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1.
J Immunother Cancer ; 11(11)2023 11 28.
Article in English | MEDLINE | ID: mdl-38016718

ABSTRACT

BACKGROUND: It is possible to induce immunomodulation in HER2-positive breast cancer (BC) by modifying the route of administration of trastuzumab. METHODS: In this multicenter randomized phase II trial, all enrolled patients (pts) with T2-T4d HER2-positive BC received 3 cycles of neoadjuvant treatment (NAT) with fluorouracil, epirubicin and cyclophosphamide every 3 weeks (q21), followed by docetaxel/pertuzumab plus intravenous trastuzumab (arm A) or, docetaxel/pertuzumab plus subcutaneous (SC) trastuzumab (arm B) q21x4 cycles. After surgical operation, each pt was treated with trastuzumab q21x14 cycles using the same SC or intravenous formulation of NAT. Primary endpoint was the proportion of subjects with high stromal tumor-infiltrating lymphocytes (sTILs) in postneoadjuvant residual disease (RD). RESULTS: Sixty-three pts (31 (arm A) and 32 (arm B)) were enrolled. Pathological complete response was obtained by 20/31 pts (64.5%; 95% CI 45.4% to 80.1%) in arm A and 19/32 pts (59.4%; 95% CI 40.1% to 76.3%) in arm B. High sTILs were observed in 27% and 46% of postneoadjuvant residual tumors in arms A and B, respectively. CD8+ T cells increased significantly in RDs of both arms (p=0.014 and 0.002 for arm A and B, respectively), whereas a significant decline in the level of CD4+ FoxP3+ regulatory T cells was observed only in arm B (p=0.016). A significant upregulation of PD-1 on sTILs was found in RD of pts enrolled in arm B (p=0.012), while programmed death-ligand 1 (PD-L1) was significantly overexpressed in residual tumors of arm A (p=0.02). A strong negative correlation was reported in arm B between expression of PD-L1 on pretreatment sTILs and CD3 expression on sTILs in RD (τ: -0.73). Grade≥3 AE incidence rates were similar between the two arms. CONCLUSIONS: SC trastuzumab induced relevant sTILs enrichment, with favorable variations of immune parameters in HER2-positive BC pts with RD after NAT. Novel immunotherapy strategies should be tested to achieve SC-specific, antitumor immune response. TRIAL REGISTRATION NUMBER: NCT03144947, and EudraCT number: 2016-000435-41.


Subject(s)
Breast Neoplasms , Humans , Female , Trastuzumab/pharmacology , Trastuzumab/therapeutic use , Breast Neoplasms/pathology , B7-H1 Antigen/therapeutic use , Docetaxel/pharmacology , Docetaxel/therapeutic use , Neoadjuvant Therapy , Neoplasm, Residual , Receptor, ErbB-2/metabolism , Treatment Outcome , Antineoplastic Combined Chemotherapy Protocols/therapeutic use
2.
Future Oncol ; 18(7): 771-779, 2022 Mar.
Article in English | MEDLINE | ID: mdl-35068173

ABSTRACT

Based on improved survival from the addition of PD-L1 inhibitors in phase III trials, the combination of immunotherapy and platinum-doublet chemotherapy has become the new standard treatment for extended-stage small-cell lung cancer (ES-SCLC). Furthermore, the antiangiogenetic agent bevacizumab showed a longer progression-free survival by targeting VEGF that has pleiotropic effects, including immunosuppressive ones. We, therefore, hypothesized that targeting angiogenesis would improve the efficacy of chemoimmunotherapy. The CeLEBrATE trial is an open-label, multicenter, phase II study designed to assess the efficacy and safety of the combination of carboplatin and etoposide plus bevacizumab and atezolizumab in treatment-naive patients with ES-SCLC. The primary end point is overall survival rate at 1 year, while secondary end points include overall response rate, progression-free survival and toxicity.


Lay abstract Extended-stage small-cell lung cancer (ES-SCLC) is a highly aggressive lung cancer subtype, accounting for 13­15% of all lung cancers. For several years, the standard treatment for this disease was based on polychemotherapy, with a rapid disease response but with an equally rapid disease progression. The new standard treatment has recently been changed, based on the results of two large clinical trials, which showed the efficacy and safety of the combination of chemotherapy with immunotherapy compared to chemotherapy alone. Nevertheless, prognosis of ES-SCLC remains poor, and new treatment strategies are urgently needed. Therefore, we designed the CeLEBrATE trial to investigate whether the combination of chemotherapy with antiangiogenetic therapy and immunotherapy is safe and could improve survival in patients with ES-SCLC.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Lung Neoplasms/drug therapy , Small Cell Lung Carcinoma/drug therapy , Antibodies, Monoclonal, Humanized/administration & dosage , Bevacizumab/administration & dosage , Carboplatin/administration & dosage , Clinical Trials, Phase II as Topic , Etoposide/administration & dosage , Humans , Lung Neoplasms/pathology , Multicenter Studies as Topic , Research Design , Small Cell Lung Carcinoma/pathology
3.
J Immunother Cancer ; 9(5)2021 05.
Article in English | MEDLINE | ID: mdl-34016723

ABSTRACT

BACKGROUND: Until now, no robust data supported the efficacy, safety and recommendation for influenza vaccination in patients with cancer receiving immune checkpoint inhibitors (ICIs). METHODS: The prospective multicenter observational INfluenza Vaccine Indication During therapy with Immune checkpoint inhibitors (INVIDIa-2) study investigated the clinical effectiveness of influenza vaccination in patients with advanced cancer receiving ICIs, enrolled in 82 Italian centers from October 2019 to January 2020. The primary endpoint was the time-adjusted incidence of influenza-like illness (ILI) until April 30, 2020. Secondary endpoints regarded ILI severity and vaccine safety. RESULTS: The study enrolled 1279 patients; 1188 patients were evaluable for the primary endpoint analysis. Of them, 48.9% (581) received influenza vaccination. The overall ILI incidence was 8.2% (98 patients). Vaccinated patients were significantly more frequently elderly (p<0.0001), males (p=0.004), with poor European Cooperative Oncology Group performance status (p=0.009), affected by lung cancer (p=0.01), and by other non-cancer comorbidities (p<0.0001) when compared with unvaccinated. ILI incidence was not different basing on influenza vaccination: the time-to-ILI was similar in vaccinated and unvaccinated patients (p=0.62). ILI complications were significantly less frequent for patients receiving the vaccination (11.8% vs 38.3% in unvaccinated, p=0.002). ILI-related intravenous therapies were significantly less frequent in vaccinated patients than in unvaccinated (11.8% vs 29.8%, p=0.027). ILI lethality was, respectively, 0% in vaccinated and 4.3% in unvaccinated patients. Vaccine-related adverse events were rare and mild (1.5%, grades 1-2). CONCLUSION: The INVIDIa-2 study results support a positive recommendation for influenza vaccination in patients with advanced cancer receiving immunotherapy.


Subject(s)
Immune Checkpoint Inhibitors/therapeutic use , Influenza Vaccines/administration & dosage , Influenza, Human/prevention & control , Neoplasms/drug therapy , Vaccination , Vaccine Efficacy , Adult , Aged , Aged, 80 and over , Female , Humans , Immune Checkpoint Inhibitors/adverse effects , Incidence , Influenza Vaccines/adverse effects , Influenza, Human/diagnosis , Influenza, Human/epidemiology , Influenza, Human/immunology , Italy/epidemiology , Male , Middle Aged , Neoplasms/diagnosis , Neoplasms/epidemiology , Neoplasms/immunology , Prospective Studies , Risk Assessment , Risk Factors , Time Factors , Treatment Outcome , Vaccination/adverse effects , Young Adult
4.
Clin Lung Cancer ; 22(5): 473-477, 2021 09.
Article in English | MEDLINE | ID: mdl-33762169

ABSTRACT

BACKGROUND: Alectinib is a potent anaplastic lymphoma kinase (ALK)-tyrosine kinase inhibitor (TKI) which is currently used in the first-line setting of advanced ALK+ non-small cell lung cancer (NSCLC). Despite favorable results in the metastatic setting, the activity of alectinib in locally-advanced ALK+ NSCLC as a neoadjuvant treatment remains to be assessed. We report the case of a patient with stage IIIA ALK+ NSCLC (cT2aN2) who received alectinib as neoadjuvant treatment, achieving major pathological response (MPR) at pathologic examination. Hence we present the treatment rationale and study design of a phase II, open-label, single-arm, multicenter clinical trial (ALNEO study, EUDRACT number 2020-003432-25). MATERIALS AND METHODS: Patients with potentially resectable stage III ALK+ NSCLC (any T with N2, T4N0-1) will be registered to receive oral alectinib 600 mg twice daily for 2 cycles of 4 weeks each (8 weeks totally) during the neoadjuvant phase. After definitive surgery, patients will enter in the adjuvant setting, during which they will receive alectinib 600 mg twice daily for 24 cycles (96 weeks). The primary endpoint is MPR, defined as ≤10% residual viable tumor cells histologically detected in the resected primary tumor and all resected lymph nodes after surgery. Secondary endpoints include pathological complete response, objective response, event-free survival, disease-free survival, overall survival, adverse events. CONCLUSIONS: Our case report supports the feasibility of alectinib as neoadjuvant treatment. ALNEO study will further explore the activity and safety of this novel treatment strategy.


Subject(s)
Carbazoles/pharmacology , Carbazoles/therapeutic use , Carcinoma, Non-Small-Cell Lung/drug therapy , Neoadjuvant Therapy , Patient Safety , Piperidines/pharmacology , Piperidines/therapeutic use , Adolescent , Adult , Anaplastic Lymphoma Kinase , Carcinoma, Non-Small-Cell Lung/surgery , Female , Humans , Male , Middle Aged , Young Adult
5.
Immunotherapy ; 12(15): 1139-1148, 2020 10.
Article in English | MEDLINE | ID: mdl-32933369

ABSTRACT

Aim: Evaluating the incidence and course of COVID-19 in cancer patients treated with immunotherapy. Patients & methods: We reported the influenza-like illness events with diagnosis of COVID-19 within the patient cohort enrolled in the prospective observational multicenter INVIDIa-2 study in the single center of Parma. Results: Among 53 patients, eight experienced influenza-like illness during the influenza season 2019/2020, and three of them had diagnosis of COVID-19. They were males, elderly, with cardiovascular disease. Radiological features of COVID-19 pneumonitis were found in all of three cases, although the pharyngeal swab resulted positive in only two. Two of these three patients died due to respiratory failure. Conclusion: Cancer patients are at high risk of severe events from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.


Subject(s)
Coronavirus Infections/epidemiology , Immunotherapy , Neoplasms/epidemiology , Neoplasms/therapy , Pneumonia, Viral/epidemiology , Adult , Aged , Aged, 80 and over , Antineoplastic Agents, Immunological/therapeutic use , Betacoronavirus/isolation & purification , COVID-19 , Coronavirus Infections/diagnosis , Coronavirus Infections/pathology , Coronavirus Infections/physiopathology , Female , Humans , Incidence , Italy/epidemiology , Lung/diagnostic imaging , Lung/pathology , Male , Middle Aged , Pandemics , Pharynx/virology , Pneumonia, Viral/diagnosis , Pneumonia, Viral/pathology , Pneumonia, Viral/physiopathology , Prospective Studies , Risk Factors , SARS-CoV-2 , Tomography, X-Ray Computed
6.
Ther Adv Med Oncol ; 12: 1758835920915983, 2020.
Article in English | MEDLINE | ID: mdl-32733604

ABSTRACT

BACKGROUND: Although immunotherapy with immune-checkpoint inhibitors (ICIs) has profoundly changed the therapeutic scenario in the treatment of advanced non-small cell lung cancer (NSCLC), trials of ICIs only enrolled NSCLC patients with common histology. Atezolizumab was approved by the United States Food and Drug Administration (US FDA) in October 2016 and by the European Medicines Agency (EMA) in September 2017 for the treatment of patients with metastatic NSCLC whose disease progressed during or following platinum-containing chemotherapy, regardless of PD-L1 expression. METHODS: We designed a single-arm, multicenter, two-stage phase II study and plan to enroll 43 patients. The primary objective of the study is to evaluate the antitumor activity of atezolizumab in advanced NSCLC patients with rare histology subtypes. Patients with prior atezolizumab or ICI treatment and with untreated, symptomatic, or progressing brain metastases will be excluded. The primary endpoint is disease control rate. Secondary objectives are toxicity and safety, overall response rate, progression-free survival, overall survival, and time to progression. Diagnosis of NSCLC with rare histology will be confirmed by central pathology revision, and will include: colloid carcinoma, fetal adenocarcinoma, non-endocrine large cell carcinoma, sarcomatoid carcinoma, salivary gland-type tumor, lymphoepithelioma-like carcinoma, and NUT-nuclear protein in testis carcinoma. Archival tumor tissue is required for correlative studies of PD-L1 expression on tumor cells and tumor infiltrating lymphocytes. CONCLUSIONS: Therapeutic options in NSCLC with rare histology subtypes, to be assessed in specifically designed trials, are an unmet need. This trial will help elucidate the role of atezolizumab as a viable option in this setting.

8.
Expert Rev Pharmacoecon Outcomes Res ; 15(1): 101-10, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25399933

ABSTRACT

The pharmacological costs of regimens used as front-line therapy in advanced colorectal cancer patients and their impact on the liver resection rates have not been considered. In this paper, we made a review of published randomized Phase II and III trials that reported the liver resection rates following upfront chemotherapy and linked this outcome to the pharmacological costs of drugs used. The costs are calculated based on the price at Pharmacy of our Hospital in Legnago (Italy), and as a measure of activity, we used the number of patients needed to treat to get one complete liver resection. Number needed to treat is highly variable among the different trials according to patient's characteristics, tumor biology and the efficacy of chemotherapy administered. The range of activity is greatly amplified when the costs are compared.


Subject(s)
Antineoplastic Agents/therapeutic use , Colorectal Neoplasms/pathology , Liver Neoplasms/therapy , Antineoplastic Agents/economics , Clinical Trials, Phase II as Topic , Clinical Trials, Phase III as Topic , Drug Costs , Humans , Italy , Liver Neoplasms/economics , Liver Neoplasms/secondary
9.
J Chemother ; 26(2): 111-6, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24090610

ABSTRACT

OBJECTIVES: We evaluated the impact of a carboplatin-based doublet in two groups of elderly patients with advanced non-small cell lung cancers (NSCLC). MATERIALS AND METHODS: A retrospective analysis of all consecutive elderly patients (≧70 year old) with advanced NSCLC who received a carboplatin-based doublet as front-line therapy at our medical oncology unit was performed. RESULTS: In the study, 57 consecutive elderly patients with advanced NSCLC were included. Carboplatin was combined with vinorelbine in 41 patients (71·9%) and with gemcitabine in 16 patients (28·1%). Overall, a total of 227 cycles were administered to 57 patients - 142 cycles were administered to patients in group 1 and 85 cycles were given to patients in group 2 - median number of administered cycles per patient was 4 (range 1-6). Of the patients, 35 (62%, group 1) were 'young-old' (70-74-year old) and 20 (38%, group 2) were 'old-old' (75-82-year old). Toxicity was mild in both subgroups (grade 3-4 neutropenia in 17·1% of group 1 and in 9·1% of group 2). At the univariate analysis, the median overall survival (OS) was 10·07 months (P = 0·789, 95% CI: 8·49-11·64), 10·1 months in group 1 and 9·8 months in group 2. CONCLUSIONS: This evaluation shows the safety and efficacy of a carboplatin-based doublet given as first-line chemotherapy in elderly advanced NSCLC patients. The combination with vinorelbine or gemcitabine is associated with a very good toxicity profile that does not seem to have a detrimental effect on efficacy.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Carcinoma, Non-Small-Cell Lung/drug therapy , Lung Neoplasms/drug therapy , Age Factors , Aged , Aged, 80 and over , Carboplatin/administration & dosage , Deoxycytidine/administration & dosage , Deoxycytidine/analogs & derivatives , Female , Humans , Male , Retrospective Studies , Vinblastine/administration & dosage , Vinblastine/analogs & derivatives , Vinorelbine , Gemcitabine
10.
Tumori ; 99(6): 650-5, 2013.
Article in English | MEDLINE | ID: mdl-24503786

ABSTRACT

AIMS AND BACKGROUND: More than 50% of patients with advanced non-small cell lung cancer are diagnosed in the elderly. Few prospective clinical data with cisplatin-based chemotherapy are available, and some authors have suggested that a non-platinum single agent should be the preferred form of cure in these patients. The aim of the study was to evaluate the efficacy and safety of first-line chemotherapy based on platinums (carboplatin or cisplatin) plus a third generation compound (vinorelbine or gemcitabine) in elderly patients with advanced non-small cell lung cancer in daily clinical practice. METHODS: A retrospective analysis of consecutive elderly (≥70 years of age) patients with advanced non-small cell lung cancer treated at our Medical Oncology Unit from February 2005 to September 2011 was performed. RESULTS: A total of 249 cycles of chemotherapy was administered to 62 patients (median age, 72 years; range, 70-81) presenting a median Charlson comorbidity index of 1 and a good ECOG PS (0-1, 52 patients; 2, 10 patients). The median number of cycles/patient was 4, and all 62 patients received a platinum-based doublet as first-line chemotherapy: 57 with carboplatin (92%) and 5 with cisplatin (8%). As best response to the treatment, 19 (31%) partial responses and 20 (32%) stable diseases were observed. Median overall survival was 9.8 months. Toxicity was mild; grade III-IV neutropenia was the most frequently observed side effect in 19 administered cycles (8%). CONCLUSIONS: Advanced non-small cell lung cancer in elderly patients can be safely treated with a platinum-based doublet. Observed toxicity is manageable, and overall survival is in keeping with data from the literature.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Carcinoma, Non-Small-Cell Lung/drug therapy , Lung Neoplasms/drug therapy , Adenocarcinoma/drug therapy , Aged , Aged, 80 and over , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Carboplatin/administration & dosage , Carcinoma, Non-Small-Cell Lung/pathology , Carcinoma, Squamous Cell/drug therapy , Cisplatin/administration & dosage , Comorbidity , Deoxycytidine/administration & dosage , Deoxycytidine/analogs & derivatives , Disease-Free Survival , Drug Administration Schedule , Female , Humans , Kaplan-Meier Estimate , Lung Neoplasms/pathology , Male , Neoplasm Staging , Retrospective Studies , Treatment Outcome , Vinblastine/administration & dosage , Vinblastine/analogs & derivatives , Vinorelbine , Gemcitabine
11.
Gastroenterology ; 125(1): 126-35, 2003 Jul.
Article in English | MEDLINE | ID: mdl-12851878

ABSTRACT

BACKGROUND & AIMS: The components of the kinin system, including kinongens, kininogenases, and B(2) and B(1) receptors, are expressed and activated during inflammation. Here, we investigated the expression of the kinin B(2) receptor messenger RNA, kininogen and kallikrein immunoreactivity, and the ability of kinins to contract control and inflamed gallbladders in vitro. METHODS: Human gallbladders, obtained from patients undergoing cholecystectomy either for acute cholecystitis secondary to gallstone disease or during elective gastro-entero-pancreatic surgery (controls), were processed for reverse-transcription polymerase chain reaction analysis, kallikrein and kininogen immunohistochemistry, binding studies, and in vitro contractility studies. RESULTS: Tissue expression of B(2) receptor messenger RNA and specific binding of [(3)H]-bradykinin increased significantly in acute cholecystitis compared to controls. Kallikrein immunoreactivity was detected in the epithelium and infiltrating leukocytes, whereas kininogen immunoreactivity in the lumen of blood vessels and interstitial space. Bradykinin contracted isolated strips of control and acute cholecystitis gallbladders. In acute cholecystitis tissue, efficacy of bradykinin was higher than that of control gallbladders and similar to that of cholecystokinin. The contraction induced by bradykinin was significantly attenuated by B(2) receptor antagonism but not by cyclooxygenase inhibition and B(1), muscarinic, or tachykinin receptor antagonism. CONCLUSIONS: All the components of the kinin system are expressed in the human gallbladder. Bradykinin is a powerful spasmogen via B(2) receptor activation in the normal and, especially, in the inflamed human gallbladder.


Subject(s)
Bradykinin/analogs & derivatives , Bradykinin/metabolism , Gallbladder Emptying/physiology , Gallbladder/physiology , Receptors, Bradykinin/genetics , Receptors, Bradykinin/metabolism , Adrenergic beta-Antagonists/pharmacology , Adult , Aged , Antipsychotic Agents/pharmacology , Atropine/pharmacology , Benzamides/pharmacology , Bradykinin/pharmacology , Bradykinin Receptor Antagonists , Cyclooxygenase Inhibitors/pharmacology , Female , Gallbladder Emptying/drug effects , Gene Expression , Humans , Immunohistochemistry , In Vitro Techniques , Indomethacin/pharmacology , Male , Middle Aged , Muscarinic Antagonists/pharmacology , Piperidines/pharmacology , Quinuclidines/pharmacology , Receptor, Bradykinin B1 , Receptor, Bradykinin B2 , Reverse Transcriptase Polymerase Chain Reaction , Tritium
12.
Br J Pharmacol ; 139(1): 21-7, 2003 May.
Article in English | MEDLINE | ID: mdl-12746219

ABSTRACT

1. The in vitro motor function of protease-activated recepter-1 (PAR-1), PAR-2 and PAR-4 and the presence by immunohistochemistry of PAR-1 in the human renal artery have been investigated. 2. Thrombin and the human PAR-1 (SFLLRN-NH(2)) activating peptide, but not the PAR-1 reverse peptide (NRLLFS-NH(2)), contracted both endothelial-intact and endothelial-denuded human renal artery strips, whereas no relaxation was observed either in strips non-precontracted or precontracted with phenylephrine. Maximum contraction by thrombin or SFLLRN-NH(2) was about 60% of phenylephrine. However, thrombin was approximately 1000-fold more potent than SFLLRN-NH(2). 3. PAR-1 desensitisation, using repeated applications of SFLLRN-NH(2), almost completely blocked the response to thrombin. The contractile effect produced by thrombin and SFLLRN-NH(2) was not affected by nitric oxide synthase inhibition, but was significantly reduced by cyclooxygenase blockade. 4. Trypsin, the PAR-2 (SLIGKV-NH(2) and SLIGRL-NH(2)) and PAR-4 (GYPGQV-NH(2) and AYPGKF-NH(2)) activating peptides did not produce any significant contraction or relaxation. 5. In agreement with the motor function data immunohistochemistry showed specific staining patterns for PAR-1 in the human renal artery. 6. Combined, these studies would suggest a possible role for PAR-1 in renal vascular homeostasis.


Subject(s)
Receptor, PAR-1/agonists , Renal Artery/physiology , Vasoconstriction/physiology , Culture Techniques , Humans , Immunohistochemistry , Nitric Oxide Synthase/antagonists & inhibitors , Oligopeptides/pharmacology , Phenylephrine/pharmacology , Receptor, PAR-1/metabolism , Receptor, PAR-1/physiology , Receptor, PAR-2/agonists , Receptors, Thrombin/agonists , Renal Artery/drug effects , Renal Artery/metabolism , Thrombin/pharmacology , Vasoconstriction/drug effects , Vasoconstrictor Agents/pharmacology , Vasodilation/drug effects , Vasodilation/physiology
13.
Br J Pharmacol ; 138(5): 977-85, 2003 Mar.
Article in English | MEDLINE | ID: mdl-12642400

ABSTRACT

(1) Stimulation of the vanilloid receptor-1 (TRPV1) results in the activation of nociceptive and neurogenic inflammatory responses. Poor specificity and potency of TRPV1 antagonists has, however, limited the clarification of the physiological role of TRPV1. (2) Recently, iodo-resiniferatoxin (I-RTX) has been reported to bind as a high affinity antagonist at the native and heterologously expressed rat TRPV1. Here we have studied the ability of I-RTX to block a series of TRPV1 mediated nociceptive and neurogenic inflammatory responses in different species (including transfected human TRPV1). (3) We have demonstrated that I-RTX inhibited capsaicin-induced mobilization of intracellular Ca(2+) in rat trigeminal neurons (IC(50) 0.87 nM) and in HEK293 cells transfected with the human TRPV1 (IC(50) 0.071 nM). (4) Furthermore, I-RTX significantly inhibited both capsaicin-induced CGRP release from slices of rat dorsal spinal cord (IC(50) 0.27 nM) and contraction of isolated guinea-pig and rat urinary bladder (pK(B) of 10.68 and 9.63, respectively), whilst I-RTX failed to alter the response to high KCl or SP. (5) Finally, in vivo I-RTX significantly inhibited acetic acid-induced writhing in mice (ED(50) 0.42 micro mol kg(-1)) and plasma extravasation in mouse urinary bladder (ED(50) 0.41 micro mol kg(-1)). (6) In in vitro and in vivo TRPV1 activated responses I-RTX was approximately 3 log units and approximately 20 times more potent than capsazepine, respectively. This high affinity antagonist, I-RTX, may be an important tool for future studies in pain and neurogenic inflammatory models.


Subject(s)
Diterpenes/pharmacology , Neurons/drug effects , Pain Measurement/drug effects , Receptors, Drug/antagonists & inhibitors , Animals , Cell Line , Dose-Response Relationship, Drug , Guinea Pigs , Humans , Male , Mice , Muscle Contraction/drug effects , Muscle Contraction/physiology , Neurons/metabolism , Pain Measurement/methods , Rats , Rats, Sprague-Dawley , Receptors, Drug/metabolism
14.
Proc Natl Acad Sci U S A ; 99(12): 8400-5, 2002 Jun 11.
Article in English | MEDLINE | ID: mdl-12060783

ABSTRACT

The vanilloid receptor VR1 is a nonselective cation channel that is most abundant in peripheral sensory fibers but also is found in several brain nuclei. VR1 is gated by protons, heat, and the pungent ingredient of "hot" chili peppers, capsaicin. To date, no endogenous compound with potency at this receptor comparable to that of capsaicin has been identified. Here we examined the hypothesis, based on previous structure-activity relationship studies and the availability of biosynthetic precursors, that N-arachidonoyl-dopamine (NADA) is an endogenous "capsaicin-like" substance in mammalian nervous tissues. We found that NADA occurs in nervous tissues, with the highest concentrations being found in the striatum, hippocampus, and cerebellum and the lowest concentrations in the dorsal root ganglion. We also gained evidence for the existence of two possible routes for NADA biosynthesis and mechanisms for its inactivation in rat brain. NADA activates both human and rat VR1 overexpressed in human embryonic kidney (HEK)293 cells, with potency (EC(50) approximately 50 nM) and efficacy similar to those of capsaicin. Furthermore, NADA potently activates native vanilloid receptors in neurons from rat dorsal root ganglion and hippocampus, thereby inducing the release of substance P and calcitonin gene-related peptide (CGRP) from dorsal spinal cord slices and enhancing hippocampal paired-pulse depression, respectively. Intradermal NADA also induces VR1-mediated thermal hyperalgesia (EC(50) = 1.5 +/- 0.3 microg). Our data demonstrate the existence of a brain substance similar to capsaicin not only with respect to its chemical structure but also to its potency at VR1 receptors.


Subject(s)
Capsaicin/pharmacology , Receptors, Drug/physiology , Animals , Cell Line , Humans , Hyperalgesia/chemically induced , Rats , Receptors, Drug/drug effects , Recombinant Proteins/drug effects , Recombinant Proteins/metabolism , Transfection
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