Capsaicin triggers autophagic cell survival which drives epithelial mesenchymal transition and chemoresistance in bladder cancer cells in an Hedgehog-dependent manner

Bladder cancer (BC) is a common urologic tumor characterized by high risk of recurrence and mortality. Capsaicin (CPS), used as an intravesical drug for overactive bladder, was demonstrated to induce cell death in different cancer cells including BC cells.Here we found that treatment of high-grade BC cells with high dose of CPS triggers autophagy. Infact, the CPS treatment alters the redox homeostasis by inducing production of radicals, mitochondrial depolarization, alterations of ADP/ATP ratio and activation of AMPK pathway stimulating the autophagic process in BC cells. The inhibition of autophagy, by using the specific inhibitor bafilomycin A or Beclin 1 knock-down, enhanced the CPS-induced cell death, demonstrating that CPS-induced autophagy acts as a pro-survival process in BC cells. By using PCR arrays and FACS analysis, we found that the CPS-treated BC cells displayed typical mesenchymal features of the epithelial mesenchymal transition (EMT) as elongated shape and over-expression of vimentin, α5 and β1 integrin subunits, integrin-like kinase and the anti-apoptotic Bcl-2 proteins. Moreover, we demonstrated that CPS treatment stimulates upregulation of Dhh/Ptch2/Zeb2 members of the Hedgehog signaling pathway, increases CD24, VEGFA and TIMP1 and decreases CD44 and ALCAM mRNA expression levels. By PTCH2 knock-down we found that the Hedgehog signaling pathway is involved in the CPS-induced autophagy and EMT phenotype.Finally, we also showed that the CPS-resistant EMT-positive BC cells displayed an increased drug-resistance to the cytotoxic effects of mitomycin C, gemcitabine and doxorubicine drugs commonly used in BC therapy

Axitinib induces senescence-associated cell death and necrosis in glioma cell lines: The proteasome inhibitor, bortezomib, potentiates axitinib-induced cytotoxicity in a p21(Waf/Cip1) dependent manner.

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

Axitinib induces DNA damage response leading to senescence, mitotic catastrophe, and increased NK cell recognition in human renal carcinoma cells.

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

Functional role of T-type calcium channels in tumour growth and progression: prospective in cancer therapy.

T-type Ca2+ channels represent a specific channel family overexpressed in different types of tumours. Their involvement in controlling the proliferation, angiogenesis and invasion of tumour cells, has been partially clarified. The article by Zhang et al. in this issue of BJP provides the first evidence of anti-tumoural effects of endostatin (ES) in U87 glioma cells. He demonstrated that ES or mibefradil (a L/T-type calcium channel blocker), reduces the proliferation and migration of U87 glioma cells in a T-type Ca2+ channel-dependent manner. However, the difference in the blocking effect of mibefradil on T-type calcium channel expression as compared with its ability to inhibit proliferation and migration, supports the idea of a broader T/L-type-independent effect of the mibefradil blocker. Overall, these findings provide new insights for the future development of a novel class of anti-T-type calcium channel blockers in the therapy of glioblastoma

TRPV1 (transient receptor potential cation channel, subfamily V, member 1)

Review on TRPV1 (transient receptor potential cation channel, subfamily V, member 1), with data on DNA, on the protein encoded, and where the gene is implicated

Pathophysiological Role of Transient Receptor Potential Mucolipin Channel 1 in Calcium-Mediated Stress-Induced Neurodegenerative Diseases

Mucolipins (TRPML) are endosome/lysosome Ca2+ permeable channels belonging to the family of transient receptor potential channels. In mammals, there are three TRPML proteins, TRPML1, 2, and 3, encoded by MCOLN1-3 genes. Among these channels, TRPML1 is a reactive oxygen species sensor localized on the lysosomal membrane that is able to control intracellular oxidative stress due to the activation of the autophagic process. Moreover, genetic or pharmacological inhibition of the TRPML1 channel stimulates oxidative stress signaling pathways. Experimental data suggest that elevated levels of reactive species play a role in several neurological disorders. There is a need to gain better understanding of the molecular mechanisms behind these neurodegenerative diseases, considering that the main sources of free radicals are mitochondria, that mitochondria/endoplasmic reticulum and lysosomes are coupled, and that growing evidence links neurodegenerative diseases to the gain or loss of function of proteins related to lysosome homeostasis. This review examines the significant roles played by the TRPML1 channel in the alterations of calcium signaling responsible for stress-mediated neurodegenerative disorders and its potential as a new therapeutic target for ameliorating neurodegeneration in our ever-aging population

The functional polymorphism rs73598374:G>A (p.Asp8Asn) of the ADA gene is associated with telomerase activity and leukocyte telomere length

Recent evidence demonstrated a relevant role of adenosine deaminase (ADA) in replicative senescence of T cells through its capacity to modulate telomerase activity (TA). Herein, we tested the impact of the functional polymorphism ADA rs73598374:G>A (c.22G>A, p.Asp8Asn) on telomere biology, by measuring TA and leukocyte telomere length (LTL) in healthy subjects selected according to rs73598374 genotype. rs73598374-A carriers showed lower TA (P=0.019) and shorter LTL (P=0.003), respectively, compared to G/G carriers. rs73598374-A carriers showed a stronger cross-sectional age reduction of LTL (r=-0.314, P=0.005) compared to G/G carriers (r=-0.243, P=0.022). The reduced ADA activity associated to rs73598374-A variant predisposes those carriers to display higher levels of adenosine compared to G/G carriers. Consequently, it may lead to an accelerated process of replicative senescence, causing a stronger reduction of TA and in turn shorter LTL. In conclusion, the crucial role played by replicative senescence of the immune system in several human diseases and in the aging process underscores the relevance of the present findings and also spurs interest into the possible involvement of rs73598374 in shaping the susceptibility to several age-related diseases

Phagocytosis depends on TRPV2-mediated calcium influx and requires TRPV2 in lipids rafts: alteration in macrophages from patients with cystic fibrosis.

Whereas many phagocytosis steps involve ionic fluxes, the underlying ion channels remain poorly defined. As reported in mice, the calcium conducting TRPV2 channel impacts the phagocytic process. Macrophage phagocytosis is critical for defense against pathogens. In cystic fibrosis (CF), macrophages have lost their capacity to act as suppressor cells and thus play a significant role in the initiating stages leading to chronic inflammation/infection. In a previous study, we demonstrated that impaired function of CF macrophages is due to a deficient phagocytosis. The aim of the present study was to investigate TRPV2 role in the phagocytosis capacity of healthy primary human macrophage by studying its activity, its membrane localization and its recruitment in lipid rafts. In primary human macrophages, we showed that P. aeruginosa recruits TRPV2 channels at the cell surface and induced a calcium influx required for bacterial phagocytosis. We presently demonstrate that to be functional and play a role in phagocytosis, TRPV2 might require a preferential localization in lipid rafts. Furthermore, CF macrophage displays a perturbed calcium homeostasis due to a defect in TRPV2. In this context, deregulated TRPV2-signaling in CF macrophages could explain their defective phagocytosis capacity that contribute to the maintenance of chronic infection

Evaluation of anti-inflammatory and immunoregulatory activities of Stimunex® and Stimunex D3® in human monocytes/macrophages stimulated with LPS or IL-4/IL-13

Macrophages exert an important role in maintaining and/or ameliorating the inflammatory response. They are involved in the activation of an immune response to pathogens, with a balance between the immunomodulatory role and tissue integrity maintenance, however, excessive macrophage activity promotes tissue injury and chronic disease pathogenesis. There is a high interest in evaluating the anti-inflammatory properties of new botanical preparations. Stimunex® and Stimunex D3® are two food supplements formulated as syrups, containing the extract of elderflower (Sambucus nigra, Caprifoliaceae), standardized in polyphenol (6%) and anthocyanins (4%), associated with wellmune WGP® β-glucan, with the addiction of vitamin D3 (in Stimunex D3® formulation). The aim of the work was the evaluation of Stimunex® and Stimunex D3® activity in human polarized-macrophages, in order to support their use as supplement for preventing and reducing the inflammatory processes. In primary human stimulated macrophages, both syrups were able to revert LPS- and IL-4/IL-13-mediated response, reducing the release of several pro-inflammatory cytokines. Results support that these standardized botanical preparations fortified with β-glucan, may have a potential use in the prevention and coadjuvant management of inflammatory process as respiratory recurrent infections and other similar conditions. Moreover, the addition of vitamin D3 revealed to be an advantage in Stimunex D3® for its important role in maintaining and enhancing the innate immune response

Advances in transient receptor potential vanilloid-2 channel expression and function in tumor growth and progression.

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