent promising targets for hematologic cancer therapy, and their exploitation may open to novel pharmaceutical and clinical approaches.

Aim of this review is to study the role of the TRPV2 channel, a member of the TRPV subfamily of TRP channels, in tumor progression. Physiologically, the triggering of TRPV2 by agonists/activators (e.g., growth factors, hormones and cannabinoids), by inducing TRPV2 translocation from the endosome to the plasmatic membrane, inhibit cell proliferation and induce necrosis and/or apoptosis. Thus, loss or alterations of TRPV2 proliferative and apoptotic signals, results in uncontrolled proliferation and augmented resistance to apoptotic stimuli. For example in prostate cancer cells, the TRPV2 activation following lysophospholipid or adrenomedullin stimulation enhances the invasiveness of cancer cells; furthermore, the increased malignancy of castration-resistant prostate cancer cells was associated with enhanced TRPV2 expression, mainly in metastatic prostate cancer cells. In addition, the TRPV2 cellular functions may also to be related to the presence of TRPV2 variants, able to interfere with the physiological functions of normal TRPV2 channels. In this regard, bladder cancer tumors show loss or reduction of a short TRPV2 variant during cancer progression, with increased malignancy and invasiveness. High expression of TRPV2 was also observed more frequently in esophageal squamous cell carcinoma patients with advanced pT stage, lymph node metastasis and advanced pathological stage.

The transient receptor potential vanilloid type-2 (TRPV2), belonging to the transient receptor potential channel family, is a specialized ion channel expressed in human and other mammalian immune cells. This channel has been found to be expressed in CD34(+) hematopoietic stem cells, where its cytosolic Ca(2) (+) activity is crucial for stem/progenitor cell cycle progression, growth, and differentiation. In innate immune cells, TRPV2 is expressed in granulocytes, macrophages, and monocytes where it stimulates fMet-Leu-Phe migration, zymosan-, immunoglobulin G-, and complement-mediated phagocytosis, and lipopolysaccharide-induced tumor necrosis factor-alpha and interleukin-6 production. In mast cells, activation of TRPV2 allows intracellular Ca(2) (+) ions flux, thus stimulating protein kinase A-dependent degranulation. In addition, TRPV2 is highly expressed in CD56(+) natural killer cells. TRPV2 orchestrates Ca(2) (+) signal in T cell activation, proliferation, and effector functions. Moreover, messenger RNA for TRPV2 are expressed in CD4(+) and CD8(+) T lymphocytes. Finally, TRPV2 is expressed in CD19(+) B lymphocytes where it regulates Ca(2) (+) release during B cell development and activation. Overall, the specific expression of TRPV2 in immune cells suggests a role in immune-mediated diseases and offers new potential targets for immunomodulation.

Glioblastoma multiforme (GBM) is the most common and malignant primary brain tumor in adults. Despite several advances, little is known about GBM-specific aberrant signalling processes. The hedgehog (Hh) signalling pathway plays a central role in GBM pathogenesis and tumor progression. Its activation is mediated by sonic hedgehog (Shh), which binds to its receptor patched, PTCH, promoting Gli1 activation. Gli1 is a member of the Kruppel family of zinc finger transcription factors. Hh/Gli1 axis controls glioma stem cells (GSCs) behaviour, which is essential to GBM chemoand radioresistance. Thus, Gli1 modulates the expression of stemness genes and the self-renewal of CD133(+) GSCs. The activation of Hh/Gli1 in GSCs seems to be dependent on the insulin-like growth factor (IGF) signaling, which also contributes to intrinsic and acquired resistance of GSCs to temozolomide (TMZ). Beyond Hh signals, Gli1 activity is also regulated by several elements, including Ras, Myc, Akt, p53 and PTEN. Recently, a truncated variant of Gli1 (tGli1) has been demonstrated to gain the ability to regulate expression of genes that are not modulated by Gli1, such as the migration/invasion-associated CD24 or the human vascular endothelial growth factor-A (VEGF-A), leading to their upregulation. This review will summarize the role of Gli proteins in GBM tumorigenesis and their potential impact on GBM therapy and treatment resistance.

The aggressive behavior of Glioblastoma multiforme (GBM) is mainly due to high invasiveness and proliferation rate as well as to high resistance to standard chemotherapy. Several chemotherapeutic agents like temozolomide (TMZ), carmustine (BCNU) or doxorubicin (DOXO) have been employed for treatment of GBM, but they display limited efficacy. Therefore, it is important to identify new treatment modalities to improve therapeutic effects and enhance GBM chemosensitivity. Recently, activation of the transient receptor potential vanilloid type 2 (TRPV2) has been found to inhibit human GBM cell proliferation and overcome BCNU resistance of GBM cells. Herein, we evaluated the involvement of cannabidiol (CBD)-induced TRPV2 activation, in the modulation of glioma cell chemosensitivity to TMZ, BCNU and DOXO. We found that CBD increases TRPV2 expression and activity. CBD by triggering TRPV2-dependent Ca(2+) influx increases drug uptake and synergizes with cytotoxic agents to induce apoptosis of glioma cells, whereas no effects were observed in normal human astrocytes. Moreover, as the pore region of transient receptor potential (TRP) channels is critical for ion channel permeation, we demonstrated that deletion of TRPV2 poredomain inhibits CBD-induced Ca(2+) influx, drug uptake and cytotoxic effects. Overall, we demonstrated that co-administration of cytotoxic agents together with the TRPV2 agonist CBD increases drug uptake and parallelly potentiates cytotoxic activity in human glioma cells.

Down-regulation with gonadodropin-releasing agonist (GnRH-a) protocol during IVF stimulation leads to a severe endogenous LH suppression, which may affect the follicular development. The aim of the study was to evaluate the effects of recombinant LH (r-LH) administration, during late follicular development stages, in recombinant FSH (r-FSH) stimulated cycles on follicular fluid (FF) parameters and on cumulus cell quality.Twenty patients undergoing IVF were stimulated in a long GnRH agonist protocol with r-FSH alone or with r-LH supplementation when the leading follicle reached diameter of 14 mm. FF was collected at the time of oocyte retrieval from 32 follicles ≥ 18 mm. Serum FSH, LH, estradiol (E(2)), and progesterone (P(4)) were evaluated on the day of hCG administration. Intra-follicular E(2), P(4), AMH and TGF-β were assayed. Total RNA from 18 individual cumuli was isolated for gene expression analyses.R-LH increased FF P(4) levels. FF TGF-β levels and PTGS2 and HAS2 expression in cumulus cells (CCs) positively correlated with increased P(4) levels observed in FFs, while a negative correlation was found between P(4) and AMH levels.FF positive correlation between P(4) and TGF-β levels and CC expression of PTGS2 and HAS2 suggest an association with a better follicle quality. In addition, our data suggest that late follicular phase r-LH supplementation leads to a more advanced stage of follicular maturation.

The aim of this study was to investigate the expression and function of the transient receptor potential vanilloid 2 (TRPV2) in human glioma cells. By Real-Time-PCR and western blot analysis, we found that TRPV2 messenger RNA (mRNA) and protein were expressed in benign astrocyte tissues, and its expression progressively declined in high-grade glioma tissues as histological grade increased (n = 49 cases), and in U87MG cells and in MZC, FCL and FSL primary glioma cells. To investigate the function of TRPV2 in glioma, small RNA interfering was used to silence TRPV2 expression in U87MG cells. As evaluated by RT-Profiler PCR array, siTRPV2-U87MG transfected cells displayed a marked downregulation of Fas and procaspase-8 mRNA expression, associated with upregulation of cyclin E1, cyclin-dependent kinase 2, E2F1 transcriptor factor 1, V-raf-1 murine leukemia viral oncogene homolog 1 and Bcl-2-associated X protein (Bcl-X(L)) mRNA expression. TRPV2 silencing increased U87MG cell proliferation as shown by the increased percentage of cells incorporating 5-bromo-2-deoxyuridine expressing beta(III)-tubulin and rescued glioma cells to Fas-induced apoptosis. These events were dependent on extracellular signal-regulated kinase (ERK) activation: indeed inhibition of ERK activation in siTRPV2-U87MG transfected cells by treatment with PD98059, a specific mitogen-activated protein kinase/extracellular signal-regulated kinase kinase inhibitor, reduced Bcl-X(L) protein levels, promoted Fas expression, and restored Akt/protein kinase B pathway activation leading to reduced U87MG cell survival and proliferation, and increased sensitivity to Fas-induced apoptosis. In addition, transfection of TRPV2 in MZC glioma cells, by inducing Fas overexpression, resulted in a reduced viability and an increased spontaneous and Fas-induced apoptosis. Overall, our findings indicate that TRPV2 negatively controls glioma cell survival and proliferation, as well as resistance to Fas-induced apoptotic cell death in an ERK-dependent manner.

Herein, we provide evidence on the expression of transient receptor potential vanilloid type 1 (TRPV1) on human urothelial cancer (UC) cells and its involvement in the apoptosis induced by the selective agonist capsaicin (CPS). We analyzed TRPV1 messenger RNA and protein expression on human UC cell lines demonstrating its progressive decrease in high-grade UC cells. Treatment of RT4 cells with CPS induced cell cycle arrest in G(0)/G(1) phase and apoptosis. These events were associated with rapid co-ordinated transcription of pro-apoptotic genes including Fas/CD95, Bcl-2 and caspase families and ataxia telangiectasia mutated (ATM)/CHK2/p53 DNA damage response pathway. CPS induced Fas/CD95 upregulation, but more importantly Fas/CD95 ligand independent, TRPV1-dependent death receptor clustering and triggering of both extrinsic and intrinsic mitochondrial-dependent pathways. Moreover, we observed that CPS activates ATM kinase that is involved in Ser15, Ser20 and Ser392 p53 phosphorylation as shown by the use of the specific inhibitor KU55933. Notably, ATM activation was also found to control upregulation of Fas/CD95 expression and its co-clustering with TRPV1 as well as RT4 cell growth and apoptosis. Altogether, we describe a novel connection between ATM DNA damage response pathway and Fas/CD95-mediated intrinsic and extrinsic apoptotic pathways triggered by TRPV1 stimulation on UC cells.

e15513 Background: Tyrosine kinase inhibitors (TKI), such as sunitinib, sorafenib and pazopanib, have replaced immunotherapy as the standard of care for metastatic renal cell carcinoma (mRCC). However, their use in sequential or combined strategies is limited by the lack of evidences on TKI-induced cell death in cancer cells. Aim of our study was to evaluate the different mechanisms responsible of the anti-proliferative and cytotoxic effects induced in vitro by µM doses of sunitinib, sorafenib and pazopanib in 5637 and J82 bladder cancer (BC) cell lines. Methods: The viability of BC cell lines were tested by MTT assay. Autophagy was evaluated by western blot analysis with anti-LC3 and anti-p62 antibodies, acridine orange staining and cytofluorimetric analysis. Necrotic cell death was evaluated by Annexin-V/PI staining and FACS analysis. The cathepsin B activation was evaluated by western blot using an anti-cathepsin B antibody; the cathepsin B proteolytic activity was determined using the fluorogenic Z-Arg-Arg-AMC peptide and the fluorescence of the hydrolyzed 7-amino-4-methyl-coumarin was detected by a SpectraMax Gemini XPS microplate reader. Results: We found that sunitinib and pazopanib markedly reduced at mM dose the viability of BC cells. Treatment for 24h with 20µM of sunitinib, by triggering “Incomplete autophagy”, induced necrosis of BC cells. In addition, sunitinib as a lysosomotropic agent, entered free within the lysosomes, where by increasing lysosomal pH and impairing cathepsin B activity, induced lysosomal-dependent necrosis. By contrast, treatment of BC cells for 72h with 20µM of pazopanib induced autophagic cell death, which was markedly reversed in a dose-dependent manner by the autophagic inhibitor 3-MA. The pazopanib-induced autophagic cell death was associated with increased procathepsin B cleavage and enhanced cathepsin B activity. Conclusions: Overall, our results show different cathepsin B-dependent cancer cell death mechanisms induced by sunitinib or pazopanib, providing the biological basis for novel molecularly targeted approaches.

e15515 Background: Several tyrosine kinase inhibitors (TKIs), have been developed and approved for clinical use in multi-targeted cancer therapy. Among these, sorafenib is an orally available multikinase inhibitor approved for the treatment of the advanced renal cell carcinoma (RCC) and hepatocellular carcinoma (HCC). Aim of our study was to evaluate the mechanisms responsible for the cytotoxic effects induced by in vitro use of µM doses of sorafenib in 5637 and J82 bladder cancer (BC) cell lines. Methods: The viability of BC cell lines were tested by MTT assay. Autophagy was evaluated by western blot analysis with the anti-LC3 and anti-p62 antibodies, acridine orange staining and cytofluorimetric analysis. Apoptosis, (ΔΨm) dissipation and ROS generation were determined by Annexin-V/PI, JC-1 and DCFDA staining, respectively and cytofluorimetric analysis. The cathepsin B activation was evaluated by western blot using an anti-cathepsin B antibody; the cathepsin B proteolytic activity was determined using the fluorogenic Z-Arg-Arg-AMC peptide and the fluorescence of the hydrolyzed 7-amino-4-methyl-coumarin was detected by a SpectraMax Gemini XPS microplate reader. Results: We found that sorafenib markedly reduced at µM dose the viability of BC cells. Treatment for 24h with 20µM of sorafenib, triggered “Incomplete autophagy”, that induced apoptosis of BC cells. Sorafenib by inducing an increased cathepsin B activity and pro-apoptotic protein BID activation, triggered a ROS-mediated-mitochondrial-dependent apoptosis of BC cells. Moreover, the increase of cathepsin B activity induced by sorafenib was inhibited by a specific tyrosine phosphatase inhibitor (e.g., orthovanadate) strongly suggesting for a contribute of tyrosine-phosphatases in sorafenib-induced apoptosis. Conclusions: Sorafenib by triggering incomplete autophagy, stimulates a cathepsin B-induced-BID-mediated-ROS- and mitochondrial-dependent apoptosis of BC cells, which is likely regulated by tyrosine-phosphatases.

270 Background: Tyrosine kinase inhibitors (TKI), such as sunitinib, sorafenib and pazopanib, have replaced immunotherapy as the standard of care for metastatic renal cell carcinoma (mRCC). However, their use in sequential or combined strategies is limited by the lack of evidences on the ability of TKIs to induce cell death in cancer cells. Aim of our study was to evaluate the different mechanisms responsible of the cytotoxic effects induced in vitro by µM doses of sunitinib, sorafenib and pazopanib in 5637 and J82 bladder cancer (BC) cell lines. Methods: The viability of BC cell lines were tested by MTT assay. Autophagy was evaluated by western blot analysis with the anti-LC3 and anti-p62 antibodies, acridine orange staining and cytofluorimetric analysis. Necrosis and apoptosis, (ΔΨm) dissipation and ROS generation were determined by Annexin-V/PI, JC-1 and DCFDA staining, respectively and cytofluorimetric analysis. The cathepsin B activity was evaluated by ELISA. Finally, by mRNA estraction and RT-PCR array the pazopanib-induced gene profile expression was evaluated. Results: We found that treatment of 5637 and J82 BC cells with the three TKI agents markedly reduced cell viability. Treatment for 24 h with sunitinib and sorafenib at 20 µM dose, triggers an incomplete autophagy of BC cells. In addition, inhibition of autophagy induced by sunitinib and sorafenib triggers cell death of BC cells. Thus, sunitinib by imparing the cathepsin B activity induces lysosomal-dependent necrosis. Similarly, sorafenib by defective lysosomial degradation triggers ROS- and mitochondrial-dependent apoptosis. As regard to pazopanib, we first demonstrate that treatment of BC cells for 72 hrs (20 µM) induces autophagic Type II cell death, which was markedly reversed in a dose-dependent manner by 3MA and chloroquine autophagic inhibitors. Finally, pazopanib upregulates the mRNA expression of α-glucosidase (GAA) and TP73 belonging to the p53 tumor suppressor genes. Conclusions: Overall, our results showing different TKI-induced cell death mechanisms provide the rationale for the sequential use of these agents and the biological basis for novel molecularly targeted approaches.

87 Background: Growing evidence supports the role of α1-ARs in the direct mitogenic effect of catecholamines on prostate cancer (PC) cell growth. The expression of α1D-AR on PC3 prostate cancer cells and the ability of noradrenalin (NA) to stimulate PC3 cell proliferation in a α1D-AR-dependent manner were reported (Quaglia et al., 2005). In addition, TRPV1 expression was also found in prostate cancers (Sanchez et al., 2006). Aim of this study was to investigate the relationship between α1D-AR and TRPV1 receptors and the involvement of TRPV1 in NA-induced proliferation in PC3 cells. Methods: By western blot analysis and confocal microscopy the expression α1D-AR and TRPV1 and localization in PC3 cells were evaluated. PC3 cells were incubated with NA alone or in combination with WS433 and capsazepine (CPZ), α1D-AR and TRPV1 antagonists. Proton release, calcium influx and cell proliferation were assessed in α1D-AR-, TRPV1- or α1D-AR/TRPV1 double-silenced PC3 cells by cytosensor and cytofluorymetric analyses. Finally, lysates from NA-treated PC3 cells alone or in combination with WS433 or CPZ were blotted with anti-phospho ERK, anti-ERK and anti-phospho-(Ser) PKC substrate Abs and Inositol-1,4,5-trisphosphate [3H] radioreceptor assay were performed. Results: α1D-AR and TRPV1 co-localize and are co-immunoprecipitated in PC3 cells. Treatment of PC3 cells with NA strongly stimulated proton release, calcium influx and cell proliferation that were reverted by α1D-AR WS433 and TRPV1 antagonist. NA-induced increase of survival and proliferation was totally abrogated in α1D-AR/TRPV1 silenced cells. In addition, NA stimulates ERK and PKC substrate phosphorylation that was inhibited by WS433 and CPZ. Finally, CPZ treatment inhibited NA-dependent PLC activation, while WS433 had no effect. Conclusions: A functional and structural cross-talk between α1D-AR and TRPV1 receptors control NA-induced proliferation of PC cells. These data strongly suggest the development of new pharmaceutical approaches based on bifunctional antibodies and molecules recognizing both α1D-AR and TRPV1 receptors.

Abstract 5003 Multiple myeloma (MM) is a disease typically characterized by repeated relapse that needs several new-drugs throughout its clinical course. Therefore, increasing knowledge of the pathways involved in the pathophysiology of MM will contribute to identified new therapeutic strategies. Specific signaling pathways as: nuclear factor kappa B (NFkB), farnelsyl-transferase (FTI), mitogenen-activated protein kinase (MAPK), proteosoma and others have been found to be disregulated in MM patients and cell lines. These findings have allowed the design of specific inhibitors that have been assessed in preclinical and clinical studies. Recent data have highlighted the contribute of ion channels (K+, Cl−, Na+ and Ca2+) in the regulation of cell proliferation, chemo-resistance, migration and invasion. Transient Receptor Potential Vanilloid type-2 (TRPV2) is a cation channel, member of the TRPV family, and its expression in human cancer cells and tissues has been reported for gliomas, prostate, bladder and pancreas, while no data were available in MM or in other hematological malignancies. TRPV2 expression has been found to influence cancer cell responses to chemo-therapeutic drugs as well as proliferation, migration and apoptosis, in part by increasing intracellular Ca2+ influx and/or by regulating specific signal pathways, like MAPK associated pathways. TRPV2 responds to noxious heat with an activation threshold of >52°C as well as to changes in osmolarity and membrane stretch; in addition, TRPV2 is activated by agonists such as 2-aminoethoxydiphenyl borate, as well as cannabinoids. The aim of this study was, firstly, to evaluate if TRPV2 was expressed in three human MM cell lines established models (RPMI, SKO-007, U266). Secondly we investigated on the role of TRPV2 activation in regulating the proteosoma inhibitor Bortezomib activity, in MM cell lines. By Real-Time PCR analysis we demonstrated that TRPV2 gene was expressed, with comparable relative levels, in the MM cell lines studied, and similar results were obtained at protein levels by Western blot analysis. Moreover, by immunofluorescence and FACS analysis we found that the percentage of TRPV2+ cells was 11% in RPMI, 3% in U266 and 2.6% in SKO-007. These data indicate that TRPV2 was expressed at low levels in MM cell lines. Since lost of TRPV2 expression was found to be associated with higher cell proliferation rate, in other tumor cell lines, and increasing of TRPV2 transcription and/or activity by specific agonists induced cell death and anti-proliferative effects, we evaluated the biological effects of TRPV2 activation in MM cell lines by MTT assay. The results showed that, after three incubation days, TRPV2 activation induced a decrease of cell viability of 70% in RPMI, 60% in U266 and 55% in SKO-007, compared to control. To evaluate if the reduced cell viability was dependent by an anti-proliferative and/or apoptotic process, the three cell lines treated with the TRPV2 agonist were analyzed by 5-bromo-2-deoxyuridine (BrdU) incorporation assay for proliferation and by Annexin-V apoptosis assays. Data shown a decrease of BrdU+ cells in TRPV2 agonist treated cells (40% in RPMI, 30% in U266 and 28% in SKO-007) compared to control, while no significant differences were observed by Annexin-V analysis. Moreover, to evaluate a putative role of TRPV2 in influencing Bortezomib cytotoxicity, RPMI, SKO-007 and U266, were co-treated with the TRPV2 agonist in combination or not with Bortezomib, for three days. By a dose-response MTT analysis we determined that TRPV2 activation reduced MM cell lines viability more than 40% in RPMI, 20 % in U266 and 15% in SKO-007, compared to Bortezomib (5 ng/ml) alone. Summarizing, these preliminary data demonstrated that the TRPV2 cation channel was expressed in human MM cell lines and that activation of TRPV2 could play a role in increasing Bortezomib cytotoxicity, by inhibiting cell proliferation rather than increasing apoptosis of MM cells. These data may open new perspectives in combination therapy, albeit the molecular mechanisms undergone TRPV2 activation needs to be clarified. Disclosures: No relevant conflicts of interest to declare.

Bladder cancer (BC) is the fifth most common non-cutaneous malignancy and the most common form of BC in Western countries is transitional cell carcinoma. Resiniferatoxin (RTX) has found therapeutic usefulness for the treatment of bladder dysfunction but no data are available on its use as chemotherapeutic agent. The aim of this work is to evaluate the use of RTX as new anti-cancer drug in BC therapy. The effects of RTX on cell viability and cell death were evaluated on T24 and 5637 BC cell lines by MTT assay, cell cycle analysis, Annexin-V/PI staining and agarose gel electrophoresis of DNA. Mitochondrial depolarization and ROS production were assessed by flow cytometry. ADP/ATP ratio was measured by bioluminescence and caspase 3 cleavage by Western blot. For in vivo experiments, athymic nude mice, xenografted with T24 cells, received subcutaneous administrations of RTX. Tumor volumes were measured and immunohistochemistry was performed on tumor sections. Our data demonstrated that RTX influences cell cycle and induces necrotic cell death of BC cells by altering mitochondrial function, leading to depolarization, increase in ADP/ATP ratio and ROS production. Moreover, RTX is able to reduce tumor growth in a xenograft mouse model. Overall, we demonstrated that RTX induces necrotic cell death of BC cells and reduces tumor growth in a xenograft mouse model of BC, suggesting RTX as a new potential anti-cancer drug in BC chemotherapy.