Evaluation of the efficiency of peptide receptor radionuclide therapy in patients with metastatic prostate carcinoma: A protocol for systematic review and meta-analysis.

BACKGROUND: Metastatic prostate carcinoma has poor prognoses with a median survival period ranging from 2 to 5 years with existing therapeutic challenges. Currently, peptide receptor radionuclide therapy is permitted as a treatment method for metastatic prostate carcinoma patients. Therefore, it is crucial to comprehend the efficiency and safety of peptide receptor radionuclide therapy among this patient population. This study aims to analyse the efficacy of peptide receptor radionuclide therapy when used to treat metastatic prostate carcinoma patients. METHODS: This research will perform a methodological search in the following electronic databases to find related randomized controlled trials: Cochrane Library, EMBASE, PubMed, Web of Science, Scopus, China National Knowledge Infrastructure (CNKI), WanFang database, and Chinese BioMedical Literature. All the databases are searched from their inauguration till November 2020. Two independent authors will screen and select literature for review. The two authors will independently utilize the Cochrane Risk of Bias tool to assess the bias risk in studies. This study also plans to conduct subgroup and sensitivity analyses to evaluate the robustness in the results. Statistical analyses will be conducted with the RevMan 5.3 software. RESULTS: A high-quality synthesis of existing evidence related to peptide receptor radionuclide therapy in the treatment of metastatic prostate carcinoma will be presented in this study. CONCLUSION: Our findings will provide evidence to judge whether peptide receptor radionuclide treatment is efficient for metastatic prostate carcinoma patients. ETHICS AND DISSEMINATION: An ethics approval is not required because the data of the present study are primarily obtained from published studies.OSF registration number: December 1, 2020.osf.io/3psx7. (https://osf.io/3psx7/).

Early Prediction of Treatment Response of Neuroendocrine Hepatic Metastases after Peptide Receptor Radionuclide Therapy with 90Y-DOTATOC Using Diffusion Weighted and Dynamic Contrast-Enhanced MRI.

The purpose of this study was to determine if parameters derived from diffusion-weighted (DW-) and dynamic contrast-enhanced (DCE-) magnetic resonance imaging (MRI) can help to assess early response to peptide receptor radionuclide therapy (PRRT) with 90Y-DOTATOC in neuroendocrine hepatic metastases (NET-HM). Twenty patients (10 male; 10 female; mean age: 59.2 years) with NET-HM were prospectively enrolled in this single-center imaging study. DW-MRI and DCE-MRI studies were performed just before and 48 hours after therapy with 90Y-DOTATOC. Abdominal SPECT/CT was performed 24 hours after therapy. This MRI imaging and therapy session was repeated after a mean interval of 10 weeks. Up to four lesions per patient were evaluated. Response to therapy was evaluated using metastasis sizes at the first and second therapy session as standard for comparison (regressive, stable, and progressive). DW-MRI analysis included the apparent diffusion coefficient (ADC) and parameters related to intravoxel incoherent motion (IVIM), namely, diffusion (D), perfusion fraction (f) and pseudo-diffusion (D ∗ ). DCE-MRI analysis comprised Ktrans, v e and k ep. For statistical analysis of group differences, one-way analysis of variance (ANOVA) and appropriate post hoc testing was performed. A total of 51 lesions were evaluated. Seven of 51 lesions (14%) showed size progression, 18/51 (35%) regression, and 26/51 (51%) remained stable. The lesion-to-spleen uptake ratio in SPECT showed a decrease between the two treatment sessions that was significantly stronger in regressive lesions compared with stable (p = 0.013) and progressive lesions (p = 0.021). ANOVA showed significant differences in mean ADC after 48 h (p = 0.026), with higher ADC values for regressive lesions. Regarding IVIM, highest values for D at baseline were seen in regressive lesions (p = 0.023). In DCE-MRI, a statistically significant increase in v e after 10 weeks (p = 0.046) was found in regressive lesions. No differences were observed for the transfer constants Ktrans and k ep. Diffusion restriction quantified as ADC was able to differentiate regressive from progressive NET-HMs as early as 48 hours after PRRT. DW-MRI therefore may complement scintigraphy/SPECT for early assessment of response to PRRT. Assessment of perfusion parameters using IVIM and DCE-MRI did not show an additional benefit.

New therapeutic targeting of Alzheimer's disease with the potential use of proline-rich polypeptide complex to modulate an innate immune response - preliminary study.

BACKGROUND: The lack of effective treatment for Alzheimer's disease (AD) stems mainly from the incomplete understanding of AD causes. Neuroinflammation has emerged as an important component of AD pathology, and a vast number of experimental and clinical data indicated a crucial role for the activation of the innate immune system in disease promotion and symptom progression. METHODS: Clinical examinations of AD patients in a different stage of disease severity in correlation with the measurement of two innate immune reactions, i.e., peripheral blood leukocyte (PBLs) resistance to viral infection (vesicular stomatitis virus, VSV) ex vivo, and cytokines: TNF-α, IFN-γ, IL-1ß, and IL-10, production with enzyme-linked immunosorbent assay (ELISA), have been investigated during this preliminary study before and after 4 weeks of oral treatment with dietary supplement proline-rich polypeptide complex (PRP) (120 µg of PRP/day). The potential effect of PRP on the distribution of PBLs' subpopulations has been specified. RESULTS: We have found a deficiency in innate immune response in AD patients. It was demonstrated for the first time that the degree of PBLs resistance to VSV infection was closely related to the stage of clinical severity of AD. Our study showed significant differences in cytokine production which pointed that in AD patients innate immune mechanisms are impaired. Administration of PRP to our patients increased innate immune response of PBLs and declined pro- and anti-inflammatory cytokine production, thus subduing the excessively developed inflammatory response, especially among patients with high severity of AD. PRP did not exhibit a pro-proliferative activity. It was showed, however, significant influence of PRP on the distribution of PBLs' subpopulations. CONCLUSION: The findings mentioned above might be crucial in the context of potential application of immunomodulatory therapy in AD patients and indicated PRP as a potential target for future treatments in neuroinflammatory diseases like AD.

The Role of Adding Somatostatin Analogues to Peptide Receptor Radionuclide Therapy as a Combination and Maintenance Therapy.

Purpose: Although somatostatin analogues (SSA) and peptide receptor radionuclide therapy (PRRT) are validated therapies in patients with advanced gastroenteropancreatic neuroendocrine tumors (GEP-NET), it remains unclear whether SSA combined with PRRT or as maintenance therapy can provide prolonged survival compared with patients treated with PRRT alone. In this retrospective study, we aimed to investigate whether there is a survival benefit to adding SSA to PRRT as a combination therapy and/or maintenance therapy.Patients and Methods: The investigation included 168 patients with unresectable GEP-NETs treated at the University Hospital Bonn, Bonn, Germany. The patients were divided into two main groups: PRRT monotherapy (N = 81, group 1) and PRRT plus SSA (N = 87, group 2) as combined therapy with PRRT and/or as maintenance therapy after PRRT.Results: Data for overall survival (OS) were available from 168 patients, of whom 160 had data for progression-free survival (PFS). The median PFS was 27 months in group 1 versus 48 months in group 2 (P = 0.012). The median OS rates were 47 months in group 1 and 91 months in group 2 (P < 0.001). The death-event rates were lower in group 2 (26%) than in group 1 (63%). SSA as a combination therapy with PRRT and/or as a maintenance therapy showed a clinical benefit rate (objective response or stable disease) of 95%, which was significantly higher than group 1 (79%).Conclusions: SSA as a combination therapy and/or maintenance therapy may play a significant role in tumor control in patients with GEP-NET who underwent a PRRT. Clin Cancer Res; 24(19); 4672-9. ©2018 AACR.

Peptide receptor radionuclide therapy: an overview.

Peptide receptor radionuclide therapy (PRRT) is a site-directed targeted therapeutic strategy that specifically uses radiolabeled peptides as biological targeting vectors designed to deliver cytotoxic levels of radiation dose to cancer cells, which overexpress specific receptors. Interest in PRRT has steadily grown because of the advantages of targeting cellular receptors in vivo with high sensitivity as well as specificity and treatment at the molecular level. Recent advances in molecular biology have not only stimulated advances in PRRT in a sustainable manner but have also pushed the field significantly forward to several unexplored possibilities. Recent decades have witnessed unprecedented endeavors for developing radiolabeled receptor-binding somatostatin analogs for the treatment of neuroendocrine tumors, which have played an important role in the evolution of PRRT and paved the way for the development of other receptor-targeting peptides. Several peptides targeting a variety of receptors have been identified, demonstrating their potential to catalyze breakthroughs in PRRT. In this review, the authors discuss several of these peptides and their analogs with regard to their applications and potential in radionuclide therapy. The advancement in the availability of combinatorial peptide libraries for peptide designing and screening provides the capability of regulating immunogenicity and chemical manipulability. Moreover, the availability of a wide range of bifunctional chelating agents opens up the scope of convenient radiolabeling. For these reasons, it would be possible to envision a future where the scope of PRRT can be tailored for patient-specific application. While PRRT lies at the interface between many disciplines, this technology is inextricably linked to the availability of the therapeutic radionuclides of required quality and activity levels and hence their production is also reviewed.

Ensayos in-vitro e in-vivo del péptido marcado 177Lu-DOTA-Sustancia P y evaluación de los cálculos dosimétricos en la etapa preclínica / Tests in-vitro and in vivo of 177Lu-DOTA-SP labeled peptide and evaluation of the dosimetric calculations in the preclinical stage

Introducción: El péptido Sustancia P (SP) es el ligando principal de los receptores de neurokininas tipo 1, los cuales se encuentran sobreexpresados en los gliomas malignos. Método: Se obtuvo 177Lu-DOTA-SP con elevada pureza radioquímica. Se realizaron biodistribuciones en ratones normales a diferentes tiempos. Se calcularon las dosis absorbidas para los diferentes órganos del ratón (cGy/uCi). Utilizando los métodos de escalación por tiempo (A) y extrapolación directa (B), se obtuvieron las dosis en los diferentes órganos humanos. Se calcularon las máximas dosis tolerables en función de los órganos críticos (mCi/kg). Resultados: La máxima actividad tolerable que puede ser inyectada sin producir toxicidad en riñones es 11,2 mCi/kg (hombre adulto) y 11,4 mCi/kg (mujer adulta) según el método A y de 47,2 mCi/kg y 56,2 mCi/kg, respectivamente según el método B. Conclusiones: Hasta el momento se pudo obtener 177Lu-DOTA-SP con Ae= 0,05mCi/ ug de péptido. La misma puede aumentarse utilizando el 177LuCl3 de mayor actividad específica.

Introduction: Substance P (SP) is the main ligand of neurokin type 1 receptors, which are consistently overexpressed in malignant gliomas. Method: 177Lu-DOTA-SP was obtained with high radiochemical purity. Biodistribution in normal mice at different times, were done. Absorbed doses were calculated for different mice organs (cGy/uCi). Absorbed doses in human organs were calculated using two different methods, time scaling (A) and data extrapolation (B). Maximum tolerated doses were calculated according to critical organs (mCi/kg). Results: Maximum tolerated dose that can be injected without kidney toxicity is 11,2 mCi/kg (adult man) and 11,4 mCi/kg (adult woman) according to method A and 47,2 mCi/kg, 56,2 mCi/kg, respectively according to method B. Conclusion: So far, 177Lu-DOTA-SP was achieved with a specific activity (S.a) of 0,05 mCi/ ug of peptide. This S.a can be increased using 177LuCl3 of higher specific activity.

Lineage-specific T-cell responses to cancer mucosa antigen oppose systemic metastases without mucosal inflammatory disease.

Cancer mucosa antigens are emerging as a new category of self-antigens expressed normally in immunologically privileged mucosal compartments and universally by their derivative tumors. These antigens leverage the established immunologic partitioning of systemic and mucosal compartments, limiting tolerance opposing systemic antitumor efficacy. An unresolved issue surrounding self-antigens as immunotherapeutic targets is autoimmunity following systemic immunization. In the context of cancer mucosa antigens, immune effectors to self-antigens risk amplifying mucosal inflammatory disease promoting carcinogenesis. Here, we examined the relationship between immunotherapy for systemic colon cancer metastases targeting the intestinal cancer mucosa antigen guanylyl cyclase C (GCC) and its effect on inflammatory bowel disease and carcinogenesis in mice. Immunization with GCC-expressing viral vectors opposed nascent tumor growth in mouse models of pulmonary metastasis, reflecting systemic lineage-specific tolerance characterized by CD8(+), but not CD4(+), T-cell or antibody responses. Responses protecting against systemic metastases spared intestinal epithelium from autoimmunity, and systemic GCC immunity did not amplify chemically induced inflammatory bowel disease. Moreover, GCC immunization failed to promote intestinal carcinogenesis induced by germ-line mutations or chronic inflammation. The established role of CD8(+) T cells in antitumor efficacy, but CD4(+) T cells in autoimmunity, suggests that lineage-specific responses to GCC are particularly advantageous to protect against systemic metastases without mucosal inflammation. These observations support the utility of GCC-targeted immunotherapy in patients at risk for systemic metastases, including those with inflammatory bowel disease, hereditary colorectal cancer syndromes, and sporadic colorectal cancer.

Adrenomedullin and adrenomedullin binding protein-1 attenuate vascular endothelial cell apoptosis in sepsis.

OBJECTIVE: To determine whether vascular endothelial cell apoptosis occurs in the late stage of sepsis and, if so, whether administration of a potent vasodilatory peptide adrenomedullin and its newly reported specific binding protein (AM/AMBP-1) prevents sepsis-induced endothelial cell apoptosis. SUMMARY BACKGROUND DATA: Polymicrobial sepsis is characterized by an early, hyperdynamic phase followed by a late, hypodynamic phase. Our recent studies have shown that administration of AM/AMBP-1 delays or even prevents the transition from the hyperdynamic phase to the hypodynamic phase of sepsis, attenuates tissue injury, and decreases sepsis-induced mortality. However, the mechanisms responsible for the beneficial effects of AM/AMBP-1 in sepsis remain unknown. METHODS: Polymicrobial sepsis was induced by cecal ligation and puncture in adult male rats. Human AMBP-1 (40 microg/kg body weight) was infused intravenously at the beginning of sepsis for 20 minutes and synthetic AM (12 microg/kg body weight) was continuously administered for the entire study period using an Alzert micro-osmotic pump, beginning 3 hours prior to the induction of sepsis. The thoracic aorta and pulmonary tissues were harvested at 20 hours after cecal ligation and puncture (ie, the late stage of sepsis). Apoptosis was determined using TUNEL assay, M30 Cytodeath immunostaining, and electromicroscopy. In addition, anti-apoptotic Bcl-2 and pro-apoptotic Bax gene expression and protein levels were assessed by RT-PCR and Western blot analysis, respectively. RESULTS: Vascular endothelial cells underwent apoptosis formation at 20 hours after cecal ligation and puncture as determined by three different methods. Moreover, partial detached endothelial cell in the aorta was observed. Bcl-2 mRNA and protein levels decreased significantly at 20 hours after the onset of sepsis while Bax was not altered. Administration of AM/AMBP-1 early after sepsis, however, significantly reduced the number of apoptotic endothelial cells. This was associated with significantly increased Bcl-2 protein levels and decreased Bax gene expression in the aortic and pulmonary tissues. CONCLUSION: The above results suggest that vascular endothelial cell apoptosis occurs in late sepsis and the anti-apoptotic effects of AM/AMBP-1 appear to be in part responsible for their beneficial effects observed under such conditions.

The melanocortin melanocyte-stimulating hormone/adrenocorticotropin(4-10) decreases body fat in humans.

The control of body fat is a prominent factor in human health. Animal studies have indicated a homeostatic central nervous system regulation of body fat with particular involvement of the melanocortin receptor pathway. This study provides evidence for a similar role for melanocortins in the long-term control of fat stores in humans. Thirty-six normal weight humans were assigned to one of three experimental groups. After a 4-week baseline, one group was treated with MSH/ACTH(4-10) (MSH/ACTH(4-10)) representing the core sequence of all melanocortins. Another group received desacetyl-alphaMSH, a selective agonist of the brain melanocortin-4 receptor, which shares the 4-10 sequence with MSH/ACTH(4-10). The third group received placebo. Treatments were given intranasally twice daily for 6 weeks, at equimolar doses (MSH/ACTH(4-10), 0.5 mg; desacetyl-alphaMSH, 0.84 mg). Body weight, body composition, and plasma hormone concentrations were measured before and after treatment. MSH/ACTH(4-10) reduced body fat, on the average, by 1.68 kg (P < 0.05) and body weight by 0.79 kg (P < 0.001). Concurrently, plasma leptin levels were decreased by 24% (P < 0.02), and insulin levels were decreased by 20% (P< 0.05) after MSH/ACTH(4-10). Changes after desacetyl-alphaMSH remained nonsignificant. The finding of reduced body adiposity after MSH/ACTH(4-10) confirms and extends to the human the findings of animal models indicating an essential role of the hypothalamic melanocortin system in body weight control.