Endothelin receptors as novel targets in tumor therapy

The endotelin (ET) axis, that includes ET-1, ET-2, ET-3, and the ET receptors, ET(A )and ET(B), plays an important physiological role, as modulator of vasomotor tone, tissue differentiation and development, cell proliferation, and hormone production. Recently, investigations into the role of the ET axis in mitogenesis, apoptosis inhibition, invasiveness, angiogenesis and bone remodeling have provided evidence of the importance of the ET-1 axis in cancer. Data suggest that ET-1 participates in the growth and progression of a variety of tumors such as prostatic, ovarian, renal, pulmonary, colorectal, cervical, breast carcinoma, Kaposi's sarcoma, brain tumors, melanoma, and bone metastases. ET-1 receptor antagonists beside providing ideal tools for dissecting the ET axis at molecular level have demonstrated their potential in developing novel therapeutic opportunity. The major relevance of ET(A )receptor in tumor development has led to an extensive search of highly selective antagonists. Atrasentan, one of such antagonists, is orally bioavailable, has suitable pharmacokinetic and toxicity profiles for clinical use. Preliminary data from clinical trials investigating atrasentan in patients with prostate cancer are encouraging. This large body of evidence demonstrates the antitumor activity of endothelin receptor antagonists and provides a rationale for the clinical evaluation of these molecules alone and in combination with cytotoxic drugs or molecular inhibitors leading to a new generation of anticancer therapies targeting endothelin receptors

Improving whole tomato transformation for prostate health: benign prostate hypertrophy as an exploratory model

It is well-established that the beneficial properties of single phytonutrients can be better attained when they are taken with the complex of the molecules present in their natural milieu. Tomato, the fruit providing the most comprehensive complex of prostate-health-preserving micronutrients, has been shown to be superior to its single-nutrient counterparts in decreasing the incidence of age-related prostate diseases. Herein, we describe a novel tomato food supplement enriched with olive polyphenols, containing cis-lycopene concentrations far exceeding those present in industry-produced tomato commodities. The supplement, endowed with antioxidant activity comparable to that of N-acetylcysteine, significantly reduced, in experimental animals, the blood levels of prostate-cancer-promoting cytokines. In prospective, randomized, double-blinded, placebo-controlled studies performed on patients affected by benign prostatic hyperplasia, its uptake significantly improved urinary symptoms and quality of life. Therefore, this supplement can complement and, in some cases, be an alternative to current benign prostatic hyperplasia management. Furthermore, the product suppressed carcinogenesis in the TRAMP mouse model of human prostate cancer and interfered with prostate cancer molecular signaling. Thus, it may offer a step forward in exploring the potential of tomato consumption to delay or prevent the onset of age-related prostate diseases in high-risk individuals

Membrane Compartmentalization of Melanosomal gp75

A melanosomal integral membrane glycoprotein of 75 kD (gp75) has been previously identified as the human homologue of the product specified by the murine brown locus. We presently report that this molecule may be susceptible to limited proteolysis and extrinsic radioiodination in intact, live cells. Consequently, it is suggested that its cellular location might include the plasma membrane and/or a cellular compartment easily accessible to proteases and to chemically catalyzed vectorial iodination. This is of interest in view of the potential applicative value of gp75 as a target for the radioimmunoscintography of melanoma lesions

Analysis of gene expression levels and their impact on survival in 31 cancer-types patients identifies novel prognostic markers and suggests unexplored immunotherapy treatment options in a wide range of malignancies

Background Immunotherapy has dramatically improved cancer treatment by inhibiting or activating specific cell receptors, thus unleashing the host anti-tumor response. However, the engagement of the three main immune checkpoints so far identified, CTLA4, PD-1 and PD-L1, is effective in a fraction of patients, therefore novel targets must be identified and tested. Methods We focused our attention on the following nine highly relevant immune checkpoint (ICR) receptors: CTLA4, PD1, PD-L1, LAG3, TIM3, OX40, GITR, 4-1BB and TIGIT. All of them are targets of existing drugs currently under clinical scrutiny in several malignancies. Their expression levels were evaluated in patient tissues of 31 different cancer types vs. proper controls, in a total of 15,038 individuals. This analysis was carried out by interrogating public databases available on GEPIA2 portal and UALCAN portal. By the Principal Component Analysis (PCA) their ability to effectively discriminate patients form controls was then investigated. Expression of the nine ICRs was also related to overall survival in 31 cancer types and expressed as Hazard Ratio, on the GEPIA2 portal and validated, for melanoma patients, in patients-datasets available on PROGgene V2 portal. Results Significant differential expression was observed for each ICR molecule in many cancer types. A 7-molecules profile was found to specifically discriminate melanoma patients from controls, while two different 6-molecules profiles discriminate pancreatic cancer patients and Testicular Germ Cell Tumors from matched controls. Highly significant survival improvement was found to be related to the expression levels of all nine ICRs in a wide spectrum of malignancies. For melanoma analysis, the relation with survival observed in TCGA datasets was validated in independent GSE melanoma datasets. Conclusion Analysis the nine ICR molecules demonstrates that their expression patterns may be considered as markers of disease and strong survival predictors in a variety of malignancies frequently associated to poor prognosis. Thus, the present findings are strongly advocating that exploratory clinical trials are worth to be performed, using available drugs, targeting these molecules

Endothelin-1 decreases gap junctional intercellular communication by inducing phosphorylation of connexin 43 in human ovarian carcinoma cells

Endothelin-1 (ET-1) is overexpressed in ovarian carcinoma and acts as an autocrine factor selectively through the ETA receptor (ETAR) to promote tumor cell proliferation, survival, neovascularization, and invasiveness. Loss of gap junctional intercellular communication (GJIC) is critical for tumor progression by allowing the cells to escape growth control. Exposure of HEY and OVCA 433 ovarian carcinoma cell lines to ET-1 led to a 50–75% inhibition in intercellular communication and to a decrease in the connexin 43 (Cx43)-based gap junction plaques. To investigate the phosphorylation state of Cx43, ovarian carcinoma cell lysates were immunoprecipitated and transient tyrosine phosphorylation of Cx43 was detected in ET-1-treated cells. BQ 123, a selective ETAR antagonist, blocked the ET-1-induced Cx43 phosphorylation and cellular uncoupling. Gap junction closure was prevented by tyrphostin 25 and by the selective c-Src inhibitor, PP2. Furthermore, the increased Cx43 tyrosine phosphorylation was correlated with ET-1-induced increase of c-Src activity, and PP2 suppressed the ET-1-induced Cx43 tyrosine phosphorylation, indicating that inhibition of Cx43-based GJIC is mainly mediated by the Src tyrosine kinase pathway. In vivo, the inhibition of human ovarian tumor growth in nude mice induced by the potent ETAR antagonist, ABT-627, was associated with a reduction of Cx43 phosphorylation. These findings indicate that the signaling mechanisms involved in GJIC disruption on ovarian carcinoma cells depend on ETAR activation, which leads to the Cx43 tyrosine phosphorylation mediated by c-Src, suggesting that ETAR blockade may contribute to the control of ovarian carcinoma growth and progression also by preventing the loss of GJIC

Identification of a public CDR3 motif and a biased utilization of T-cell receptor V beta and J beta chains in HLA-A2/Melan-A-specific T-cell clonotypes of melanoma patients

<p>Abstract</p> <p>Background</p> <p>Assessment of T-cell diversity, besides giving insights about the molecular basis of tumor antigen recognition, has clinical implications since it provides criteria for evaluating antigen-specific T cells clinically relevant for spontaneous and vaccine-induced anti-tumor activity. Melan-A is one of the melanoma antigens most frequently recognized by peripheral and tumor-infiltrating lymphocytes in HLA-A2+ melanoma patients. Many clinical trials involving anti-tumor vaccination have been conducted using modified versions of this peptide.</p> <p>Methods</p> <p>We conducted an in-depth characterization of 210 T-cell receptor beta chain (TRB) clonotypes derived from T cells of HLA-A2+ melanoma patients displaying cytotoxic activity against natural and A27L-modified Melan-A peptides. One hundred and thirteen Melan-A-specific clonotypes from melanoma-free subjects, 199 clonotypes from T-cell clones from melanoma patients specific for melanoma antigens other than Melan-A, and 305 clonotypes derived from T cells of HLA-A2+ individuals showing unrelated specificities, were used as control. After sequence analysis, performed according to the IMGT definitions, TRBV and TRBJ usage, CDR3 length and amino acid composition were compared in the four groups of clonotypes.</p> <p>Results</p> <p>TRB sequences of Melan-A-specific clonotypes obtained from melanoma patients were highly heterogeneous, but displayed a preferential usage of few TRBV and TRBJ segments. Furthermore, they included a recurrent "public" amino acid motif (Glycine-Leucine-Glycine at positions 110-112-113 of the CDR3) rearranged with dominant TRBV and TRBJ segments and, in one case, associated with a full conservation of the entire TRB sequence.</p> <p>Conclusion</p> <p>Contrary to what observed for public anti-Melan-A T-cell receptor alpha motifs, which had been identified in several clonotypes of both melanoma patients and healthy controls, the unexpectedly high contribution of a public TRB motif in the recognition of a dominant melanoma epitope in melanoma patients may provide important information about the biology of anti-tumor T-cell responses and improve monitoring strategies of anti-tumor vaccines.</p

Recombinant Anti-Human Melanoma Antibodies Are Versatile Molecules

The low cost, high versatility, and reliable production of bacterially produced recombinant antibody fragments speeds up the development of tumor-targeting agents. High-quality recombinant anti-melanoma antibodies are much sought after in the scientific community. We cloned the murine antibody 225.28S, currently used in radioimmunoimaging of human melanoma lesions, in single-chain Fv configuration (scFv) for soluble expression in bacteria. The recombinant antibody fragment conserved the binding specificity of the parental antibody. In order to arm the scFv(225.28S) with biologically useful effector functions, we developed vectors for soluble expression of scFv(225.28S) in bacteria that allow both covalent and noncovalent chemical antibody modification at positions that do not interfere with antigen binding. An expression vector was developed that appends a cysteine residue at the C-terminal extremity of the recombinant antibody, thus allowing reaction with thiol-specific reagents, including 99mTc labeling, at a position that does not interfere with antigen binding. The scFv(225.28S) was also successfully expressed with a casein kinase II substrate tag that enables efficient and stable 32P labeling. For noncovalent antibody modification, we developed an expression vector that appends the human calmodulin gene at the C-terminal extremity of scFv(225.28S). The calmodulin domain is poorly immunogenic and can be targeted with chemically modified high-affinity calmodulin ligands. The recombinant anti-human melanoma antibodies described in this article should prove useful “building blocks” for the development of anti-melanoma diagnostic and therapeutic strategies

Quantitation of regional ejection fractions using gated tomographic imaging with Tc-99m-sestamibi

BACKGROUND: A new oro-dispersible film (ODF) formulation of sildenafil has been developed for the treatment of erectile dysfunction (ED) to overcome the drawbacks that some patients experience when taking the conventional film-coated tablet (FCT). AIM: To assess the effectiveness and safety of sildenafil ODF formulation in patients with ED who were using the conventional FCT. METHODS: From May 2017 through July 2017, 139 patients with ED were enrolled. Data from penile color-duplex ultrasound, medical history, hormonal evaluation, and patient self-administered questionnaires were collected. All patients were administered sildenafil 100-mg FCT for 4 weeks. Thereafter, they underwent a 2-week washout period and subsequently took sildenafil 75-mg ODF for 4 weeks. OUTCOMES: The International Index of Erectile Function (IIEF-15), Hospital Anxiety and Depression Scale (HADS), Patient Global Impressions of Improvement (PGI-I), and Clinician Global Impressions of Improvement (CGI-I) questionnaires were administered and severity of ED was classified as severe (IIEF-15 score ≤ 10), moderate (IIEF-15 score 11-16), or mild (IIEF-15 score = 17-25). RESULTS: All patients completed the final protocol. Differences in mean IIEF scores for erectile function, orgasmic function, sexual desire, and intercourse satisfaction were significantly in favor of sildenafil 100-mg FCT, whereas the mean score for overall satisfaction was in favor of sildenafil 75-mg ODF. A significant difference in changes in HADS score was found from washout to final follow-up (mean difference = -0.19; P < .01). For the ODF formulation, the median CGI-I score was 3.5 (interquartile range [IQR] = 2.5-4.5) and the median PGI-I score was 3.0 (IQR = 2.0-4.0). The median action time was 20.0 minutes (IQR = 15.0-30.0) and the median mouth time was 60.0 seconds (IQR = 30.0-120.0). CLINICAL IMPLICATIONS: The ODF formulation of a widely known drug, with the same safety and effectiveness of the FCT, was better appreciated by patients in overall satisfaction. STRENGTHS AND LIMITATIONS: This is the first clinical trial to assess the efficacy of a new formulation of sildenafil in patients with ED. The limitations of the study are related to the methodology used: it was not a case-control study and the patients were not drug-naïve for ED treatment. Therefore, only the "additional" side effects of the ODF formulation compared with FCT are reported. CONCLUSION: The new ODF formulation is as efficient and safe as the FCT formulation and offers a new choice of treatment to specialists for more precisely tailored therapy. Cocci A, Capece M, Cito G, et al. Effectiveness and Safety of Oro-Dispersible Sildenafil in a New Film Formulation for the Treatment of Erectile Dysfunction: Comparison Between Sildenafil 100-mg Film-Coated Tablet and 75-mg Oro-Dispersible Film. J Sex Med 2017;X:XXX-XXX